diff --git a/tools/pathops_visualizer.htm b/tools/pathops_visualizer.htm
new file mode 100644
index 0000000..c7f7804
--- /dev/null
+++ b/tools/pathops_visualizer.htm
@@ -0,0 +1,3925 @@
+<html>
+<head>
+<div height="0" hidden="true">
+<div id="rects4">
+  RunTestSet [rects4]
+
+{{0,0}, {1,0}},
+{{1,0}, {1,1}},
+{{1,1}, {0,1}},
+{{0,1}, {0,0}},
+{{0,0}, {2,0}},
+{{2,0}, {2,2}},
+{{2,2}, {0,2}},
+{{0,2}, {0,0}},
+op difference
+{{0,0}, {2,0}},
+{{2,0}, {2,2}},
+{{2,2}, {0,2}},
+{{0,2}, {0,0}},
+{{0,0}, {3,0}},
+{{3,0}, {3,3}},
+{{3,3}, {0,3}},
+{{0,3}, {0,0}},
+debugShowLineIntersection wtTs[0]=0 {{1,0}, {1,1}} {{1,0}} wnTs[0]=1 {{0,0}, {1,0}}
+debugShowLineIntersection wtTs[0]=1 {{0,1}, {0,0}} {{0,0}} wnTs[0]=0 {{0,0}, {1,0}}
+debugShowLineIntersection wtTs[0]=0 {{1,1}, {0,1}} {{1,1}} wnTs[0]=1 {{1,0}, {1,1}}
+debugShowLineIntersection wtTs[0]=0 {{0,1}, {0,0}} {{0,1}} wnTs[0]=1 {{1,1}, {0,1}}
+debugShowLineIntersection wtTs[0]=0 {{0,0}, {2,0}} {{0,0}} wtTs[1]=0.5 {{1,0}} wnTs[0]=0 {{0,0}, {1,0}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=1 {{0,2}, {0,0}} {{0,0}} wnTs[0]=0 {{0,0}, {1,0}}
+debugShowLineIntersection wtTs[0]=0.5 {{0,0}, {2,0}} {{1,0}} wnTs[0]=0 {{1,0}, {1,1}}
+debugShowLineIntersection wtTs[0]=0.5 {{0,2}, {0,0}} {{0,1}} wnTs[0]=1 {{1,1}, {0,1}}
+debugShowLineIntersection wtTs[0]=0 {{0,0}, {2,0}} {{0,0}} wnTs[0]=1 {{0,1}, {0,0}}
+debugShowLineIntersection wtTs[0]=0.5 {{0,2}, {0,0}} {{0,1}} wtTs[1]=1 {{0,0}} wnTs[0]=0 {{0,1}, {0,0}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=0 {{0,0}, {2,0}} {{0,0}} wtTs[1]=0.5 {{1,0}} wnTs[0]=0 {{0,0}, {1,0}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=1 {{0,2}, {0,0}} {{0,0}} wnTs[0]=0 {{0,0}, {1,0}}
+debugShowLineIntersection wtTs[0]=0.5 {{0,0}, {2,0}} {{1,0}} wnTs[0]=0 {{1,0}, {1,1}}
+debugShowLineIntersection wtTs[0]=0.5 {{0,2}, {0,0}} {{0,1}} wnTs[0]=1 {{1,1}, {0,1}}
+debugShowLineIntersection wtTs[0]=0 {{0,0}, {2,0}} {{0,0}} wnTs[0]=1 {{0,1}, {0,0}}
+debugShowLineIntersection wtTs[0]=0.5 {{0,2}, {0,0}} {{0,1}} wtTs[1]=1 {{0,0}} wnTs[0]=0 {{0,1}, {0,0}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=0 {{0,0}, {3,0}} {{0,0}} wtTs[1]=0.333333333 {{1,0}} wnTs[0]=0 {{0,0}, {1,0}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=1 {{0,3}, {0,0}} {{0,0}} wnTs[0]=0 {{0,0}, {1,0}}
+debugShowLineIntersection wtTs[0]=0.333333333 {{0,0}, {3,0}} {{1,0}} wnTs[0]=0 {{1,0}, {1,1}}
+debugShowLineIntersection wtTs[0]=0.666666667 {{0,3}, {0,0}} {{0,1}} wnTs[0]=1 {{1,1}, {0,1}}
+debugShowLineIntersection wtTs[0]=0 {{0,0}, {3,0}} {{0,0}} wnTs[0]=1 {{0,1}, {0,0}}
+debugShowLineIntersection wtTs[0]=0.666666667 {{0,3}, {0,0}} {{0,1}} wtTs[1]=1 {{0,0}} wnTs[0]=0 {{0,1}, {0,0}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=0 {{2,0}, {2,2}} {{2,0}} wnTs[0]=1 {{0,0}, {2,0}}
+debugShowLineIntersection wtTs[0]=1 {{0,2}, {0,0}} {{0,0}} wnTs[0]=0 {{0,0}, {2,0}}
+debugShowLineIntersection wtTs[0]=0 {{2,2}, {0,2}} {{2,2}} wnTs[0]=1 {{2,0}, {2,2}}
+debugShowLineIntersection wtTs[0]=0 {{0,2}, {0,0}} {{0,2}} wnTs[0]=1 {{2,2}, {0,2}}
+debugShowLineIntersection wtTs[0]=0 {{0,0}, {2,0}} {{0,0}} wtTs[1]=1 {{2,0}} wnTs[0]=0 {{0,0}, {2,0}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=0 {{2,0}, {2,2}} {{2,0}} wnTs[0]=1 {{0,0}, {2,0}}
+debugShowLineIntersection wtTs[0]=1 {{0,2}, {0,0}} {{0,0}} wnTs[0]=0 {{0,0}, {2,0}}
+debugShowLineIntersection wtTs[0]=1 {{0,0}, {2,0}} {{2,0}} wnTs[0]=0 {{2,0}, {2,2}}
+debugShowLineIntersection wtTs[0]=0 {{2,0}, {2,2}} {{2,0}} wtTs[1]=1 {{2,2}} wnTs[0]=0 {{2,0}, {2,2}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=0 {{2,2}, {0,2}} {{2,2}} wnTs[0]=1 {{2,0}, {2,2}}
+debugShowLineIntersection wtTs[0]=1 {{2,0}, {2,2}} {{2,2}} wnTs[0]=0 {{2,2}, {0,2}}
+debugShowLineIntersection wtTs[0]=0 {{2,2}, {0,2}} {{2,2}} wtTs[1]=1 {{0,2}} wnTs[0]=0 {{2,2}, {0,2}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=0 {{0,2}, {0,0}} {{0,2}} wnTs[0]=1 {{2,2}, {0,2}}
+debugShowLineIntersection wtTs[0]=0 {{0,0}, {2,0}} {{0,0}} wnTs[0]=1 {{0,2}, {0,0}}
+debugShowLineIntersection wtTs[0]=1 {{2,2}, {0,2}} {{0,2}} wnTs[0]=0 {{0,2}, {0,0}}
+debugShowLineIntersection wtTs[0]=0 {{0,2}, {0,0}} {{0,2}} wtTs[1]=1 {{0,0}} wnTs[0]=0 {{0,2}, {0,0}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=0 {{0,0}, {3,0}} {{0,0}} wtTs[1]=0.666666667 {{2,0}} wnTs[0]=0 {{0,0}, {2,0}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=1 {{0,3}, {0,0}} {{0,0}} wnTs[0]=0 {{0,0}, {2,0}}
+debugShowLineIntersection wtTs[0]=0.666666667 {{0,0}, {3,0}} {{2,0}} wnTs[0]=0 {{2,0}, {2,2}}
+debugShowLineIntersection wtTs[0]=0.333333333 {{0,3}, {0,0}} {{0,2}} wnTs[0]=1 {{2,2}, {0,2}}
+debugShowLineIntersection wtTs[0]=0 {{0,0}, {3,0}} {{0,0}} wnTs[0]=1 {{0,2}, {0,0}}
+debugShowLineIntersection wtTs[0]=0.333333333 {{0,3}, {0,0}} {{0,2}} wtTs[1]=1 {{0,0}} wnTs[0]=0 {{0,2}, {0,0}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=0 {{2,0}, {2,2}} {{2,0}} wnTs[0]=1 {{0,0}, {2,0}}
+debugShowLineIntersection wtTs[0]=1 {{0,2}, {0,0}} {{0,0}} wnTs[0]=0 {{0,0}, {2,0}}
+debugShowLineIntersection wtTs[0]=0 {{2,2}, {0,2}} {{2,2}} wnTs[0]=1 {{2,0}, {2,2}}
+debugShowLineIntersection wtTs[0]=0 {{0,2}, {0,0}} {{0,2}} wnTs[0]=1 {{2,2}, {0,2}}
+debugShowLineIntersection wtTs[0]=0 {{0,0}, {3,0}} {{0,0}} wtTs[1]=0.666666667 {{2,0}} wnTs[0]=0 {{0,0}, {2,0}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=1 {{0,3}, {0,0}} {{0,0}} wnTs[0]=0 {{0,0}, {2,0}}
+debugShowLineIntersection wtTs[0]=0.666666667 {{0,0}, {3,0}} {{2,0}} wnTs[0]=0 {{2,0}, {2,2}}
+debugShowLineIntersection wtTs[0]=0.333333333 {{0,3}, {0,0}} {{0,2}} wnTs[0]=1 {{2,2}, {0,2}}
+debugShowLineIntersection wtTs[0]=0 {{0,0}, {3,0}} {{0,0}} wnTs[0]=1 {{0,2}, {0,0}}
+debugShowLineIntersection wtTs[0]=0.333333333 {{0,3}, {0,0}} {{0,2}} wtTs[1]=1 {{0,0}} wnTs[0]=0 {{0,2}, {0,0}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=0 {{3,0}, {3,3}} {{3,0}} wnTs[0]=1 {{0,0}, {3,0}}
+debugShowLineIntersection wtTs[0]=1 {{0,3}, {0,0}} {{0,0}} wnTs[0]=0 {{0,0}, {3,0}}
+debugShowLineIntersection wtTs[0]=0 {{3,3}, {0,3}} {{3,3}} wnTs[0]=1 {{3,0}, {3,3}}
+debugShowLineIntersection wtTs[0]=0 {{0,3}, {0,0}} {{0,3}} wnTs[0]=1 {{3,3}, {0,3}}
+SkOpSegment::debugShowTs - id=0 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=1 t=1 1,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=4 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=1 t=0.5 1,0 w=1 o=0] [o=9,5 t=1 2,0 w=1 o=0]
+SkOpSegment::addTPair addTPair this=4 0.5 other=0 1
+SkOpSegment::debugShowTs + id=0 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=4,1 t=1 1,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=4 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.5 1,0 w=1 o=0] [o=9,5 t=1 2,0 w=1 o=0]
+SkOpSegment::debugShowTs - id=3 [o=2 t=0 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=7 [o=10,6 t=0 0,2 w=1 o=0] [o=2 t=0.5 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::addTPair addTPair this=3 0 other=7 0.5
+SkOpSegment::debugShowTs + id=3 [o=7,2 t=0 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=7 [o=10,6 t=0 0,2 w=1 o=0] [o=3,2 t=0.5 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::debugShowTs - id=0 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=4,1 t=1 1,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=8 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=1 t=0.5 1,0 w=1 o=0] [o=9,5 t=1 2,0 w=1 o=0] operand
+SkOpSegment::addTPair addTPair this=8 0.5 other=0 1
+SkOpSegment::debugShowTs + id=0 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=8,4,1 t=1 1,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=8 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.5 1,0 w=1 o=0] [o=9,5 t=1 2,0 w=1 o=0] operand
+SkOpSegment::debugShowTs - id=3 [o=7,2 t=0 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=11 [o=10,6 t=0 0,2 w=1 o=0] [o=2 t=0.5 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::addTPair addTPair this=3 0 other=11 0.5
+SkOpSegment::debugShowTs + id=3 [o=11,7,2 t=0 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=11 [o=10,6 t=0 0,2 w=1 o=0] [o=3,2 t=0.5 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::debugShowTs - id=0 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=8,4,1 t=1 1,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=12 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=1 t=0.333 1,0 w=1 o=0] [o=9,5 t=0.667 2,0 w=1 o=0] [o=13 t=1 3,0 w=1 o=0] operand
+SkOpSegment::addTPair addTPair this=12 0.333333333 other=0 1
+SkOpSegment::debugShowTs + id=0 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=12,8,4,1 t=1 1,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=12 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.333 1,0 w=1 o=0] [o=9,5 t=0.667 2,0 w=1 o=0] [o=13 t=1 3,0 w=1 o=0] operand
+SkOpSegment::debugShowTs - id=3 [o=11,7,2 t=0 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=15 [o=14 t=0 0,3 w=1 o=0] [o=10,6 t=0.333 0,2 w=1 o=0] [o=2 t=0.667 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::addTPair addTPair this=3 0 other=15 0.666666667
+SkOpSegment::debugShowTs + id=3 [o=15,11,7,2 t=0 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=15 [o=14 t=0 0,3 w=1 o=0] [o=10,6 t=0.333 0,2 w=1 o=0] [o=3,2 t=0.667 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::debugShowTs - id=4 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.5 1,0 w=1 o=0] [o=9,5 t=1 2,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=8 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.5 1,0 w=1 o=0] [o=9,5 t=1 2,0 w=1 o=0] operand
+SkOpSegment::debugShowTs + id=4 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.5 1,0 w=1 o=0] [o=9,5 t=1 2,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=8 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.5 1,0 w=1 o=0] [o=9,5 t=1 2,0 w=1 o=0] operand
+SkOpSegment::debugShowTs - id=5 [o=12,8,4 t=0 2,0 w=1 o=0] [o=10,6 t=1 2,2 w=1 o=0]
+SkOpSegment::debugShowTs o id=9 [o=12,8,4 t=0 2,0 w=1 o=0] [o=10,6 t=1 2,2 w=1 o=0] operand
+SkOpSegment::debugShowTs + id=5 [o=12,8,4 t=0 2,0 w=1 o=0] [o=10,6 t=1 2,2 w=1 o=0]
+SkOpSegment::debugShowTs o id=9 [o=12,8,4 t=0 2,0 w=1 o=0] [o=10,6 t=1 2,2 w=1 o=0] operand
+SkOpSegment::debugShowTs - id=6 [o=9,5 t=0 2,2 w=1 o=0] [o=15,11,7 t=1 0,2 w=1 o=0]
+SkOpSegment::debugShowTs o id=10 [o=9,5 t=0 2,2 w=1 o=0] [o=15,11,7 t=1 0,2 w=1 o=0] operand
+SkOpSegment::debugShowTs + id=6 [o=9,5 t=0 2,2 w=1 o=0] [o=15,11,7 t=1 0,2 w=1 o=0]
+SkOpSegment::debugShowTs o id=10 [o=9,5 t=0 2,2 w=1 o=0] [o=15,11,7 t=1 0,2 w=1 o=0] operand
+SkOpSegment::debugShowTs - id=7 [o=10,6 t=0 0,2 w=1 o=0] [o=3,2 t=0.5 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=11 [o=10,6 t=0 0,2 w=1 o=0] [o=3,2 t=0.5 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::debugShowTs + id=7 [o=10,6 t=0 0,2 w=1 o=0] [o=3,2 t=0.5 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=11 [o=10,6 t=0 0,2 w=1 o=0] [o=3,2 t=0.5 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::debugShowTs - id=4 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.5 1,0 w=1 o=0] [o=9,5 t=1 2,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=12 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.333 1,0 w=1 o=0] [o=9,5 t=0.667 2,0 w=1 o=0] [o=13 t=1 3,0 w=1 o=0] operand
+SkOpSegment::addTPair addTPair this=12 0.666666667 other=4 1
+SkOpSegment::debugShowTs + id=4 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.5 1,0 w=1 o=0] [o=12,9,5 t=1 2,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=12 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.333 1,0 w=1 o=0] [o=4,9,5 t=0.667 2,0 w=1 o=0] [o=13 t=1 3,0 w=1 o=0] operand
+SkOpSegment::debugShowTs - id=7 [o=10,6 t=0 0,2 w=1 o=0] [o=3,2 t=0.5 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=15 [o=14 t=0 0,3 w=1 o=0] [o=10,6 t=0.333 0,2 w=1 o=0] [o=3,2 t=0.667 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::addTPair addTPair this=7 0 other=15 0.333333333
+SkOpSegment::debugShowTs + id=7 [o=15,10,6 t=0 0,2 w=1 o=0] [o=3,2 t=0.5 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=15 [o=14 t=0 0,3 w=1 o=0] [o=7,10,6 t=0.333 0,2 w=1 o=0] [o=3,2 t=0.667 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::debugShowTs - id=8 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.5 1,0 w=1 o=0] [o=9,5 t=1 2,0 w=1 o=0] operand
+SkOpSegment::debugShowTs o id=12 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.333 1,0 w=1 o=0] [o=4,9,5 t=0.667 2,0 w=1 o=0] [o=13 t=1 3,0 w=1 o=0] operand
+SkOpSegment::addTPair addTPair this=12 0.666666667 other=8 1
+SkOpSegment::debugShowTs + id=8 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.5 1,0 w=1 o=0] [o=12,9,5 t=1 2,0 w=1 o=0] operand
+SkOpSegment::debugShowTs o id=12 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.333 1,0 w=1 o=0] [o=8,4,9,5 t=0.667 2,0 w=1 o=0] [o=13 t=1 3,0 w=1 o=0] operand
+SkOpSegment::debugShowTs - id=11 [o=10,6 t=0 0,2 w=1 o=0] [o=3,2 t=0.5 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::debugShowTs o id=15 [o=14 t=0 0,3 w=1 o=0] [o=7,10,6 t=0.333 0,2 w=1 o=0] [o=3,2 t=0.667 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::addTPair addTPair this=11 0 other=15 0.333333333
+SkOpSegment::debugShowTs + id=11 [o=15,10,6 t=0 0,2 w=1 o=0] [o=3,2 t=0.5 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::debugShowTs o id=15 [o=14 t=0 0,3 w=1 o=0] [o=11,7,10,6 t=0.333 0,2 w=1 o=0] [o=3,2 t=0.667 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpContour::calcCoincidentWinding count=6
+SkOpSegment::debugShowTs p id=0 [o=15,11,7,3 t=0 0,0 w=0 o=0] [o=12,8,4,1 t=1 1,0 w=1 o=0] done
+SkOpSegment::debugShowTs o id=4 [o=15,11,7,3 t=0 0,0 w=0 o=0] [o=0,1 t=0.5 1,0 w=1 o=0] [o=12,9,5 t=1 2,0 w=1 o=0]
+SkOpSegment::debugShowTs p id=3 [o=15,11,7,2 t=0 0,1 w=0 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] done
+SkOpSegment::debugShowTs o id=7 [o=15,10,6 t=0 0,2 w=1 o=0] [o=3,2 t=0.5 0,1 w=0 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpContour::calcCoincidentWinding count=6
+SkOpSegment::debugShowTs p id=4 [o=15,11,7,3 t=0 0,0 w=0 o=0] [o=0,1 t=0.5 1,0 w=1 o=1] [o=12,9,5 t=1 2,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=8 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.5 1,0 w=0 o=0] [o=12,9,5 t=1 2,0 w=1 o=0] operand
+SkOpSegment::debugShowTs p id=5 [o=12,8,4 t=0 2,0 w=1 o=1] [o=10,6 t=1 2,2 w=1 o=0]
+SkOpSegment::debugShowTs o id=9 [o=12,8,4 t=0 2,0 w=0 o=0] [o=10,6 t=1 2,2 w=1 o=0] operand done
+SkOpSegment::debugShowTs p id=6 [o=9,5 t=0 2,2 w=1 o=1] [o=15,11,7 t=1 0,2 w=1 o=0]
+SkOpSegment::debugShowTs o id=10 [o=9,5 t=0 2,2 w=0 o=0] [o=15,11,7 t=1 0,2 w=1 o=0] operand done
+SkOpSegment::debugShowTs p id=7 [o=15,10,6 t=0 0,2 w=1 o=1] [o=3,2 t=0.5 0,1 w=0 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=11 [o=15,10,6 t=0 0,2 w=0 o=0] [o=3,2 t=0.5 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::debugShowTs p id=4 [o=15,11,7,3 t=0 0,0 w=0 o=0] [o=0,1 t=0.5 1,0 w=1 o=2] [o=12,9,5 t=1 2,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=12 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.333 1,0 w=0 o=0] [o=8,4,9,5 t=0.667 2,0 w=1 o=0] [o=13 t=1 3,0 w=1 o=0] operand
+SkOpSegment::debugShowTs p id=7 [o=15,10,6 t=0 0,2 w=1 o=2] [o=3,2 t=0.5 0,1 w=0 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=15 [o=14 t=0 0,3 w=1 o=0] [o=11,7,10,6 t=0.333 0,2 w=0 o=0] [o=3,2 t=0.667 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpContour::calcCoincidentWinding count=2
+SkOpSegment::debugShowTs p id=8 [o=15,11,7,3 t=0 0,0 w=2 o=0] [o=0,1 t=0.5 1,0 w=0 o=0] [o=12,9,5 t=1 2,0 w=1 o=0] operand
+SkOpSegment::debugShowTs o id=12 [o=15,11,7,3 t=0 0,0 w=0 o=0] [o=0,1 t=0.333 1,0 w=0 o=0] [o=8,4,9,5 t=0.667 2,0 w=1 o=0] [o=13 t=1 3,0 w=1 o=0] operand
+SkOpSegment::debugShowTs p id=11 [o=15,10,6 t=0 0,2 w=0 o=0] [o=3,2 t=0.5 0,1 w=2 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::debugShowTs o id=15 [o=14 t=0 0,3 w=1 o=0] [o=11,7,10,6 t=0.333 0,2 w=0 o=0] [o=3,2 t=0.667 0,1 w=0 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::addTPair addTPair this=12 0.333333333 other=8 0.5
+SkOpSegment::addTPair addTPair this=12 0.333333333 other=4 0.5
+SkOpSegment::addTPair addTPair duplicate this=8 0.5 other=12 0.333333333
+SkOpSegment::addTPair addTPair this=8 0.5 other=4 0.5
+SkOpSegment::addTPair addTPair duplicate this=4 0.5 other=8 0.5
+SkOpSegment::addTPair addTPair duplicate this=4 0.5 other=12 0.333333333
+SkOpSegment::addTPair addTPair this=15 0.666666667 other=11 0.5
+SkOpSegment::addTPair addTPair this=15 0.666666667 other=7 0.5
+SkOpSegment::addTPair addTPair duplicate this=11 0.5 other=15 0.666666667
+SkOpSegment::addTPair addTPair this=11 0.5 other=7 0.5
+SkOpSegment::addTPair addTPair duplicate this=7 0.5 other=11 0.5
+SkOpSegment::addTPair addTPair duplicate this=7 0.5 other=15 0.666666667
+SkOpSegment::addTPair addTPair this=4 1 other=8 1
+SkOpSegment::addTPair addTPair this=5 0 other=9 0
+SkOpSegment::addTPair addTPair duplicate this=5 0 other=9 0
+SkOpSegment::addTPair addTPair duplicate this=5 0 other=9 0
+SkOpSegment::addTPair addTPair this=6 1 other=10 1
+SkOpSegment::addTPair addTPair this=7 0 other=11 0
+SkOpSegment::addTPair addTPair duplicate this=7 0 other=11 0
+SkOpSegment::addTPair addTPair duplicate this=7 0 other=11 0
+SkOpContour::joinCoincidence count=6
+SkOpContour::joinCoincidence count=6
+SkOpContour::joinCoincidence count=2
+SkOpSegment::sortAngles [1] tStart=0 [1]
+SkOpAngle::after [1/1] 23/23 tStart=0 tEnd=1 < [4/1] 31/31 tStart=0.5 tEnd=1 < [8/2] 15/15 tStart=0.5 tEnd=0  T 4
+SkOpSegment::sortAngles [2] tStart=1 [2]
+SkOpAngle::after [2/1] 31/31 tStart=1 tEnd=0 < [7/2] 23/23 tStart=0.5 tEnd=0 < [11/1] 7/7 tStart=0.5 tEnd=1  F 4
+SkOpSegment::sortAngles [4] tStart=1 [9]
+SkOpAngle::after [4/2] 15/15 tStart=1 tEnd=0.5 < [5/1] 23/23 tStart=0 tEnd=1 < [12/1] 31/31 tStart=0.666666667 tEnd=1  T 4
+SkOpSegment::sortAngles [5] tStart=1 [5]
+SkOpSegment::sortAngles [6] tStart=1 [3]
+SkOpAngle::after [6/2] 31/31 tStart=1 tEnd=0 < [7/1] 7/7 tStart=0 tEnd=0.5 < [15/1] 23/23 tStart=0.333333333 tEnd=0  T 4
+SkOpSegment::sortAngles [8] tStart=0 [1]
+SkOpSegment::debugShowActiveSpans id=1 (1,0 1,1) t=0 (1,0) tEnd=1 other=12 otherT=0.333333333 otherIndex=7 windSum=? windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=2 (1,1 0,1) t=0 (1,1) tEnd=1 other=1 otherT=1 otherIndex=4 windSum=? windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=4 (0,0 2,0) t=0.5 (1,0) tEnd=1 other=8 otherT=0.5 otherIndex=4 windSum=? windValue=1 oppValue=2
+SkOpSegment::debugShowActiveSpans id=5 (2,0 2,2) t=0 (2,0) tEnd=1 other=9 otherT=0 otherIndex=0 windSum=? windValue=1 oppValue=1
+SkOpSegment::debugShowActiveSpans id=6 (2,2 0,2) t=0 (2,2) tEnd=1 other=9 otherT=1 otherIndex=5 windSum=? windValue=1 oppValue=1
+SkOpSegment::debugShowActiveSpans id=7 (0,2 0,0) t=0 (0,2) tEnd=0.5 other=11 otherT=0 otherIndex=0 windSum=? windValue=1 oppValue=2
+SkOpSegment::debugShowActiveSpans id=8 (0,0 2,0) t=0 (0,0) tEnd=0.5 other=15 otherT=1 otherIndex=10 windSum=? windValue=2 oppValue=0
+SkOpSegment::debugShowActiveSpans id=11 (0,2 0,0) t=0.5 (0,1) tEnd=1 other=7 otherT=0.5 otherIndex=4 windSum=? windValue=2 oppValue=0
+SkOpSegment::debugShowActiveSpans id=12 (0,0 3,0) t=0.666666667 (2,0) tEnd=1 other=8 otherT=1 otherIndex=9 windSum=? windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=13 (3,0 3,3) t=0 (3,0) tEnd=1 other=12 otherT=1 otherIndex=12 windSum=? windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=14 (3,3 0,3) t=0 (3,3) tEnd=1 other=13 otherT=1 otherIndex=1 windSum=? windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=15 (0,3 0,0) t=0 (0,3) tEnd=0.333333333 other=14 otherT=1 otherIndex=1 windSum=? windValue=1 oppValue=0
+SkOpSegment::findTop
+SkOpAngle::dumpOne [11/2] next=8/1 sect=23/23  s=1 [11] e=0.5 [7] sgn=1 windVal=2 windSum=? operand
+SkOpAngle::dumpOne [8/1] next=11/2 sect=31/31  s=0 [0] e=0.5 [4] sgn=-1 windVal=2 windSum=? operand stop
+SkOpSegment::markWinding id=11 (0,2 0,0) t=0.5 [6] (0,1) tEnd=0.5 newWindSum=-2 newOppSum=0 oppSum=? windSum=? windValue=2 oppValue=0
+SkOpSegment::markWinding id=11 (0,2 0,0) t=0.5 [5] (0,1) tEnd=0.5 newWindSum=-2 newOppSum=0 oppSum=? windSum=? windValue=2 oppValue=0
+SkOpSegment::markWinding id=11 (0,2 0,0) t=0.5 [4] (0,1) tEnd=0.5 newWindSum=-2 newOppSum=0 oppSum=? windSum=? windValue=2 oppValue=0
+SkOpSegment::markWinding id=11 (0,2 0,0) t=0.5 [7] (0,1) tEnd=1 newWindSum=-2 newOppSum=0 oppSum=? windSum=? windValue=2 oppValue=0
+SkOpSegment::nextChase mismatched signs
+SkOpSegment::markWinding id=8 (0,0 2,0) t=0 [0] (0,0) tEnd=0 newWindSum=-2 newOppSum=0 oppSum=? windSum=? windValue=2 oppValue=0
+SkOpSegment::markWinding id=8 (0,0 2,0) t=0 [1] (0,0) tEnd=0 newWindSum=-2 newOppSum=0 oppSum=? windSum=? windValue=2 oppValue=0
+SkOpSegment::markWinding id=8 (0,0 2,0) t=0 [2] (0,0) tEnd=0 newWindSum=-2 newOppSum=0 oppSum=? windSum=? windValue=2 oppValue=0
+SkOpSegment::markWinding id=8 (0,0 2,0) t=0 [3] (0,0) tEnd=0.5 newWindSum=-2 newOppSum=0 oppSum=? windSum=? windValue=2 oppValue=0
+SkOpSegment::markWinding id=11 (0,2 0,0) t=0.5 [6] (0,1) tEnd=0.5 newWindSum=-2 newOppSum=0 oppSum=0 windSum=-2 windValue=2 oppValue=0
+SkOpSegment::markWinding id=11 (0,2 0,0) t=0.5 [5] (0,1) tEnd=0.5 newWindSum=-2 newOppSum=0 oppSum=0 windSum=-2 windValue=2 oppValue=0
+SkOpSegment::markWinding id=11 (0,2 0,0) t=0.5 [4] (0,1) tEnd=0.5 newWindSum=-2 newOppSum=0 oppSum=0 windSum=-2 windValue=2 oppValue=0
+SkOpSegment::markWinding id=11 (0,2 0,0) t=0.5 [7] (0,1) tEnd=1 newWindSum=-2 newOppSum=0 oppSum=0 windSum=-2 windValue=2 oppValue=0
+SkOpSegment::activeOp id=11 t=0.5 tEnd=1 op=diff miFrom=0 miTo=0 suFrom=1 suTo=0 result=0
+SkOpSegment::markDoneBinary id=11 (0,2 0,0) t=0.5 [6] (0,1) tEnd=0.5 newWindSum=-2 newOppSum=0 oppSum=0 windSum=-2 windValue=2 oppValue=0
+SkOpSegment::markDoneBinary id=11 (0,2 0,0) t=0.5 [5] (0,1) tEnd=0.5 newWindSum=-2 newOppSum=0 oppSum=0 windSum=-2 windValue=2 oppValue=0
+SkOpSegment::markDoneBinary id=11 (0,2 0,0) t=0.5 [4] (0,1) tEnd=0.5 newWindSum=-2 newOppSum=0 oppSum=0 windSum=-2 windValue=2 oppValue=0
+SkOpSegment::markDoneBinary id=11 (0,2 0,0) t=0.5 [7] (0,1) tEnd=1 newWindSum=-2 newOppSum=0 oppSum=0 windSum=-2 windValue=2 oppValue=0
+SkOpSegment::nextChase mismatched signs
+SkOpSegment::markDoneBinary id=8 (0,0 2,0) t=0 [0] (0,0) tEnd=0 newWindSum=-2 newOppSum=0 oppSum=0 windSum=-2 windValue=2 oppValue=0
+SkOpSegment::markDoneBinary id=8 (0,0 2,0) t=0 [1] (0,0) tEnd=0 newWindSum=-2 newOppSum=0 oppSum=0 windSum=-2 windValue=2 oppValue=0
+SkOpSegment::markDoneBinary id=8 (0,0 2,0) t=0 [2] (0,0) tEnd=0 newWindSum=-2 newOppSum=0 oppSum=0 windSum=-2 windValue=2 oppValue=0
+SkOpSegment::markDoneBinary id=8 (0,0 2,0) t=0 [3] (0,0) tEnd=0.5 newWindSum=-2 newOppSum=0 oppSum=0 windSum=-2 windValue=2 oppValue=0
+bridgeOp chase.append id=8 windSum=-2147483647 small=0
+SkOpSegment::markWinding id=1 (1,0 1,1) t=0 [0] (1,0) tEnd=0 newWindSum=1 newOppSum=-2 oppSum=? windSum=? windValue=1 oppValue=0
+SkOpSegment::markWinding id=1 (1,0 1,1) t=0 [1] (1,0) tEnd=0 newWindSum=1 newOppSum=-2 oppSum=? windSum=? windValue=1 oppValue=0
+SkOpSegment::markWinding id=1 (1,0 1,1) t=0 [2] (1,0) tEnd=0 newWindSum=1 newOppSum=-2 oppSum=? windSum=? windValue=1 oppValue=0
+SkOpSegment::markWinding id=1 (1,0 1,1) t=0 [3] (1,0) tEnd=1 newWindSum=1 newOppSum=-2 oppSum=? windSum=? windValue=1 oppValue=0
+SkOpSegment::markWinding id=2 (1,1 0,1) t=0 [0] (1,1) tEnd=1 newWindSum=1 newOppSum=-2 oppSum=? windSum=? windValue=1 oppValue=0
+SkOpSegment::markAngle last id=2 windSum=? small=0
+SkOpSegment::markWinding id=4 (0,0 2,0) t=0.5 [4] (1,0) tEnd=0.5 newWindSum=2 newOppSum=-2 oppSum=? windSum=? windValue=1 oppValue=2
+SkOpSegment::markWinding id=4 (0,0 2,0) t=0.5 [5] (1,0) tEnd=0.5 newWindSum=2 newOppSum=-2 oppSum=? windSum=? windValue=1 oppValue=2
+SkOpSegment::markWinding id=4 (0,0 2,0) t=0.5 [6] (1,0) tEnd=0.5 newWindSum=2 newOppSum=-2 oppSum=? windSum=? windValue=1 oppValue=2
+SkOpSegment::markWinding id=4 (0,0 2,0) t=0.5 [7] (1,0) tEnd=1 newWindSum=2 newOppSum=-2 oppSum=? windSum=? windValue=1 oppValue=2
+SkOpSegment::markAngle last id=4 windSum=? small=0
+SkOpSegment::debugShowActiveSpans id=1 (1,0 1,1) t=0 (1,0) tEnd=1 other=12 otherT=0.333333333 otherIndex=7 windSum=1 windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=2 (1,1 0,1) t=0 (1,1) tEnd=1 other=1 otherT=1 otherIndex=4 windSum=1 windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=4 (0,0 2,0) t=0.5 (1,0) tEnd=1 other=8 otherT=0.5 otherIndex=4 windSum=2 windValue=1 oppValue=2
+SkOpSegment::debugShowActiveSpans id=5 (2,0 2,2) t=0 (2,0) tEnd=1 other=9 otherT=0 otherIndex=0 windSum=? windValue=1 oppValue=1
+SkOpSegment::debugShowActiveSpans id=6 (2,2 0,2) t=0 (2,2) tEnd=1 other=9 otherT=1 otherIndex=5 windSum=? windValue=1 oppValue=1
+SkOpSegment::debugShowActiveSpans id=7 (0,2 0,0) t=0 (0,2) tEnd=0.5 other=11 otherT=0 otherIndex=0 windSum=? windValue=1 oppValue=2
+SkOpSegment::debugShowActiveSpans id=12 (0,0 3,0) t=0.666666667 (2,0) tEnd=1 other=8 otherT=1 otherIndex=9 windSum=? windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=13 (3,0 3,3) t=0 (3,0) tEnd=1 other=12 otherT=1 otherIndex=12 windSum=? windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=14 (3,3 0,3) t=0 (3,3) tEnd=1 other=13 otherT=1 otherIndex=1 windSum=? windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=15 (0,3 0,0) t=0 (0,3) tEnd=0.333333333 other=14 otherT=1 otherIndex=1 windSum=? windValue=1 oppValue=0
+SkOpSegment::activeOp id=1 t=0 tEnd=1 op=diff miFrom=0 miTo=1 suFrom=1 suTo=1 result=0
+SkOpSegment::markDoneBinary id=1 (1,0 1,1) t=0 [0] (1,0) tEnd=0 newWindSum=1 newOppSum=-2 oppSum=-2 windSum=1 windValue=1 oppValue=0
+SkOpSegment::markDoneBinary id=1 (1,0 1,1) t=0 [1] (1,0) tEnd=0 newWindSum=1 newOppSum=-2 oppSum=-2 windSum=1 windValue=1 oppValue=0
+SkOpSegment::markDoneBinary id=1 (1,0 1,1) t=0 [2] (1,0) tEnd=0 newWindSum=1 newOppSum=-2 oppSum=-2 windSum=1 windValue=1 oppValue=0
+SkOpSegment::markDoneBinary id=1 (1,0 1,1) t=0 [3] (1,0) tEnd=1 newWindSum=1 newOppSum=-2 oppSum=-2 windSum=1 windValue=1 oppValue=0
+SkOpSegment::markDoneBinary id=2 (1,1 0,1) t=0 [0] (1,1) tEnd=1 newWindSum=1 newOppSum=-2 oppSum=-2 windSum=1 windValue=1 oppValue=0
+bridgeOp chase.append id=2 windSum=-2147483647 small=0
+SkOpSegment::markWinding id=7 (0,2 0,0) t=0 [0] (0,2) tEnd=0 newWindSum=-1 newOppSum=-2 oppSum=? windSum=? windValue=1 oppValue=2
+SkOpSegment::markWinding id=7 (0,2 0,0) t=0 [1] (0,2) tEnd=0 newWindSum=-1 newOppSum=-2 oppSum=? windSum=? windValue=1 oppValue=2
+SkOpSegment::markWinding id=7 (0,2 0,0) t=0 [2] (0,2) tEnd=0 newWindSum=-1 newOppSum=-2 oppSum=? windSum=? windValue=1 oppValue=2
+SkOpSegment::markWinding id=7 (0,2 0,0) t=0 [3] (0,2) tEnd=0.5 newWindSum=-1 newOppSum=-2 oppSum=? windSum=? windValue=1 oppValue=2
+SkOpSegment::markAngle last id=7 windSum=-1 small=0
+SkOpSegment::debugShowActiveSpans id=4 (0,0 2,0) t=0.5 (1,0) tEnd=1 other=8 otherT=0.5 otherIndex=4 windSum=2 windValue=1 oppValue=2
+SkOpSegment::debugShowActiveSpans id=5 (2,0 2,2) t=0 (2,0) tEnd=1 other=9 otherT=0 otherIndex=0 windSum=? windValue=1 oppValue=1
+SkOpSegment::debugShowActiveSpans id=6 (2,2 0,2) t=0 (2,2) tEnd=1 other=9 otherT=1 otherIndex=5 windSum=? windValue=1 oppValue=1
+SkOpSegment::debugShowActiveSpans id=7 (0,2 0,0) t=0 (0,2) tEnd=0.5 other=11 otherT=0 otherIndex=0 windSum=-1 windValue=1 oppValue=2
+SkOpSegment::debugShowActiveSpans id=12 (0,0 3,0) t=0.666666667 (2,0) tEnd=1 other=8 otherT=1 otherIndex=9 windSum=? windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=13 (3,0 3,3) t=0 (3,0) tEnd=1 other=12 otherT=1 otherIndex=12 windSum=? windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=14 (3,3 0,3) t=0 (3,3) tEnd=1 other=13 otherT=1 otherIndex=1 windSum=? windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=15 (0,3 0,0) t=0 (0,3) tEnd=0.333333333 other=14 otherT=1 otherIndex=1 windSum=? windValue=1 oppValue=0
+SkOpSegment::activeOp id=7 t=0.5 tEnd=0 op=diff miFrom=0 miTo=1 suFrom=0 suTo=1 result=0
+SkOpSegment::markDoneBinary id=7 (0,2 0,0) t=0 [0] (0,2) tEnd=0 newWindSum=-1 newOppSum=-2 oppSum=-2 windSum=-1 windValue=1 oppValue=2
+SkOpSegment::markDoneBinary id=7 (0,2 0,0) t=0 [1] (0,2) tEnd=0 newWindSum=-1 newOppSum=-2 oppSum=-2 windSum=-1 windValue=1 oppValue=2
+SkOpSegment::markDoneBinary id=7 (0,2 0,0) t=0 [2] (0,2) tEnd=0 newWindSum=-1 newOppSum=-2 oppSum=-2 windSum=-1 windValue=1 oppValue=2
+SkOpSegment::markDoneBinary id=7 (0,2 0,0) t=0 [3] (0,2) tEnd=0.5 newWindSum=-1 newOppSum=-2 oppSum=-2 windSum=-1 windValue=1 oppValue=2
+bridgeOp chase.append id=7 windSum=-1 small=0
+SkOpSegment::markWinding id=15 (0,3 0,0) t=0 [0] (0,3) tEnd=0.333333333 newWindSum=-1 newOppSum=0 oppSum=? windSum=? windValue=1 oppValue=0
+SkOpSegment::markWinding id=14 (3,3 0,3) t=0 [0] (3,3) tEnd=1 newWindSum=-1 newOppSum=0 oppSum=? windSum=? windValue=1 oppValue=0
+SkOpSegment::markWinding id=13 (3,0 3,3) t=0 [0] (3,0) tEnd=1 newWindSum=-1 newOppSum=0 oppSum=? windSum=? windValue=1 oppValue=0
+SkOpSegment::markWinding id=12 (0,0 3,0) t=0.666666667 [10] (2,0) tEnd=0.666666667 newWindSum=-1 newOppSum=0 oppSum=? windSum=? windValue=1 oppValue=0
+SkOpSegment::markWinding id=12 (0,0 3,0) t=0.666666667 [9] (2,0) tEnd=0.666666667 newWindSum=-1 newOppSum=0 oppSum=? windSum=? windValue=1 oppValue=0
+SkOpSegment::markWinding id=12 (0,0 3,0) t=0.666666667 [8] (2,0) tEnd=0.666666667 newWindSum=-1 newOppSum=0 oppSum=? windSum=? windValue=1 oppValue=0
+SkOpSegment::markWinding id=12 (0,0 3,0) t=0.666666667 [11] (2,0) tEnd=1 newWindSum=-1 newOppSum=0 oppSum=? windSum=? windValue=1 oppValue=0
+SkOpSegment::markAngle last id=12 windSum=-1 small=0
+SkOpSegment::markWinding id=6 (2,2 0,2) t=0 [0] (2,2) tEnd=0 newWindSum=-1 newOppSum=-2 oppSum=? windSum=? windValue=1 oppValue=1
+SkOpSegment::markWinding id=6 (2,2 0,2) t=0 [1] (2,2) tEnd=1 newWindSum=-1 newOppSum=-2 oppSum=? windSum=? windValue=1 oppValue=1
+SkOpSegment::nextChase mismatched signs
+SkOpSegment::markAngle last id=6 windSum=-1 small=0
+SkOpSegment::debugShowActiveSpans id=4 (0,0 2,0) t=0.5 (1,0) tEnd=1 other=8 otherT=0.5 otherIndex=4 windSum=2 windValue=1 oppValue=2
+SkOpSegment::debugShowActiveSpans id=5 (2,0 2,2) t=0 (2,0) tEnd=1 other=9 otherT=0 otherIndex=0 windSum=? windValue=1 oppValue=1
+SkOpSegment::debugShowActiveSpans id=6 (2,2 0,2) t=0 (2,2) tEnd=1 other=9 otherT=1 otherIndex=5 windSum=-1 windValue=1 oppValue=1
+SkOpSegment::debugShowActiveSpans id=12 (0,0 3,0) t=0.666666667 (2,0) tEnd=1 other=8 otherT=1 otherIndex=9 windSum=-1 windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=13 (3,0 3,3) t=0 (3,0) tEnd=1 other=12 otherT=1 otherIndex=12 windSum=-1 windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=14 (3,3 0,3) t=0 (3,3) tEnd=1 other=13 otherT=1 otherIndex=1 windSum=-1 windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=15 (0,3 0,0) t=0 (0,3) tEnd=0.333333333 other=14 otherT=1 otherIndex=1 windSum=-1 windValue=1 oppValue=0
+SkOpSegment::activeOp id=15 t=0.333333333 tEnd=0 op=diff miFrom=0 miTo=0 suFrom=0 suTo=1 result=0
+SkOpSegment::markDoneBinary id=15 (0,3 0,0) t=0 [0] (0,3) tEnd=0.333333333 newWindSum=-1 newOppSum=0 oppSum=0 windSum=-1 windValue=1 oppValue=0
+SkOpSegment::markDoneBinary id=14 (3,3 0,3) t=0 [0] (3,3) tEnd=1 newWindSum=-1 newOppSum=0 oppSum=0 windSum=-1 windValue=1 oppValue=0
+SkOpSegment::markDoneBinary id=13 (3,0 3,3) t=0 [0] (3,0) tEnd=1 newWindSum=-1 newOppSum=0 oppSum=0 windSum=-1 windValue=1 oppValue=0
+SkOpSegment::markDoneBinary id=12 (0,0 3,0) t=0.666666667 [10] (2,0) tEnd=0.666666667 newWindSum=-1 newOppSum=0 oppSum=0 windSum=-1 windValue=1 oppValue=0
+SkOpSegment::markDoneBinary id=12 (0,0 3,0) t=0.666666667 [9] (2,0) tEnd=0.666666667 newWindSum=-1 newOppSum=0 oppSum=0 windSum=-1 windValue=1 oppValue=0
+SkOpSegment::markDoneBinary id=12 (0,0 3,0) t=0.666666667 [8] (2,0) tEnd=0.666666667 newWindSum=-1 newOppSum=0 oppSum=0 windSum=-1 windValue=1 oppValue=0
+SkOpSegment::markDoneBinary id=12 (0,0 3,0) t=0.666666667 [11] (2,0) tEnd=1 newWindSum=-1 newOppSum=0 oppSum=0 windSum=-1 windValue=1 oppValue=0
+bridgeOp chase.append id=12 windSum=-1 small=0
+SkOpSegment::debugShowActiveSpans id=4 (0,0 2,0) t=0.5 (1,0) tEnd=1 other=8 otherT=0.5 otherIndex=4 windSum=2 windValue=1 oppValue=2
+SkOpSegment::debugShowActiveSpans id=5 (2,0 2,2) t=0 (2,0) tEnd=1 other=9 otherT=0 otherIndex=0 windSum=? windValue=1 oppValue=1
+SkOpSegment::debugShowActiveSpans id=6 (2,2 0,2) t=0 (2,2) tEnd=1 other=9 otherT=1 otherIndex=5 windSum=-1 windValue=1 oppValue=1
+SkOpSegment::activeOp id=4 t=1 tEnd=0.5 op=diff miFrom=0 miTo=1 suFrom=0 suTo=1 result=0
+SkOpSegment::markDoneBinary id=4 (0,0 2,0) t=0.5 [6] (1,0) tEnd=0.5 newWindSum=2 newOppSum=-2 oppSum=-2 windSum=2 windValue=1 oppValue=2
+SkOpSegment::markDoneBinary id=4 (0,0 2,0) t=0.5 [5] (1,0) tEnd=0.5 newWindSum=2 newOppSum=-2 oppSum=-2 windSum=2 windValue=1 oppValue=2
+SkOpSegment::markDoneBinary id=4 (0,0 2,0) t=0.5 [4] (1,0) tEnd=0.5 newWindSum=2 newOppSum=-2 oppSum=-2 windSum=2 windValue=1 oppValue=2
+SkOpSegment::markDoneBinary id=4 (0,0 2,0) t=0.5 [7] (1,0) tEnd=1 newWindSum=2 newOppSum=-2 oppSum=-2 windSum=2 windValue=1 oppValue=2
+bridgeOp chase.append id=4 windSum=2 small=0
+SkOpSegment::markWinding id=5 (2,0 2,2) t=0 [0] (2,0) tEnd=0 newWindSum=2 newOppSum=-2 oppSum=? windSum=? windValue=1 oppValue=1
+SkOpSegment::markWinding id=5 (2,0 2,2) t=0 [1] (2,0) tEnd=0 newWindSum=2 newOppSum=-2 oppSum=? windSum=? windValue=1 oppValue=1
+SkOpSegment::markWinding id=5 (2,0 2,2) t=0 [2] (2,0) tEnd=0 newWindSum=2 newOppSum=-2 oppSum=? windSum=? windValue=1 oppValue=1
+SkOpSegment::markWinding id=5 (2,0 2,2) t=0 [3] (2,0) tEnd=1 newWindSum=2 newOppSum=-2 oppSum=? windSum=? windValue=1 oppValue=1
+SkOpSegment::nextChase mismatched signs
+</div>
+
+<div id="refRects4">
+  RunTestSet [rects4]
+
+{{0,0}, {1,0}},
+{{1,0}, {1,1}},
+{{1,1}, {0,1}},
+{{0,1}, {0,0}},
+{{0,0}, {2,0}},
+{{2,0}, {2,2}},
+{{2,2}, {0,2}},
+{{0,2}, {0,0}},
+op difference
+{{0,0}, {2,0}},
+{{2,0}, {2,2}},
+{{2,2}, {0,2}},
+{{0,2}, {0,0}},
+{{0,0}, {3,0}},
+{{3,0}, {3,3}},
+{{3,3}, {0,3}},
+{{0,3}, {0,0}},
+debugShowLineIntersection wtTs[0]=0 {{1,0}, {1,1}} {{1,0}} wnTs[0]=1 {{0,0}, {1,0}}
+debugShowLineIntersection wtTs[0]=1 {{0,1}, {0,0}} {{0,0}} wnTs[0]=0 {{0,0}, {1,0}}
+debugShowLineIntersection wtTs[0]=0 {{1,1}, {0,1}} {{1,1}} wnTs[0]=1 {{1,0}, {1,1}}
+debugShowLineIntersection wtTs[0]=0 {{0,1}, {0,0}} {{0,1}} wnTs[0]=1 {{1,1}, {0,1}}
+debugShowLineIntersection wtTs[0]=0 {{0,0}, {2,0}} {{0,0}} wtTs[1]=0.5 {{1,0}} wnTs[0]=0 {{0,0}, {1,0}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=1 {{0,2}, {0,0}} {{0,0}} wnTs[0]=0 {{0,0}, {1,0}}
+debugShowLineIntersection wtTs[0]=0.5 {{0,0}, {2,0}} {{1,0}} wnTs[0]=0 {{1,0}, {1,1}}
+debugShowLineIntersection wtTs[0]=0.5 {{0,2}, {0,0}} {{0,1}} wnTs[0]=1 {{1,1}, {0,1}}
+debugShowLineIntersection wtTs[0]=0 {{0,0}, {2,0}} {{0,0}} wnTs[0]=1 {{0,1}, {0,0}}
+debugShowLineIntersection wtTs[0]=0.5 {{0,2}, {0,0}} {{0,1}} wtTs[1]=1 {{0,0}} wnTs[0]=0 {{0,1}, {0,0}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=0 {{0,0}, {2,0}} {{0,0}} wtTs[1]=0.5 {{1,0}} wnTs[0]=0 {{0,0}, {1,0}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=1 {{0,2}, {0,0}} {{0,0}} wnTs[0]=0 {{0,0}, {1,0}}
+debugShowLineIntersection wtTs[0]=0.5 {{0,0}, {2,0}} {{1,0}} wnTs[0]=0 {{1,0}, {1,1}}
+debugShowLineIntersection wtTs[0]=0.5 {{0,2}, {0,0}} {{0,1}} wnTs[0]=1 {{1,1}, {0,1}}
+debugShowLineIntersection wtTs[0]=0 {{0,0}, {2,0}} {{0,0}} wnTs[0]=1 {{0,1}, {0,0}}
+debugShowLineIntersection wtTs[0]=0.5 {{0,2}, {0,0}} {{0,1}} wtTs[1]=1 {{0,0}} wnTs[0]=0 {{0,1}, {0,0}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=0 {{0,0}, {3,0}} {{0,0}} wtTs[1]=0.333333333 {{1,0}} wnTs[0]=0 {{0,0}, {1,0}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=1 {{0,3}, {0,0}} {{0,0}} wnTs[0]=0 {{0,0}, {1,0}}
+debugShowLineIntersection wtTs[0]=0.333333333 {{0,0}, {3,0}} {{1,0}} wnTs[0]=0 {{1,0}, {1,1}}
+debugShowLineIntersection wtTs[0]=0.666666667 {{0,3}, {0,0}} {{0,1}} wnTs[0]=1 {{1,1}, {0,1}}
+debugShowLineIntersection wtTs[0]=0 {{0,0}, {3,0}} {{0,0}} wnTs[0]=1 {{0,1}, {0,0}}
+debugShowLineIntersection wtTs[0]=0.666666667 {{0,3}, {0,0}} {{0,1}} wtTs[1]=1 {{0,0}} wnTs[0]=0 {{0,1}, {0,0}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=0 {{2,0}, {2,2}} {{2,0}} wnTs[0]=1 {{0,0}, {2,0}}
+debugShowLineIntersection wtTs[0]=1 {{0,2}, {0,0}} {{0,0}} wnTs[0]=0 {{0,0}, {2,0}}
+debugShowLineIntersection wtTs[0]=0 {{2,2}, {0,2}} {{2,2}} wnTs[0]=1 {{2,0}, {2,2}}
+debugShowLineIntersection wtTs[0]=0 {{0,2}, {0,0}} {{0,2}} wnTs[0]=1 {{2,2}, {0,2}}
+debugShowLineIntersection wtTs[0]=0 {{0,0}, {2,0}} {{0,0}} wtTs[1]=1 {{2,0}} wnTs[0]=0 {{0,0}, {2,0}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=0 {{2,0}, {2,2}} {{2,0}} wnTs[0]=1 {{0,0}, {2,0}}
+debugShowLineIntersection wtTs[0]=1 {{0,2}, {0,0}} {{0,0}} wnTs[0]=0 {{0,0}, {2,0}}
+debugShowLineIntersection wtTs[0]=1 {{0,0}, {2,0}} {{2,0}} wnTs[0]=0 {{2,0}, {2,2}}
+debugShowLineIntersection wtTs[0]=0 {{2,0}, {2,2}} {{2,0}} wtTs[1]=1 {{2,2}} wnTs[0]=0 {{2,0}, {2,2}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=0 {{2,2}, {0,2}} {{2,2}} wnTs[0]=1 {{2,0}, {2,2}}
+debugShowLineIntersection wtTs[0]=1 {{2,0}, {2,2}} {{2,2}} wnTs[0]=0 {{2,2}, {0,2}}
+debugShowLineIntersection wtTs[0]=0 {{2,2}, {0,2}} {{2,2}} wtTs[1]=1 {{0,2}} wnTs[0]=0 {{2,2}, {0,2}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=0 {{0,2}, {0,0}} {{0,2}} wnTs[0]=1 {{2,2}, {0,2}}
+debugShowLineIntersection wtTs[0]=0 {{0,0}, {2,0}} {{0,0}} wnTs[0]=1 {{0,2}, {0,0}}
+debugShowLineIntersection wtTs[0]=1 {{2,2}, {0,2}} {{0,2}} wnTs[0]=0 {{0,2}, {0,0}}
+debugShowLineIntersection wtTs[0]=0 {{0,2}, {0,0}} {{0,2}} wtTs[1]=1 {{0,0}} wnTs[0]=0 {{0,2}, {0,0}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=0 {{0,0}, {3,0}} {{0,0}} wtTs[1]=0.666666667 {{2,0}} wnTs[0]=0 {{0,0}, {2,0}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=1 {{0,3}, {0,0}} {{0,0}} wnTs[0]=0 {{0,0}, {2,0}}
+debugShowLineIntersection wtTs[0]=0.666666667 {{0,0}, {3,0}} {{2,0}} wnTs[0]=0 {{2,0}, {2,2}}
+debugShowLineIntersection wtTs[0]=0.333333333 {{0,3}, {0,0}} {{0,2}} wnTs[0]=1 {{2,2}, {0,2}}
+debugShowLineIntersection wtTs[0]=0 {{0,0}, {3,0}} {{0,0}} wnTs[0]=1 {{0,2}, {0,0}}
+debugShowLineIntersection wtTs[0]=0.333333333 {{0,3}, {0,0}} {{0,2}} wtTs[1]=1 {{0,0}} wnTs[0]=0 {{0,2}, {0,0}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=0 {{2,0}, {2,2}} {{2,0}} wnTs[0]=1 {{0,0}, {2,0}}
+debugShowLineIntersection wtTs[0]=1 {{0,2}, {0,0}} {{0,0}} wnTs[0]=0 {{0,0}, {2,0}}
+debugShowLineIntersection wtTs[0]=0 {{2,2}, {0,2}} {{2,2}} wnTs[0]=1 {{2,0}, {2,2}}
+debugShowLineIntersection wtTs[0]=0 {{0,2}, {0,0}} {{0,2}} wnTs[0]=1 {{2,2}, {0,2}}
+debugShowLineIntersection wtTs[0]=0 {{0,0}, {3,0}} {{0,0}} wtTs[1]=0.666666667 {{2,0}} wnTs[0]=0 {{0,0}, {2,0}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=1 {{0,3}, {0,0}} {{0,0}} wnTs[0]=0 {{0,0}, {2,0}}
+debugShowLineIntersection wtTs[0]=0.666666667 {{0,0}, {3,0}} {{2,0}} wnTs[0]=0 {{2,0}, {2,2}}
+debugShowLineIntersection wtTs[0]=0.333333333 {{0,3}, {0,0}} {{0,2}} wnTs[0]=1 {{2,2}, {0,2}}
+debugShowLineIntersection wtTs[0]=0 {{0,0}, {3,0}} {{0,0}} wnTs[0]=1 {{0,2}, {0,0}}
+debugShowLineIntersection wtTs[0]=0.333333333 {{0,3}, {0,0}} {{0,2}} wtTs[1]=1 {{0,0}} wnTs[0]=0 {{0,2}, {0,0}} wnTs[1]=1
+debugShowLineIntersection wtTs[0]=0 {{3,0}, {3,3}} {{3,0}} wnTs[0]=1 {{0,0}, {3,0}}
+debugShowLineIntersection wtTs[0]=1 {{0,3}, {0,0}} {{0,0}} wnTs[0]=0 {{0,0}, {3,0}}
+debugShowLineIntersection wtTs[0]=0 {{3,3}, {0,3}} {{3,3}} wnTs[0]=1 {{3,0}, {3,3}}
+debugShowLineIntersection wtTs[0]=0 {{0,3}, {0,0}} {{0,3}} wnTs[0]=1 {{3,3}, {0,3}}
+SkOpSegment::debugShowTs - id=0 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=1 t=1 1,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=4 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=1 t=0.5 1,0 w=1 o=0] [o=9,5 t=1 2,0 w=1 o=0]
+SkOpSegment::addTPair addTPair this=4 0.5 other=0 1
+SkOpSegment::debugShowTs + id=0 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=4,1 t=1 1,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=4 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.5 1,0 w=1 o=0] [o=9,5 t=1 2,0 w=1 o=0]
+SkOpSegment::debugShowTs - id=3 [o=2 t=0 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=7 [o=10,6 t=0 0,2 w=1 o=0] [o=2 t=0.5 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::addTPair addTPair this=3 0 other=7 0.5
+SkOpSegment::debugShowTs + id=3 [o=7,2 t=0 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=7 [o=10,6 t=0 0,2 w=1 o=0] [o=3,2 t=0.5 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::debugShowTs - id=0 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=4,1 t=1 1,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=8 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=1 t=0.5 1,0 w=1 o=0] [o=9,5 t=1 2,0 w=1 o=0] operand
+SkOpSegment::addTPair addTPair this=8 0.5 other=0 1
+SkOpSegment::debugShowTs + id=0 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=8,4,1 t=1 1,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=8 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.5 1,0 w=1 o=0] [o=9,5 t=1 2,0 w=1 o=0] operand
+SkOpSegment::debugShowTs - id=3 [o=7,2 t=0 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=11 [o=10,6 t=0 0,2 w=1 o=0] [o=2 t=0.5 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::addTPair addTPair this=3 0 other=11 0.5
+SkOpSegment::debugShowTs + id=3 [o=11,7,2 t=0 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=11 [o=10,6 t=0 0,2 w=1 o=0] [o=3,2 t=0.5 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::debugShowTs - id=0 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=8,4,1 t=1 1,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=12 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=1 t=0.333 1,0 w=1 o=0] [o=9,5 t=0.667 2,0 w=1 o=0] [o=13 t=1 3,0 w=1 o=0] operand
+SkOpSegment::addTPair addTPair this=12 0.333333333 other=0 1
+SkOpSegment::debugShowTs + id=0 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=12,8,4,1 t=1 1,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=12 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.333 1,0 w=1 o=0] [o=9,5 t=0.667 2,0 w=1 o=0] [o=13 t=1 3,0 w=1 o=0] operand
+SkOpSegment::debugShowTs - id=3 [o=11,7,2 t=0 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=15 [o=14 t=0 0,3 w=1 o=0] [o=10,6 t=0.333 0,2 w=1 o=0] [o=2 t=0.667 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::addTPair addTPair this=3 0 other=15 0.666666667
+SkOpSegment::debugShowTs + id=3 [o=15,11,7,2 t=0 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=15 [o=14 t=0 0,3 w=1 o=0] [o=10,6 t=0.333 0,2 w=1 o=0] [o=3,2 t=0.667 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::debugShowTs - id=4 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.5 1,0 w=1 o=0] [o=9,5 t=1 2,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=8 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.5 1,0 w=1 o=0] [o=9,5 t=1 2,0 w=1 o=0] operand
+SkOpSegment::debugShowTs + id=4 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.5 1,0 w=1 o=0] [o=9,5 t=1 2,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=8 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.5 1,0 w=1 o=0] [o=9,5 t=1 2,0 w=1 o=0] operand
+SkOpSegment::debugShowTs - id=5 [o=12,8,4 t=0 2,0 w=1 o=0] [o=10,6 t=1 2,2 w=1 o=0]
+SkOpSegment::debugShowTs o id=9 [o=12,8,4 t=0 2,0 w=1 o=0] [o=10,6 t=1 2,2 w=1 o=0] operand
+SkOpSegment::debugShowTs + id=5 [o=12,8,4 t=0 2,0 w=1 o=0] [o=10,6 t=1 2,2 w=1 o=0]
+SkOpSegment::debugShowTs o id=9 [o=12,8,4 t=0 2,0 w=1 o=0] [o=10,6 t=1 2,2 w=1 o=0] operand
+SkOpSegment::debugShowTs - id=6 [o=9,5 t=0 2,2 w=1 o=0] [o=15,11,7 t=1 0,2 w=1 o=0]
+SkOpSegment::debugShowTs o id=10 [o=9,5 t=0 2,2 w=1 o=0] [o=15,11,7 t=1 0,2 w=1 o=0] operand
+SkOpSegment::debugShowTs + id=6 [o=9,5 t=0 2,2 w=1 o=0] [o=15,11,7 t=1 0,2 w=1 o=0]
+SkOpSegment::debugShowTs o id=10 [o=9,5 t=0 2,2 w=1 o=0] [o=15,11,7 t=1 0,2 w=1 o=0] operand
+SkOpSegment::debugShowTs - id=7 [o=10,6 t=0 0,2 w=1 o=0] [o=3,2 t=0.5 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=11 [o=10,6 t=0 0,2 w=1 o=0] [o=3,2 t=0.5 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::debugShowTs + id=7 [o=10,6 t=0 0,2 w=1 o=0] [o=3,2 t=0.5 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=11 [o=10,6 t=0 0,2 w=1 o=0] [o=3,2 t=0.5 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::debugShowTs - id=4 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.5 1,0 w=1 o=0] [o=9,5 t=1 2,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=12 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.333 1,0 w=1 o=0] [o=9,5 t=0.667 2,0 w=1 o=0] [o=13 t=1 3,0 w=1 o=0] operand
+SkOpSegment::addTPair addTPair this=12 0.666666667 other=4 1
+SkOpSegment::debugShowTs + id=4 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.5 1,0 w=1 o=0] [o=12,9,5 t=1 2,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=12 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.333 1,0 w=1 o=0] [o=4,9,5 t=0.667 2,0 w=1 o=0] [o=13 t=1 3,0 w=1 o=0] operand
+SkOpSegment::debugShowTs - id=7 [o=10,6 t=0 0,2 w=1 o=0] [o=3,2 t=0.5 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=15 [o=14 t=0 0,3 w=1 o=0] [o=10,6 t=0.333 0,2 w=1 o=0] [o=3,2 t=0.667 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::addTPair addTPair this=7 0 other=15 0.333333333
+SkOpSegment::debugShowTs + id=7 [o=15,10,6 t=0 0,2 w=1 o=0] [o=3,2 t=0.5 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=15 [o=14 t=0 0,3 w=1 o=0] [o=7,10,6 t=0.333 0,2 w=1 o=0] [o=3,2 t=0.667 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::debugShowTs - id=8 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.5 1,0 w=1 o=0] [o=9,5 t=1 2,0 w=1 o=0] operand
+SkOpSegment::debugShowTs o id=12 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.333 1,0 w=1 o=0] [o=4,9,5 t=0.667 2,0 w=1 o=0] [o=13 t=1 3,0 w=1 o=0] operand
+SkOpSegment::addTPair addTPair this=12 0.666666667 other=8 1
+SkOpSegment::debugShowTs + id=8 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.5 1,0 w=1 o=0] [o=12,9,5 t=1 2,0 w=1 o=0] operand
+SkOpSegment::debugShowTs o id=12 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.333 1,0 w=1 o=0] [o=8,4,9,5 t=0.667 2,0 w=1 o=0] [o=13 t=1 3,0 w=1 o=0] operand
+SkOpSegment::debugShowTs - id=11 [o=10,6 t=0 0,2 w=1 o=0] [o=3,2 t=0.5 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::debugShowTs o id=15 [o=14 t=0 0,3 w=1 o=0] [o=7,10,6 t=0.333 0,2 w=1 o=0] [o=3,2 t=0.667 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::addTPair addTPair this=11 0 other=15 0.333333333
+SkOpSegment::debugShowTs + id=11 [o=15,10,6 t=0 0,2 w=1 o=0] [o=3,2 t=0.5 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::debugShowTs o id=15 [o=14 t=0 0,3 w=1 o=0] [o=11,7,10,6 t=0.333 0,2 w=1 o=0] [o=3,2 t=0.667 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpContour::calcCoincidentWinding count=6
+SkOpSegment::debugShowTs p id=0 [o=15,11,7,3 t=0 0,0 w=0 o=0] [o=12,8,4,1 t=1 1,0 w=1 o=0] done
+SkOpSegment::debugShowTs o id=4 [o=15,11,7,3 t=0 0,0 w=0 o=0] [o=0,1 t=0.5 1,0 w=1 o=0] [o=12,9,5 t=1 2,0 w=1 o=0]
+SkOpSegment::debugShowTs p id=3 [o=15,11,7,2 t=0 0,1 w=0 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] done
+SkOpSegment::debugShowTs o id=7 [o=15,10,6 t=0 0,2 w=1 o=0] [o=3,2 t=0.5 0,1 w=0 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpContour::calcCoincidentWinding count=6
+SkOpSegment::debugShowTs p id=4 [o=15,11,7,3 t=0 0,0 w=0 o=0] [o=0,1 t=0.5 1,0 w=1 o=1] [o=12,9,5 t=1 2,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=8 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.5 1,0 w=0 o=0] [o=12,9,5 t=1 2,0 w=1 o=0] operand
+SkOpSegment::debugShowTs p id=5 [o=12,8,4 t=0 2,0 w=1 o=1] [o=10,6 t=1 2,2 w=1 o=0]
+SkOpSegment::debugShowTs o id=9 [o=12,8,4 t=0 2,0 w=0 o=0] [o=10,6 t=1 2,2 w=1 o=0] operand done
+SkOpSegment::debugShowTs p id=6 [o=9,5 t=0 2,2 w=1 o=1] [o=15,11,7 t=1 0,2 w=1 o=0]
+SkOpSegment::debugShowTs o id=10 [o=9,5 t=0 2,2 w=0 o=0] [o=15,11,7 t=1 0,2 w=1 o=0] operand done
+SkOpSegment::debugShowTs p id=7 [o=15,10,6 t=0 0,2 w=1 o=1] [o=3,2 t=0.5 0,1 w=0 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=11 [o=15,10,6 t=0 0,2 w=0 o=0] [o=3,2 t=0.5 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::debugShowTs p id=4 [o=15,11,7,3 t=0 0,0 w=0 o=0] [o=0,1 t=0.5 1,0 w=1 o=2] [o=12,9,5 t=1 2,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=12 [o=15,11,7,3 t=0 0,0 w=1 o=0] [o=0,1 t=0.333 1,0 w=0 o=0] [o=8,4,9,5 t=0.667 2,0 w=1 o=0] [o=13 t=1 3,0 w=1 o=0] operand
+SkOpSegment::debugShowTs p id=7 [o=15,10,6 t=0 0,2 w=1 o=2] [o=3,2 t=0.5 0,1 w=0 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0]
+SkOpSegment::debugShowTs o id=15 [o=14 t=0 0,3 w=1 o=0] [o=11,7,10,6 t=0.333 0,2 w=0 o=0] [o=3,2 t=0.667 0,1 w=1 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpContour::calcCoincidentWinding count=2
+SkOpSegment::debugShowTs p id=8 [o=15,11,7,3 t=0 0,0 w=2 o=0] [o=0,1 t=0.5 1,0 w=0 o=0] [o=12,9,5 t=1 2,0 w=1 o=0] operand
+SkOpSegment::debugShowTs o id=12 [o=15,11,7,3 t=0 0,0 w=0 o=0] [o=0,1 t=0.333 1,0 w=0 o=0] [o=8,4,9,5 t=0.667 2,0 w=1 o=0] [o=13 t=1 3,0 w=1 o=0] operand
+SkOpSegment::debugShowTs p id=11 [o=15,10,6 t=0 0,2 w=0 o=0] [o=3,2 t=0.5 0,1 w=2 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::debugShowTs o id=15 [o=14 t=0 0,3 w=1 o=0] [o=11,7,10,6 t=0.333 0,2 w=0 o=0] [o=3,2 t=0.667 0,1 w=0 o=0] [o=12,8,4,0 t=1 0,0 w=1 o=0] operand
+SkOpSegment::addTPair addTPair this=12 0.333333333 other=8 0.5
+SkOpSegment::addTPair addTPair this=12 0.333333333 other=4 0.5
+SkOpSegment::addTPair addTPair duplicate this=8 0.5 other=12 0.333333333
+SkOpSegment::addTPair addTPair this=8 0.5 other=4 0.5
+SkOpSegment::addTPair addTPair duplicate this=4 0.5 other=8 0.5
+SkOpSegment::addTPair addTPair duplicate this=4 0.5 other=12 0.333333333
+SkOpSegment::addTPair addTPair this=15 0.666666667 other=11 0.5
+SkOpSegment::addTPair addTPair this=15 0.666666667 other=7 0.5
+SkOpSegment::addTPair addTPair duplicate this=11 0.5 other=15 0.666666667
+SkOpSegment::addTPair addTPair this=11 0.5 other=7 0.5
+SkOpSegment::addTPair addTPair duplicate this=7 0.5 other=11 0.5
+SkOpSegment::addTPair addTPair duplicate this=7 0.5 other=15 0.666666667
+SkOpSegment::addTPair addTPair this=4 1 other=8 1
+SkOpSegment::addTPair addTPair this=5 0 other=9 0
+SkOpSegment::addTPair addTPair duplicate this=5 0 other=9 0
+SkOpSegment::addTPair addTPair duplicate this=5 0 other=9 0
+SkOpSegment::addTPair addTPair this=6 1 other=10 1
+SkOpSegment::addTPair addTPair this=7 0 other=11 0
+SkOpSegment::addTPair addTPair duplicate this=7 0 other=11 0
+SkOpSegment::addTPair addTPair duplicate this=7 0 other=11 0
+SkOpContour::joinCoincidence count=6
+SkOpContour::joinCoincidence count=6
+SkOpContour::joinCoincidence count=2
+SkOpSegment::sortAngles [1] tStart=0 [1]
+SkOpAngle::after [1/0] 23/23 tStart=0 tEnd=1 < [4/0] 31/31 tStart=0.5 tEnd=1 < [8/1] 15/15 tStart=0.5 tEnd=0  T 4
+SkOpSegment::sortAngles [2] tStart=1 [2]
+SkOpAngle::after [2/0] 31/31 tStart=1 tEnd=0 < [7/1] 23/23 tStart=0.5 tEnd=0 < [11/0] 7/7 tStart=0.5 tEnd=1  F 4
+SkOpSegment::sortAngles [4] tStart=1 [9]
+SkOpAngle::after [4/1] 15/15 tStart=1 tEnd=0.5 < [5/0] 23/23 tStart=0 tEnd=1 < [12/0] 31/31 tStart=0.666666667 tEnd=1  T 4
+SkOpSegment::sortAngles [5] tStart=1 [5]
+SkOpSegment::sortAngles [6] tStart=1 [3]
+SkOpAngle::after [6/1] 31/31 tStart=1 tEnd=0 < [7/0] 7/7 tStart=0 tEnd=0.5 < [15/0] 23/23 tStart=0.333333333 tEnd=0  T 4
+SkOpSegment::sortAngles [8] tStart=0 [1]
+SkOpSegment::debugShowActiveSpans id=1 (1,0 1,1) t=0 (1,0) tEnd=1 other=12 otherT=0.333333333 otherIndex=7 windSum=? windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=2 (1,1 0,1) t=0 (1,1) tEnd=1 other=1 otherT=1 otherIndex=4 windSum=? windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=4 (0,0 2,0) t=0.5 (1,0) tEnd=1 other=8 otherT=0.5 otherIndex=4 windSum=? windValue=1 oppValue=2
+SkOpSegment::debugShowActiveSpans id=5 (2,0 2,2) t=0 (2,0) tEnd=1 other=9 otherT=0 otherIndex=0 windSum=? windValue=1 oppValue=1
+SkOpSegment::debugShowActiveSpans id=6 (2,2 0,2) t=0 (2,2) tEnd=1 other=9 otherT=1 otherIndex=5 windSum=? windValue=1 oppValue=1
+SkOpSegment::debugShowActiveSpans id=7 (0,2 0,0) t=0 (0,2) tEnd=0.5 other=11 otherT=0 otherIndex=0 windSum=? windValue=1 oppValue=2
+SkOpSegment::debugShowActiveSpans id=8 (0,0 2,0) t=0 (0,0) tEnd=0.5 other=15 otherT=1 otherIndex=10 windSum=? windValue=2 oppValue=0
+SkOpSegment::debugShowActiveSpans id=11 (0,2 0,0) t=0.5 (0,1) tEnd=1 other=7 otherT=0.5 otherIndex=4 windSum=? windValue=2 oppValue=0
+SkOpSegment::debugShowActiveSpans id=12 (0,0 3,0) t=0.666666667 (2,0) tEnd=1 other=8 otherT=1 otherIndex=9 windSum=? windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=13 (3,0 3,3) t=0 (3,0) tEnd=1 other=12 otherT=1 otherIndex=12 windSum=? windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=14 (3,3 0,3) t=0 (3,3) tEnd=1 other=13 otherT=1 otherIndex=1 windSum=? windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=15 (0,3 0,0) t=0 (0,3) tEnd=0.333333333 other=14 otherT=1 otherIndex=1 windSum=? windValue=1 oppValue=0
+SkOpSegment::findTop
+SkOpAngle::debugOne [11/1] next=8/0 sect=23/23  s=1 [11] e=0.5 [7] sgn=1 windVal=2 windSum=? operand
+SkOpAngle::debugOne [8/0] next=11/1 sect=31/31  s=0 [0] e=0.5 [4] sgn=-1 windVal=2 windSum=? operand stop
+SkOpSegment::markWinding id=11 (0,2 0,0) t=0.5 [6] (0,1) tEnd=0.5 newWindSum=-2 newOppSum=0 oppSum=? windSum=? windValue=2
+SkOpSegment::markWinding id=11 (0,2 0,0) t=0.5 [5] (0,1) tEnd=0.5 newWindSum=-2 newOppSum=0 oppSum=? windSum=? windValue=2
+SkOpSegment::markWinding id=11 (0,2 0,0) t=0.5 [4] (0,1) tEnd=0.5 newWindSum=-2 newOppSum=0 oppSum=? windSum=? windValue=2
+SkOpSegment::markWinding id=11 (0,2 0,0) t=0.5 [7] (0,1) tEnd=1 newWindSum=-2 newOppSum=0 oppSum=? windSum=? windValue=2
+SkOpSegment::markWinding id=11 (0,2 0,0) t=0.5 [6] (0,1) tEnd=0.5 newWindSum=-2 newOppSum=0 oppSum=0 windSum=-2 windValue=2
+SkOpSegment::markWinding id=11 (0,2 0,0) t=0.5 [5] (0,1) tEnd=0.5 newWindSum=-2 newOppSum=0 oppSum=0 windSum=-2 windValue=2
+SkOpSegment::markWinding id=11 (0,2 0,0) t=0.5 [4] (0,1) tEnd=0.5 newWindSum=-2 newOppSum=0 oppSum=0 windSum=-2 windValue=2
+SkOpSegment::markWinding id=11 (0,2 0,0) t=0.5 [7] (0,1) tEnd=1 newWindSum=-2 newOppSum=0 oppSum=0 windSum=-2 windValue=2
+SkOpSegment::activeOp op=diff miFrom=0 miTo=0 suFrom=1 suTo=0 result=0
+SkOpSegment::markDoneBinary id=11 (0,2 0,0) t=0.5 [6] (0,1) tEnd=0.5 newWindSum=-2 newOppSum=0 oppSum=0 windSum=-2 windValue=2
+SkOpSegment::markDoneBinary id=11 (0,2 0,0) t=0.5 [5] (0,1) tEnd=0.5 newWindSum=-2 newOppSum=0 oppSum=0 windSum=-2 windValue=2
+SkOpSegment::markDoneBinary id=11 (0,2 0,0) t=0.5 [4] (0,1) tEnd=0.5 newWindSum=-2 newOppSum=0 oppSum=0 windSum=-2 windValue=2
+SkOpSegment::markDoneBinary id=11 (0,2 0,0) t=0.5 [7] (0,1) tEnd=1 newWindSum=-2 newOppSum=0 oppSum=0 windSum=-2 windValue=2
+SkOpSegment::markWinding id=8 (0,0 2,0) t=0 [0] (0,0) tEnd=0 newWindSum=-2 newOppSum=0 oppSum=? windSum=? windValue=2
+SkOpSegment::markWinding id=8 (0,0 2,0) t=0 [1] (0,0) tEnd=0 newWindSum=-2 newOppSum=0 oppSum=? windSum=? windValue=2
+SkOpSegment::markWinding id=8 (0,0 2,0) t=0 [2] (0,0) tEnd=0 newWindSum=-2 newOppSum=0 oppSum=? windSum=? windValue=2
+SkOpSegment::markWinding id=8 (0,0 2,0) t=0 [3] (0,0) tEnd=0.5 newWindSum=-2 newOppSum=0 oppSum=? windSum=? windValue=2
+SkOpSegment::markAngle last id=8 windSum=? small=0
+SkOpSegment::debugShowActiveSpans id=1 (1,0 1,1) t=0 (1,0) tEnd=1 other=12 otherT=0.333333333 otherIndex=7 windSum=? windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=2 (1,1 0,1) t=0 (1,1) tEnd=1 other=1 otherT=1 otherIndex=4 windSum=? windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=4 (0,0 2,0) t=0.5 (1,0) tEnd=1 other=8 otherT=0.5 otherIndex=4 windSum=? windValue=1 oppValue=2
+SkOpSegment::debugShowActiveSpans id=5 (2,0 2,2) t=0 (2,0) tEnd=1 other=9 otherT=0 otherIndex=0 windSum=? windValue=1 oppValue=1
+SkOpSegment::debugShowActiveSpans id=6 (2,2 0,2) t=0 (2,2) tEnd=1 other=9 otherT=1 otherIndex=5 windSum=? windValue=1 oppValue=1
+SkOpSegment::debugShowActiveSpans id=7 (0,2 0,0) t=0 (0,2) tEnd=0.5 other=11 otherT=0 otherIndex=0 windSum=? windValue=1 oppValue=2
+SkOpSegment::debugShowActiveSpans id=8 (0,0 2,0) t=0 (0,0) tEnd=0.5 other=15 otherT=1 otherIndex=10 windSum=-2 windValue=2 oppValue=0
+SkOpSegment::debugShowActiveSpans id=12 (0,0 3,0) t=0.666666667 (2,0) tEnd=1 other=8 otherT=1 otherIndex=9 windSum=? windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=13 (3,0 3,3) t=0 (3,0) tEnd=1 other=12 otherT=1 otherIndex=12 windSum=? windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=14 (3,3 0,3) t=0 (3,3) tEnd=1 other=13 otherT=1 otherIndex=1 windSum=? windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=15 (0,3 0,0) t=0 (0,3) tEnd=0.333333333 other=14 otherT=1 otherIndex=1 windSum=? windValue=1 oppValue=0
+SkOpSegment::activeOp op=diff miFrom=0 miTo=0 suFrom=1 suTo=0 result=0
+SkOpSegment::markDoneBinary id=8 (0,0 2,0) t=0 [0] (0,0) tEnd=0 newWindSum=-2 newOppSum=0 oppSum=0 windSum=-2 windValue=2
+SkOpSegment::markDoneBinary id=8 (0,0 2,0) t=0 [1] (0,0) tEnd=0 newWindSum=-2 newOppSum=0 oppSum=0 windSum=-2 windValue=2
+SkOpSegment::markDoneBinary id=8 (0,0 2,0) t=0 [2] (0,0) tEnd=0 newWindSum=-2 newOppSum=0 oppSum=0 windSum=-2 windValue=2
+SkOpSegment::markDoneBinary id=8 (0,0 2,0) t=0 [3] (0,0) tEnd=0.5 newWindSum=-2 newOppSum=0 oppSum=0 windSum=-2 windValue=2
+SkOpSegment::markWinding id=1 (1,0 1,1) t=0 [0] (1,0) tEnd=0 newWindSum=1 newOppSum=-2 oppSum=? windSum=? windValue=1
+SkOpSegment::markWinding id=1 (1,0 1,1) t=0 [1] (1,0) tEnd=0 newWindSum=1 newOppSum=-2 oppSum=? windSum=? windValue=1
+SkOpSegment::markWinding id=1 (1,0 1,1) t=0 [2] (1,0) tEnd=0 newWindSum=1 newOppSum=-2 oppSum=? windSum=? windValue=1
+SkOpSegment::markWinding id=1 (1,0 1,1) t=0 [3] (1,0) tEnd=1 newWindSum=1 newOppSum=-2 oppSum=? windSum=? windValue=1
+SkOpSegment::markWinding id=2 (1,1 0,1) t=0 [0] (1,1) tEnd=1 newWindSum=1 newOppSum=-2 oppSum=? windSum=? windValue=1
+SkOpSegment::markAngle last id=2 windSum=? small=0
+SkOpSegment::markWinding id=4 (0,0 2,0) t=0.5 [4] (1,0) tEnd=0.5 newWindSum=2 newOppSum=-2 oppSum=? windSum=? windValue=1
+SkOpSegment::markWinding id=4 (0,0 2,0) t=0.5 [5] (1,0) tEnd=0.5 newWindSum=2 newOppSum=-2 oppSum=? windSum=? windValue=1
+SkOpSegment::markWinding id=4 (0,0 2,0) t=0.5 [6] (1,0) tEnd=0.5 newWindSum=2 newOppSum=-2 oppSum=? windSum=? windValue=1
+SkOpSegment::markWinding id=4 (0,0 2,0) t=0.5 [7] (1,0) tEnd=1 newWindSum=2 newOppSum=-2 oppSum=? windSum=? windValue=1
+SkOpSegment::markAngle last id=4 windSum=? small=0
+SkOpSegment::debugShowActiveSpans id=1 (1,0 1,1) t=0 (1,0) tEnd=1 other=12 otherT=0.333333333 otherIndex=7 windSum=1 windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=2 (1,1 0,1) t=0 (1,1) tEnd=1 other=1 otherT=1 otherIndex=4 windSum=1 windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=4 (0,0 2,0) t=0.5 (1,0) tEnd=1 other=8 otherT=0.5 otherIndex=4 windSum=2 windValue=1 oppValue=2
+SkOpSegment::debugShowActiveSpans id=5 (2,0 2,2) t=0 (2,0) tEnd=1 other=9 otherT=0 otherIndex=0 windSum=? windValue=1 oppValue=1
+SkOpSegment::debugShowActiveSpans id=6 (2,2 0,2) t=0 (2,2) tEnd=1 other=9 otherT=1 otherIndex=5 windSum=? windValue=1 oppValue=1
+SkOpSegment::debugShowActiveSpans id=7 (0,2 0,0) t=0 (0,2) tEnd=0.5 other=11 otherT=0 otherIndex=0 windSum=? windValue=1 oppValue=2
+SkOpSegment::debugShowActiveSpans id=12 (0,0 3,0) t=0.666666667 (2,0) tEnd=1 other=8 otherT=1 otherIndex=9 windSum=? windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=13 (3,0 3,3) t=0 (3,0) tEnd=1 other=12 otherT=1 otherIndex=12 windSum=? windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=14 (3,3 0,3) t=0 (3,3) tEnd=1 other=13 otherT=1 otherIndex=1 windSum=? windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=15 (0,3 0,0) t=0 (0,3) tEnd=0.333333333 other=14 otherT=1 otherIndex=1 windSum=? windValue=1 oppValue=0
+SkOpSegment::activeOp op=diff miFrom=0 miTo=1 suFrom=1 suTo=1 result=0
+SkOpSegment::markDoneBinary id=1 (1,0 1,1) t=0 [0] (1,0) tEnd=0 newWindSum=1 newOppSum=-2 oppSum=-2 windSum=1 windValue=1
+SkOpSegment::markDoneBinary id=1 (1,0 1,1) t=0 [1] (1,0) tEnd=0 newWindSum=1 newOppSum=-2 oppSum=-2 windSum=1 windValue=1
+SkOpSegment::markDoneBinary id=1 (1,0 1,1) t=0 [2] (1,0) tEnd=0 newWindSum=1 newOppSum=-2 oppSum=-2 windSum=1 windValue=1
+SkOpSegment::markDoneBinary id=1 (1,0 1,1) t=0 [3] (1,0) tEnd=1 newWindSum=1 newOppSum=-2 oppSum=-2 windSum=1 windValue=1
+SkOpSegment::markDoneBinary id=2 (1,1 0,1) t=0 [0] (1,1) tEnd=1 newWindSum=1 newOppSum=-2 oppSum=-2 windSum=1 windValue=1
+SkOpSegment::markWinding id=7 (0,2 0,0) t=0 [0] (0,2) tEnd=0 newWindSum=-1 newOppSum=-2 oppSum=? windSum=? windValue=1
+SkOpSegment::markWinding id=7 (0,2 0,0) t=0 [1] (0,2) tEnd=0 newWindSum=-1 newOppSum=-2 oppSum=? windSum=? windValue=1
+SkOpSegment::markWinding id=7 (0,2 0,0) t=0 [2] (0,2) tEnd=0 newWindSum=-1 newOppSum=-2 oppSum=? windSum=? windValue=1
+SkOpSegment::markWinding id=7 (0,2 0,0) t=0 [3] (0,2) tEnd=0.5 newWindSum=-1 newOppSum=-2 oppSum=? windSum=? windValue=1
+SkOpSegment::markAngle last id=7 windSum=-1 small=0
+SkOpSegment::debugShowActiveSpans id=4 (0,0 2,0) t=0.5 (1,0) tEnd=1 other=8 otherT=0.5 otherIndex=4 windSum=2 windValue=1 oppValue=2
+SkOpSegment::debugShowActiveSpans id=5 (2,0 2,2) t=0 (2,0) tEnd=1 other=9 otherT=0 otherIndex=0 windSum=? windValue=1 oppValue=1
+SkOpSegment::debugShowActiveSpans id=6 (2,2 0,2) t=0 (2,2) tEnd=1 other=9 otherT=1 otherIndex=5 windSum=? windValue=1 oppValue=1
+SkOpSegment::debugShowActiveSpans id=7 (0,2 0,0) t=0 (0,2) tEnd=0.5 other=11 otherT=0 otherIndex=0 windSum=-1 windValue=1 oppValue=2
+SkOpSegment::debugShowActiveSpans id=12 (0,0 3,0) t=0.666666667 (2,0) tEnd=1 other=8 otherT=1 otherIndex=9 windSum=? windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=13 (3,0 3,3) t=0 (3,0) tEnd=1 other=12 otherT=1 otherIndex=12 windSum=? windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=14 (3,3 0,3) t=0 (3,3) tEnd=1 other=13 otherT=1 otherIndex=1 windSum=? windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=15 (0,3 0,0) t=0 (0,3) tEnd=0.333333333 other=14 otherT=1 otherIndex=1 windSum=? windValue=1 oppValue=0
+SkOpSegment::activeOp op=diff miFrom=0 miTo=1 suFrom=0 suTo=1 result=0
+SkOpSegment::markDoneBinary id=7 (0,2 0,0) t=0 [0] (0,2) tEnd=0 newWindSum=-1 newOppSum=-2 oppSum=-2 windSum=-1 windValue=1
+SkOpSegment::markDoneBinary id=7 (0,2 0,0) t=0 [1] (0,2) tEnd=0 newWindSum=-1 newOppSum=-2 oppSum=-2 windSum=-1 windValue=1
+SkOpSegment::markDoneBinary id=7 (0,2 0,0) t=0 [2] (0,2) tEnd=0 newWindSum=-1 newOppSum=-2 oppSum=-2 windSum=-1 windValue=1
+SkOpSegment::markDoneBinary id=7 (0,2 0,0) t=0 [3] (0,2) tEnd=0.5 newWindSum=-1 newOppSum=-2 oppSum=-2 windSum=-1 windValue=1
+SkOpSegment::markWinding id=15 (0,3 0,0) t=0 [0] (0,3) tEnd=0.333333333 newWindSum=-1 newOppSum=0 oppSum=? windSum=? windValue=1
+SkOpSegment::markWinding id=14 (3,3 0,3) t=0 [0] (3,3) tEnd=1 newWindSum=-1 newOppSum=0 oppSum=? windSum=? windValue=1
+SkOpSegment::markWinding id=13 (3,0 3,3) t=0 [0] (3,0) tEnd=1 newWindSum=-1 newOppSum=0 oppSum=? windSum=? windValue=1
+SkOpSegment::markWinding id=12 (0,0 3,0) t=0.666666667 [10] (2,0) tEnd=0.666666667 newWindSum=-1 newOppSum=0 oppSum=? windSum=? windValue=1
+SkOpSegment::markWinding id=12 (0,0 3,0) t=0.666666667 [9] (2,0) tEnd=0.666666667 newWindSum=-1 newOppSum=0 oppSum=? windSum=? windValue=1
+SkOpSegment::markWinding id=12 (0,0 3,0) t=0.666666667 [8] (2,0) tEnd=0.666666667 newWindSum=-1 newOppSum=0 oppSum=? windSum=? windValue=1
+SkOpSegment::markWinding id=12 (0,0 3,0) t=0.666666667 [11] (2,0) tEnd=1 newWindSum=-1 newOppSum=0 oppSum=? windSum=? windValue=1
+SkOpSegment::markAngle last id=12 windSum=-1 small=0
+SkOpSegment::markWinding id=6 (2,2 0,2) t=0 [0] (2,2) tEnd=0 newWindSum=-1 newOppSum=-2 oppSum=? windSum=? windValue=1
+SkOpSegment::markWinding id=6 (2,2 0,2) t=0 [1] (2,2) tEnd=1 newWindSum=-1 newOppSum=-2 oppSum=? windSum=? windValue=1
+SkOpSegment::markAngle last id=6 windSum=-1 small=0
+SkOpSegment::debugShowActiveSpans id=4 (0,0 2,0) t=0.5 (1,0) tEnd=1 other=8 otherT=0.5 otherIndex=4 windSum=2 windValue=1 oppValue=2
+SkOpSegment::debugShowActiveSpans id=5 (2,0 2,2) t=0 (2,0) tEnd=1 other=9 otherT=0 otherIndex=0 windSum=? windValue=1 oppValue=1
+SkOpSegment::debugShowActiveSpans id=6 (2,2 0,2) t=0 (2,2) tEnd=1 other=9 otherT=1 otherIndex=5 windSum=-1 windValue=1 oppValue=1
+SkOpSegment::debugShowActiveSpans id=12 (0,0 3,0) t=0.666666667 (2,0) tEnd=1 other=8 otherT=1 otherIndex=9 windSum=-1 windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=13 (3,0 3,3) t=0 (3,0) tEnd=1 other=12 otherT=1 otherIndex=12 windSum=-1 windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=14 (3,3 0,3) t=0 (3,3) tEnd=1 other=13 otherT=1 otherIndex=1 windSum=-1 windValue=1 oppValue=0
+SkOpSegment::debugShowActiveSpans id=15 (0,3 0,0) t=0 (0,3) tEnd=0.333333333 other=14 otherT=1 otherIndex=1 windSum=-1 windValue=1 oppValue=0
+SkOpSegment::activeOp op=diff miFrom=0 miTo=0 suFrom=0 suTo=1 result=0
+SkOpSegment::markDoneBinary id=15 (0,3 0,0) t=0 [0] (0,3) tEnd=0.333333333 newWindSum=-1 newOppSum=0 oppSum=0 windSum=-1 windValue=1
+SkOpSegment::markDoneBinary id=14 (3,3 0,3) t=0 [0] (3,3) tEnd=1 newWindSum=-1 newOppSum=0 oppSum=0 windSum=-1 windValue=1
+SkOpSegment::markDoneBinary id=13 (3,0 3,3) t=0 [0] (3,0) tEnd=1 newWindSum=-1 newOppSum=0 oppSum=0 windSum=-1 windValue=1
+SkOpSegment::markDoneBinary id=12 (0,0 3,0) t=0.666666667 [10] (2,0) tEnd=0.666666667 newWindSum=-1 newOppSum=0 oppSum=0 windSum=-1 windValue=1
+SkOpSegment::markDoneBinary id=12 (0,0 3,0) t=0.666666667 [9] (2,0) tEnd=0.666666667 newWindSum=-1 newOppSum=0 oppSum=0 windSum=-1 windValue=1
+SkOpSegment::markDoneBinary id=12 (0,0 3,0) t=0.666666667 [8] (2,0) tEnd=0.666666667 newWindSum=-1 newOppSum=0 oppSum=0 windSum=-1 windValue=1
+SkOpSegment::markDoneBinary id=12 (0,0 3,0) t=0.666666667 [11] (2,0) tEnd=1 newWindSum=-1 newOppSum=0 oppSum=0 windSum=-1 windValue=1
+SkOpSegment::debugShowActiveSpans id=4 (0,0 2,0) t=0.5 (1,0) tEnd=1 other=8 otherT=0.5 otherIndex=4 windSum=2 windValue=1 oppValue=2
+SkOpSegment::debugShowActiveSpans id=5 (2,0 2,2) t=0 (2,0) tEnd=1 other=9 otherT=0 otherIndex=0 windSum=? windValue=1 oppValue=1
+SkOpSegment::debugShowActiveSpans id=6 (2,2 0,2) t=0 (2,2) tEnd=1 other=9 otherT=1 otherIndex=5 windSum=-1 windValue=1 oppValue=1
+SkOpSegment::activeOp op=diff miFrom=0 miTo=1 suFrom=0 suTo=1 result=0
+SkOpSegment::markDoneBinary id=4 (0,0 2,0) t=0.5 [6] (1,0) tEnd=0.5 newWindSum=2 newOppSum=-2 oppSum=-2 windSum=2 windValue=1
+SkOpSegment::markDoneBinary id=4 (0,0 2,0) t=0.5 [5] (1,0) tEnd=0.5 newWindSum=2 newOppSum=-2 oppSum=-2 windSum=2 windValue=1
+SkOpSegment::markDoneBinary id=4 (0,0 2,0) t=0.5 [4] (1,0) tEnd=0.5 newWindSum=2 newOppSum=-2 oppSum=-2 windSum=2 windValue=1
+SkOpSegment::markDoneBinary id=4 (0,0 2,0) t=0.5 [7] (1,0) tEnd=1 newWindSum=2 newOppSum=-2 oppSum=-2 windSum=2 windValue=1
+SkOpSegment::markWinding id=5 (2,0 2,2) t=0 [0] (2,0) tEnd=0 newWindSum=2 newOppSum=-2 oppSum=? windSum=? windValue=1
+SkOpSegment::markWinding id=5 (2,0 2,2) t=0 [1] (2,0) tEnd=0 newWindSum=2 newOppSum=-2 oppSum=? windSum=? windValue=1
+SkOpSegment::markWinding id=5 (2,0 2,2) t=0 [2] (2,0) tEnd=0 newWindSum=2 newOppSum=-2 oppSum=? windSum=? windValue=1
+SkOpSegment::markWinding id=5 (2,0 2,2) t=0 [3] (2,0) tEnd=1 newWindSum=2 newOppSum=-2 oppSum=? windSum=? windValue=1
+SkOpSegment::markAngle last id=5 windSum=? small=0
+SkOpSegment::debugShowActiveSpans id=5 (2,0 2,2) t=0 (2,0) tEnd=1 other=9 otherT=0 otherIndex=0 windSum=2 windValue=1 oppValue=1
+SkOpSegment::debugShowActiveSpans id=6 (2,2 0,2) t=0 (2,2) tEnd=1 other=9 otherT=1 otherIndex=5 windSum=-1 windValue=1 oppValue=1
+SkOpSegment::activeOp op=diff miFrom=1 miTo=0 suFrom=1 suTo=1 result=0
+SkOpSegment::markDoneBinary id=5 (2,0 2,2) t=0 [0] (2,0) tEnd=0 newWindSum=2 newOppSum=-2 oppSum=-2 windSum=2 windValue=1
+SkOpSegment::markDoneBinary id=5 (2,0 2,2) t=0 [1] (2,0) tEnd=0 newWindSum=2 newOppSum=-2 oppSum=-2 windSum=2 windValue=1
+SkOpSegment::markDoneBinary id=5 (2,0 2,2) t=0 [2] (2,0) tEnd=0 newWindSum=2 newOppSum=-2 oppSum=-2 windSum=2 windValue=1
+SkOpSegment::markDoneBinary id=5 (2,0 2,2) t=0 [3] (2,0) tEnd=1 newWindSum=2 newOppSum=-2 oppSum=-2 windSum=2 windValue=1
+SkOpSegment::debugShowActiveSpans id=6 (2,2 0,2) t=0 (2,2) tEnd=1 other=9 otherT=1 otherIndex=5 windSum=-1 windValue=1 oppValue=1
+SkOpSegment::activeOp op=diff miFrom=1 miTo=0 suFrom=1 suTo=1 result=0
+SkOpSegment::markDoneBinary id=6 (2,2 0,2) t=0 [0] (2,2) tEnd=0 newWindSum=-1 newOppSum=-2 oppSum=-2 windSum=-1 windValue=1
+SkOpSegment::markDoneBinary id=6 (2,2 0,2) t=0 [1] (2,2) tEnd=1 newWindSum=-1 newOppSum=-2 oppSum=-2 windSum=-1 windValue=1
+</div>
+
+</div>
+
+<script type="text/javascript">
+
+var testDivs = [
+    rects4,
+    refRects4,
+];
+
+var decimal_places = 3; // make this 3 to show more precision
+
+var tests = [];
+var testLines = [];
+var testTitles = [];
+var testIndex = 0;
+var ctx;
+
+var xmin, xmax, focusXmin, focusXmax;
+var ymin, ymax, focusYmin, focusYmax;
+var scale;
+var mouseX, mouseY;
+var srcLeft, srcTop;
+var screenWidth, screenHeight;
+var drawnPts, drawnLines, drawnQuads, drawnCubics;
+var curveT = 0;
+
+var pt_labels = 2;
+var collect_bounds = false;
+var control_lines = 0;
+var curve_t = false;
+var debug_xy = 1;
+var focus_enabled = false;
+var focus_on_selection = false;
+var step_limit = 0;
+var draw_active = false;
+var draw_add = false;
+var draw_angle = 0;
+var draw_deriviatives = 0;
+var draw_hints = false;
+var draw_hodo = 0;
+var draw_id = false;
+var draw_intersection = 0;
+var draw_intersectT = false;
+var draw_legend = true;
+var draw_log = false;
+var draw_mark = false;
+var draw_midpoint = false;
+var draw_op = 0;
+var draw_sequence = false;
+var draw_sort = 0;
+var draw_path = 3;
+var draw_computed = 0;
+var retina_scale = !!window.devicePixelRatio;
+
+var activeCount = 0;
+var addCount = 0;
+var angleCount = 0;
+var opCount = 0;
+var sectCount = 0;
+var sortCount = 0;
+var markCount = 0;
+var activeMax = 0;
+var addMax = 0;
+var angleMax = 0;
+var sectMax = 0;
+var sectMax2 = 0;
+var sortMax = 0;
+var markMax = 0;
+var opMax = 0;
+var stepMax = 0;
+var lastIndex = 0;
+var hasPath = false;
+var hasComputedPath = false;
+
+var firstActiveSpan = -1;
+var logStart = -1;
+var logRange = 0;
+
+var SPAN_ID = 0;
+var SPAN_X1 = SPAN_ID + 1;
+var SPAN_Y1 = SPAN_X1 + 1;
+var SPAN_X2 = SPAN_Y1 + 1;
+var SPAN_Y2 = SPAN_X2 + 1;
+var SPAN_L_T = SPAN_Y2 + 1;
+var SPAN_L_TX = SPAN_L_T + 1;
+var SPAN_L_TY = SPAN_L_TX + 1;
+var SPAN_L_TEND = SPAN_L_TY + 1;
+var SPAN_L_OTHER = SPAN_L_TEND + 1;
+var SPAN_L_OTHERT = SPAN_L_OTHER + 1;
+var SPAN_L_OTHERI = SPAN_L_OTHERT + 1;
+var SPAN_L_SUM = SPAN_L_OTHERI + 1;
+var SPAN_L_VAL = SPAN_L_SUM + 1;
+var SPAN_L_OPP = SPAN_L_VAL + 1;
+
+var SPAN_X3 = SPAN_Y2 + 1;
+var SPAN_Y3 = SPAN_X3 + 1;
+var SPAN_Q_T = SPAN_Y3 + 1;
+var SPAN_Q_TX = SPAN_Q_T + 1;
+var SPAN_Q_TY = SPAN_Q_TX + 1;
+var SPAN_Q_TEND = SPAN_Q_TY + 1;
+var SPAN_Q_OTHER = SPAN_Q_TEND + 1;
+var SPAN_Q_OTHERT = SPAN_Q_OTHER + 1;
+var SPAN_Q_OTHERI = SPAN_Q_OTHERT + 1;
+var SPAN_Q_SUM = SPAN_Q_OTHERI + 1;
+var SPAN_Q_VAL = SPAN_Q_SUM + 1;
+var SPAN_Q_OPP = SPAN_Q_VAL + 1;
+
+var SPAN_X4 = SPAN_Y3 + 1;
+var SPAN_Y4 = SPAN_X4 + 1;
+var SPAN_C_T = SPAN_Y4 + 1;
+var SPAN_C_TX = SPAN_C_T + 1;
+var SPAN_C_TY = SPAN_C_TX + 1;
+var SPAN_C_TEND = SPAN_C_TY + 1;
+var SPAN_C_OTHER = SPAN_C_TEND + 1;
+var SPAN_C_OTHERT = SPAN_C_OTHER + 1;
+var SPAN_C_OTHERI = SPAN_C_OTHERT + 1;
+var SPAN_C_SUM = SPAN_C_OTHERI + 1;
+var SPAN_C_VAL = SPAN_C_SUM + 1;
+var SPAN_C_OPP = SPAN_C_VAL + 1;
+
+var ACTIVE_LINE_SPAN =        1;
+var ACTIVE_QUAD_SPAN =        ACTIVE_LINE_SPAN + 1;
+var ACTIVE_CUBIC_SPAN =       ACTIVE_QUAD_SPAN + 1;
+
+var ADD_MOVETO =              ACTIVE_CUBIC_SPAN + 1;
+var ADD_LINETO =              ADD_MOVETO + 1;
+var ADD_QUADTO =              ADD_LINETO + 1;
+var ADD_CUBICTO =             ADD_QUADTO + 1;
+var ADD_CLOSE =               ADD_CUBICTO + 1;
+var ADD_FILL =                ADD_CLOSE + 1;
+
+var PATH_LINE =               ADD_FILL + 1;
+var PATH_QUAD =               PATH_LINE + 1;
+var PATH_CUBIC =              PATH_QUAD + 1;
+
+var INTERSECT_LINE =          PATH_CUBIC + 1;
+var INTERSECT_LINE_2 =        INTERSECT_LINE + 1;
+var INTERSECT_LINE_NO =       INTERSECT_LINE_2 + 1;
+var INTERSECT_QUAD_LINE =     INTERSECT_LINE_NO + 1;
+var INTERSECT_QUAD_LINE_2 =   INTERSECT_QUAD_LINE + 1;
+var INTERSECT_QUAD_LINE_NO =  INTERSECT_QUAD_LINE_2 + 1;
+var INTERSECT_QUAD =          INTERSECT_QUAD_LINE_NO + 1;
+var INTERSECT_QUAD_2 =        INTERSECT_QUAD + 1;
+var INTERSECT_QUAD_NO =       INTERSECT_QUAD_2 + 1;
+var INTERSECT_SELF_CUBIC =    INTERSECT_QUAD_NO + 1;
+var INTERSECT_SELF_CUBIC_NO = INTERSECT_SELF_CUBIC + 1;
+var INTERSECT_CUBIC_LINE =    INTERSECT_SELF_CUBIC_NO + 1;
+var INTERSECT_CUBIC_LINE_2 =  INTERSECT_CUBIC_LINE + 1;
+var INTERSECT_CUBIC_LINE_3 =  INTERSECT_CUBIC_LINE_2 + 1;
+var INTERSECT_CUBIC_LINE_NO = INTERSECT_CUBIC_LINE_3 + 1;
+var INTERSECT_CUBIC_QUAD =    INTERSECT_CUBIC_LINE_NO + 1;
+var INTERSECT_CUBIC_QUAD_2 =  INTERSECT_CUBIC_QUAD + 1;
+var INTERSECT_CUBIC_QUAD_3 =  INTERSECT_CUBIC_QUAD_2 + 1;
+var INTERSECT_CUBIC_QUAD_4 =  INTERSECT_CUBIC_QUAD_3 + 1;
+var INTERSECT_CUBIC_QUAD_NO = INTERSECT_CUBIC_QUAD_4 + 1;
+var INTERSECT_CUBIC =         INTERSECT_CUBIC_QUAD_NO + 1;
+var INTERSECT_CUBIC_2 =       INTERSECT_CUBIC + 1;
+var INTERSECT_CUBIC_3 =       INTERSECT_CUBIC_2 + 1;
+var INTERSECT_CUBIC_4 =       INTERSECT_CUBIC_3 + 1;
+// FIXME: add cubic 5- 9
+var INTERSECT_CUBIC_NO =      INTERSECT_CUBIC_4 + 1;
+
+var SORT_UNARY =              INTERSECT_CUBIC_NO + 1;
+var SORT_BINARY =             SORT_UNARY + 1;
+
+var OP_DIFFERENCE =           SORT_BINARY + 1;
+var OP_INTERSECT =            OP_DIFFERENCE + 1;
+var OP_UNION =                OP_INTERSECT + 1;
+var OP_XOR =                  OP_UNION + 1;
+
+var MARK_LINE =               OP_XOR + 1;
+var MARK_QUAD =               MARK_LINE + 1;
+var MARK_CUBIC =              MARK_QUAD + 1;
+var MARK_DONE_LINE =          MARK_CUBIC + 1;
+var MARK_DONE_QUAD =          MARK_DONE_LINE + 1;
+var MARK_DONE_CUBIC =         MARK_DONE_QUAD + 1;
+var MARK_UNSORTABLE_LINE =    MARK_DONE_CUBIC + 1;
+var MARK_UNSORTABLE_QUAD =    MARK_UNSORTABLE_LINE + 1;
+var MARK_UNSORTABLE_CUBIC =   MARK_UNSORTABLE_QUAD + 1;
+var MARK_SIMPLE_LINE =        MARK_UNSORTABLE_CUBIC + 1;
+var MARK_SIMPLE_QUAD =        MARK_SIMPLE_LINE + 1;
+var MARK_SIMPLE_CUBIC =       MARK_SIMPLE_QUAD + 1;
+var MARK_SIMPLE_DONE_LINE =   MARK_SIMPLE_CUBIC + 1;
+var MARK_SIMPLE_DONE_QUAD =   MARK_SIMPLE_DONE_LINE + 1;
+var MARK_SIMPLE_DONE_CUBIC =  MARK_SIMPLE_DONE_QUAD + 1;
+var MARK_DONE_UNARY_LINE =    MARK_SIMPLE_DONE_CUBIC + 1;
+var MARK_DONE_UNARY_QUAD =    MARK_DONE_UNARY_LINE + 1;
+var MARK_DONE_UNARY_CUBIC =   MARK_DONE_UNARY_QUAD + 1;
+var MARK_ANGLE_LAST =         MARK_DONE_UNARY_CUBIC + 1;
+
+var COMPUTED_SET_1 =          MARK_ANGLE_LAST + 1;
+var COMPUTED_SET_2 =          COMPUTED_SET_1 + 1;
+
+var ANGLE_AFTER =             COMPUTED_SET_2;
+var ANGLE_AFTER2 =            ANGLE_AFTER + 1;
+
+var ACTIVE_OP =               ANGLE_AFTER2 + 1;
+
+var FRAG_TYPE_LAST =          ACTIVE_OP;
+
+var REC_TYPE_UNKNOWN = -1;
+var REC_TYPE_PATH = 0;
+var REC_TYPE_SECT = 1;
+var REC_TYPE_ACTIVE = 2;
+var REC_TYPE_ADD = 3;
+var REC_TYPE_SORT = 4;
+var REC_TYPE_OP = 5;
+var REC_TYPE_MARK = 6;
+var REC_TYPE_COMPUTED = 7;
+var REC_TYPE_COIN = 8;
+var REC_TYPE_ANGLE = 9;
+var REC_TYPE_ACTIVE_OP = 10;
+var REC_TYPE_LAST = REC_TYPE_ACTIVE_OP;
+
+function strs_to_nums(strs) {
+    var result = [];
+    for (var idx = 1; idx < strs.length; ++idx) {
+        var str = strs[idx];
+        var num = parseFloat(str);
+        if (isNaN(num)) {
+            result.push(str);
+        } else {
+            result.push(num);
+        }
+    }
+    return result;
+}
+
+function filter_str_by(id, str, regex, array) {
+    if (regex.test(str)) {
+        var strs = regex.exec(str);
+        var result = strs_to_nums(strs);
+        array.push(id);
+        array.push(result);
+        return true;
+    }
+    return false;
+}
+
+function construct_regexp2(pattern) {
+    var escape = pattern.replace(/[-/\\^$*+?.()|[\]{}]/g, '\\$&');
+    escape = escape.replace(/UNSORTABLE/g, "\\*\\*\\* UNSORTABLE \\*\\*\\*");
+    escape = escape.replace(/CUBIC_VAL/g, "\\(P_VAL P_VAL P_VAL P_VAL\\)");
+    escape = escape.replace(/QUAD_VAL/g, "\\(P_VAL P_VAL P_VAL\\)");
+    escape = escape.replace(/LINE_VAL/g, "\\(P_VAL P_VAL\\)");
+    escape = escape.replace(/FILL_TYPE/g, "SkPath::k[a-zA-Z]+_FillType");
+    escape = escape.replace(/PT_VAL/g, "\\(P_VAL\\)");
+    escape = escape.replace(/P_VAL/g, "(-?\\d+\\.?\\d*(?:e-?\\d+)?)[Ff]?, ?(-?\\d+\\.?\\d*(?:e-?\\d+)?)[Ff]?");
+    escape = escape.replace(/T_VAL/g, "(-?\\d+\\.?\\d*(?:e-?\\d+)?)");
+    escape = escape.replace(/PATH/g, "pathB?");
+    escape = escape.replace(/IDX/g, "(\\d+)");
+    escape = escape.replace(/NUM/g, "(-?\\d+)");
+    escape = escape.replace(/OPT/g, "(\\?|-?\\d+)");
+    return new RegExp(escape, 'i');
+}
+
+function construct_regexp2c(pattern) {
+    var escape = pattern.replace(/[-/\\^$*+?.()|[\]{}]/g, '\\$&');
+    escape = escape.replace(/UNSORTABLE/g, "\\*\\*\\* UNSORTABLE \\*\\*\\*");
+    escape = escape.replace(/CUBIC_VAL/g, "(?:\\$\\d = )?\\{\\{P_VAL\\}, \\{P_VAL\\}, \\{P_VAL\\}, \\{P_VAL\\}\\}");
+    escape = escape.replace(/QUAD_VAL/g, "(?:\\$\\d = )?\\{\\{P_VAL\\}, \\{P_VAL\\}, \\{P_VAL\\}\\}");
+    escape = escape.replace(/LINE_VAL/g, "(?:\\$\\d = )?\\{\\{P_VAL\\}, \\{P_VAL\\}\\}");
+    escape = escape.replace(/FILL_TYPE/g, "SkPath::k[a-zA-Z]+_FillType");
+    escape = escape.replace(/PT_VAL/g, "\\{\\{P_VAL\\}\\}");
+    escape = escape.replace(/P_VAL/g, "(?:f?[xX] = )?(-?\\d+\\.?\\d*(?:e-?\\d+)?)[Ff]?,(?: f?[yY] = )?(-?\\d+\\.?\\d*(?:e-?\\d+)?)[Ff]?");
+    escape = escape.replace(/T_VAL/g, "(-?\\d+\\.?\\d*(?:e-?\\d+)?)");
+    escape = escape.replace(/OPER/g, "[a-z]+");
+    escape = escape.replace(/PATH/g, "pathB?");
+    escape = escape.replace(/T_F/g, "([TF])");
+    escape = escape.replace(/IDX/g, "(\\d+)");
+    escape = escape.replace(/NUM/g, "(-?\\d+)");
+    escape = escape.replace(/OPT/g, "(\\?|-?\\d+)");
+    return new RegExp(escape, 'i');
+}
+
+function match_regexp(str, lineNo, array, id, pattern) {
+    var regex = construct_regexp2(pattern);
+    if (filter_str_by(id, str, regex, array)) {
+        return true;
+    }
+    regex = construct_regexp2c(pattern);
+    return filter_str_by(id, str, regex, array);
+}
+
+function endsWith(str, suffix) {
+    return str.indexOf(suffix, str.length - suffix.length) !== -1;
+}
+
+function parse_all(test) {
+    var lines = test.match(/[^\r\n]+/g);
+    var records = []; // a rec can be the original paths, a set of intersections, a set of active spans, a sort, or a path add
+    var record = [];
+    var recType = REC_TYPE_UNKNOWN;
+    var lastLineNo;
+    var moveX, moveY;
+    for (var lineNo = 0; lineNo < lines.length; ++lineNo) {
+        var line = lines[lineNo];
+        if (line.length == 0) {
+            continue;
+        }
+        var opStart = "SkOpSegment::";
+        if (line.lastIndexOf(opStart, 0) === 0) {
+            line = line.substr(opStart.length);
+        }
+        var angleStart = "SkOpAngle::";
+        if (line.lastIndexOf(angleStart, 0) === 0) {
+            line = line.substr(angleStart.length);
+        }
+        var type = line.lastIndexOf("debugShowActiveSpans", 0) === 0 ? REC_TYPE_ACTIVE 
+                : line.lastIndexOf("debugShowTs", 0) === 0 ? REC_TYPE_COIN 
+                : line.lastIndexOf("debugShow", 0) === 0 ? REC_TYPE_SECT
+                : line.lastIndexOf("activeOp", 0) === 0 ? REC_TYPE_ACTIVE_OP
+                : line.lastIndexOf("computed", 0) === 0 ? REC_TYPE_COMPUTED
+                : line.lastIndexOf("debugOne", 0) === 0 ? REC_TYPE_SORT
+                : line.lastIndexOf("dumpOne", 0) === 0 ? REC_TYPE_SORT
+                : line.lastIndexOf("pathB.", 0) === 0 ? REC_TYPE_ADD
+                : line.lastIndexOf("path.", 0) === 0 ? REC_TYPE_ADD
+                : line.lastIndexOf("after", 0) === 0 ? REC_TYPE_ANGLE
+                : line.lastIndexOf("mark", 0) === 0 ? REC_TYPE_MARK
+                : line.lastIndexOf("  {{", 0) === 0 ? REC_TYPE_COMPUTED
+                : line.lastIndexOf("{{", 0) === 0 ? REC_TYPE_PATH
+                : line.lastIndexOf("op", 0) === 0 ? REC_TYPE_OP
+                : line.lastIndexOf("$", 0) === 0 ? REC_TYPE_PATH
+                : REC_TYPE_UNKNOWN;
+        if (recType != type || recType == REC_TYPE_ADD || recType == REC_TYPE_SECT
+                || recType == REC_TYPE_ACTIVE_OP || recType == REC_TYPE_ANGLE) {
+            if (recType != REC_TYPE_UNKNOWN) {
+                records.push(recType);
+                records.push(lastLineNo);
+                records.push(record);
+            }
+            record = [];
+            recType = type;
+            lastLineNo = lineNo;
+        }
+        var found = false;
+        switch (recType) {
+            case REC_TYPE_ACTIVE:
+                found = match_regexp(line, lineNo, record, ACTIVE_LINE_SPAN, "debugShowActiveSpans" +
+" id=IDX LINE_VAL t=T_VAL PT_VAL tEnd=T_VAL other=IDX otherT=T_VAL otherIndex=IDX windSum=OPT windValue=IDX oppValue=NUM"
+                ) || match_regexp(line, lineNo, record, ACTIVE_QUAD_SPAN, "debugShowActiveSpans" +
+" id=IDX QUAD_VAL t=T_VAL PT_VAL tEnd=T_VAL other=IDX otherT=T_VAL otherIndex=IDX windSum=OPT windValue=IDX oppValue=NUM"
+                ) || match_regexp(line, lineNo, record, ACTIVE_CUBIC_SPAN, "debugShowActiveSpans" +
+" id=IDX CUBIC_VAL t=T_VAL PT_VAL tEnd=T_VAL other=IDX otherT=T_VAL otherIndex=IDX windSum=OPT windValue=IDX oppValue=NUM"
+                );
+                break;
+            case REC_TYPE_ACTIVE_OP:
+                found = match_regexp(line, lineNo, record, ACTIVE_OP, "activeOp" +
+" id=IDX t=T_VAL tEnd=T_VAL op=OPER miFrom=NUM miTo=NUM suFrom=NUM suTo=NUM result=IDX"
+                );
+                break;
+            case REC_TYPE_ADD:
+                if (match_regexp(line, lineNo, record, ADD_MOVETO, "PATH.moveTo(P_VAL);")) {
+                    moveX = record[1][0];
+                    moveY = record[1][1];
+                    found = true;
+                } else if (match_regexp(line, lineNo, record, ADD_LINETO, "PATH.lineTo(P_VAL);")) {
+                    record[1].unshift(moveY);
+                    record[1].unshift(moveX);
+                    moveX = record[1][2];
+                    moveY = record[1][3];
+                    found = true;
+                } else if (match_regexp(line, lineNo, record, ADD_QUADTO, "PATH.quadTo(P_VAL, P_VAL);")) {
+                    record[1].unshift(moveY);
+                    record[1].unshift(moveX);
+                    moveX = record[1][4];
+                    moveY = record[1][5];
+                    found = true;
+                } else if (match_regexp(line, lineNo, record, ADD_CUBICTO, "PATH.cubicTo(P_VAL, P_VAL, P_VAL);")) {
+                    record[1].unshift(moveY);
+                    record[1].unshift(moveX);
+                    moveX = record[1][6];
+                    moveY = record[1][7];
+                    found = true;
+                } else if (match_regexp(line, lineNo, record, ADD_FILL, "PATH.setFillType(FILL_TYPE);")) {
+                    found = true;
+                } else {
+                    found = match_regexp(line, lineNo, record, ADD_CLOSE, "PATH.close();");
+                }
+                break;
+            case REC_TYPE_ANGLE:
+                found = match_regexp(line, lineNo, record, ANGLE_AFTER, "after " +
+"id=IDX IDX/IDX tStart=T_VAL tEnd=T_VAL < id=IDX IDX/IDX tStart=T_VAL tEnd=T_VAL < id=IDX IDX/IDX tStart=T_VAL tEnd=T_VAL  T_F IDX");
+                if (found) {
+                    break;
+                }
+                found = match_regexp(line, lineNo, record, ANGLE_AFTER2, "after " +
+"[IDX/IDX] NUM/NUM tStart=T_VAL tEnd=T_VAL < [IDX/IDX] NUM/NUM tStart=T_VAL tEnd=T_VAL < [IDX/IDX] NUM/NUM tStart=T_VAL tEnd=T_VAL  T_F IDX");
+                break;
+            case REC_TYPE_COIN:
+                found = true;
+                break;
+            case REC_TYPE_COMPUTED:
+                found = line ==  "computed quadratics given"
+                  || match_regexp(line, lineNo, record, COMPUTED_SET_1, "computed quadratics set 1"
+                ) || match_regexp(line, lineNo, record, COMPUTED_SET_2, "computed quadratics set 2"
+                ) || match_regexp(line, lineNo, record, PATH_QUAD, "  QUAD_VAL,"
+                ) || match_regexp(line, lineNo, record, PATH_CUBIC, "  CUBIC_VAL,"
+                );
+                break;
+            case REC_TYPE_PATH:
+                found = match_regexp(line, lineNo, record, PATH_LINE, "LINE_VAL"
+                ) || match_regexp(line, lineNo, record, PATH_QUAD, "QUAD_VAL"
+                ) || match_regexp(line, lineNo, record, PATH_CUBIC, "CUBIC_VAL"
+                );
+                break;
+            case REC_TYPE_SECT:
+                found = match_regexp(line, lineNo, record, INTERSECT_LINE, "debugShowLineIntersection" +
+" wtTs[0]=T_VAL LINE_VAL PT_VAL wnTs[0]=T_VAL LINE_VAL"
+                ) || match_regexp(line, lineNo, record, INTERSECT_LINE_2, "debugShowLineIntersection" +
+" wtTs[0]=T_VAL LINE_VAL PT_VAL wtTs[1]=T_VAL PT_VAL wnTs[0]=T_VAL LINE_VAL wnTs[1]=T_VAL"
+                ) || match_regexp(line, lineNo, record, INTERSECT_LINE_NO, "debugShowLineIntersection" +
+" no intersect LINE_VAL LINE_VAL"
+                ) || match_regexp(line, lineNo, record, INTERSECT_QUAD_LINE, "debugShowQuadLineIntersection" +
+" wtTs[0]=T_VAL QUAD_VAL PT_VAL wnTs[0]=T_VAL LINE_VAL"
+                ) || match_regexp(line, lineNo, record, INTERSECT_QUAD_LINE_2, "debugShowQuadLineIntersection" +
+" wtTs[0]=T_VAL QUAD_VAL PT_VAL wtTs[1]=T_VAL PT_VAL wnTs[0]=T_VAL LINE_VAL wnTs[1]=T_VAL"
+                ) || match_regexp(line, lineNo, record, INTERSECT_QUAD_LINE_NO, "debugShowQuadLineIntersection" +
+" no intersect QUAD_VAL LINE_VAL"
+                ) || match_regexp(line, lineNo, record, INTERSECT_QUAD, "debugShowQuadIntersection" +
+" wtTs[0]=T_VAL QUAD_VAL PT_VAL wnTs[0]=T_VAL QUAD_VAL"
+                ) || match_regexp(line, lineNo, record, INTERSECT_QUAD_2, "debugShowQuadIntersection" +
+" wtTs[0]=T_VAL QUAD_VAL PT_VAL wtTs[1]=T_VAL PT_VAL wnTs[0]=T_VAL QUAD_VAL wnTs[1]=T_VAL"
+                ) || match_regexp(line, lineNo, record, INTERSECT_QUAD_NO, "debugShowQuadIntersection" +
+" no intersect QUAD_VAL QUAD_VAL"
+                ) || match_regexp(line, lineNo, record, INTERSECT_CUBIC_LINE, "debugShowCubicLineIntersection" +
+" wtTs[0]=T_VAL CUBIC_VAL PT_VAL wnTs[0]=T_VAL LINE_VAL"
+                ) || match_regexp(line, lineNo, record, INTERSECT_CUBIC_LINE_2, "debugShowCubicLineIntersection" +
+" wtTs[0]=T_VAL CUBIC_VAL PT_VAL wtTs[1]=T_VAL PT_VAL wnTs[0]=T_VAL LINE_VAL wnTs[1]=T_VAL"
+                ) || match_regexp(line, lineNo, record, INTERSECT_CUBIC_LINE_3, "debugShowCubicLineIntersection" +
+" wtTs[0]=T_VAL CUBIC_VAL PT_VAL wtTs[1]=T_VAL PT_VAL wtTs[2]=T_VAL PT_VAL wnTs[0]=T_VAL LINE_VAL wnTs[1]=T_VAL wnTs[2]=T_VAL"
+                ) || match_regexp(line, lineNo, record, INTERSECT_CUBIC_LINE_NO, "debugShowCubicLineIntersection" +
+" no intersect CUBIC_VAL LINE_VAL"
+                ) || match_regexp(line, lineNo, record, INTERSECT_CUBIC_QUAD, "debugShowCubicQuadIntersection" +
+" wtTs[0]=T_VAL CUBIC_VAL PT_VAL wnTs[0]=T_VAL QUAD_VAL"
+                ) || match_regexp(line, lineNo, record, INTERSECT_CUBIC_QUAD_2, "debugShowCubicQuadIntersection" +
+" wtTs[0]=T_VAL CUBIC_VAL PT_VAL wtTs[1]=T_VAL PT_VAL wnTs[0]=T_VAL QUAD_VAL wnTs[1]=T_VAL"
+                ) || match_regexp(line, lineNo, record, INTERSECT_CUBIC_QUAD_3, "debugShowCubicQuadIntersection" +
+" wtTs[0]=T_VAL CUBIC_VAL PT_VAL wtTs[1]=T_VAL PT_VAL wtTs[2]=T_VAL PT_VAL wnTs[0]=T_VAL QUAD_VAL wnTs[1]=T_VAL wnTs[2]=T_VAL"
+                ) || match_regexp(line, lineNo, record, INTERSECT_CUBIC_QUAD_4, "debugShowCubicQuadIntersection" +
+" wtTs[0]=T_VAL CUBIC_VAL PT_VAL wtTs[1]=T_VAL PT_VAL wtTs[2]=T_VAL wtTs[3]=T_VAL PT_VAL wnTs[0]=T_VAL QUAD_VAL wnTs[1]=T_VAL wnTs[2]=T_VAL wnTs[3]=T_VAL"
+                ) || match_regexp(line, lineNo, record, INTERSECT_CUBIC_QUAD_NO, "debugShowCubicQuadIntersection" +
+" no intersect CUBIC_VAL QUAD_VAL"
+                ) || match_regexp(line, lineNo, record, INTERSECT_CUBIC, "debugShowCubicIntersection" +
+" wtTs[0]=T_VAL CUBIC_VAL PT_VAL wnTs[0]=T_VAL CUBIC_VAL"
+                ) || match_regexp(line, lineNo, record, INTERSECT_CUBIC_2, "debugShowCubicIntersection" +
+" wtTs[0]=T_VAL CUBIC_VAL PT_VAL wtTs[1]=T_VAL PT_VAL wnTs[0]=T_VAL CUBIC_VAL wnTs[1]=T_VAL"
+                ) || match_regexp(line, lineNo, record, INTERSECT_CUBIC_3, "debugShowCubicIntersection" +
+" wtTs[0]=T_VAL CUBIC_VAL PT_VAL wtTs[1]=T_VAL PT_VAL wtTs[2]=T_VAL PT_VAL wnTs[0]=T_VAL CUBIC_VAL wnTs[1]=T_VAL wnTs[2]=T_VAL"
+                ) || match_regexp(line, lineNo, record, INTERSECT_CUBIC_4, "debugShowCubicIntersection" +
+" wtTs[0]=T_VAL CUBIC_VAL PT_VAL wtTs[1]=T_VAL PT_VAL wtTs[2]=T_VAL PT_VAL wtTs[3]=T_VAL PT_VAL wnTs[0]=T_VAL CUBIC_VAL wnTs[1]=T_VAL wnTs[2]=T_VAL wnTs[3]=T_VAL"
+                ) || match_regexp(line, lineNo, record, INTERSECT_CUBIC_NO, "debugShowCubicIntersection" +
+" no intersect CUBIC_VAL CUBIC_VAL"
+                ) || match_regexp(line, lineNo, record, INTERSECT_SELF_CUBIC, "debugShowCubicIntersection" +
+" wtTs[0]=T_VAL CUBIC_VAL PT_VAL wtTs[1]=T_VAL"
+                ) || match_regexp(line, lineNo, record, INTERSECT_SELF_CUBIC_NO, "debugShowCubicIntersection" +
+" no self intersect CUBIC_VAL"
+                );
+                break;
+            case REC_TYPE_SORT:
+                var hasDone = / done/.test(line);
+                var hasUnorderable = / unorderable/.test(line);
+                var hasSmall = / small/.test(line);
+                var hasTiny = / tiny/.test(line);
+                var hasOperand = / operand/.test(line);
+                var hasStop = / stop/.test(line);
+                line.replace(/[ a-z]+$/, "");
+                found = match_regexp(line, lineNo, record, SORT_UNARY, "debugOne" +
+" [IDX/IDX] next=IDX/IDX sect=IDX/IDX  s=T_VAL [IDX] e=T_VAL [IDX] sgn=NUM windVal=IDX windSum=OPT"
+                ) || match_regexp(line, lineNo, record, SORT_BINARY, "debugOne" +
+" [IDX/IDX] next=IDX/IDX sect=IDX/IDX  s=T_VAL [IDX] e=T_VAL [IDX] sgn=NUM windVal=IDX windSum=OPT oppVal=IDX oppSum=OPT"
+                ) || match_regexp(line, lineNo, record, SORT_UNARY, "dumpOne" +
+" [IDX/IDX] next=IDX/IDX sect=NUM/NUM  s=T_VAL [IDX] e=T_VAL [IDX] sgn=NUM windVal=IDX windSum=OPT"
+                ) || match_regexp(line, lineNo, record, SORT_BINARY, "dumpOne" +
+" [IDX/IDX] next=IDX/IDX sect=NUM/NUM  s=T_VAL [IDX] e=T_VAL [IDX] sgn=NUM windVal=IDX windSum=OPT oppVal=IDX oppSum=OPT"
+                );
+                if (found) {
+                    record[1].push(hasDone);
+                    record[1].push(hasUnorderable);
+                    record[1].push(hasSmall);
+                    record[1].push(hasTiny);
+                    record[1].push(hasOperand);
+                    record[1].push(hasStop);
+                }
+                break;
+            case REC_TYPE_MARK:
+                found = match_regexp(line, lineNo, record, MARK_LINE, "markWinding" +
+" id=IDX LINE_VAL t=T_VAL [IDX] PT_VAL tEnd=T_VAL newWindSum=NUM newOppSum=NUM oppSum=OPT windSum=OPT windValue=IDX"
+                ) || match_regexp(line, lineNo, record, MARK_QUAD, "markWinding" +
+" id=IDX QUAD_VAL t=T_VAL [IDX] PT_VAL tEnd=T_VAL newWindSum=NUM newOppSum=NUM oppSum=OPT windSum=OPT windValue=IDX"
+                ) || match_regexp(line, lineNo, record, MARK_CUBIC, "markWinding" +
+" id=IDX CUBIC_VAL t=T_VAL [IDX] PT_VAL tEnd=T_VAL newWindSum=NUM newOppSum=NUM oppSum=OPT windSum=OPT windValue=IDX"
+                ) || match_regexp(line, lineNo, record, MARK_DONE_LINE, "markDoneBinary" +
+" id=IDX LINE_VAL t=T_VAL [IDX] PT_VAL tEnd=T_VAL newWindSum=NUM newOppSum=NUM oppSum=OPT windSum=OPT windValue=IDX"
+                ) || match_regexp(line, lineNo, record, MARK_DONE_QUAD, "markDoneBinary" +
+" id=IDX QUAD_VAL t=T_VAL [IDX] PT_VAL tEnd=T_VAL newWindSum=NUM newOppSum=NUM oppSum=OPT windSum=OPT windValue=IDX"
+                ) || match_regexp(line, lineNo, record, MARK_DONE_CUBIC, "markDoneBinary" +
+" id=IDX CUBIC_VAL t=T_VAL [IDX] PT_VAL tEnd=T_VAL newWindSum=NUM newOppSum=NUM oppSum=OPT windSum=OPT windValue=IDX"
+                ) || match_regexp(line, lineNo, record, MARK_UNSORTABLE_LINE, "markUnsortable" +
+" id=IDX LINE_VAL t=T_VAL [IDX] PT_VAL tEnd=T_VAL newWindSum=NUM windSum=OPT windValue=IDX"
+                ) || match_regexp(line, lineNo, record, MARK_UNSORTABLE_QUAD, "markUnsortable" +
+" id=IDX QUAD_VAL t=T_VAL [IDX] PT_VAL tEnd=T_VAL newWindSum=NUM windSum=OPT windValue=IDX"
+                ) || match_regexp(line, lineNo, record, MARK_UNSORTABLE_CUBIC, "markUnsortable" +
+" id=IDX CUBIC_VAL t=T_VAL [IDX] PT_VAL tEnd=T_VAL newWindSum=NUM windSum=OPT windValue=IDX"
+                ) || match_regexp(line, lineNo, record, MARK_SIMPLE_LINE, "markWinding" +
+" id=IDX LINE_VAL t=T_VAL [IDX] PT_VAL tEnd=T_VAL newWindSum=NUM windSum=OPT windValue=IDX"
+                ) || match_regexp(line, lineNo, record, MARK_SIMPLE_QUAD, "markWinding" +
+" id=IDX QUAD_VAL t=T_VAL [IDX] PT_VAL tEnd=T_VAL newWindSum=NUM windSum=OPT windValue=IDX"
+                ) || match_regexp(line, lineNo, record, MARK_SIMPLE_CUBIC, "markWinding" +
+" id=IDX CUBIC_VAL t=T_VAL [IDX] PT_VAL tEnd=T_VAL newWindSum=NUM windSum=OPT windValue=IDX"
+                ) || match_regexp(line, lineNo, record, MARK_SIMPLE_DONE_LINE, "markDone" +
+" id=IDX LINE_VAL t=T_VAL [IDX] PT_VAL tEnd=T_VAL newWindSum=NUM windSum=OPT windValue=IDX"
+                ) || match_regexp(line, lineNo, record, MARK_SIMPLE_DONE_QUAD, "markDone" +
+" id=IDX QUAD_VAL t=T_VAL [IDX] PT_VAL tEnd=T_VAL newWindSum=NUM windSum=OPT windValue=IDX"
+                ) || match_regexp(line, lineNo, record, MARK_SIMPLE_DONE_CUBIC, "markDone" +
+" id=IDX CUBIC_VAL t=T_VAL [IDX] PT_VAL tEnd=T_VAL newWindSum=NUM windSum=OPT windValue=IDX"
+                ) || match_regexp(line, lineNo, record, MARK_DONE_UNARY_LINE, "markDoneUnary" +
+" id=IDX LINE_VAL t=T_VAL [IDX] PT_VAL tEnd=T_VAL newWindSum=NUM windSum=OPT windValue=IDX"
+                ) || match_regexp(line, lineNo, record, MARK_DONE_UNARY_QUAD, "markDoneUnary" +
+" id=IDX QUAD_VAL t=T_VAL [IDX] PT_VAL tEnd=T_VAL newWindSum=NUM windSum=OPT windValue=IDX"
+                ) || match_regexp(line, lineNo, record, MARK_DONE_UNARY_CUBIC, "markDoneUnary" +
+" id=IDX CUBIC_VAL t=T_VAL [IDX] PT_VAL tEnd=T_VAL newWindSum=NUM windSum=OPT windValue=IDX"
+                ) || match_regexp(line, lineNo, record, MARK_ANGLE_LAST, "markAngle" +
+" last id=IDX windSum=OPT small=IDX");
+                break;
+            case REC_TYPE_OP:
+                if (line.lastIndexOf("oppSign oppSign=", 0) === 0
+                        || line.lastIndexOf("operator<", 0) === 0) {
+                    found = true;
+                    break;
+                }
+                found = match_regexp(line, lineNo, record, OP_DIFFERENCE, "op difference"
+                ) || match_regexp(line, lineNo, record, OP_INTERSECT, "op intersect"
+                ) || match_regexp(line, lineNo, record, OP_UNION, "op union"
+                ) || match_regexp(line, lineNo, record, OP_XOR, "op xor"
+                );
+                break;
+            case REC_TYPE_UNKNOWN:
+                found = true;
+                break;
+        }
+        if (!found) {
+            console.log(line + " [" + lineNo + "] of type " + type + " not found");
+        }
+    }
+    if (recType != REC_TYPE_UNKNOWN) {
+        records.push(recType);
+        records.push(lastLineNo);
+        records.push(record);
+    }
+    if (records.length >= 1) {
+        tests[testIndex] = records;
+        testLines[testIndex] = lines;
+    }
+}
+
+function init(test) {
+    var canvas = document.getElementById('canvas');
+    if (!canvas.getContext) return;
+    ctx = canvas.getContext('2d');
+    var resScale = retina_scale && window.devicePixelRatio ? window.devicePixelRatio : 1;
+    var unscaledWidth = window.innerWidth - 20;
+    var unscaledHeight = window.innerHeight - 20;
+    screenWidth = unscaledWidth;
+    screenHeight = unscaledHeight;
+    canvas.width = unscaledWidth * resScale;
+    canvas.height = unscaledHeight * resScale;
+    canvas.style.width = unscaledWidth + 'px';
+    canvas.style.height = unscaledHeight + 'px';
+    if (resScale != 1) {
+        ctx.scale(resScale, resScale);
+    }
+    xmin = Infinity;
+    xmax = -Infinity;
+    ymin = Infinity;
+    ymax = -Infinity;
+    hasPath = hasComputedPath = false;
+    firstActiveSpan = -1;
+    for (var tIndex = 0; tIndex < test.length; tIndex += 3) {
+        var recType = test[tIndex];
+        if (!typeof recType == 'number' || recType < REC_TYPE_UNKNOWN || recType > REC_TYPE_LAST) {
+            console.log("unknown rec type: " + recType);
+            throw "stop execution";
+        }
+        var records = test[tIndex + 2];
+        for (var recordIndex = 0; recordIndex < records.length; recordIndex += 2) {
+            var fragType = records[recordIndex];
+            if (!typeof fragType == 'number' || fragType < 1 || fragType > FRAG_TYPE_LAST) {
+                console.log("unknown in range frag type: " + fragType);
+                throw "stop execution";
+            }
+            var frags = records[recordIndex + 1];
+            var first = 0;
+            var last = -1;
+            var first2 = 0;
+            var last2 = 0;
+            switch (recType) {
+                case REC_TYPE_COMPUTED:
+                    if (fragType == COMPUTED_SET_1 || fragType == COMPUTED_SET_2) {
+                        break;
+                    }
+                    hasComputedPath = true;
+                case REC_TYPE_PATH:
+                    switch (fragType) {
+                        case PATH_LINE:
+                            last = 4;
+                            break;
+                        case PATH_QUAD:
+                            last = 6;
+                            break;
+                        case PATH_CUBIC:
+                            last = 8;
+                            break;
+                        default:
+                            console.log("unknown " + (recType == REC_TYPE_PATH ? "REC_TYPE_PATH" 
+                                    : "REC_TYPE_COMPUTED") + " frag type:" + fragType);
+                            throw "stop execution";
+                    }
+                    if (recType == REC_TYPE_PATH) {
+                        hasPath = true;
+                    }
+                    break;
+                case REC_TYPE_ACTIVE:
+                    if (firstActiveSpan < 0) {
+                        firstActiveSpan = tIndex;
+                    }
+                    first = 1;
+                    switch (fragType) {
+                        case ACTIVE_LINE_SPAN:
+                            last = 5;
+                            break;
+                        case ACTIVE_QUAD_SPAN:
+                            last = 7;
+                            break;
+                        case ACTIVE_CUBIC_SPAN:
+                            last = 9;
+                            break;
+                        default:
+                            console.log("unknown REC_TYPE_ACTIVE frag type: " + fragType);
+                            throw "stop execution";
+                    }
+                    break;
+                case REC_TYPE_ADD:
+                    switch (fragType) {
+                        case ADD_MOVETO:
+                            break;
+                        case ADD_LINETO:
+                            last = 4;
+                            break;
+                        case ADD_QUADTO:
+                            last = 6;
+                            break;
+                        case ADD_CUBICTO:
+                            last = 8;
+                            break;
+                        case ADD_CLOSE:
+                        case ADD_FILL:
+                            break;
+                        default:
+                            console.log("unknown REC_TYPE_ADD frag type: " + fragType);
+                            throw "stop execution";
+                    }
+                    break;
+                case REC_TYPE_SECT:
+                    switch (fragType) {
+                        case INTERSECT_LINE:
+                            first = 1; last = 5; first2 = 8; last2 = 12;
+                            break;
+                        case INTERSECT_LINE_2:
+                            first = 1; last = 5; first2 = 11; last2 = 15;
+                            break;
+                        case INTERSECT_LINE_NO:
+                            first = 0; last = 4; first2 = 4; last2 = 8;
+                            break;
+                        case INTERSECT_QUAD_LINE:
+                            first = 1; last = 7; first2 = 10; last2 = 14;
+                            break;
+                        case INTERSECT_QUAD_LINE_2:
+                            first = 1; last = 7; first2 = 13; last2 = 17;
+                            break;
+                        case INTERSECT_QUAD_LINE_NO:
+                            first = 0; last = 6; first2 = 6; last2 = 10;
+                            break;
+                        case INTERSECT_QUAD:
+                            first = 1; last = 7; first2 = 10; last2 = 16;
+                            break;
+                        case INTERSECT_QUAD_2:
+                            first = 1; last = 7; first2 = 13; last2 = 19;
+                            break;
+                        case INTERSECT_QUAD_NO:
+                            first = 0; last = 6; first2 = 6; last2 = 12;
+                            break;
+                        case INTERSECT_SELF_CUBIC:
+                            first = 1; last = 9;
+                            break;
+                        case INTERSECT_SELF_CUBIC_NO:
+                            first = 0; last = 8;
+                            break;
+                        case INTERSECT_CUBIC_LINE:
+                            first = 1; last = 9; first2 = 12; last2 = 16;
+                            break;
+                        case INTERSECT_CUBIC_LINE_2:
+                            first = 1; last = 9; first2 = 15; last2 = 19;
+                            break;
+                        case INTERSECT_CUBIC_LINE_3:
+                            first = 1; last = 9; first2 = 18; last2 = 22;
+                            break;
+                        case INTERSECT_CUBIC_LINE_NO:
+                            first = 0; last = 8; first2 = 8; last2 = 12;
+                            break;
+                        case INTERSECT_CUBIC_QUAD:
+                            first = 1; last = 9; first2 = 12; last2 = 18;
+                            break;
+                        case INTERSECT_CUBIC_QUAD_2:
+                            first = 1; last = 9; first2 = 15; last2 = 21;
+                            break;
+                        case INTERSECT_CUBIC_QUAD_3:
+                            first = 1; last = 9; first2 = 18; last2 = 24;
+                            break;
+                        case INTERSECT_CUBIC_QUAD_4:
+                            first = 1; last = 9; first2 = 21; last2 = 27;
+                            break;
+                        case INTERSECT_CUBIC_QUAD_NO:
+                            first = 0; last = 8; first2 = 8; last2 = 14;
+                            break;
+                        case INTERSECT_CUBIC:
+                            first = 1; last = 9; first2 = 12; last2 = 20;
+                            break;
+                        case INTERSECT_CUBIC_2:
+                            first = 1; last = 9; first2 = 15; last2 = 23;
+                            break;
+                        case INTERSECT_CUBIC_3:
+                            first = 1; last = 9; first2 = 18; last2 = 26;
+                            break;
+                        case INTERSECT_CUBIC_4:
+                            first = 1; last = 9; first2 = 21; last2 = 29;
+                            break;
+                        case INTERSECT_CUBIC_NO:
+                            first = 0; last = 8; first2 = 8; last2 = 16;
+                            break;
+                        default:
+                            console.log("unknown REC_TYPE_SECT frag type: " + fragType);
+                            throw "stop execution";
+                    }
+                    break;
+                default:
+                    continue;
+            }
+            for (var idx = first; idx < last; idx += 2) {
+                xmin = Math.min(xmin, frags[idx]);
+                xmax = Math.max(xmax, frags[idx]);
+                ymin = Math.min(ymin, frags[idx + 1]);
+                ymax = Math.max(ymax, frags[idx + 1]);
+            }
+            for (var idx = first2; idx < last2; idx += 2) {
+                xmin = Math.min(xmin, frags[idx]);
+                xmax = Math.max(xmax, frags[idx]);
+                ymin = Math.min(ymin, frags[idx + 1]);
+                ymax = Math.max(ymax, frags[idx + 1]);
+            }
+        }
+    }
+    var angleBounds = [Infinity, Infinity, -Infinity, -Infinity];
+    for (var tIndex = 0; tIndex < test.length; tIndex += 3) {
+        var recType = test[tIndex];
+        var records = test[tIndex + 2];
+        for (var recordIndex = 0; recordIndex < records.length; recordIndex += 2) {
+            var fragType = records[recordIndex];
+            var frags = records[recordIndex + 1];
+            switch (recType) {
+                case REC_TYPE_ACTIVE_OP:
+                    if (!draw_op) {
+                        break;
+                    }
+                    {
+                        var curve = curvePartialByID(test, frags[0], frags[1], frags[2]);
+                        curve_extremes(curve, angleBounds);
+                    }
+                    break;
+                case REC_TYPE_ANGLE:
+                    if (!draw_angle) {
+                        break;
+                    }
+                    if (fragType == ANGLE_AFTER) {
+                        var curve = curvePartialByID(test, frags[0], frags[3], frags[4]);
+                        curve_extremes(curve, angleBounds);
+                        curve = curvePartialByID(test, frags[5], frags[8], frags[9]);
+                        curve_extremes(curve, angleBounds);
+                        curve = curvePartialByID(test, frags[10], frags[13], frags[14]);
+                    } else if (fragType == ANGLE_AFTER2) {
+                        var curve = curvePartialByID(test, frags[0], frags[4], frags[5]);
+                        curve_extremes(curve, angleBounds);
+                        curve = curvePartialByID(test, frags[6], frags[10], frags[11]);
+                        curve_extremes(curve, angleBounds);
+                        curve = curvePartialByID(test, frags[12], frags[16], frags[17]);
+                    }
+                    break;
+                case REC_TYPE_SORT:
+                    if (!draw_sort) {
+                        break;
+                    }
+                    if (fragType == SORT_UNARY || fragType == SORT_BINARY) {
+                        var curve = curvePartialByID(test, frags[0], frags[6], frags[8]);
+                        curve_extremes(curve, angleBounds);
+                    }
+                    break;
+            }
+        }
+    }
+    xmin = Math.min(xmin, angleBounds[0]);
+    ymin = Math.min(ymin, angleBounds[1]);
+    xmax = Math.max(xmax, angleBounds[2]);
+    ymax = Math.max(ymax, angleBounds[3]);
+    setScale(xmin, xmax, ymin, ymax);
+    if (hasPath == false && hasComputedPath == true && !draw_computed) {
+        draw_computed = 3; // show both quadratics and cubics
+    }
+    if (hasPath == true && hasComputedPath == false && draw_computed) {
+        draw_computed = 0;
+    }
+}
+
+function curveByID(test, id) {
+    var tIndex = firstActiveSpan;
+    if (tIndex < 0) {
+        return [];
+    }
+    while (tIndex < test.length) {
+        var recType = test[tIndex];
+        if (recType != REC_TYPE_ACTIVE) {
+            return [];
+        }
+        var records = test[tIndex + 2];
+        for (var recordIndex = 0; recordIndex < records.length; recordIndex += 2) {
+            var fragType = records[recordIndex];
+            var frags = records[recordIndex + 1];
+            if (frags[0] == id) {
+                switch (fragType) {
+                    case ACTIVE_LINE_SPAN:
+                        return [frags[1], frags[2], frags[3], frags[4]];
+                    case ACTIVE_QUAD_SPAN:
+                        return [frags[1], frags[2], frags[3], frags[4],
+                                frags[5], frags[6]];
+                    case ACTIVE_CUBIC_SPAN:
+                        return [frags[1], frags[2], frags[3], frags[4],
+                                frags[5], frags[6], frags[7], frags[8]];
+                }
+            }
+        }
+        tIndex += 3;
+    }
+    return [];
+}
+
+function curvePartialByID(test, id, t0, t1) {
+    var tIndex = firstActiveSpan;
+    if (tIndex < 0) {
+        return [];
+    }
+    while (tIndex < test.length) {
+        var recType = test[tIndex];
+        if (recType != REC_TYPE_ACTIVE) {
+            return [];
+        }
+        var records = test[tIndex + 2];
+        for (var recordIndex = 0; recordIndex < records.length; recordIndex += 2) {
+            var fragType = records[recordIndex];
+            var frags = records[recordIndex + 1];
+            if (frags[0] == id) {
+                switch (fragType) {
+                    case ACTIVE_LINE_SPAN:
+                        return linePartial(frags[1], frags[2], frags[3], frags[4], t0, t1);
+                    case ACTIVE_QUAD_SPAN:
+                        return quadPartial(frags[1], frags[2], frags[3], frags[4],
+                                frags[5], frags[6], t0, t1);
+                    case ACTIVE_CUBIC_SPAN:
+                        return cubicPartial(frags[1], frags[2], frags[3], frags[4],
+                                frags[5], frags[6], frags[7], frags[8], t0, t1);
+                }
+            }
+        }
+        tIndex += 3;
+    }
+    return [];
+}
+
+function idByCurve(test, frag, type) {
+    var tIndex = firstActiveSpan;
+    if (tIndex < 0) {
+        return -1;
+    }
+    while (tIndex < test.length) {
+        var recType = test[tIndex];
+        if (recType != REC_TYPE_ACTIVE) {
+            return -1;
+        }
+        var records = test[tIndex + 2];
+        for (var recordIndex = 0; recordIndex < records.length; recordIndex += 2) {
+            var fragType = records[recordIndex];
+            var frags = records[recordIndex + 1];
+            switch (fragType) {
+                case ACTIVE_LINE_SPAN:
+                    if (type != PATH_LINE) {
+                        continue;
+                    }
+                    if (frag[0] != frags[1] || frag[1] != frags[2]
+                            || frag[2] != frags[3] || frag[3] != frags[4]) {
+                        continue;
+                    }
+                    return frags[0];
+                case ACTIVE_QUAD_SPAN:
+                    if (type != PATH_QUAD) {
+                        continue;
+                    }
+                    if (frag[0] != frags[1] || frag[1] != frags[2]
+                            || frag[2] != frags[3] || frag[3] != frags[4]
+                            || frag[4] != frags[5] || frag[5] != frags[6]) {
+                        continue;
+                    }
+                    return frags[0];
+                case ACTIVE_CUBIC_SPAN:
+                    if (type != PATH_CUBIC) {
+                        continue;
+                    }
+                    if (frag[0] != frags[1] || frag[1] != frags[2]
+                            || frag[2] != frags[3] || frag[3] != frags[4]
+                            || frag[4] != frags[5] || frag[5] != frags[6]
+                            || frag[6] != frags[7] || frag[7] != frags[8]) {
+                        continue;
+                    }
+                    return frags[0];
+            }
+        }
+        ++tIndex;
+    }
+    return -1;
+}
+
+function curve_extremes(curve, bounds) {
+    for (var index = 0; index < curve.length; index += 2) {
+        var x = curve[index];
+        var y = curve[index + 1];
+        bounds[0] = Math.min(bounds[0], x);
+        bounds[1] = Math.min(bounds[1], y);
+        bounds[2] = Math.max(bounds[2], x);
+        bounds[3] = Math.max(bounds[3], y);
+    }
+}
+
+function setScale(x0, x1, y0, y1) {
+    var srcWidth = x1 - x0;
+    var srcHeight = y1 - y0;
+    var usableWidth = screenWidth;
+    var xDigits = Math.ceil(Math.log(Math.abs(xmax)) / Math.log(10));
+    var yDigits = Math.ceil(Math.log(Math.abs(ymax)) / Math.log(10));
+    usableWidth -= (xDigits + yDigits) * 10;
+    usableWidth -= decimal_places * 10;
+    if (draw_legend) {
+        usableWidth -= 40;
+    }
+    var hscale = usableWidth / srcWidth;
+    var vscale = screenHeight / srcHeight;
+    scale = Math.min(hscale, vscale);
+    var invScale = 1 / scale;
+    var sxmin = x0 - invScale * 5;
+    var symin = y0 - invScale * 10;
+    var sxmax = x1 + invScale * (6 * decimal_places + 10);
+    var symax = y1 + invScale * 10;
+    srcWidth = sxmax - sxmin;
+    srcHeight = symax - symin;
+    hscale = usableWidth / srcWidth;
+    vscale = screenHeight / srcHeight;
+    scale = Math.min(hscale, vscale);
+    srcLeft = sxmin;
+    srcTop = symin;
+}
+
+function drawArc(curve, op, from, to) {
+    var type = PATH_LINE + (curve.length / 2 - 2);
+    var pt = pointAtT(curve, type, op ? 0.4 : 0.6);
+    var dy = pt.y - curve[1];
+    var dx = pt.x - curve[0];
+    var dist = Math.sqrt(dy * dy + dx * dx);
+    var _dist = dist * scale;
+    var angle = Math.atan2(dy, dx);
+    var _px = (curve[0] - srcLeft) * scale;
+    var _py = (curve[1] - srcTop) * scale;
+    var divisor = 4;
+    var endDist;
+    do {
+        var ends = [];
+        for (var index = -1; index <= 1; index += 2) {
+            var px = Math.cos(index * Math.PI / divisor);
+            var py = Math.sin(index * Math.PI / divisor);
+            ends.push(px);
+            ends.push(py);
+        }
+        var endDx = (ends[2] - ends[0]) * scale * dist;
+        var endDy = (ends[3] - ends[1]) * scale * dist;
+        endDist = Math.sqrt(endDx * endDx + endDy * endDy);
+        if (endDist < 100) {
+            break;
+        }
+        divisor *= 2;
+    } while (true);
+    if (endDist < 30) {
+        return;
+    }
+    if (op) {
+        divisor *= 2;
+    }
+    ctx.strokeStyle = op ? "rgba(210,0,45, 0.4)" : "rgba(90,90,90, 0.5)";
+    ctx.beginPath();
+    ctx.arc(_px, _py, _dist, angle - Math.PI / divisor, angle + Math.PI / divisor, false);
+    ctx.stroke();
+    var saveAlign = ctx.textAlign;
+    var saveStyle = ctx.fillStyle;
+    var saveFont = ctx.font;
+    ctx.textAlign = "center";
+    ctx.fillStyle = "black";
+    ctx.font = "normal 24px Arial";
+    divisor *= 0.8;
+    for (var index = -1; index <= 1; index += 2) {
+        var px = curve[0] + Math.cos(angle + index * Math.PI / divisor) * dist;
+        var py = curve[1] + Math.sin(angle + index * Math.PI / divisor) * dist;
+        var _px = (px - srcLeft) * scale;
+        var _py = (py - srcTop) * scale;
+        ctx.fillText(index < 0 ? to.toString() : from.toString(), _px, _py + 8);
+    }
+    ctx.textAlign = saveAlign;
+    ctx.fillStyle = saveStyle;
+    ctx.font = saveFont;
+}
+
+function drawPoint(px, py, end) {
+    for (var pts = 0; pts < drawnPts.length; pts += 2) {
+        var x = drawnPts[pts];
+        var y = drawnPts[pts + 1];
+        if (px == x && py == y) {
+            return;
+        }
+    }
+    drawnPts.push(px);
+    drawnPts.push(py);
+    var label = px.toFixed(decimal_places) + ", " + py.toFixed(decimal_places);
+    var _px = (px - srcLeft) * scale;
+    var _py = (py - srcTop) * scale;
+    ctx.beginPath();
+    ctx.arc(_px, _py, 3, 0, Math.PI*2, true);
+    ctx.closePath();
+    if (end) {
+        ctx.fill();
+    } else {
+        ctx.stroke();
+    }
+    if (debug_xy) {
+        ctx.textAlign = "left";
+        ctx.fillText(label, _px + 5, _py);
+    }
+}
+
+function drawPoints(ptArray, curveType, drawControls) {
+    var count = (curveType - PATH_LINE + 2) * 2;
+    for (var idx = 0; idx < count; idx += 2) {
+        if (!drawControls && idx != 0 && idx != count - 2) {
+            continue;
+        }
+        drawPoint(ptArray[idx], ptArray[idx + 1], idx == 0 || idx == count - 2);
+    }
+}
+
+function drawControlLines(curve, curveType, drawEnd) {
+    if (curveType == PATH_LINE) {
+        return;
+    }
+    ctx.strokeStyle = "rgba(0,0,0, 0.3)";
+    drawLine(curve[0], curve[1], curve[2], curve[3]);
+    drawLine(curve[2], curve[3], curve[4], curve[5]);
+    if (curveType == PATH_CUBIC) {
+        drawLine(curve[4], curve[5], curve[6], curve[7]);
+        if (drawEnd > 1) {
+            drawLine(curve[6], curve[7], curve[0], curve[1]);
+            if (drawEnd > 2) {
+                drawLine(curve[0], curve[1], curve[4], curve[5]);
+                drawLine(curve[6], curve[7], curve[2], curve[3]);
+            }
+        }
+    } else if (drawEnd > 1) {
+        drawLine(curve[4], curve[5], curve[0], curve[1]);
+    }
+}
+
+function pointAtT(curve, curveType, t) {
+    var xy = {};
+    switch (curveType) {
+        case PATH_LINE:
+            var a = 1 - t;
+            var b = t;
+            xy.x = a * curve[0] + b * curve[2];
+            xy.y = a * curve[1] + b * curve[3];
+            break;
+        case PATH_QUAD:
+            var one_t = 1 - t;
+            var a = one_t * one_t;
+            var b = 2 * one_t * t;
+            var c = t * t;
+            xy.x = a * curve[0] + b * curve[2] + c * curve[4];
+            xy.y = a * curve[1] + b * curve[3] + c * curve[5];
+            break;
+        case PATH_CUBIC:
+            var one_t = 1 - t;
+            var one_t2 = one_t * one_t;
+            var a = one_t2 * one_t;
+            var b = 3 * one_t2 * t;
+            var t2 = t * t;
+            var c = 3 * one_t * t2;
+            var d = t2 * t;
+            xy.x = a * curve[0] + b * curve[2] + c * curve[4] + d * curve[6];
+            xy.y = a * curve[1] + b * curve[3] + c * curve[5] + d * curve[7];
+            break;
+    }
+    return xy;
+}
+    
+function drawPointAtT(curve, curveType) {
+    var x, y;
+    var xy = pointAtT(curve, curveType, curveT);
+    drawPoint(xy.x, xy.y, true);
+    if (!draw_intersectT) {
+        return;
+    }
+    ctx.fillStyle = "red";
+    drawTAtPointUp(xy.x, xy.y, curveT);
+}
+
+function drawTAtPointUp(px, py, t) {
+    var label = t.toFixed(decimal_places);
+    var _px = (px - srcLeft)* scale;
+    var _py = (py - srcTop) * scale;
+    ctx.fillText(label, _px + 5, _py - 10);
+}
+
+function drawTAtPointDown(px, py, t) {
+    var label = t.toFixed(decimal_places);
+    var _px = (px - srcLeft)* scale;
+    var _py = (py - srcTop) * scale;
+    ctx.fillText(label, _px + 5, _py + 10);
+}
+
+function alreadyDrawnLine(x1, y1, x2, y2) {
+    if (collect_bounds) {
+        if (focus_enabled) {
+            focusXmin = Math.min(focusXmin, x1, x2);
+            focusYmin = Math.min(focusYmin, y1, y2);
+            focusXmax = Math.max(focusXmax, x1, x2);
+            focusYmax = Math.max(focusYmax, y1, y2);
+        }
+        return true;
+    }
+    for (var pts = 0; pts < drawnLines.length; pts += 4) {
+        if (x1 == drawnLines[pts] && y1 == drawnLines[pts + 1]
+                && x2 == drawnLines[pts + 2] && y2 == drawnLines[pts + 3]) {
+            return true;
+        }
+    }
+    drawnLines.push(x1);
+    drawnLines.push(y1);
+    drawnLines.push(x2);
+    drawnLines.push(y2);
+    return false;
+}
+
+function drawLine(x1, y1, x2, y2) {
+    if (alreadyDrawnLine(x1, y1, x2, y2)) {
+        return;
+    }
+    ctx.beginPath();
+    ctx.moveTo((x1 - srcLeft) * scale,
+            (y1 - srcTop) * scale);
+    ctx.lineTo((x2 - srcLeft) * scale,
+            (y2 - srcTop) * scale);
+    ctx.stroke();
+}
+
+function linePartial(x1, y1, x2, y2, t1, t2) {
+    var dx = x1 - x2;
+    var dy = y1 - y2;
+    var array = [
+        x1 - t1 * dx,
+        y1 - t1 * dy,
+        x1 - t2 * dx,
+        y1 - t2 * dy
+    ];
+    return array;
+}
+
+function drawLinePartial(x1, y1, x2, y2, t1, t2) {
+    var a = linePartial(x1, y1, x2, y2, t1, t2);
+    var ax = a[0];
+    var ay = a[1];
+    var bx = a[2];
+    var by = a[3];
+    if (alreadyDrawnLine(ax, ay, bx, by)) {
+        return;
+    }
+    ctx.beginPath();
+    ctx.moveTo((ax - srcLeft) * scale,
+            (ay - srcTop) * scale);
+    ctx.lineTo((bx - srcLeft) * scale,
+            (by - srcTop) * scale);
+    ctx.stroke();
+}
+
+function alreadyDrawnQuad(x1, y1, x2, y2, x3, y3) {
+    if (collect_bounds) {
+        if (focus_enabled) {
+            focusXmin = Math.min(focusXmin, x1, x2, x3);
+            focusYmin = Math.min(focusYmin, y1, y2, y3);
+            focusXmax = Math.max(focusXmax, x1, x2, x3);
+            focusYmax = Math.max(focusYmax, y1, y2, y3);
+        }
+        return true;
+    }
+    for (var pts = 0; pts < drawnQuads.length; pts += 6) {
+        if (x1 == drawnQuads[pts] && y1 == drawnQuads[pts + 1]
+                && x2 == drawnQuads[pts + 2] && y2 == drawnQuads[pts + 3]
+                && x3 == drawnQuads[pts + 4] && y3 == drawnQuads[pts + 5]) {
+            return true;
+        }
+    }
+    drawnQuads.push(x1);
+    drawnQuads.push(y1);
+    drawnQuads.push(x2);
+    drawnQuads.push(y2);
+    drawnQuads.push(x3);
+    drawnQuads.push(y3);
+    return false;
+}
+
+function drawQuad(x1, y1, x2, y2, x3, y3) {
+    if (alreadyDrawnQuad(x1, y1, x2, y2, x3, y3)) {
+        return;
+    }
+    ctx.beginPath();
+    ctx.moveTo((x1 - srcLeft) * scale,
+            (y1 - srcTop) * scale);
+    ctx.quadraticCurveTo((x2 - srcLeft) * scale,
+            (y2 - srcTop) * scale,
+            (x3 - srcLeft) * scale,
+            (y3 - srcTop) * scale);
+    ctx.stroke();
+}
+
+function interp(A, B, t) {
+    return A + (B - A) * t;
+}
+
+function interp_quad_coords(x1, x2, x3, t)
+{
+    var ab = interp(x1, x2, t);
+    var bc = interp(x2, x3, t);
+    var abc = interp(ab, bc, t);
+    return abc;
+}
+
+function quadPartial(x1, y1, x2, y2, x3, y3, t1, t2) {
+    var ax = interp_quad_coords(x1, x2, x3, t1);
+    var ay = interp_quad_coords(y1, y2, y3, t1);
+    var dx = interp_quad_coords(x1, x2, x3, (t1 + t2) / 2);
+    var dy = interp_quad_coords(y1, y2, y3, (t1 + t2) / 2);
+    var cx = interp_quad_coords(x1, x2, x3, t2);
+    var cy = interp_quad_coords(y1, y2, y3, t2);
+    var bx = 2*dx - (ax + cx)/2;
+    var by = 2*dy - (ay + cy)/2;
+    var array = [
+        ax, ay, bx, by, cx, cy
+    ];
+    return array;
+}
+
+function drawQuadPartial(x1, y1, x2, y2, x3, y3, t1, t2) {
+    var a = quadPartial(x1, y1, x2, y2, x3, y3, t1, t2);
+    var ax = a[0];
+    var ay = a[1];
+    var bx = a[2];
+    var by = a[3];
+    var cx = a[4];
+    var cy = a[5];
+    if (alreadyDrawnQuad(ax, ay, bx, by, cx, cy)) {
+        return;
+    }
+    ctx.beginPath();
+    ctx.moveTo((ax - srcLeft) * scale,
+            (ay - srcTop) * scale);
+    ctx.quadraticCurveTo((bx - srcLeft) * scale,
+            (by - srcTop) * scale,
+            (cx - srcLeft) * scale,
+            (cy - srcTop) * scale);
+    ctx.stroke();
+}
+
+function alreadyDrawnCubic(x1, y1, x2, y2, x3, y3, x4, y4) {
+    if (collect_bounds) {
+        if (focus_enabled) {
+            focusXmin = Math.min(focusXmin, x1, x2, x3, x4);
+            focusYmin = Math.min(focusYmin, y1, y2, y3, y4);
+            focusXmax = Math.max(focusXmax, x1, x2, x3, x4);
+            focusYmax = Math.max(focusYmax, y1, y2, y3, y4);
+        }
+        return true;
+    }
+    for (var pts = 0; pts < drawnCubics.length; pts += 8) {
+        if (x1 == drawnCubics[pts] && y1 == drawnCubics[pts + 1]
+                && x2 == drawnCubics[pts + 2] && y2 == drawnCubics[pts + 3] 
+                && x3 == drawnCubics[pts + 4] && y3 == drawnCubics[pts + 5] 
+                && x4 == drawnCubics[pts + 6] && y4 == drawnCubics[pts + 7]) {
+            return true;
+        }
+    }
+    drawnCubics.push(x1);
+    drawnCubics.push(y1);
+    drawnCubics.push(x2);
+    drawnCubics.push(y2);
+    drawnCubics.push(x3);
+    drawnCubics.push(y3);
+    drawnCubics.push(x4);
+    drawnCubics.push(y4);
+    return false;
+}
+
+function drawCubic(x1, y1, x2, y2, x3, y3, x4, y4) {
+    if (alreadyDrawnCubic(x1, y1, x2, y2, x3, y3, x4, y4)) {
+        return;
+    }
+    ctx.beginPath();
+    ctx.moveTo((x1 - srcLeft) * scale,
+            (y1 - srcTop) * scale);
+    ctx.bezierCurveTo((x2 - srcLeft) * scale,
+            (y2 - srcTop) * scale,
+            (x3 - srcLeft) * scale,
+            (y3 - srcTop) * scale,
+            (x4 - srcLeft) * scale,
+            (y4 - srcTop) * scale);
+    ctx.stroke();
+}
+
+function interp_cubic_coords(x1, x2, x3, x4, t)
+{
+    var ab = interp(x1, x2, t);
+    var bc = interp(x2, x3, t);
+    var cd = interp(x3, x4, t);
+    var abc = interp(ab, bc, t);
+    var bcd = interp(bc, cd, t);
+    var abcd = interp(abc, bcd, t);
+    return abcd;
+}
+
+function cubicPartial(x1, y1, x2, y2, x3, y3, x4, y4, t1, t2) {
+    var ax = interp_cubic_coords(x1, x2, x3, x4, t1);
+    var ay = interp_cubic_coords(y1, y2, y3, y4, t1);
+    var ex = interp_cubic_coords(x1, x2, x3, x4, (t1*2+t2)/3);
+    var ey = interp_cubic_coords(y1, y2, y3, y4, (t1*2+t2)/3);
+    var fx = interp_cubic_coords(x1, x2, x3, x4, (t1+t2*2)/3);
+    var fy = interp_cubic_coords(y1, y2, y3, y4, (t1+t2*2)/3);
+    var dx = interp_cubic_coords(x1, x2, x3, x4, t2);
+    var dy = interp_cubic_coords(y1, y2, y3, y4, t2);
+    var mx = ex * 27 - ax * 8 - dx;
+    var my = ey * 27 - ay * 8 - dy;
+    var nx = fx * 27 - ax - dx * 8;
+    var ny = fy * 27 - ay - dy * 8;
+    var bx = (mx * 2 - nx) / 18;
+    var by = (my * 2 - ny) / 18;
+    var cx = (nx * 2 - mx) / 18;
+    var cy = (ny * 2 - my) / 18;
+    var array = [
+        ax, ay, bx, by, cx, cy, dx, dy
+    ];
+    return array;
+}
+    
+function drawCubicPartial(x1, y1, x2, y2, x3, y3, x4, y4, t1, t2) {
+    var a = cubicPartial(x1, y1, x2, y2, x3, y3, x4, y4, t1, t2);
+    var ax = a[0];
+    var ay = a[1];
+    var bx = a[2];
+    var by = a[3];
+    var cx = a[4];
+    var cy = a[5];
+    var dx = a[6];
+    var dy = a[7];
+    if (alreadyDrawnCubic(ax, ay, bx, by, cx, cy, dx, dy)) {
+        return;
+    }
+    ctx.beginPath();
+    ctx.moveTo((ax - srcLeft) * scale,
+            (ay - srcTop) * scale);
+    ctx.bezierCurveTo((bx - srcLeft) * scale,
+            (by - srcTop) * scale,
+            (cx - srcLeft) * scale,
+            (cy - srcTop) * scale,
+            (dx - srcLeft) * scale,
+            (dy - srcTop) * scale);
+    ctx.stroke();
+}
+
+function drawCurve(c) {
+    switch (c.length) {
+        case 4:
+            drawLine(c[0], c[1], c[2], c[3]);
+            break;
+        case 6:
+            drawQuad(c[0], c[1], c[2], c[3], c[4], c[5]);
+            break;
+        case 8:
+            drawCubic(c[0], c[1], c[2], c[3], c[4], c[5], c[6], c[7]);
+            break;
+    }
+}
+
+function boundsWidth(pts) {
+    var min = pts[0];
+    var max = pts[0];
+    for (var idx = 2; idx < pts.length; idx += 2) {
+        min = Math.min(min, pts[idx]);
+        max = Math.max(max, pts[idx]);
+    }
+    return max - min;
+}
+
+function boundsHeight(pts) {
+    var min = pts[1];
+    var max = pts[1];
+    for (var idx = 3; idx < pts.length; idx += 2) {
+        min = Math.min(min, pts[idx]);
+        max = Math.max(max, pts[idx]);
+    }
+    return max - min;
+}
+
+function tangent(pts) {
+    var dx = pts[2] - pts[0];
+    var dy = pts[3] - pts[1];
+    if (dx == 0 && dy == 0 && pts.length > 4) {
+        dx = pts[4] - pts[0];
+        dy = pts[5] - pts[1];
+        if (dx == 0 && dy == 0 && pts.length > 6) {
+            dx = pts[6] - pts[0];
+            dy = pts[7] - pts[1];
+        }
+    }
+    return Math.atan2(-dy, dx);
+}
+
+function hodograph(cubic) {
+    var hodo = [];
+    hodo[0] = 3 * (cubic[2] - cubic[0]);
+    hodo[1] = 3 * (cubic[3] - cubic[1]);
+    hodo[2] = 3 * (cubic[4] - cubic[2]);
+    hodo[3] = 3 * (cubic[5] - cubic[3]);
+    hodo[4] = 3 * (cubic[6] - cubic[4]);
+    hodo[5] = 3 * (cubic[7] - cubic[5]);
+    return hodo;
+}
+
+function hodograph2(cubic) {
+    var quad = hodograph(cubic);
+    var hodo = [];
+    hodo[0] = 2 * (quad[2] - quad[0]);
+    hodo[1] = 2 * (quad[3] - quad[1]);
+    hodo[2] = 2 * (quad[4] - quad[2]);
+    hodo[3] = 2 * (quad[5] - quad[3]);
+    return hodo;
+}
+
+function quadraticRootsReal(A, B, C, s) {
+    if (A == 0) {
+        if (B == 0) {
+            s[0] = 0;
+            return C == 0;
+        }
+        s[0] = -C / B;
+        return 1;
+    }
+    /* normal form: x^2 + px + q = 0 */
+    var p = B / (2 * A);
+    var q = C / A;
+    var p2 = p * p;
+    if (p2 < q) {
+        return 0;
+    }
+    var sqrt_D = 0;
+    if (p2 > q) {
+        sqrt_D = sqrt(p2 - q);
+    }
+    s[0] = sqrt_D - p;
+    s[1] = -sqrt_D - p;
+    return 1 + s[0] != s[1];
+}
+
+function add_valid_ts(s, realRoots, t) {
+    var foundRoots = 0;
+    for (var index = 0; index < realRoots; ++index) {
+        var tValue = s[index];
+        if (tValue >= 0 && tValue <= 1) {
+            for (var idx2 = 0; idx2 < foundRoots; ++idx2) {
+                if (t[idx2] != tValue) {
+                    t[foundRoots++] = tValue;
+                }
+            }
+        }
+    }
+    return foundRoots;
+}
+
+function quadraticRootsValidT(a, b, c, t) {
+    var s = [];
+    var realRoots = quadraticRootsReal(A, B, C, s);
+    var foundRoots = add_valid_ts(s, realRoots, t);
+    return foundRoots != 0;
+}
+
+function find_cubic_inflections(cubic, tValues) {
+    var Ax = src[2] - src[0];
+    var Ay = src[3] - src[1];
+    var Bx = src[4] - 2 * src[2] + src[0];
+    var By = src[5] - 2 * src[3] + src[1];
+    var Cx = src[6] + 3 * (src[2] - src[4]) - src[0];
+    var Cy = src[7] + 3 * (src[3] - src[5]) - src[1];
+    return quadraticRootsValidT(Bx * Cy - By * Cx, (Ax * Cy - Ay * Cx),
+            Ax * By - Ay * Bx, tValues);
+}
+
+function dxy_at_t(curve, type, t) {
+    var dxy = {};
+    if (type == PATH_QUAD) {
+        var a = t - 1;
+        var b = 1 - 2 * t;
+        var c = t;
+        dxy.x = a * curve[0] + b * curve[2] + c * curve[4];
+        dxy.y = a * curve[1] + b * curve[3] + c * curve[5];
+    } else if (type == PATH_CUBIC) {
+        var one_t = 1 - t;
+        var a = curve[0];
+        var b = curve[2];
+        var c = curve[4];
+        var d = curve[6];
+        dxy.x = 3 * ((b - a) * one_t * one_t + 2 * (c - b) * t * one_t + (d - c) * t * t);
+        a = curve[1];
+        b = curve[3];
+        c = curve[5];
+        d = curve[7];
+        dxy.y = 3 * ((b - a) * one_t * one_t + 2 * (c - b) * t * one_t + (d - c) * t * t);
+    }
+    return dxy;
+}
+
+function drawLabel(num, px, py) {
+    ctx.beginPath();
+    ctx.arc(px, py, 8, 0, Math.PI*2, true);
+    ctx.closePath();
+    ctx.strokeStyle = "rgba(0,0,0, 0.4)";
+    ctx.lineWidth = num == 0 || num == 3 ? 2 : 1;
+    ctx.stroke();
+    ctx.fillStyle = "black";
+    ctx.font = "normal 10px Arial";
+  //  ctx.rotate(0.001);
+    ctx.fillText(num, px - 2, py + 3);
+  //  ctx.rotate(-0.001);
+}
+
+function drawLabelX(ymin, num, loc) {
+    var px = (loc - srcLeft) * scale;
+    var py = (ymin - srcTop) * scale - 20;
+    drawLabel(num, px, py);
+}
+
+function drawLabelY(xmin, num, loc) {
+    var px = (xmin - srcLeft) * scale - 20;
+    var py = (loc - srcTop) * scale;
+    drawLabel(num, px, py);
+}
+
+function drawHodoOrigin(hx, hy, hMinX, hMinY, hMaxX, hMaxY) {
+    ctx.beginPath();
+    ctx.moveTo(hx, hy - 100);
+    ctx.lineTo(hx, hy);
+    ctx.strokeStyle = hMinY < 0 ? "green" : "blue";
+    ctx.stroke();
+    ctx.beginPath();
+    ctx.moveTo(hx, hy);
+    ctx.lineTo(hx, hy + 100);
+    ctx.strokeStyle = hMaxY > 0 ? "green" : "blue";
+    ctx.stroke();
+    ctx.beginPath();
+    ctx.moveTo(hx - 100, hy);
+    ctx.lineTo(hx, hy);
+    ctx.strokeStyle = hMinX < 0 ? "green" : "blue";
+    ctx.stroke();
+    ctx.beginPath();
+    ctx.moveTo(hx, hy);
+    ctx.lineTo(hx + 100, hy);
+    ctx.strokeStyle = hMaxX > 0 ? "green" : "blue";
+    ctx.stroke();
+}
+
+function scalexy(x, y, mag) {
+    var length = Math.sqrt(x * x + y * y);
+    return mag / length;
+}
+
+function drawArrow(x, y, dx, dy) {
+    var dscale = scalexy(dx, dy, 1 / scale * 100);
+    dx *= dscale;
+    dy *= dscale;
+    ctx.beginPath();
+    ctx.moveTo((x - srcLeft) * scale, (y - srcTop) * scale);
+    x += dx;
+    y += dy;
+    ctx.lineTo((x - srcLeft) * scale, (y - srcTop) * scale);
+    dx /= 10;
+    dy /= 10;
+    ctx.lineTo((x - dy - srcLeft) * scale, (y + dx - srcTop) * scale);
+    ctx.lineTo((x + dx * 2 - srcLeft) * scale, (y + dy * 2 - srcTop) * scale);
+    ctx.lineTo((x + dy - srcLeft) * scale, (y - dx - srcTop) * scale);
+    ctx.lineTo((x - srcLeft) * scale, (y - srcTop) * scale);
+    ctx.strokeStyle = "rgba(0,75,0, 0.4)";
+    ctx.stroke();
+}
+
+function x_at_t(curve, t) {
+    var one_t = 1 - t;
+    if (curve.length == 4) {
+        return one_t * curve[0] + t * curve[2];
+    }
+    var one_t2 = one_t * one_t;
+    var t2 = t * t;
+    if (curve.length == 6) {
+        return one_t2 * curve[0] + 2 * one_t * t * curve[2] + t2 * curve[4];
+    }
+    var a = one_t2 * one_t;
+    var b = 3 * one_t2 * t;
+    var c = 3 * one_t * t2;
+    var d = t2 * t;
+    return a * curve[0] + b * curve[2] + c * curve[4] + d * curve[6];
+}
+
+function y_at_t(curve, t) {
+    var one_t = 1 - t;
+    if (curve.length == 4) {
+        return one_t * curve[1] + t * curve[3];
+    }
+    var one_t2 = one_t * one_t;
+    var t2 = t * t;
+    if (curve.length == 6) {
+        return one_t2 * curve[1] + 2 * one_t * t * curve[3] + t2 * curve[5];
+    }
+    var a = one_t2 * one_t;
+    var b = 3 * one_t2 * t;
+    var c = 3 * one_t * t2;
+    var d = t2 * t;
+    return a * curve[1] + b * curve[3] + c * curve[5] + d * curve[7];
+}
+
+function drawOrder(curve, label) {
+    var px = x_at_t(curve, 0.75);
+    var py = y_at_t(curve, 0.75);
+    var _px = (px - srcLeft) * scale;
+    var _py = (py - srcTop) * scale;
+    ctx.beginPath();
+    ctx.arc(_px, _py, 15, 0, Math.PI * 2, true);
+    ctx.closePath();
+    ctx.fillStyle = "white";
+    ctx.fill();
+    if (label == 'L') {
+        ctx.strokeStyle = "rgba(255,0,0, 1)";
+        ctx.fillStyle = "rgba(255,0,0, 1)";
+    } else {
+        ctx.strokeStyle = "rgba(0,0,255, 1)";
+        ctx.fillStyle = "rgba(0,0,255, 1)";
+    }
+    ctx.stroke();
+    ctx.font = "normal 16px Arial";
+    ctx.textAlign = "center";
+    ctx.fillText(label, _px, _py + 5);
+    ctx.font = "normal 10px Arial";
+}
+
+function drawID(curve, id) {
+    var px = x_at_t(curve, 0.5);
+    var py = y_at_t(curve, 0.5);
+    var _px = (px - srcLeft) * scale;
+    var _py = (py - srcTop) * scale;
+    draw_id_at(id, _px, _py);
+}
+
+function draw_id_at(id, _px, _py) {
+    ctx.beginPath();
+    ctx.arc(_px, _py, 15, 0, Math.PI * 2, true);
+    ctx.closePath();
+    ctx.fillStyle = "white";
+    ctx.fill();
+    ctx.strokeStyle = "rgba(127,127,0, 1)";
+    ctx.fillStyle = "rgba(127,127,0, 1)";
+    ctx.stroke();
+    ctx.font = "normal 16px Arial";
+    ctx.textAlign = "center";
+    ctx.fillText(id, _px, _py + 5);
+    ctx.font = "normal 10px Arial";
+}
+
+function drawLinePartialID(id, x1, y1, x2, y2, t1, t2) {
+    var curve = [x1, y1, x2, y2];
+    drawCurvePartialID(id, curve, t1, t2);
+}
+
+function drawQuadPartialID(id, x1, y1, x2, y2, x3, y3, t1, t2) {
+    var curve = [x1, y1, x2, y2, x3, y3];
+    drawCurvePartialID(id, curve, t1, t2);
+}
+
+function drawCubicPartialID(id, x1, y1, x2, y2, x3, y3, x4, y4, t1, t2) {
+    var curve = [x1, y1, x2, y2, x3, y3, x4, y4];
+    drawCurvePartialID(id, curve, t1, t2);
+}
+
+function  drawCurvePartialID(id, curve, t1, t2) {
+    var px = x_at_t(curve, (t1 + t2) / 2);
+    var py = y_at_t(curve, (t1 + t2) / 2);
+    var _px = (px - srcLeft) * scale;
+    var _py = (py - srcTop) * scale;
+    draw_id_at(id, _px, _py);
+}
+
+function drawCurveSpecials(test, curve, type) {
+    if (pt_labels) {
+        drawPoints(curve, type, pt_labels == 2);
+    }
+    if (control_lines != 0) {
+        drawControlLines(curve, type, control_lines);
+    }
+    if (curve_t) {
+        drawPointAtT(curve, type);
+    }
+    if (draw_midpoint) {
+        var mid = pointAtT(curve, type, 0.5);
+        drawPoint(mid.x, mid.y, true);
+    }
+    if (draw_id) {
+        var id = idByCurve(test, curve, type);
+        if (id >= 0) {
+            drawID(curve, id);
+        }
+    }
+    if (type == PATH_LINE) {
+        return;
+    }
+    if (draw_deriviatives > 0) {
+        var d = dxy_at_t(curve, type, 0);
+        drawArrow(curve[0], curve[1], d.x, d.y);
+        if (draw_deriviatives == 2) {
+            d = dxy_at_t(curve, type, 1);
+            if (type == PATH_CUBIC) {
+                drawArrow(curve[6], curve[7], d.x, d.y);
+            } else {
+                drawArrow(curve[4], curve[5], d.x, d.y);
+            }
+        }
+        if (draw_midpoint) {
+            var mid = pointAtT(curve, type, 0.5);
+            d = dxy_at_t(curve, type, 0.5);
+            drawArrow(mid.x, mid.y, d.x, d.y);
+        }
+    }
+    if (type != PATH_CUBIC) {
+        return;
+    }
+    if (draw_hodo == 1 || draw_hodo == 2) {
+        var hodo = hodograph(curve);
+        var hMinX = Math.min(0, hodo[0], hodo[2], hodo[4]);
+        var hMinY = Math.min(0, hodo[1], hodo[3], hodo[5]);
+        var hMaxX = Math.max(0, hodo[0], hodo[2], hodo[4]);
+        var hMaxY = Math.max(0, hodo[1], hodo[3], hodo[5]);
+        var hScaleX = hMaxX - hMinX > 0 ? screenWidth / (hMaxX - hMinX) : 1;
+        var hScaleY = hMaxY - hMinY > 0 ? screenHeight / (hMaxY - hMinY) : 1;
+        var hUnit = Math.min(hScaleX, hScaleY);
+        hUnit /= 2;
+        var hx = xoffset - hMinX * hUnit;
+        var hy = yoffset - hMinY * hUnit;
+        ctx.moveTo(hx + hodo[0] * hUnit, hy + hodo[1] * hUnit);
+        ctx.quadraticCurveTo(
+            hx + hodo[2] * hUnit, hy + hodo[3] * hUnit,
+            hx + hodo[4] * hUnit, hy + hodo[5] * hUnit);
+        ctx.strokeStyle = "red";
+        ctx.stroke();
+        if (draw_hodo == 1) {
+            drawHodoOrigin(hx, hy, hMinX, hMinY, hMaxX, hMaxY);
+        }
+    }
+    if (draw_hodo == 3) {
+        var hodo = hodograph2(curve);
+        var hMinX = Math.min(0, hodo[0], hodo[2]);
+        var hMinY = Math.min(0, hodo[1], hodo[3]);
+        var hMaxX = Math.max(0, hodo[0], hodo[2]);
+        var hMaxY = Math.max(0, hodo[1], hodo[3]);
+        var hScaleX = hMaxX - hMinX > 0 ? screenWidth / (hMaxX - hMinX) : 1;
+        var hScaleY = hMaxY - hMinY > 0 ? screenHeight / (hMaxY - hMinY) : 1;
+        var hUnit = Math.min(hScaleX, hScaleY);
+        hUnit /= 2;
+        var hx = xoffset - hMinX * hUnit;
+        var hy = yoffset - hMinY * hUnit;
+        ctx.moveTo(hx + hodo[0] * hUnit, hy + hodo[1] * hUnit);
+        ctx.lineTo(hx + hodo[2] * hUnit, hy + hodo[3] * hUnit);
+        ctx.strokeStyle = "red";
+        ctx.stroke();
+        drawHodoOrigin(hx, hy, hMinX, hMinY, hMaxX, hMaxY);
+    }
+    if (draw_sequence) {
+        var ymin = Math.min(curve[1], curve[3], curve[5], curve[7]);
+        for (var i = 0; i < 8; i+= 2) {
+            drawLabelX(ymin, i >> 1, curve[i]);
+        }
+        var xmin = Math.min(curve[0], curve[2], curve[4], curve[6]);
+        for (var i = 1; i < 8; i+= 2) {
+            drawLabelY(xmin, i >> 1, curve[i]);
+        }
+    }
+}
+
+function logCurves(test) {
+    for (curves in test) {
+        var curve = test[curves];
+        dumpCurve(curve);
+    }
+}
+
+function curveToString(curve) {
+    var str = "{{";
+    for (i = 0; i < curve.length; i += 2) {
+        str += curve[i].toFixed(decimal_places) + "," + curve[i + 1].toFixed(decimal_places);
+        if (i < curve.length - 2) {
+            str += "}, {";
+        }
+    }
+    str += "}}";
+    return str;
+}
+
+function dumpCurve(curve) {
+    console.log(curveToString(curve));
+}
+
+function draw(test, lines, title) {
+    ctx.fillStyle = "rgba(0,0,0, 0.1)";
+    ctx.font = "normal 50px Arial";
+    ctx.textAlign = "left";
+    ctx.fillText(title, 50, 50);
+    ctx.font = "normal 10px Arial";
+    ctx.lineWidth = "1.001"; "0.999";
+    var secondPath = test.length;
+    var closeCount = 0;
+    logStart = -1;
+    logRange = 0;
+    // find last active rec type at this step
+    var curType = test[0];
+    var curStep = 0;
+    var hasOp = false;
+    var lastActive = 0;
+    var lastAdd = 0;
+    var lastSect = 0;
+    var lastSort = 0;
+    var lastMark = 0;
+    activeCount = 0;
+    addCount = 0;
+    angleCount = 0;
+    opCount = 0;
+    sectCount = 0;
+    sortCount = 0;
+    markCount = 0;
+    activeMax = 0;
+    addMax = 0;
+    angleMax = 0;
+    opMax = 0;
+    sectMax = 0;
+    sectMax2 = 0;
+    sortMax = 0;
+    markMax = 0;
+    lastIndex = test.length - 3;
+    for (var tIndex = 0; tIndex < test.length; tIndex += 3) {
+        var recType = test[tIndex];
+        if (!typeof recType == 'number' || recType < REC_TYPE_UNKNOWN || recType > REC_TYPE_LAST) {
+            console.log("unknown rec type: " + recType);
+            throw "stop execution";
+        }
+   //     if (curType == recType && curType != REC_TYPE_ADD) {
+   //         continue;
+   //     }
+        var inStepRange = step_limit == 0 || curStep < step_limit;
+        curType = recType;
+        if (recType == REC_TYPE_OP) {
+            hasOp = true;
+            continue;
+        }
+        if (recType == REC_TYPE_UNKNOWN) {
+            // these types do not advance step
+            continue;
+        }
+        var bumpStep = false;
+        var records = test[tIndex + 2];
+        var fragType = records[0];
+        if (recType == REC_TYPE_ADD) {
+            if (records.length != 2) {
+                console.log("expect only two elements: " + records.length);
+                throw "stop execution";
+            }
+            if (fragType == ADD_MOVETO || fragType == ADD_CLOSE) {
+                continue;
+            }
+            ++addMax;
+            if (!draw_add || !inStepRange) {
+                continue;
+            }
+            lastAdd = tIndex;
+            ++addCount;
+            bumpStep = true;
+        }
+        if (recType == REC_TYPE_PATH && hasOp) {
+            secondPath = tIndex;
+        }
+        if (recType == REC_TYPE_ACTIVE) {
+            ++activeMax;
+            if (!draw_active || !inStepRange) {
+                continue;
+            }
+            lastActive = tIndex;
+            ++activeCount;
+            bumpStep = true;
+        }
+        if (recType == REC_TYPE_ACTIVE_OP) {
+            ++opMax;
+            if (!draw_op || !inStepRange) {
+                continue;
+            }
+            lastOp = tIndex;
+            ++opCount;
+            bumpStep = true;
+        }
+        if (recType == REC_TYPE_ANGLE) {
+            ++angleMax;
+            if (!draw_angle || !inStepRange) {
+                continue;
+            }
+            lastAngle = tIndex;
+            ++angleCount;
+            bumpStep = true;
+        }
+        if (recType == REC_TYPE_SECT) {
+            if (records.length != 2) {
+                console.log("expect only two elements: " + records.length);
+                throw "stop execution";
+            }
+            ++sectMax;
+            var sectBump = 1;
+            switch (fragType) {
+                case INTERSECT_LINE:
+                case INTERSECT_QUAD_LINE:
+                case INTERSECT_QUAD:
+                case INTERSECT_SELF_CUBIC:
+                case INTERSECT_CUBIC_LINE:
+                case INTERSECT_CUBIC_QUAD:
+                case INTERSECT_CUBIC:
+                    sectBump = 1;
+                    break;
+                case INTERSECT_LINE_2:
+                case INTERSECT_QUAD_LINE_2:
+                case INTERSECT_QUAD_2:
+                case INTERSECT_CUBIC_LINE_2:
+                case INTERSECT_CUBIC_QUAD_2:
+                case INTERSECT_CUBIC_2:
+                    sectBump = 2;
+                    break;
+                case INTERSECT_LINE_NO:
+                case INTERSECT_QUAD_LINE_NO:
+                case INTERSECT_QUAD_NO:
+                case INTERSECT_SELF_CUBIC_NO:
+                case INTERSECT_CUBIC_LINE_NO:
+                case INTERSECT_CUBIC_QUAD_NO:
+                case INTERSECT_CUBIC_NO:
+                    sectBump = 0;
+                    break;
+                case INTERSECT_CUBIC_LINE_3:
+                case INTERSECT_CUBIC_QUAD_3:
+                case INTERSECT_CUBIC_3:
+                    sectBump = 3;
+                    break;
+                case INTERSECT_CUBIC_QUAD_4:
+                case INTERSECT_CUBIC_4:
+                    sectBump = 4;
+                    break;
+                default:
+                    console.log("missing case " + records.length);
+                    throw "stop execution";
+            }
+            sectMax2 += sectBump;
+            if (draw_intersection <= 1 || !inStepRange) {
+                continue;
+            }
+            lastSect = tIndex;
+            sectCount += sectBump;
+            bumpStep = true;
+        }
+        if (recType == REC_TYPE_SORT) {
+            ++sortMax;
+            if (!draw_sort || !inStepRange) {
+                continue;
+            }
+            lastSort = tIndex;
+            ++sortCount;
+            bumpStep = true;
+        }
+        if (recType == REC_TYPE_MARK) {
+            ++markMax;
+            if (!draw_mark || !inStepRange) {
+                continue;
+            }
+            lastMark = tIndex;
+            ++markCount;
+            bumpStep = true;
+        }
+        if (bumpStep) {
+            lastIndex = tIndex;
+            logStart = test[tIndex + 1];
+            logRange = records.length / 2;
+            ++curStep;
+        }
+    }
+    stepMax = (draw_add ? addMax : 0)
+            + (draw_active ? activeMax : 0)
+            + (draw_op ? opMax : 0)
+            + (draw_angle ? angleMax : 0)
+            + (draw_sort ? sortMax : 0)
+            + (draw_mark ? markMax : 0)
+            + (draw_intersection == 2 ? sectMax : draw_intersection == 3 ? sectMax2 : 0);
+    if (stepMax == 0) {
+        stepMax = addMax + activeMax + angleMax + opMax + sortMax + markMax;
+    }
+    drawnPts = [];
+    drawnLines = [];
+    drawnQuads = [];
+    drawnCubics = [];
+    focusXmin = focusYmin = Infinity;
+    focusXmax = focusYmax = -Infinity;
+    var pathIndex = 0;
+    var opLetter = 'S';
+    for (var tIndex = lastIndex; tIndex >= 0; tIndex -= 3) {
+        var recType = test[tIndex];
+        var records = test[tIndex + 2];
+        for (var recordIndex = 0; recordIndex < records.length; recordIndex += 2) {
+            var fragType = records[recordIndex];
+            if (!typeof fragType == 'number' || fragType < 1 || fragType > FRAG_TYPE_LAST) {
+                console.log("unknown in range frag type: " + fragType);
+                throw "stop execution";
+            }
+            var frags = records[recordIndex + 1];
+            focus_enabled = false;
+            switch (recType) {
+                case REC_TYPE_COMPUTED:
+                    if (draw_computed == 0) {
+                        continue;
+                    }
+                    ctx.lineWidth = 1;
+                    ctx.strokeStyle = pathIndex == 0 ? "black" : "red";
+                    ctx.fillStyle = "blue";
+                    var drawThis = false;
+                    switch (fragType) {
+                        case PATH_QUAD:
+                            if ((draw_computed & 5) == 1 || ((draw_computed & 4) != 0
+                                    && (draw_computed & 1) == pathIndex)) {
+                                drawQuad(frags[0], frags[1], frags[2], frags[3],
+                                        frags[4], frags[5]);
+                                drawThis = true;
+                            }
+                            break;
+                        case PATH_CUBIC:
+                            if ((draw_computed & 6) == 2 || ((draw_computed & 4) != 0
+                                     && (draw_computed & 1) != pathIndex)) {
+                                drawCubic(frags[0], frags[1], frags[2], frags[3],
+                                        frags[4], frags[5], frags[6], frags[7]);
+                                drawThis = true;
+                            }
+                            ++pathIndex;
+                            break;
+                        case COMPUTED_SET_1:
+                            pathIndex = 0;
+                            break;
+                        case COMPUTED_SET_2:
+                            pathIndex = 1;
+                            break;
+                        default:
+                            console.log("unknown REC_TYPE_COMPUTED frag type: " + fragType);
+                            throw "stop execution";
+                    }
+                    if (!drawThis || collect_bounds) {
+                        break;
+                    }
+                    drawCurveSpecials(test, frags, fragType);
+                    break;
+                case REC_TYPE_PATH:
+                    if (!draw_path) {
+                        continue;
+                    }
+                    var firstPath = tIndex < secondPath;
+                    if ((draw_path & (firstPath ? 1 : 2)) == 0) {
+                        continue;
+                    }
+                    ctx.lineWidth = 1;
+                    ctx.strokeStyle = firstPath ? "black" : "red";
+                    ctx.fillStyle = "blue";
+                    switch (fragType) {
+                        case PATH_LINE:
+                            drawLine(frags[0], frags[1], frags[2], frags[3]);
+                            break;
+                        case PATH_QUAD:
+                            drawQuad(frags[0], frags[1], frags[2], frags[3],
+                                    frags[4], frags[5]);
+                            break;
+                        case PATH_CUBIC:
+                            drawCubic(frags[0], frags[1], frags[2], frags[3],
+                                    frags[4], frags[5], frags[6], frags[7]);
+                            break;
+                        default:
+                            console.log("unknown REC_TYPE_PATH frag type: " + fragType);
+                            throw "stop execution";
+                    }
+                    if (collect_bounds) {
+                        break;
+                    }
+                    drawCurveSpecials(test, frags, fragType);
+                    break;
+                case REC_TYPE_OP:
+                    switch (fragType) {
+                        case OP_INTERSECT: opLetter = 'I'; break;
+                        case OP_DIFFERENCE: opLetter = 'D'; break;
+                        case OP_UNION: opLetter = 'U'; break;
+                        case OP_XOR: opLetter = 'X'; break;
+                        default:
+                            console.log("unknown REC_TYPE_OP frag type: " + fragType);
+                            throw "stop execution";
+                    }
+                    break;
+                case REC_TYPE_ACTIVE:
+                    if (!draw_active || (step_limit > 0 && tIndex < lastActive)) {
+                        continue;
+                    }
+                    var x1 = frags[SPAN_X1];
+                    var y1 = frags[SPAN_Y1];
+                    var x2 = frags[SPAN_X2];
+                    var y2 = frags[SPAN_Y2];
+                    var x3, y3, x3, y4, t1, t2;
+                    ctx.lineWidth = 3;
+                    ctx.strokeStyle = "rgba(0,0,255, 0.3)";
+                    focus_enabled = true;
+                    switch (fragType) {
+                        case ACTIVE_LINE_SPAN:
+                            t1 = frags[SPAN_L_T];
+                            t2 = frags[SPAN_L_TEND];
+                            drawLinePartial(x1, y1, x2, y2, t1, t2);
+                            if (draw_id) {
+                                drawLinePartialID(frags[0], x1, y1, x2, y2, t1, t2);
+                            }
+                             break;
+                        case ACTIVE_QUAD_SPAN:
+                            x3 = frags[SPAN_X3];
+                            y3 = frags[SPAN_Y3];
+                            t1 = frags[SPAN_Q_T];
+                            t2 = frags[SPAN_Q_TEND];
+                            drawQuadPartial(x1, y1, x2, y2, x3, y3, t1, t2);
+                            if (draw_id) {
+                                drawQuadPartialID(frags[0], x1, y1, x2, y2, x3, y3, t1, t2);
+                            }
+                            break;
+                        case ACTIVE_CUBIC_SPAN:
+                            x3 = frags[SPAN_X3];
+                            y3 = frags[SPAN_Y3];
+                            x4 = frags[SPAN_X4];
+                            y4 = frags[SPAN_Y4];
+                            t1 = frags[SPAN_C_T];
+                            t2 = frags[SPAN_C_TEND];
+                            drawCubicPartial(x1, y1, x2, y2, x3, y3, x4, y4, t1, t2);
+                            if (draw_id) {
+                                drawCubicPartialID(frags[0], x1, y1, x2, y2, x3, y3, x4, y4, t1, t2);
+                            }
+                            break;
+                        default:
+                            console.log("unknown REC_TYPE_ACTIVE frag type: " + fragType);
+                            throw "stop execution";
+                    }
+                    break;
+                case REC_TYPE_ACTIVE_OP:
+                    if (!draw_op || (step_limit > 0 && tIndex < lastOp)) {
+                        continue;
+                    }
+                    focus_enabled = true;
+                    ctx.lineWidth = 3;
+                    var activeSpan = frags[7] == "1";
+                    ctx.strokeStyle = activeSpan ? "rgba(45,160,0, 0.3)" : "rgba(255,45,0, 0.5)";
+                    var curve = curvePartialByID(test, frags[0], frags[1], frags[2]);
+                    drawCurve(curve);
+                    if (draw_op > 1) {
+                        drawArc(curve, false, frags[3], frags[4]);
+                        drawArc(curve, true, frags[5], frags[6]);
+                    }
+                    break;
+                case REC_TYPE_ADD:
+                    if (!draw_add) {
+                        continue;
+                    }
+                    ctx.lineWidth = 3;
+                    ctx.strokeStyle = closeCount == 0 ? "rgba(0,0,255, 0.3)"
+                            : closeCount == 1 ? "rgba(0,127,0, 0.3)"
+                            : closeCount == 2 ? "rgba(0,127,127, 0.3)"
+                            : closeCount == 3 ? "rgba(127,127,0, 0.3)"
+                            : "rgba(127,0,127, 0.3)";
+                    focus_enabled = true;
+                    switch (fragType) {
+                        case ADD_MOVETO:
+                            break;
+                        case ADD_LINETO:
+                            if (step_limit == 0 || tIndex >= lastAdd) {
+                                drawLine(frags[0], frags[1], frags[2], frags[3]);
+                            }
+                            break;
+                        case ADD_QUADTO:
+                            if (step_limit == 0 || tIndex >= lastAdd) {
+                                drawQuad(frags[0], frags[1], frags[2], frags[3], frags[4], frags[5]);
+                            }
+                            break;
+                        case ADD_CUBICTO:
+                            if (step_limit == 0 || tIndex >= lastAdd) {
+                                drawCubic(frags[0], frags[1], frags[2], frags[3],
+                                        frags[4], frags[5], frags[6], frags[7]);
+                            }
+                            break;
+                        case ADD_CLOSE:
+                            ++closeCount;
+                            break;
+                        case ADD_FILL:
+                            break;
+                        default:
+                            console.log("unknown REC_TYPE_ADD frag type: " + fragType);
+                            throw "stop execution";
+                    }
+                    break;
+                case REC_TYPE_ANGLE:
+                    if (!draw_angle || (step_limit > 0 && tIndex < lastAngle)) {
+                        continue;
+                    }
+                    if (fragType != ANGLE_AFTER && fragType != ANGLE_AFTER2) {
+                        continue;
+                    }
+                    focus_enabled = true;
+                    ctx.lineWidth = 3;
+                    ctx.strokeStyle = "rgba(127,45,127, 0.3)";
+                    var leftCurve, midCurve, rightCurve;
+                    if (fragType == ANGLE_AFTER) {
+                        leftCurve = curvePartialByID(test, frags[0], frags[3], frags[4]);
+                        midCurve = curvePartialByID(test, frags[5], frags[8], frags[9]);
+                        rightCurve = curvePartialByID(test, frags[10], frags[13], frags[14]);
+                    } else {
+                        leftCurve = curvePartialByID(test, frags[0], frags[4], frags[5]);
+                        midCurve = curvePartialByID(test, frags[6], frags[10], frags[11]);
+                        rightCurve = curvePartialByID(test, frags[12], frags[16], frags[17]);
+                    }
+                    drawCurve(leftCurve);
+                    drawCurve(rightCurve);
+                    var inBetween = frags[fragType == ANGLE_AFTER ? 15 : 18] == "T";
+                    ctx.strokeStyle = inBetween ? "rgba(0,160,45, 0.3)" : "rgba(255,0,45, 0.5)";
+                    drawCurve(midCurve);
+                    if (draw_angle > 1) {
+                        drawOrder(leftCurve, 'L');
+                        drawOrder(rightCurve, 'R');
+                    }
+                    break;
+                case REC_TYPE_SECT:
+                    if (!draw_intersection) {
+                        continue;
+                    }
+                    if (draw_intersection != 1 && (step_limit > 0 && tIndex < lastSect)) {
+                        continue;
+                    }
+                    // draw_intersection == 1 : show all
+                    // draw_intersection == 2 : step == 0 ? show all : show intersection line #step
+                    // draw_intersection == 3 : step == 0 ? show all : show intersection #step
+                    ctx.lineWidth = 1;
+                    ctx.strokeStyle = "rgba(0,0,255, 0.3)";
+                    ctx.fillStyle = "blue";
+                    focus_enabled = true;
+                    var f = [];
+                    var c1s;
+                    var c1l;
+                    var c2s;
+                    var c2l;
+                    switch (fragType) {
+                        case INTERSECT_LINE:
+                            f.push(5, 6, 0, 7);
+                            c1s = 1; c1l = 4; c2s = 8; c2l = 4;
+                            break;
+                        case INTERSECT_LINE_2:
+                            f.push(5, 6, 0, 10);
+                            f.push(8, 9, 7, 15);
+                            c1s = 1; c1l = 4; c2s = 11; c2l = 4;
+                            break;
+                        case INTERSECT_LINE_NO:
+                            c1s = 0; c1l = 4; c2s = 4; c2l = 4;
+                            break;
+                        case INTERSECT_QUAD_LINE:
+                            f.push(7, 8, 0, 9);
+                            c1s = 1; c1l = 6; c2s = 10; c2l = 4;
+                            break;
+                        case INTERSECT_QUAD_LINE_2:
+                            f.push(7, 8, 0, 12);
+                            f.push(10, 11, 9, 17);
+                            c1s = 1; c1l = 6; c2s = 13; c2l = 4;
+                            break;
+                        case INTERSECT_QUAD_LINE_NO:
+                            c1s = 0; c1l = 6; c2s = 6; c2l = 4;
+                            break;
+                        case INTERSECT_QUAD:
+                            f.push(7, 8, 0, 9);
+                            c1s = 1; c1l = 6; c2s = 10; c2l = 6;
+                            break;
+                        case INTERSECT_QUAD_2:
+                            f.push(7, 8, 0, 12);
+                            f.push(10, 11, 9, 19);
+                            c1s = 1; c1l = 6; c2s = 13; c2l = 6;
+                            break;
+                        case INTERSECT_QUAD_NO:
+                            c1s = 0; c1l = 6; c2s = 6; c2l = 6;
+                            break;
+                        case INTERSECT_SELF_CUBIC:
+                            f.push(9, 10, 0, 11);
+                            c1s = 1; c1l = 8; c2s = 0; c2l = 0;
+                            break;
+                        case INTERSECT_SELF_CUBIC_NO:
+                            c1s = 0; c1l = 8; c2s = 0; c2l = 0;
+                            break;
+                        case INTERSECT_CUBIC_LINE:
+                            f.push(9, 10, 0, 11);
+                            c1s = 1; c1l = 8; c2s = 12; c2l = 4;
+                            break;
+                        case INTERSECT_CUBIC_LINE_2:
+                            f.push(9, 10, 0, 14);
+                            f.push(12, 13, 11, 19);
+                            c1s = 1; c1l = 8; c2s = 15; c2l = 4;
+                            break;
+                        case INTERSECT_CUBIC_LINE_3:
+                            f.push(9, 10, 0, 17);
+                            f.push(12, 13, 11, 22);
+                            f.push(15, 16, 14, 23);
+                            c1s = 1; c1l = 8; c2s = 18; c2l = 4;
+                            break;
+                        case INTERSECT_CUBIC_QUAD_NO:
+                            c1s = 0; c1l = 8; c2s = 8; c2l = 6;
+                            break;
+                        case INTERSECT_CUBIC_QUAD:
+                            f.push(9, 10, 0, 11);
+                            c1s = 1; c1l = 8; c2s = 12; c2l = 6;
+                            break;
+                        case INTERSECT_CUBIC_QUAD_2:
+                            f.push(9, 10, 0, 14);
+                            f.push(12, 13, 11, 21);
+                            c1s = 1; c1l = 8; c2s = 15; c2l = 6;
+                            break;
+                        case INTERSECT_CUBIC_QUAD_3:
+                            f.push(9, 10, 0, 17);
+                            f.push(12, 13, 11, 24);
+                            f.push(15, 16, 14, 25);
+                            c1s = 1; c1l = 8; c2s = 18; c2l = 6;
+                            break;
+                        case INTERSECT_CUBIC_QUAD_4:
+                            f.push(9, 10, 0, 20);
+                            f.push(12, 13, 11, 27);
+                            f.push(15, 16, 14, 28);
+                            f.push(18, 19, 17, 29);
+                            c1s = 1; c1l = 8; c2s = 21; c2l = 6;
+                            break;
+                        case INTERSECT_CUBIC_LINE_NO:
+                            c1s = 0; c1l = 8; c2s = 8; c2l = 4;
+                            break;
+                        case INTERSECT_CUBIC:
+                            f.push(9, 10, 0, 11);
+                            c1s = 1; c1l = 8; c2s = 12; c2l = 8;
+                            break;
+                        case INTERSECT_CUBIC_2:
+                            f.push(9, 10, 0, 14);
+                            f.push(12, 13, 11, 23);
+                            c1s = 1; c1l = 8; c2s = 15; c2l = 8;
+                            break;
+                        case INTERSECT_CUBIC_3:
+                            f.push(9, 10, 0, 17);
+                            f.push(12, 13, 11, 26);
+                            f.push(15, 16, 14, 27);
+                            c1s = 1; c1l = 8; c2s = 18; c2l = 8;
+                            break;
+                        case INTERSECT_CUBIC_4:
+                            f.push(9, 10, 0, 20);
+                            f.push(12, 13, 11, 29);
+                            f.push(15, 16, 14, 30);
+                            f.push(18, 19, 17, 31);
+                            c1s = 1; c1l = 8; c2s = 21; c2l = 8;
+                            break;
+                        case INTERSECT_CUBIC_NO:
+                            c1s = 0; c1l = 8; c2s = 8; c2l = 8;
+                            break;
+                        default:
+                            console.log("unknown REC_TYPE_SECT frag type: " + fragType);
+                            throw "stop execution";
+                    }
+                    if (draw_intersection != 1) {
+                        var id = -1;
+                        var curve;
+                        switch (c1l) {
+                            case 4: 
+                                drawLine(frags[c1s], frags[c1s + 1], frags[c1s + 2], frags[c1s + 3]);
+                                if (draw_id) {
+                                    curve = [frags[c1s], frags[c1s + 1], frags[c1s + 2], frags[c1s + 3]];
+                                    id = idByCurve(test, curve, PATH_LINE);
+                                }
+                                break;
+                            case 6:
+                                drawQuad(frags[c1s], frags[c1s + 1], frags[c1s + 2], frags[c1s + 3],
+                                        frags[c1s + 4], frags[c1s + 5]);
+                                if (draw_id) {
+                                    curve = [frags[c1s], frags[c1s + 1], frags[c1s + 2], frags[c1s + 3],
+                                            frags[c1s + 4], frags[c1s + 5]];
+                                    id = idByCurve(test, curve, PATH_QUAD);
+                                }
+                                break;
+                            case 8:
+                                drawCubic(frags[c1s], frags[c1s + 1], frags[c1s + 2], frags[c1s + 3],
+                                        frags[c1s + 4], frags[c1s + 5], frags[c1s + 6], frags[c1s + 7]);
+                                if (draw_id) {
+                                    curve = [frags[c1s], frags[c1s + 1], frags[c1s + 2], frags[c1s + 3],
+                                            frags[c1s + 4], frags[c1s + 5], frags[c1s + 6], frags[c1s + 7]];
+                                    id = idByCurve(test, curve, PATH_CUBIC);
+                                }
+                                break;
+                        }
+                        if (id >= 0) {
+                            drawID(curve, id);
+                        }
+                        id = -1;
+                        switch (c2l) {
+                            case 0:
+                                break;
+                            case 4: 
+                                drawLine(frags[c2s], frags[c2s + 1], frags[c2s + 2], frags[c2s + 3]);
+                                if (draw_id) {
+                                    curve = [frags[c2s], frags[c2s + 1], frags[c2s + 2], frags[c2s + 3]];
+                                    id = idByCurve(test, curve, PATH_LINE);
+                                }
+                                break;
+                            case 6:
+                                drawQuad(frags[c2s], frags[c2s + 1], frags[c2s + 2], frags[c2s + 3],
+                                        frags[c2s + 4], frags[c2s + 5]);
+                                if (draw_id) {
+                                    curve = [frags[c2s], frags[c2s + 1], frags[c2s + 2], frags[c2s + 3],
+                                            frags[c2s + 4], frags[c2s + 5]];
+                                    id = idByCurve(test, curve, PATH_QUAD);
+                                }
+                                break;
+                            case 8:
+                                drawCubic(frags[c2s], frags[c2s + 1], frags[c2s + 2], frags[c2s + 3],
+                                        frags[c2s + 4], frags[c2s + 5], frags[c2s + 6], frags[c2s + 7]);
+                                if (draw_id) {
+                                    curve = [frags[c2s], frags[c2s + 1], frags[c2s + 2], frags[c2s + 3],
+                                            frags[c2s + 4], frags[c2s + 5], frags[c2s + 6], frags[c2s + 7]];
+                                    id = idByCurve(test, curve, PATH_CUBIC);
+                                }
+                                break;
+                        }
+                        if (id >= 0) {
+                            drawID(curve, id);
+                        }
+                    }
+                    if (collect_bounds) {
+                        break;
+                    }
+                    for (var idx = 0; idx < f.length; idx += 4) {
+                        if (draw_intersection != 3 || idx == lastSect - tIndex) {
+                            drawPoint(frags[f[idx]], frags[f[idx + 1]], true);
+                        }
+                    }
+                    if (!draw_intersectT) {
+                        break;
+                    }
+                    ctx.fillStyle = "red";
+                    for (var idx = 0; idx < f.length; idx += 4) {
+                        if (draw_intersection != 3 || idx == lastSect - tIndex) {
+                            drawTAtPointUp(frags[f[idx]], frags[f[idx + 1]], frags[f[idx + 2]]);
+                            drawTAtPointDown(frags[f[idx]], frags[f[idx + 1]], frags[f[idx + 3]]);
+                        }
+                    }
+                    break;
+                case REC_TYPE_SORT:
+                    if (!draw_sort || (step_limit > 0 && tIndex < lastSort)) {
+                        continue;
+                    }
+                    ctx.lineWidth = 3;
+                    ctx.strokeStyle = "rgba(127,127,0, 0.5)";
+                    focus_enabled = true;
+                    switch (fragType) {
+                        case SORT_UNARY:
+                        case SORT_BINARY:
+                            var curve = curvePartialByID(test, frags[0], frags[6], frags[8]);
+                            drawCurve(curve);
+                            break;
+                        default:
+                            console.log("unknown REC_TYPE_SORT frag type: " + fragType);
+                            throw "stop execution";
+                    }
+                    break;
+                case REC_TYPE_MARK:
+                    if (!draw_mark || (step_limit > 0 && tIndex < lastMark)) {
+                        continue;
+                    }
+                    ctx.lineWidth = 3;
+                    ctx.strokeStyle = fragType >= MARK_DONE_LINE ?
+                            "rgba(127,0,127, 0.5)" : "rgba(127,127,0, 0.5)";
+                    focus_enabled = true;
+                    switch (fragType) {
+                        case MARK_LINE:
+                        case MARK_DONE_LINE:
+                        case MARK_UNSORTABLE_LINE:
+                        case MARK_SIMPLE_LINE:
+                        case MARK_SIMPLE_DONE_LINE:
+                        case MARK_DONE_UNARY_LINE:
+                            drawLinePartial(frags[1], frags[2], frags[3], frags[4],
+                                frags[5], frags[9]);
+                            if (draw_id) {
+                                drawLinePartialID(frags[0], frags[1], frags[2], frags[3], frags[4],
+                                frags[5], frags[9]);
+                            }
+                            break;
+                        case MARK_QUAD:
+                        case MARK_DONE_QUAD:
+                        case MARK_UNSORTABLE_QUAD:
+                        case MARK_SIMPLE_QUAD:
+                        case MARK_SIMPLE_DONE_QUAD:
+                        case MARK_DONE_UNARY_QUAD:
+                            drawQuadPartial(frags[1], frags[2], frags[3], frags[4],
+                                frags[5], frags[6], frags[7], frags[11]);
+                            if (draw_id) {
+                                drawQuadPartialID(frags[0], frags[1], frags[2], frags[3], frags[4],
+                                frags[5], frags[6], frags[7], frags[11]);
+                            }
+                            break;
+                        case MARK_CUBIC:
+                        case MARK_DONE_CUBIC:
+                        case MARK_UNSORTABLE_CUBIC:
+                        case MARK_SIMPLE_CUBIC:
+                        case MARK_SIMPLE_DONE_CUBIC:
+                        case MARK_DONE_UNARY_CUBIC:
+                            drawCubicPartial(frags[1], frags[2], frags[3], frags[4],
+                                frags[5], frags[6], frags[7], frags[8], frags[9], frags[13]);
+                            if (draw_id) {
+                                drawCubicPartialID(frags[0], frags[1], frags[2], frags[3], frags[4],
+                                frags[5], frags[6], frags[7], frags[8], frags[9], frags[13]);
+                            }
+                            break;
+                        case MARK_ANGLE_LAST:
+                            // FIXME: ignored for now
+                            break;
+                        default:
+                            console.log("unknown REC_TYPE_MARK frag type: " + fragType);
+                            throw "stop execution";
+                    }
+                    break;
+                default:
+                    continue;
+            }
+        }
+        switch (recType) {
+            case REC_TYPE_SORT:
+                if (!draw_sort || (step_limit > 0 && tIndex < lastSort)) {
+                    break;
+                }
+                var angles = []; // use tangent lines to describe arcs
+                var windFrom = [];
+                var windTo = [];
+                var opp = [];
+                var minXY = Number.MAX_VALUE;
+                var partial;
+                focus_enabled = true;
+                var someUnsortable = false;
+                for (var recordIndex = 0; recordIndex < records.length; recordIndex += 2) {
+                    var fragType = records[recordIndex];
+                    var frags = records[recordIndex + 1];
+                    var unsortable = (fragType == SORT_UNARY && frags[14]) ||
+                            (fragType == SORT_BINARY && frags[16]);
+                    someUnsortable |= unsortable;
+                    switch (fragType) {
+                        case SORT_UNARY:
+                        case SORT_BINARY:
+                            partial = curvePartialByID(test, frags[0], frags[6], frags[8]);
+                            break;
+                        default:
+                            console.log("unknown REC_TYPE_SORT frag type: " + fragType);
+                            throw "stop execution";
+                    }
+                    var dx = boundsWidth(partial);
+                    var dy = boundsHeight(partial);
+                    minXY = Math.min(minXY, dx * dx + dy * dy);
+                    if (collect_bounds) {
+                        continue;
+                    }
+                    angles.push(tangent(partial));
+                    var from = frags[12];
+                    var to = frags[12];
+                    var sgn = frags[10];
+                    if (sgn < 0) {
+                        from -= frags[11];
+                    } else if (sgn > 0) {
+                        to -= frags[11];
+                    }
+                    windFrom.push(from + (unsortable ? "!" : ""));
+                    windTo.push(to + (unsortable ? "!" : ""));
+                    opp.push(fragType == SORT_BINARY);
+                    if (draw_sort == 1) {
+                        drawOrder(partial, frags[12]);
+                    } else {
+                        drawOrder(partial, (recordIndex / 2) + 1);
+                    }
+                }
+                var radius = Math.sqrt(minXY) / 2 * scale;
+                radius = Math.min(50, radius);
+                var scaledRadius = radius / scale;
+                var centerX = partial[0];
+                var centerY = partial[1];
+                if (collect_bounds) {
+                    if (focus_enabled) {
+                        focusXmin = Math.min(focusXmin, centerX - scaledRadius);
+                        focusYmin = Math.min(focusYmin, centerY - scaledRadius);
+                        focusXmax = Math.max(focusXmax, centerX + scaledRadius);
+                        focusYmax = Math.max(focusYmax, centerY + scaledRadius);
+                    }
+                    break;
+                }
+                break;
+            default:
+                break;
+        }
+    }
+    if (collect_bounds) {
+        return;
+    }
+    if (draw_log && logStart >= 0) {
+        ctx.font = "normal 10px Arial";
+        ctx.textAlign = "left";
+        ctx.beginPath();
+        var top = screenHeight - 20 - (logRange + 2) * 10;
+        ctx.rect(50, top, screenWidth - 100, (logRange + 2) * 10);
+        ctx.fillStyle = "white";
+        ctx.fill();
+        ctx.fillStyle = "rgba(0,0,0, 0.5)";
+        if (logStart > 0) {
+            ctx.fillText(lines[logStart - 1], 50, top + 8);
+        }
+        ctx.fillStyle = "black";
+        for (var idx = 0; idx < logRange; ++idx) {
+            ctx.fillText(lines[logStart + idx], 50, top + 18 + 10 * idx);
+        }
+        ctx.fillStyle = "rgba(0,0,0, 0.5)";
+        if (logStart + logRange < lines.length) {
+            ctx.fillText(lines[logStart + logRange], 50, top + 18 + 10 * logRange);
+        }
+    }
+    if (draw_legend) {
+        var pos = 0;
+        var drawSomething = draw_add | draw_active | draw_sort | draw_mark;
+   //     drawBox(pos++, "yellow", "black", opLetter, true, '');
+        drawBox(pos++, "rgba(0,0,255, 0.3)", "black", draw_intersection > 1 ? sectCount : sectMax2, draw_intersection, intersectionKey);
+        drawBox(pos++, "rgba(0,0,255, 0.3)", "black", draw_add ? addCount : addMax, draw_add, addKey);
+        drawBox(pos++, "rgba(0,0,255, 0.3)", "black", draw_active ? activeCount : activeMax, draw_active, activeKey);
+        drawBox(pos++, "rgba(127,127,0, 0.3)", "black", draw_angle ? angleCount : angleMax, draw_angle, angleKey);
+        drawBox(pos++, "rgba(127,127,0, 0.3)", "black", draw_op ? opCount : opMax, draw_op, opKey);
+        drawBox(pos++, "rgba(127,127,0, 0.3)", "black", draw_sort ? sortCount : sortMax, draw_sort, sortKey);
+        drawBox(pos++, "rgba(127,0,127, 0.3)", "black", draw_mark ? markCount : markMax, draw_mark, markKey);
+        drawBox(pos++, "black", "white", 
+                (new Array('P', 'P1', 'P2', 'P'))[draw_path], draw_path != 0, pathKey);
+        drawBox(pos++, "rgba(0,63,0, 0.7)", "white",
+                (new Array('Q', 'Q', 'C', 'QC', 'Qc', 'Cq'))[draw_computed],
+                draw_computed != 0, computedKey);
+        drawBox(pos++, "green", "black", step_limit, drawSomething, '');
+        drawBox(pos++, "green", "black", stepMax, drawSomething, '');
+        drawBox(pos++, "rgba(255,0,0, 0.6)", "black", lastIndex, drawSomething & draw_log, '');
+        drawBox(pos++, "rgba(255,0,0, 0.6)", "black", test.length - 1, drawSomething & draw_log, '');
+        if (curve_t) {
+            drawCurveTControl();
+        }
+        ctx.font = "normal 20px Arial";
+        ctx.fillStyle = "rgba(0,0,0, 0.3)";
+        ctx.textAlign = "right";
+        ctx.fillText(scale.toFixed(decimal_places) + 'x' , screenWidth - 10, screenHeight - 5);
+    }
+    if (draw_hints) {
+        ctx.font = "normal 10px Arial";
+        ctx.fillStyle = "rgba(0,0,0, 0.5)";
+        ctx.textAlign = "right";
+        var y = 4;
+        ctx.fillText("control lines : " +  controlLinesKey, ctx.screenWidthwidth - 10, pos * 50 + y++ * 10);
+        ctx.fillText("curve t : " +  curveTKey, screenWidth - 10, pos * 50 + y++ * 10);
+        ctx.fillText("deriviatives : " +  deriviativesKey, screenWidth - 10, pos * 50 + y++ * 10);
+        ctx.fillText("intersect t : " +  intersectTKey, screenWidth - 10, pos * 50 + y++ * 10);
+        ctx.fillText("hodo : " +  hodoKey, screenWidth - 10, pos * 50 + y++ * 10);
+        ctx.fillText("log : " +  logKey, screenWidth - 10, pos * 50 + y++ * 10);
+        ctx.fillText("log curve : " +  logCurvesKey, screenWidth - 10, pos * 50 + y++ * 10);
+        ctx.fillText("mid point : " +  midpointKey, screenWidth - 10, pos * 50 + y++ * 10);
+        ctx.fillText("points : " +  ptsKey, screenWidth - 10, pos * 50 + y++ * 10);
+        ctx.fillText("sequence : " +  sequenceKey, screenWidth - 10, pos * 50 + y++ * 10);
+        ctx.fillText("xy : " +  xyKey, screenWidth - 10, pos * 50 + y++ * 10);
+    }
+}
+
+function drawBox(y, backC, foreC, str, enable, label) {
+    ctx.beginPath();
+    ctx.fillStyle = backC;
+    ctx.rect(screenWidth - 40, y * 50 + 10, 40, 30);
+    ctx.fill();
+    ctx.font = "normal 16px Arial";
+    ctx.fillStyle = foreC;
+    ctx.textAlign = "center";
+    ctx.fillText(str, screenWidth - 20, y * 50 + 32);
+    if (!enable) {
+        ctx.fillStyle = "rgba(255,255,255, 0.5)";
+        ctx.fill();
+    }
+    if (label != '') {
+        ctx.font = "normal 9px Arial";
+        ctx.fillStyle = "black";
+        ctx.fillText(label, screenWidth - 47, y * 50 + 40);
+    }
+}
+
+function drawCurveTControl() {
+    ctx.lineWidth = 2;
+    ctx.strokeStyle = "rgba(0,0,0, 0.3)";
+    ctx.beginPath();
+    ctx.rect(screenWidth - 80, 40, 28, screenHeight - 80);
+    ctx.stroke();
+    var ty = 40 + curveT * (screenHeight - 80);
+    ctx.beginPath();
+    ctx.moveTo(screenWidth - 80, ty);
+    ctx.lineTo(screenWidth - 85, ty - 5);
+    ctx.lineTo(screenWidth - 85, ty + 5);
+    ctx.lineTo(screenWidth - 80, ty);
+    ctx.fillStyle = "rgba(0,0,0, 0.6)";
+    ctx.fill();
+    var num = curveT.toFixed(decimal_places);
+    ctx.font = "normal 10px Arial";
+    ctx.textAlign = "left";
+    ctx.fillText(num, screenWidth - 78, ty);
+}
+
+function ptInTControl() {
+    var e = window.event;
+	var tgt = e.target || e.srcElement;
+    var left = tgt.offsetLeft;
+    var top = tgt.offsetTop;
+    var x = (e.clientX - left);
+    var y = (e.clientY - top);
+    if (x < screenWidth - 80 || x > screenWidth - 50) {
+        return false;
+    }
+    if (y < 40 || y > screenHeight - 80) {
+        return false;
+    }
+    curveT = (y - 40) / (screenHeight - 120);
+    if (curveT < 0 || curveT > 1) {
+        throw "stop execution";
+    }
+    return true;
+}
+
+function drawTop() {
+    if (tests[testIndex] == null) {
+        var str = testDivs[testIndex].textContent;
+        parse_all(str);
+        var title = testDivs[testIndex].id.toString();
+        testTitles[testIndex] = title;
+    }
+    init(tests[testIndex]);
+    redraw();
+}
+
+function redraw() {
+    if (focus_on_selection) {
+        collect_bounds = true;
+        draw(tests[testIndex], testLines[testIndex], testTitles[testIndex]);
+        collect_bounds = false;
+        if (focusXmin < focusXmax && focusYmin < focusYmax) {
+            setScale(focusXmin, focusXmax, focusYmin, focusYmax);
+        }
+    }
+    ctx.beginPath();
+    ctx.fillStyle = "white";
+    ctx.rect(0, 0, screenWidth, screenHeight);
+    ctx.fill();
+    draw(tests[testIndex], testLines[testIndex], testTitles[testIndex]);
+}
+
+function dumpCurvePartial(test, id, t0, t1) {
+    var curve = curveByID(test, id);
+    var name = ["line", "quad", "cubic"][curve.length / 2 - 2];
+    console.log("id=" + id + " " + name + "=" +  curveToString(curve)
+        + " t0=" + t0 + " t1=" + t1
+        + " partial=" + curveToString(curvePartialByID(test, id, t0, t1)));
+}
+
+function dumpAngleTest(test, id, t0, t1) {
+    var curve = curveByID(test, id);
+    console.log("    { {" + curveToString(curve) + "}, " 
+            + curve.length / 2 + ", " + t0 + ", " + t1 + ", {} }, //");
+}
+
+function dumpLogToConsole() {
+    if (logStart < 0) {
+        return;
+    }
+    var test = tests[testIndex];
+    var recType = REC_TYPE_UNKNOWN;
+    var records;
+    for (var index = 0; index < test.length; index += 3) {
+        var lastLineNo = test[index + 1];
+        if (lastLineNo >= logStart && lastLineNo < logStart + logRange) {
+            recType = test[index];
+            records = test[index + 2];
+            break;
+        }
+    }
+    if (recType == REC_TYPE_UNKNOWN) {
+        return;
+    }
+    var lines = testLines[testIndex];
+    for (var idx = 0; idx < logRange; ++idx) {
+        var line = lines[logStart + idx];
+        console.log(line);
+        for (var recordIndex = 0; recordIndex < records.length; recordIndex += 2) {
+            var fragType = records[recordIndex];
+            var frags = records[recordIndex + 1];
+            if (recType == REC_TYPE_ANGLE && fragType == ANGLE_AFTER) {
+                dumpCurvePartial(test, frags[0], frags[3], frags[4]);
+                dumpCurvePartial(test, frags[5], frags[8], frags[9]);
+                dumpCurvePartial(test, frags[10], frags[13], frags[14]);
+                console.log("\nstatic IntersectData intersectDataSet[] = {");
+                dumpAngleTest(test, frags[0], frags[3], frags[4]);
+                dumpAngleTest(test, frags[5], frags[8], frags[9]);
+                dumpAngleTest(test, frags[10], frags[13], frags[14]);
+                console.log("};");
+            } else if (recType == REC_TYPE_ANGLE && fragType == ANGLE_AFTER2) {
+                dumpCurvePartial(test, frags[0], frags[4], frags[5]);
+                dumpCurvePartial(test, frags[6], frags[10], frags[11]);
+                dumpCurvePartial(test, frags[12], frags[16], frags[17]);
+                console.log("\nstatic IntersectData intersectDataSet[] = { //");
+                dumpAngleTest(test, frags[0], frags[4], frags[5]);
+                dumpAngleTest(test, frags[6], frags[10], frags[11]);
+                dumpAngleTest(test, frags[12], frags[16], frags[17]);
+                console.log("}; //");
+            }
+        }
+    }
+}
+
+var activeKey = 'a';
+var pathKey = 'b';
+var pathBackKey = 'B';
+var centerKey = 'c';
+var addKey = 'd';
+var deriviativesKey = 'f';
+var angleKey = 'g';
+var angleBackKey = 'G';
+var hodoKey = 'h';
+var intersectionKey = 'i';
+var intersectionBackKey = 'I';
+var sequenceKey = 'j';
+var midpointKey = 'k';
+var logKey = 'l';
+var logToConsoleKey = 'L';
+var markKey = 'm';
+var sortKey = 'o';
+var opKey = 'p';
+var opBackKey = 'P';
+var computedKey = 'q';
+var computedBackKey = 'Q';
+var stepKey = 's';
+var stepBackKey = 'S';
+var intersectTKey = 't';
+var curveTKey = 'u';
+var controlLinesBackKey = 'V';
+var controlLinesKey = 'v';
+var ptsKey = 'x';
+var xyKey = 'y';
+var logCurvesKey = 'z';
+var focusKey = '`';
+var idKey = '.';
+var retinaKey = '\\';
+
+function doKeyPress(evt) {
+    var char = String.fromCharCode(evt.charCode);
+    var focusWasOn = false;
+    switch (char) {
+    case '0':
+    case '1':
+    case '2':
+    case '3':
+    case '4':
+    case '5':
+    case '6':
+    case '7':
+    case '8':
+    case '9':
+        decimal_places = char - '0';
+        redraw();
+        break;
+    case activeKey:
+        draw_active ^= true;
+        redraw(); 
+        break;
+    case addKey:
+        draw_add ^= true;
+        redraw(); 
+        break;
+    case angleKey:
+        draw_angle = (draw_angle + 1) % 3;
+        redraw();
+        break;
+    case angleBackKey:
+        draw_angle = (draw_angle + 2) % 3;
+        redraw();
+        break;
+    case centerKey:
+        setScale(xmin, xmax, ymin, ymax);
+        redraw(); 
+        break;
+    case controlLinesBackKey:
+        control_lines = (control_lines + 3) % 4;
+        redraw(); 
+        break;
+    case controlLinesKey:
+        control_lines = (control_lines + 1) % 4;
+        redraw(); 
+        break;
+    case computedBackKey:
+        draw_computed = (draw_computed + 5) % 6;
+        redraw(); 
+        break;
+    case computedKey:
+        draw_computed = (draw_computed + 1) % 6;
+        redraw(); 
+        break;
+    case curveTKey:
+        curve_t ^= true;
+        if (curve_t) {
+            draw_legend = true;
+        }
+        redraw();
+        break;
+    case deriviativesKey:
+        draw_deriviatives = (draw_deriviatives + 1) % 3;
+        redraw();
+        break;
+    case focusKey:
+        focus_on_selection ^= true;
+        setScale(xmin, xmax, ymin, ymax);
+        redraw();
+        break;
+    case hodoKey:
+        draw_hodo = (draw_hodo + 1) % 4;
+        redraw();
+        break;
+    case idKey:
+        draw_id ^= true;
+        redraw();
+        break;
+    case intersectionBackKey:
+        draw_intersection = (draw_intersection + 3) % 4;
+        redraw(); 
+        break;
+    case intersectionKey:
+        draw_intersection = (draw_intersection + 1) % 4;
+        redraw(); 
+        break;
+    case intersectTKey:
+        draw_intersectT ^= true;
+        redraw();
+        break;
+    case logCurvesKey:
+        logCurves(tests[testIndex]);
+        break;
+    case logKey:
+        draw_log ^= true;
+        redraw();
+        break;
+    case logToConsoleKey:
+        if (draw_log) {
+            dumpLogToConsole();
+        }
+        break;
+    case markKey:
+        draw_mark ^= true;
+        redraw();
+        break;
+    case midpointKey:
+        draw_midpoint ^= true;
+        redraw();
+        break;
+    case opKey:
+        draw_op = (draw_op + 1) % 3;
+        redraw();
+        break;
+    case opBackKey:
+        draw_op = (draw_op + 2) % 3;
+        redraw();
+        break;
+    case pathKey:
+        draw_path = (draw_path + 1) % 4;
+        redraw(); 
+        break;
+    case pathBackKey:
+        draw_path = (draw_path + 3) % 4;
+        redraw(); 
+        break;
+    case ptsKey:
+        pt_labels = (pt_labels + 1) % 3;
+        redraw();
+        break;
+    case retinaKey:
+        retina_scale ^= true;
+        drawTop();
+        break;
+    case sequenceKey:
+        draw_sequence ^= true;
+        redraw();
+        break;
+    case sortKey:
+        draw_sort = (draw_sort + 1) % 3;
+        drawTop();
+        break;
+    case stepKey:
+        step_limit++;
+        if (step_limit > stepMax) {
+            step_limit = stepMax;
+        }
+        redraw();
+        break;
+    case stepBackKey:
+        step_limit--;
+        if (step_limit < 0) {
+            step_limit = 0;
+        }
+        redraw();
+        break;
+    case xyKey:
+        debug_xy = (debug_xy + 1) % 3;
+        redraw();
+        break;
+    case '-':
+        focusWasOn = focus_on_selection;
+        if (focusWasOn) {
+            focus_on_selection = false;
+            scale /= 1.2;
+        } else {
+            scale /= 2;
+            calcLeftTop();
+        }
+        redraw();
+        focus_on_selection = focusWasOn;
+        break;
+    case '=':
+    case '+':
+        focusWasOn = focus_on_selection;
+        if (focusWasOn) {
+            focus_on_selection = false;
+            scale *= 1.2;
+        } else {
+            scale *= 2;
+            calcLeftTop();
+        }
+        redraw();
+        focus_on_selection = focusWasOn;
+        break;
+    case '?':
+        draw_hints ^= true;
+        if (draw_hints && !draw_legend) {
+            draw_legend = true;
+        }
+        redraw();
+        break;
+    case '/':
+        draw_legend ^= true;
+        redraw();
+        break;
+    }
+}
+
+function doKeyDown(evt) {
+    var char = evt.keyCode;
+    var preventDefault = false;
+    switch (char) {
+    case 37: // left arrow
+        if (evt.shiftKey) {
+            testIndex -= 9;
+        }
+        if (--testIndex < 0)
+            testIndex = tests.length - 1;
+        drawTop();
+        preventDefault = true;
+        break;
+    case 39: // right arrow
+        if (evt.shiftKey) {
+            testIndex += 9;
+        }
+        if (++testIndex >= tests.length)
+            testIndex = 0;
+        drawTop();
+        preventDefault = true;
+        break;
+    }
+    if (preventDefault) {
+          evt.preventDefault();
+          return false;
+    }
+    return true;
+}
+
+(function() {
+    var hidden = "hidden";
+
+    // Standards:
+    if (hidden in document)
+        document.addEventListener("visibilitychange", onchange);
+    else if ((hidden = "mozHidden") in document)
+        document.addEventListener("mozvisibilitychange", onchange);
+    else if ((hidden = "webkitHidden") in document)
+        document.addEventListener("webkitvisibilitychange", onchange);
+    else if ((hidden = "msHidden") in document)
+        document.addEventListener("msvisibilitychange", onchange);
+    // IE 9 and lower:
+    else if ('onfocusin' in document)
+        document.onfocusin = document.onfocusout = onchange;
+    // All others:
+    else
+        window.onpageshow = window.onpagehide 
+            = window.onfocus = window.onblur = onchange;
+
+    function onchange (evt) {
+        var v = 'visible', h = 'hidden',
+            evtMap = { 
+                focus:v, focusin:v, pageshow:v, blur:h, focusout:h, pagehide:h 
+            };
+
+        evt = evt || window.event;
+        if (evt.type in evtMap)
+            document.body.className = evtMap[evt.type];
+        else        
+            document.body.className = this[hidden] ? "hidden" : "visible";
+    }
+})();
+
+function calcXY() {
+    var e = window.event;
+	var tgt = e.target || e.srcElement;
+    var left = tgt.offsetLeft;
+    var top = tgt.offsetTop;
+    mouseX = (e.clientX - left) / scale + srcLeft;
+    mouseY = (e.clientY - top) / scale + srcTop;
+}
+
+function calcLeftTop() {
+    srcLeft = mouseX - screenWidth / 2 / scale;
+    srcTop = mouseY - screenHeight / 2 / scale;
+}
+
+var disableClick = false;
+
+function handleMouseClick() {
+    if (disableClick) {
+        return;
+    }
+    if (!curve_t || !ptInTControl()) {
+        calcXY();
+        calcLeftTop();
+    }
+    redraw();
+//    if (!curve_t || !ptInTControl()) {
+//        mouseX = screenWidth / 2 / scale + srcLeft;
+//        mouseY = screenHeight / 2 / scale + srcTop;
+//    }
+}
+
+function handleMouseOver() {
+    calcXY();
+    if (debug_xy != 2) {
+        return;
+    }
+    var num = mouseX.toFixed(decimal_places) + ", " + mouseY.toFixed(decimal_places);
+    ctx.beginPath();
+    ctx.rect(300,100,num.length * 6,10);
+    ctx.fillStyle="white";
+    ctx.fill();
+    ctx.font = "normal 10px Arial";
+    ctx.fillStyle="black";
+    ctx.textAlign = "left";
+    ctx.fillText(num, 300, 108);
+}
+
+function start() {
+    for (var i = 0; i < testDivs.length; ++i) {
+        tests[i] = null;
+    }
+    testIndex = 0;
+    drawTop();
+    window.addEventListener('keypress', doKeyPress, true);
+    window.addEventListener('keydown', doKeyDown, true);
+    window.onresize = function() {
+        drawTop();
+    }
+    /*
+    window.onpagehide = function() {
+        disableClick = true;
+    }
+    */
+    window.onpageshow = function () {
+        disableClick = false;
+    }
+}
+
+</script>
+</head>
+
+<body onLoad="start();">
+<canvas id="canvas" width="750" height="500"
+    onmousemove="handleMouseOver()"
+    onclick="handleMouseClick()"
+    ></canvas >
+</body>
+</html>