cumulative pathops patch

Replace the implicit curve intersection with a geometric curve intersection. The implicit intersection proved mathematically unstable and took a long time to zero in on an answer.

Use pointers instead of indices to refer to parts of curves. Indices required awkward renumbering.

Unify t and point values so that small intervals can be eliminated in one pass.

Break cubics up front to eliminate loops and cusps.

Make the Simplify and Op code more regular and eliminate arbitrary differences.

Add a builder that takes an array of paths and operators.

Delete unused code.

BUG=skia:3588
R=reed@google.com

Review URL: https://codereview.chromium.org/1037573004
diff --git a/tests/PathOpsAngleIdeas.cpp b/tests/PathOpsAngleIdeas.cpp
index 901cab2..1a2bce7 100755
--- a/tests/PathOpsAngleIdeas.cpp
+++ b/tests/PathOpsAngleIdeas.cpp
@@ -6,8 +6,8 @@
  */
 #include "PathOpsTestCommon.h"
 #include "SkIntersections.h"
+#include "SkOpContour.h"
 #include "SkOpSegment.h"
-#include "SkPathOpsTriangle.h"
 #include "SkRandom.h"
 #include "SkTArray.h"
 #include "SkTSort.h"
@@ -18,12 +18,12 @@
 
 class PathOpsAngleTester {
 public:
-    static int ConvexHullOverlaps(const SkOpAngle& lh, const SkOpAngle& rh) {
-        return lh.convexHullOverlaps(rh);
+    static int ConvexHullOverlaps(SkOpAngle& lh, SkOpAngle& rh) {
+        return lh.convexHullOverlaps(&rh);
     }
 
-    static int EndsIntersect(const SkOpAngle& lh, const SkOpAngle& rh) {
-        return lh.endsIntersect(rh);
+    static int EndsIntersect(SkOpAngle& lh, SkOpAngle& rh) {
+        return lh.endsIntersect(&rh);
     }
 };
 
@@ -406,28 +406,29 @@
     return ccw == upperRange.ccw;
 }
 
-class PathOpsSegmentTester {
-public:
-    static void ConstructQuad(SkOpSegment* segment, SkPoint shortQuad[3]) {
-        segment->debugConstructQuad(shortQuad);
-    }
-};
-
-static void makeSegment(const SkDQuad& quad, SkPoint shortQuad[3], SkOpSegment* result) {
+static void makeSegment(SkOpContour* contour, const SkDQuad& quad, SkPoint shortQuad[3],
+        SkChunkAlloc* allocator) {
     shortQuad[0] = quad[0].asSkPoint();
     shortQuad[1] = quad[1].asSkPoint();
     shortQuad[2] = quad[2].asSkPoint();
-    PathOpsSegmentTester::ConstructQuad(result, shortQuad);
+    contour->addQuad(shortQuad, allocator);
 }
 
 static void testQuadAngles(skiatest::Reporter* reporter, const SkDQuad& quad1, const SkDQuad& quad2,
-        int testNo) {
+        int testNo, SkChunkAlloc* allocator) {
     SkPoint shortQuads[2][3];
-    SkOpSegment seg[2];
-    makeSegment(quad1, shortQuads[0], &seg[0]);
-    makeSegment(quad2, shortQuads[1], &seg[1]);
-    int realOverlap = PathOpsAngleTester::ConvexHullOverlaps(*seg[0].debugLastAngle(),
-            *seg[1].debugLastAngle());
+
+    SkOpContour contour;
+    SkOpGlobalState state(NULL  PATH_OPS_DEBUG_PARAMS(&contour));
+    contour.init(&state, false, false);
+    makeSegment(&contour, quad1, shortQuads[0], allocator);
+    makeSegment(&contour, quad1, shortQuads[1], allocator);
+    SkOpSegment* seg1 = contour.first();
+    seg1->debugAddAngle(0, 1, allocator);
+    SkOpSegment* seg2 = seg1->next();
+    seg2->debugAddAngle(0, 1, allocator);
+    int realOverlap = PathOpsAngleTester::ConvexHullOverlaps(*seg1->debugLastAngle(),
+            *seg2->debugLastAngle());
     const SkDPoint& origin = quad1[0];
     REPORTER_ASSERT(reporter, origin == quad2[0]);
     double a1s = atan2(origin.fY - quad1[1].fY, quad1[1].fX - origin.fX);
@@ -545,25 +546,27 @@
     }
     if (overlap < 0) {
         SkDEBUGCODE(int realEnds =)
-                PathOpsAngleTester::EndsIntersect(*seg[0].debugLastAngle(),
-                *seg[1].debugLastAngle());
+                PathOpsAngleTester::EndsIntersect(*seg1->debugLastAngle(),
+                *seg2->debugLastAngle());
         SkASSERT(realEnds == (firstInside ? 1 : 0));
     }
     bruteForce(reporter, quad1, quad2, firstInside);
 }
 
 DEF_TEST(PathOpsAngleOverlapHullsOne, reporter) {
+    SkChunkAlloc allocator(4096);
 //    gPathOpsAngleIdeasVerbose = true;
     const SkDQuad quads[] = {
 {{{939.4808349609375, 914.355224609375}, {-357.7921142578125, 590.842529296875}, {736.8936767578125, -350.717529296875}}},
 {{{939.4808349609375, 914.355224609375}, {-182.85418701171875, 634.4552001953125}, {-509.62615966796875, 576.1182861328125}}}
     };
     for (int index = 0; index < (int) SK_ARRAY_COUNT(quads); index += 2) {
-        testQuadAngles(reporter, quads[index], quads[index + 1], 0);
+        testQuadAngles(reporter, quads[index], quads[index + 1], 0, &allocator);
     }
 }
 
 DEF_TEST(PathOpsAngleOverlapHulls, reporter) {
+    SkChunkAlloc allocator(4096);
     if (!gPathOpsAngleIdeasVerbose) {  // takes a while to run -- so exclude it by default
         return;
     }
@@ -587,7 +590,7 @@
         if (i.used() > 1) {
             continue;
         }
-        testQuadAngles(reporter, quad1, quad2, index);
+        testQuadAngles(reporter, quad1, quad2, index, &allocator);
     }
 }