path ops work in progress
path ops work in progress
BUG=
Review URL: https://codereview.chromium.org/21359002
git-svn-id: http://skia.googlecode.com/svn/trunk@11291 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/pathops/SkPathOpsLine.cpp b/src/pathops/SkPathOpsLine.cpp
index 48c042a..1b548fc 100644
--- a/src/pathops/SkPathOpsLine.cpp
+++ b/src/pathops/SkPathOpsLine.cpp
@@ -78,9 +78,7 @@
}
double t = numer / denom;
SkDPoint realPt = ptAtT(t);
- SkDVector distU = xy - realPt;
- double distSq = distU.fX * distU.fX + distU.fY * distU.fY;
- double dist = sqrt(distSq); // OPTIMIZATION: can we compare against distSq instead ?
+ double dist = realPt.distance(xy); // OPTIMIZATION: can we compare against distSq instead ?
// find the ordinal in the original line with the largest unsigned exponent
double tiniest = SkTMin(SkTMin(SkTMin(fPts[0].fX, fPts[0].fY), fPts[1].fX), fPts[1].fY);
double largest = SkTMax(SkTMax(SkTMax(fPts[0].fX, fPts[0].fY), fPts[1].fX), fPts[1].fY);
@@ -93,6 +91,35 @@
return t;
}
+bool SkDLine::nearRay(const SkDPoint& xy) const {
+ // project a perpendicular ray from the point to the line; find the T on the line
+ SkDVector len = fPts[1] - fPts[0]; // the x/y magnitudes of the line
+ double denom = len.fX * len.fX + len.fY * len.fY; // see DLine intersectRay
+ SkDVector ab0 = xy - fPts[0];
+ double numer = len.fX * ab0.fX + ab0.fY * len.fY;
+ double t = numer / denom;
+ SkDPoint realPt = ptAtT(t);
+ double dist = realPt.distance(xy); // OPTIMIZATION: can we compare against distSq instead ?
+ // find the ordinal in the original line with the largest unsigned exponent
+ double tiniest = SkTMin(SkTMin(SkTMin(fPts[0].fX, fPts[0].fY), fPts[1].fX), fPts[1].fY);
+ double largest = SkTMax(SkTMax(SkTMax(fPts[0].fX, fPts[0].fY), fPts[1].fX), fPts[1].fY);
+ largest = SkTMax(largest, -tiniest);
+ return RoughlyEqualUlps(largest, largest + dist); // is the dist within ULPS tolerance?
+}
+
+// Returns true if a ray from (0,0) to (x1,y1) is coincident with a ray (0,0) to (x2,y2)
+// OPTIMIZE: a specialty routine could speed this up -- may not be called very often though
+bool SkDLine::NearRay(double x1, double y1, double x2, double y2) {
+ double denom1 = x1 * x1 + y1 * y1;
+ double denom2 = x2 * x2 + y2 * y2;
+ SkDLine line = {{{0, 0}, {x1, y1}}};
+ SkDPoint pt = {x2, y2};
+ if (denom2 > denom1) {
+ SkTSwap(line[1], pt);
+ }
+ return line.nearRay(pt);
+}
+
double SkDLine::ExactPointH(const SkDPoint& xy, double left, double right, double y) {
if (xy.fY == y) {
if (xy.fX == left) {
@@ -106,7 +133,7 @@
}
double SkDLine::NearPointH(const SkDPoint& xy, double left, double right, double y) {
- if (!AlmostEqualUlps(xy.fY, y)) {
+ if (!AlmostBequalUlps(xy.fY, y)) {
return -1;
}
if (!AlmostBetweenUlps(left, xy.fX, right)) {
@@ -115,6 +142,18 @@
double t = (xy.fX - left) / (right - left);
t = SkPinT(t);
SkASSERT(between(0, t, 1));
+ double realPtX = (1 - t) * left + t * right;
+ SkDVector distU = {xy.fY - y, xy.fX - realPtX};
+ double distSq = distU.fX * distU.fX + distU.fY * distU.fY;
+ double dist = sqrt(distSq); // OPTIMIZATION: can we compare against distSq instead ?
+ double tiniest = SkTMin(SkTMin(y, left), right);
+ double largest = SkTMax(SkTMax(y, left), right);
+ largest = SkTMax(largest, -tiniest);
+ if (!AlmostEqualUlps(largest, largest + dist)) { // is the dist within ULPS tolerance?
+ return -1;
+ }
+ t = SkPinT(t);
+ SkASSERT(between(0, t, 1));
return t;
}
@@ -131,7 +170,7 @@
}
double SkDLine::NearPointV(const SkDPoint& xy, double top, double bottom, double x) {
- if (!AlmostEqualUlps(xy.fX, x)) {
+ if (!AlmostBequalUlps(xy.fX, x)) {
return -1;
}
if (!AlmostBetweenUlps(top, xy.fY, bottom)) {
@@ -140,5 +179,27 @@
double t = (xy.fY - top) / (bottom - top);
t = SkPinT(t);
SkASSERT(between(0, t, 1));
+ double realPtY = (1 - t) * top + t * bottom;
+ SkDVector distU = {xy.fX - x, xy.fY - realPtY};
+ double distSq = distU.fX * distU.fX + distU.fY * distU.fY;
+ double dist = sqrt(distSq); // OPTIMIZATION: can we compare against distSq instead ?
+ double tiniest = SkTMin(SkTMin(x, top), bottom);
+ double largest = SkTMax(SkTMax(x, top), bottom);
+ largest = SkTMax(largest, -tiniest);
+ if (!AlmostEqualUlps(largest, largest + dist)) { // is the dist within ULPS tolerance?
+ return -1;
+ }
+ t = SkPinT(t);
+ SkASSERT(between(0, t, 1));
return t;
}
+
+#ifdef SK_DEBUG
+void SkDLine::dump() {
+ SkDebugf("{{");
+ fPts[0].dump();
+ SkDebugf(", ");
+ fPts[1].dump();
+ SkDebugf("}}\n");
+}
+#endif