break out of cubic stroker loop on degenerate case
The looper can generate more than one quad, but if any one is degenerate,
give up, but not before generating the state for the line join to
produce the correct end.
Before, the early return allowed the inside path to contain multiple
movetos that caused reversePath to assert.
R=reed@google.com
Review URL: https://codereview.chromium.org/948043002
diff --git a/gm/dashcubics.cpp b/gm/dashcubics.cpp
index 9a7d6d7..246d054 100644
--- a/gm/dashcubics.cpp
+++ b/gm/dashcubics.cpp
@@ -26,7 +26,28 @@
}
virtual SkISize onISize() {
- return SkISize::Make(640, 480);
+ return SkISize::Make(860, 700);
+ }
+
+ void flower(SkCanvas* canvas, const SkPath& path, SkScalar intervals[2], SkPaint::Join join) {
+ SkPathEffect* pe = SkDashPathEffect::Create(intervals, 2, 0);
+
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ paint.setStyle(SkPaint::kStroke_Style);
+ paint.setStrokeJoin(join);
+ paint.setStrokeWidth(42);
+ canvas->drawPath(path, paint);
+
+ paint.setColor(SK_ColorRED);
+ paint.setStrokeWidth(21);
+ paint.setPathEffect(pe)->unref();
+ canvas->drawPath(path, paint);
+
+ paint.setColor(SK_ColorGREEN);
+ paint.setPathEffect(NULL);
+ paint.setStrokeWidth(0);
+ canvas->drawPath(path, paint);
}
virtual void onDraw(SkCanvas* canvas) {
@@ -42,26 +63,16 @@
"C 283,231 344,195 338,98";
SkParsePath::FromSVGString(d, &path);
-
- SkScalar intervals[] = { 5, 10 };
- SkPathEffect* pe = SkDashPathEffect::Create(intervals, 2, 0);
-
- SkPaint paint;
- paint.setAntiAlias(true);
- paint.setStyle(SkPaint::kStroke_Style);
-
- paint.setStrokeWidth(42);
- canvas->drawPath(path, paint);
-
- paint.setColor(SK_ColorRED);
- paint.setStrokeWidth(21);
- paint.setPathEffect(pe)->unref();
- canvas->drawPath(path, paint);
-
- paint.setColor(SK_ColorGREEN);
- paint.setPathEffect(NULL);
- paint.setStrokeWidth(0);
- canvas->drawPath(path, paint);
+ canvas->translate(-35.f, -55.f);
+ for (int x = 0; x < 2; ++x) {
+ for (int y = 0; y < 2; ++y) {
+ canvas->save();
+ canvas->translate(x * 430.f, y * 355.f);
+ SkScalar intervals[] = { 5 + (x ? 0 : 0.0001f + 0.0001f), 10 };
+ flower(canvas, path, intervals, y ? SkPaint::kDefault_Join : SkPaint::kRound_Join);
+ canvas->restore();
+ }
+ }
}
private:
diff --git a/src/core/SkStroke.cpp b/src/core/SkStroke.cpp
index 1a44a3a..5c65e6e 100644
--- a/src/core/SkStroke.cpp
+++ b/src/core/SkStroke.cpp
@@ -905,9 +905,10 @@
// compute the perpendicular point and its tangent.
void SkPathStroker::setRayPts(const SkPoint& tPt, SkVector* dxy, SkPoint* onPt,
SkPoint* tangent) const {
+ SkPoint oldDxy = *dxy;
if (!dxy->setLength(fRadius)) { // consider moving double logic into SkPoint::setLength
- double xx = dxy->fX;
- double yy = dxy->fY;
+ double xx = oldDxy.fX;
+ double yy = oldDxy.fY;
double dscale = fRadius / sqrt(xx * xx + yy * yy);
dxy->fX = SkDoubleToScalar(xx * dscale);
dxy->fY = SkDoubleToScalar(yy * dscale);
@@ -1412,14 +1413,16 @@
SkQuadConstruct quadPts;
this->init(kOuter_StrokeType, &quadPts, lastT, nextT);
if (!this->cubicStroke(cubic, &quadPts)) {
- return;
+ break;
}
this->init(kInner_StrokeType, &quadPts, lastT, nextT);
if (!this->cubicStroke(cubic, &quadPts)) {
- return;
+ break;
}
lastT = nextT;
}
+ // emit the join even if one stroke succeeded but the last one failed
+ // this avoids reversing an inner stroke with a partial path followed by another moveto
this->setCubicEndNormal(cubic, normalAB, unitAB, &normalCD, &unitCD);
#else
bool degenerateAB = SkPath::IsLineDegenerate(fPrevPt, pt1);