Fix bug where SkPath will convert an arc to an oval and change the starting point.
Adds unit tests to test the behavior of addArc to oval conversions.
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2017743002
Review-Url: https://codereview.chromium.org/2017743002
diff --git a/src/core/SkPath.cpp b/src/core/SkPath.cpp
index 03bc317..aabcafd 100644
--- a/src/core/SkPath.cpp
+++ b/src/core/SkPath.cpp
@@ -5,6 +5,7 @@
* found in the LICENSE file.
*/
+#include <cmath>
#include "SkBuffer.h"
#include "SkCubicClipper.h"
#include "SkErrorInternals.h"
@@ -1421,10 +1422,21 @@
const SkScalar kFullCircleAngle = SkIntToScalar(360);
if (sweepAngle >= kFullCircleAngle || sweepAngle <= -kFullCircleAngle) {
- this->addOval(oval, sweepAngle > 0 ? kCW_Direction : kCCW_Direction);
- } else {
- this->arcTo(oval, startAngle, sweepAngle, true);
+ // We can treat the arc as an oval if it begins at one of our legal starting positions.
+ // See SkPath::addOval() docs.
+ SkScalar startOver90 = startAngle / 90.f;
+ SkScalar startOver90I = SkScalarRoundToScalar(startOver90);
+ SkScalar error = startOver90 - startOver90I;
+ if (SkScalarNearlyEqual(error, 0)) {
+ // Index 1 is at startAngle == 0.
+ SkScalar startIndex = std::fmod(startOver90I + 1.f, 4.f);
+ startIndex = startIndex < 0 ? startIndex + 4.f : startIndex;
+ this->addOval(oval, sweepAngle > 0 ? kCW_Direction : kCCW_Direction,
+ (unsigned) startIndex);
+ return;
+ }
}
+ this->arcTo(oval, startAngle, sweepAngle, true);
}
/*