Index: src/core/SkPath.cpp |
diff --git a/src/core/SkPath.cpp b/src/core/SkPath.cpp |
index 94dd6518afbec24535f24ed5f219abc404429684..60cfe0373c08628573cf5be16ff829f428e7cd0f 100644 |
--- a/src/core/SkPath.cpp |
+++ b/src/core/SkPath.cpp |
@@ -1083,23 +1083,21 @@ void SkPath::addRoundRect(const SkRect& rect, SkScalar rx, SkScalar ry, |
} else if (skip_vert) { |
ry = halfH; |
} |
- |
#ifdef SK_IGNORE_QUAD_RR_CORNERS_OPT |
SkScalar sx = SkScalarMul(rx, CUBIC_ARC_FACTOR); |
SkScalar sy = SkScalarMul(ry, CUBIC_ARC_FACTOR); |
this->incReserve(17); |
#else |
- // Please see SkBuildQuadArc for more information but, we need to pull |
- // the off-curve quadratic points in a little bit to make the round |
- // rects convex. |
- static const SkScalar kOffCurveEpsilon = 0.0001f; |
- |
- SkScalar midPtX = rx * SK_ScalarRoot2Over2; |
- SkScalar midPtY = ry * SK_ScalarRoot2Over2; |
+// The mid point of the quadratic arc approximation is half way between the two |
+// control points. The float epsilon adjustment moves the on curve point out by |
+// two bits, distributing the convex test error between the round rect approximation |
+// and the convex cross product sign equality test. |
+ SkScalar midPtX = rx * (SK_Scalar1 + SK_ScalarTanPIOver8 + FLT_EPSILON * 4) / 2; |
+ SkScalar midPtY = ry * (SK_Scalar1 + SK_ScalarTanPIOver8 + FLT_EPSILON * 4) / 2; |
- SkScalar offPtX = rx * SK_ScalarTanPIOver8 - kOffCurveEpsilon; |
- SkScalar offPtY = ry * SK_ScalarTanPIOver8 - kOffCurveEpsilon; |
+ SkScalar offPtX = rx * SK_ScalarTanPIOver8; |
+ SkScalar offPtY = ry * SK_ScalarTanPIOver8; |
this->incReserve(21); |
#endif |
@@ -1113,9 +1111,9 @@ void SkPath::addRoundRect(const SkRect& rect, SkScalar rx, SkScalar ry, |
rect.fLeft, rect.fTop + ry - sy, |
rect.fLeft, rect.fTop + ry); // top-left |
#else |
- this->quadTo(rect.fLeft + rx - offPtX, rect.fTop + kOffCurveEpsilon, |
+ this->quadTo(rect.fLeft + rx - offPtX, rect.fTop, |
rect.fLeft + rx - midPtX, rect.fTop + ry - midPtY); |
- this->quadTo(rect.fLeft + kOffCurveEpsilon, rect.fTop + ry - offPtY, |
+ this->quadTo(rect.fLeft, rect.fTop + ry - offPtY, |
rect.fLeft, rect.fTop + ry); |
#endif |
if (!skip_vert) { |
@@ -1126,9 +1124,9 @@ void SkPath::addRoundRect(const SkRect& rect, SkScalar rx, SkScalar ry, |
rect.fLeft + rx - sx, rect.fBottom, |
rect.fLeft + rx, rect.fBottom); // bot-left |
#else |
- this->quadTo(rect.fLeft + kOffCurveEpsilon, rect.fBottom - ry + offPtY, |
+ this->quadTo(rect.fLeft, rect.fBottom - ry + offPtY, |
rect.fLeft + rx - midPtX, rect.fBottom - ry + midPtY); |
- this->quadTo(rect.fLeft + rx - offPtX, rect.fBottom - kOffCurveEpsilon, |
+ this->quadTo(rect.fLeft + rx - offPtX, rect.fBottom, |
rect.fLeft + rx, rect.fBottom); |
#endif |
if (!skip_hori) { |
@@ -1139,9 +1137,9 @@ void SkPath::addRoundRect(const SkRect& rect, SkScalar rx, SkScalar ry, |
rect.fRight, rect.fBottom - ry + sy, |
rect.fRight, rect.fBottom - ry); // bot-right |
#else |
- this->quadTo(rect.fRight - rx + offPtX, rect.fBottom - kOffCurveEpsilon, |
+ this->quadTo(rect.fRight - rx + offPtX, rect.fBottom, |
rect.fRight - rx + midPtX, rect.fBottom - ry + midPtY); |
- this->quadTo(rect.fRight - kOffCurveEpsilon, rect.fBottom - ry + offPtY, |
+ this->quadTo(rect.fRight, rect.fBottom - ry + offPtY, |
rect.fRight, rect.fBottom - ry); |
#endif |
if (!skip_vert) { |
@@ -1152,9 +1150,9 @@ void SkPath::addRoundRect(const SkRect& rect, SkScalar rx, SkScalar ry, |
rect.fRight - rx + sx, rect.fTop, |
rect.fRight - rx, rect.fTop); // top-right |
#else |
- this->quadTo(rect.fRight - kOffCurveEpsilon, rect.fTop + ry - offPtY, |
+ this->quadTo(rect.fRight, rect.fTop + ry - offPtY, |
rect.fRight - rx + midPtX, rect.fTop + ry - midPtY); |
- this->quadTo(rect.fRight - rx + offPtX, rect.fTop + kOffCurveEpsilon, |
+ this->quadTo(rect.fRight - rx + offPtX, rect.fTop, |
rect.fRight - rx, rect.fTop); |
#endif |
} else { |
@@ -1163,9 +1161,9 @@ void SkPath::addRoundRect(const SkRect& rect, SkScalar rx, SkScalar ry, |
rect.fRight, rect.fTop + ry - sy, |
rect.fRight, rect.fTop + ry); // top-right |
#else |
- this->quadTo(rect.fRight - rx + offPtX, rect.fTop + kOffCurveEpsilon, |
+ this->quadTo(rect.fRight - rx + offPtX, rect.fTop, |
rect.fRight - rx + midPtX, rect.fTop + ry - midPtY); |
- this->quadTo(rect.fRight - kOffCurveEpsilon, rect.fTop + ry - offPtY, |
+ this->quadTo(rect.fRight, rect.fTop + ry - offPtY, |
rect.fRight, rect.fTop + ry); |
#endif |
if (!skip_vert) { |
@@ -1176,9 +1174,9 @@ void SkPath::addRoundRect(const SkRect& rect, SkScalar rx, SkScalar ry, |
rect.fRight - rx + sx, rect.fBottom, |
rect.fRight - rx, rect.fBottom); // bot-right |
#else |
- this->quadTo(rect.fRight - kOffCurveEpsilon, rect.fBottom - ry + offPtY, |
+ this->quadTo(rect.fRight, rect.fBottom - ry + offPtY, |
rect.fRight - rx + midPtX, rect.fBottom - ry + midPtY); |
- this->quadTo(rect.fRight - rx + offPtX, rect.fBottom - kOffCurveEpsilon, |
+ this->quadTo(rect.fRight - rx + offPtX, rect.fBottom, |
rect.fRight - rx, rect.fBottom); |
#endif |
if (!skip_hori) { |
@@ -1189,9 +1187,9 @@ void SkPath::addRoundRect(const SkRect& rect, SkScalar rx, SkScalar ry, |
rect.fLeft, rect.fBottom - ry + sy, |
rect.fLeft, rect.fBottom - ry); // bot-left |
#else |
- this->quadTo(rect.fLeft + rx - offPtX, rect.fBottom - kOffCurveEpsilon, |
+ this->quadTo(rect.fLeft + rx - offPtX, rect.fBottom, |
rect.fLeft + rx - midPtX, rect.fBottom - ry + midPtY); |
- this->quadTo(rect.fLeft + kOffCurveEpsilon, rect.fBottom - ry + offPtY, |
+ this->quadTo(rect.fLeft, rect.fBottom - ry + offPtY, |
rect.fLeft, rect.fBottom - ry); |
#endif |
if (!skip_vert) { |
@@ -1202,9 +1200,9 @@ void SkPath::addRoundRect(const SkRect& rect, SkScalar rx, SkScalar ry, |
rect.fLeft + rx - sx, rect.fTop, |
rect.fLeft + rx, rect.fTop); // top-left |
#else |
- this->quadTo(rect.fLeft + kOffCurveEpsilon, rect.fTop + ry - offPtY, |
+ this->quadTo(rect.fLeft, rect.fTop + ry - offPtY, |
rect.fLeft + rx - midPtX, rect.fTop + ry - midPtY); |
- this->quadTo(rect.fLeft + rx - offPtX, rect.fTop + kOffCurveEpsilon, |
+ this->quadTo(rect.fLeft + rx - offPtX, rect.fTop, |
rect.fLeft + rx, rect.fTop); |
#endif |
if (!skip_hori) { |
@@ -2263,8 +2261,20 @@ void SkPath::validate() const { |
static int sign(SkScalar x) { return x < 0; } |
#define kValueNeverReturnedBySign 2 |
-static int CrossProductSign(const SkVector& a, const SkVector& b) { |
- return SkScalarSignAsInt(SkPoint::CrossProduct(a, b)); |
+static bool AlmostEqual(SkScalar compA, SkScalar compB) { |
scroggo
2013/11/01 16:04:10
Is this deliberately different from SkScalarNearly
|
+ // The error epsilon was empirically derived; worse case round rects |
+ // with a mid point outset by 2x float epsilon in tests had an error |
+ // of 12. |
+ const int epsilon = 16; |
+ if (!SkScalarIsFinite(compA) || !SkScalarIsFinite(compB)) { |
+ return false; |
+ } |
+ if (sk_float_abs(compA) <= FLT_EPSILON && sk_float_abs(compB) <= FLT_EPSILON) { |
+ return true; |
+ } |
+ int aBits = SkFloatAs2sCompliment(compA); |
+ int bBits = SkFloatAs2sCompliment(compB); |
+ return aBits < bBits + epsilon && bBits < aBits + epsilon; |
} |
// only valid for a single contour |
@@ -2275,6 +2285,7 @@ struct Convexicator { |
, fDirection(SkPath::kUnknown_Direction) { |
fSign = 0; |
// warnings |
+ fLastPt.set(0, 0); |
fCurrPt.set(0, 0); |
fVec0.set(0, 0); |
fVec1.set(0, 0); |
@@ -2300,6 +2311,7 @@ struct Convexicator { |
} else { |
SkVector vec = pt - fCurrPt; |
if (vec.fX || vec.fY) { |
+ fLastPt = fCurrPt; |
fCurrPt = pt; |
if (++fPtCount == 2) { |
fFirstVec = fVec1 = vec; |
@@ -2333,7 +2345,11 @@ private: |
SkASSERT(vec.fX || vec.fY); |
fVec0 = fVec1; |
fVec1 = vec; |
- int sign = CrossProductSign(fVec0, fVec1); |
+ SkScalar cross = SkPoint::CrossProduct(fVec0, fVec1); |
+ SkScalar smallest = SkTMin(fCurrPt.fX, SkTMin(fCurrPt.fY, SkTMin(fLastPt.fX, fLastPt.fY))); |
+ SkScalar largest = SkTMax(fCurrPt.fX, SkTMax(fCurrPt.fY, SkTMax(fLastPt.fX, fLastPt.fY))); |
+ largest = SkTMax(largest, -smallest); |
+ int sign = AlmostEqual(largest, largest + cross) ? 0 : SkScalarSignAsInt(cross); |
if (0 == fSign) { |
fSign = sign; |
if (1 == sign) { |
@@ -2349,6 +2365,7 @@ private: |
} |
} |
+ SkPoint fLastPt; |
SkPoint fCurrPt; |
SkVector fVec0, fVec1, fFirstVec; |
int fPtCount; // non-degenerate points |