Fix for degenerate stroke rect
BUG=skia:
Review URL: https://codereview.chromium.org/1359453002
diff --git a/src/gpu/batches/GrAAStrokeRectBatch.cpp b/src/gpu/batches/GrAAStrokeRectBatch.cpp
index 0a9601f..baea72f 100644
--- a/src/gpu/batches/GrAAStrokeRectBatch.cpp
+++ b/src/gpu/batches/GrAAStrokeRectBatch.cpp
@@ -53,6 +53,7 @@
SkRect fDevOutsideAssist;
SkRect fDevInside;
GrColor fColor;
+ bool fDegenerate;
};
static AAStrokeRectBatch* Create(const SkMatrix& viewMatrix, bool miterStroke) {
@@ -77,17 +78,19 @@
}
void append(GrColor color, const SkRect& devOutside, const SkRect& devOutsideAssist,
- const SkRect& devInside) {
+ const SkRect& devInside, bool degenerate) {
Geometry& geometry = fGeoData.push_back();
geometry.fColor = color;
geometry.fDevOutside = devOutside;
geometry.fDevOutsideAssist = devOutsideAssist;
geometry.fDevInside = devInside;
+ geometry.fDegenerate = degenerate;
}
void appendAndUpdateBounds(GrColor color, const SkRect& devOutside,
- const SkRect& devOutsideAssist, const SkRect& devInside) {
- this->append(color, devOutside, devOutsideAssist, devInside);
+ const SkRect& devOutsideAssist, const SkRect& devInside,
+ bool degenerate) {
+ this->append(color, devOutside, devOutsideAssist, devInside, degenerate);
SkRect bounds;
this->updateBounds(&bounds, fGeoData.back());
@@ -145,6 +148,7 @@
const SkRect& devOutsideAssist,
const SkRect& devInside,
bool miterStroke,
+ bool degenerate,
bool tweakAlphaForCoverage) const;
struct BatchTracker {
@@ -226,6 +230,7 @@
args.fDevOutsideAssist,
args.fDevInside,
fMiterStroke,
+ args.fDegenerate,
canTweakAlphaForCoverage);
}
helper.recordDraw(target);
@@ -356,6 +361,15 @@
return true;
}
+static void setup_scale(int* scale, SkScalar inset) {
+ if (inset < SK_ScalarHalf) {
+ *scale = SkScalarFloorToInt(512.0f * inset / (inset + SK_ScalarHalf));
+ SkASSERT(*scale >= 0 && *scale <= 255);
+ } else {
+ *scale = 0xff;
+ }
+}
+
void AAStrokeRectBatch::generateAAStrokeRectGeometry(void* vertices,
size_t offset,
size_t vertexStride,
@@ -366,6 +380,7 @@
const SkRect& devOutsideAssist,
const SkRect& devInside,
bool miterStroke,
+ bool degenerate,
bool tweakAlphaForCoverage) const {
intptr_t verts = reinterpret_cast<intptr_t>(vertices) + offset;
@@ -382,18 +397,34 @@
#ifndef SK_IGNORE_THIN_STROKED_RECT_FIX
// TODO: this only really works if the X & Y margins are the same all around
// the rect (or if they are all >= 1.0).
- SkScalar inset = SkMinScalar(SK_Scalar1, devOutside.fRight - devInside.fRight);
- inset = SkMinScalar(inset, devInside.fLeft - devOutside.fLeft);
- inset = SkMinScalar(inset, devInside.fTop - devOutside.fTop);
- if (miterStroke) {
- inset = SK_ScalarHalf * SkMinScalar(inset, devOutside.fBottom - devInside.fBottom);
+ SkScalar inset;
+ if (!degenerate) {
+ inset = SkMinScalar(SK_Scalar1, devOutside.fRight - devInside.fRight);
+ inset = SkMinScalar(inset, devInside.fLeft - devOutside.fLeft);
+ inset = SkMinScalar(inset, devInside.fTop - devOutside.fTop);
+ if (miterStroke) {
+ inset = SK_ScalarHalf * SkMinScalar(inset, devOutside.fBottom - devInside.fBottom);
+ } else {
+ inset = SK_ScalarHalf * SkMinScalar(inset, devOutsideAssist.fBottom -
+ devInside.fBottom);
+ }
+ SkASSERT(inset >= 0);
} else {
- inset = SK_ScalarHalf * SkMinScalar(inset, devOutsideAssist.fBottom -
- devInside.fBottom);
+ // TODO use real devRect here
+ inset = SkMinScalar(devOutside.width(), SK_Scalar1);
+ inset = SK_ScalarHalf * SkMinScalar(inset, SkTMax(devOutside.height(),
+ devOutsideAssist.height()));
}
- SkASSERT(inset >= 0);
#else
- SkScalar inset = SK_ScalarHalf;
+ SkScalar inset;
+ if (!degenerate) {
+ inset = SK_ScalarHalf;
+ } else {
+ // TODO use real devRect here
+ inset = SkMinScalar(devOutside.width(), SK_Scalar1);
+ inset = SK_ScalarHalf * SkMinScalar(inset, SkTMax(devOutside.height(),
+ devOutsideAssist.height()));
+ }
#endif
if (miterStroke) {
@@ -401,9 +432,19 @@
set_inset_fan(fan0Pos, vertexStride, devOutside, -SK_ScalarHalf, -SK_ScalarHalf);
// inner two
set_inset_fan(fan1Pos, vertexStride, devOutside, inset, inset);
- set_inset_fan(fan2Pos, vertexStride, devInside, -inset, -inset);
- // innermost
- set_inset_fan(fan3Pos, vertexStride, devInside, SK_ScalarHalf, SK_ScalarHalf);
+ if (!degenerate) {
+ set_inset_fan(fan2Pos, vertexStride, devInside, -inset, -inset);
+ // innermost
+ set_inset_fan(fan3Pos, vertexStride, devInside, SK_ScalarHalf, SK_ScalarHalf);
+ } else {
+ // When the interior rect has become degenerate we smoosh to a single point
+ SkASSERT(devInside.fLeft == devInside.fRight &&
+ devInside.fTop == devInside.fBottom);
+ fan2Pos->setRectFan(devInside.fLeft, devInside.fTop,
+ devInside.fRight, devInside.fBottom, vertexStride);
+ fan3Pos->setRectFan(devInside.fLeft, devInside.fTop,
+ devInside.fRight, devInside.fBottom, vertexStride);
+ }
} else {
SkPoint* fan0AssistPos = reinterpret_cast<SkPoint*>(verts + 4 * vertexStride);
SkPoint* fan1AssistPos = reinterpret_cast<SkPoint*>(verts +
@@ -416,10 +457,20 @@
// outer one of the inner two
set_inset_fan(fan1Pos, vertexStride, devOutside, inset, inset);
set_inset_fan(fan1AssistPos, vertexStride, devOutsideAssist, inset, inset);
- // inner one of the inner two
- set_inset_fan(fan2Pos, vertexStride, devInside, -inset, -inset);
- // innermost
- set_inset_fan(fan3Pos, vertexStride, devInside, SK_ScalarHalf, SK_ScalarHalf);
+ if (!degenerate) {
+ // inner one of the inner two
+ set_inset_fan(fan2Pos, vertexStride, devInside, -inset, -inset);
+ // innermost
+ set_inset_fan(fan3Pos, vertexStride, devInside, SK_ScalarHalf, SK_ScalarHalf);
+ } else {
+ // When the interior rect has become degenerate we smoosh to a single point
+ SkASSERT(devInside.fLeft == devInside.fRight &&
+ devInside.fTop == devInside.fBottom);
+ fan2Pos->setRectFan(devInside.fLeft, devInside.fTop,
+ devInside.fRight, devInside.fBottom, vertexStride);
+ fan3Pos->setRectFan(devInside.fLeft, devInside.fTop,
+ devInside.fRight, devInside.fBottom, vertexStride);
+ }
}
// Make verts point to vertex color and then set all the color and coverage vertex attrs
@@ -436,12 +487,7 @@
// scale is the coverage for the the inner two rects.
int scale;
- if (inset < SK_ScalarHalf) {
- scale = SkScalarFloorToInt(512.0f * inset / (inset + SK_ScalarHalf));
- SkASSERT(scale >= 0 && scale <= 255);
- } else {
- scale = 0xff;
- }
+ setup_scale(&scale, inset);
float innerCoverage = GrNormalizeByteToFloat(scale);
GrColor scaledColor = (0xff == scale) ? color : SkAlphaMulQ(color, scale);
@@ -452,19 +498,24 @@
*reinterpret_cast<GrColor*>(verts + i * vertexStride) = scaledColor;
} else {
*reinterpret_cast<GrColor*>(verts + i * vertexStride) = color;
- *reinterpret_cast<float*>(verts + i * vertexStride + sizeof(GrColor)) =
- innerCoverage;
+ *reinterpret_cast<float*>(verts + i * vertexStride + sizeof(GrColor)) = innerCoverage;
}
}
- // The innermost rect has 0 coverage
+ // The innermost rect has 0 coverage, unless we are degenerate, in which case we must apply the
+ // scaled coverage
verts += (outerVertexNum + innerVertexNum) * vertexStride;
+ if (!degenerate) {
+ innerCoverage = 0;
+ scaledColor = 0;
+ }
+
for (int i = 0; i < innerVertexNum; ++i) {
if (tweakAlphaForCoverage) {
- *reinterpret_cast<GrColor*>(verts + i * vertexStride) = 0;
+ *reinterpret_cast<GrColor*>(verts + i * vertexStride) = scaledColor;
} else {
*reinterpret_cast<GrColor*>(verts + i * vertexStride) = color;
- *reinterpret_cast<GrColor*>(verts + i * vertexStride + sizeof(GrColor)) = 0;
+ *reinterpret_cast<float*>(verts + i * vertexStride + sizeof(GrColor)) = innerCoverage;
}
}
}
@@ -476,9 +527,10 @@
const SkRect& devOutside,
const SkRect& devOutsideAssist,
const SkRect& devInside,
- bool miterStroke) {
+ bool miterStroke,
+ bool degenerate) {
AAStrokeRectBatch* batch = AAStrokeRectBatch::Create(viewMatrix, miterStroke);
- batch->append(color, devOutside, devOutsideAssist, devInside);
+ batch->append(color, devOutside, devOutsideAssist, devInside, degenerate);
batch->init();
return batch;
}
@@ -489,7 +541,8 @@
const SkRect& devOutside,
const SkRect& devOutsideAssist,
const SkRect& devInside,
- bool miterStroke) {
+ bool miterStroke,
+ bool degenerate) {
AAStrokeRectBatch* batch = origBatch->cast<AAStrokeRectBatch>();
// we can't batch across vm changes
@@ -497,7 +550,7 @@
return false;
}
- batch->appendAndUpdateBounds(color, devOutside, devOutsideAssist, devInside);
+ batch->appendAndUpdateBounds(color, devOutside, devOutsideAssist, devInside, degenerate);
return true;
}
@@ -511,6 +564,7 @@
DRAW_BATCH_TEST_DEFINE(AAStrokeRectBatch) {
bool miterStroke = random->nextBool();
+ bool degenerate = random->nextBool();
// Create mock stroke rect
SkRect outside = GrTest::TestRect(random);
@@ -524,7 +578,7 @@
GrColor color = GrRandomColor(random);
return GrAAStrokeRectBatch::Create(color, GrTest::TestMatrix(random), outside, outsideAssist,
- inside, miterStroke);
+ inside, degenerate, miterStroke);
}
#endif
diff --git a/src/gpu/batches/GrAAStrokeRectBatch.h b/src/gpu/batches/GrAAStrokeRectBatch.h
index 1af4f15..242597b 100644
--- a/src/gpu/batches/GrAAStrokeRectBatch.h
+++ b/src/gpu/batches/GrAAStrokeRectBatch.h
@@ -23,7 +23,8 @@
const SkRect& devOutside,
const SkRect& devOutsideAssist,
const SkRect& devInside,
- bool miterStroke);
+ bool miterStroke,
+ bool degenerate);
bool Append(GrBatch*,
GrColor color,
@@ -31,7 +32,8 @@
const SkRect& devOutside,
const SkRect& devOutsideAssist,
const SkRect& devInside,
- bool miterStroke);
+ bool miterStroke,
+ bool degenerate);
};
diff --git a/src/gpu/batches/GrRectBatchFactory.cpp b/src/gpu/batches/GrRectBatchFactory.cpp
index eed18ad..f34a8c0 100644
--- a/src/gpu/batches/GrRectBatchFactory.cpp
+++ b/src/gpu/batches/GrRectBatchFactory.cpp
@@ -33,13 +33,6 @@
const SkScalar rx = SkScalarMul(dx, SK_ScalarHalf);
const SkScalar ry = SkScalarMul(dy, SK_ScalarHalf);
- SkScalar spare;
- {
- SkScalar w = devRect.width() - dx;
- SkScalar h = devRect.height() - dy;
- spare = SkTMin(w, h);
- }
-
SkRect devOutside(devRect);
devOutside.outset(rx, ry);
@@ -51,13 +44,25 @@
miterStroke = false;
}
- if (spare <= 0 && miterStroke) {
- return CreateAAFill(color, viewMatrix, devOutside, devOutside);
- }
-
SkRect devInside(devRect);
devInside.inset(rx, ry);
+ // If we have a degenerate stroking rect(ie the stroke is larger than inner rect) then we
+ // make a degenerate inside rect to avoid double hitting. We will also jam all of the points
+ // together when we render these rects.
+ SkScalar spare;
+ {
+ SkScalar w = devRect.width() - dx;
+ SkScalar h = devRect.height() - dy;
+ spare = SkTMin(w, h);
+ }
+
+ bool degenerate = spare <= 0;
+ if (degenerate) {
+ devInside.fLeft = devInside.fRight = devRect.centerX();
+ devInside.fTop = devInside.fBottom = devRect.centerY();
+ }
+
SkRect devOutsideAssist(devRect);
// For bevel-stroke, use 2 SkRect instances(devOutside and devOutsideAssist)
@@ -69,7 +74,7 @@
}
return GrAAStrokeRectBatch::Create(color, viewMatrix, devOutside, devOutsideAssist, devInside,
- miterStroke);
+ miterStroke, degenerate);
}
GrDrawBatch* CreateAAFillNestedRects(GrColor color,
@@ -82,11 +87,8 @@
viewMatrix.mapRect(&devOutside, rects[0]);
viewMatrix.mapRect(&devInside, rects[1]);
- if (devInside.isEmpty()) {
- return CreateAAFill(color, viewMatrix, devOutside, devOutside);
- }
-
- return GrAAStrokeRectBatch::Create(color, viewMatrix, devOutside, devOutside, devInside, true);
+ return GrAAStrokeRectBatch::Create(color, viewMatrix, devOutside, devOutside, devInside, true,
+ devInside.isEmpty());
}
};