More polyutils fixes
Bug: chromium:954891, oss-fuzz:14079
Change-Id: Ia1ee0a15ab4bfc93e67188ff02e6aa436432a3be
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/211602
Commit-Queue: Jim Van Verth <jvanverth@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
diff --git a/src/utils/SkPolyUtils.cpp b/src/utils/SkPolyUtils.cpp
index ee1ae1e..86212f1 100644
--- a/src/utils/SkPolyUtils.cpp
+++ b/src/utils/SkPolyUtils.cpp
@@ -1052,16 +1052,16 @@
return false;
}
- // need to be able to represent all the vertices in the 16-bit indices
- if (polygonSize > std::numeric_limits<uint16_t>::max()) {
- return false;
- }
-
// If it's convex, it's simple
if (SkIsConvexPolygon(polygon, polygonSize)) {
return true;
}
+ // practically speaking, it takes too long to process large polygons
+ if (polygonSize > 2048) {
+ return false;
+ }
+
SkTDPQueue <Vertex, Vertex::Left> vertexQueue(polygonSize);
for (int i = 0; i < polygonSize; ++i) {
Vertex newVertex;
@@ -1146,7 +1146,8 @@
return (side*winding*offset < 0);
}
-bool SkOffsetSimplePolygon(const SkPoint* inputPolygonVerts, int inputPolygonSize, SkScalar offset,
+bool SkOffsetSimplePolygon(const SkPoint* inputPolygonVerts, int inputPolygonSize,
+ const SkRect& bounds, SkScalar offset,
SkTDArray<SkPoint>* offsetPolygon, SkTDArray<int>* polygonIndices) {
if (inputPolygonSize < 3) {
return false;
@@ -1161,6 +1162,12 @@
return false;
}
+ // can't inset more than the half bounds of the polygon
+ if (offset > SkTMin(SkTAbs(SK_ScalarHalf*bounds.width()),
+ SkTAbs(SK_ScalarHalf*bounds.height()))) {
+ return false;
+ }
+
// offsetting close to zero just returns the original poly
if (SkScalarNearlyZero(offset)) {
for (int i = 0; i < inputPolygonSize; ++i) {
diff --git a/src/utils/SkPolyUtils.h b/src/utils/SkPolyUtils.h
index a7b3b79..6c3403e 100644
--- a/src/utils/SkPolyUtils.h
+++ b/src/utils/SkPolyUtils.h
@@ -13,6 +13,8 @@
#include "include/core/SkPoint.h"
#include "include/private/SkTDArray.h"
+struct SkRect;
+
/**
* Generates a polygon that is inset a constant from the boundary of a given convex polygon.
*
@@ -33,6 +35,7 @@
*
* @param inputPolygonVerts Array of points representing the vertices of the original polygon.
* @param inputPolygonSize Number of vertices in the original polygon.
+ * @param bounds Bounding rectangle for the original polygon.
* @param offset How far we wish to offset the polygon.
* Positive values indicate insetting, negative values outsetting.
* @param offsetPolgon The resulting offset polygon, if any.
@@ -40,7 +43,7 @@
* @return true if an offset simple polygon exists, false otherwise.
*/
bool SkOffsetSimplePolygon(const SkPoint* inputPolygonVerts, int inputPolygonSize,
- SkScalar offset, SkTDArray<SkPoint>* offsetPolygon,
+ const SkRect& bounds, SkScalar offset, SkTDArray<SkPoint>* offsetPolygon,
SkTDArray<int>* polygonIndices = nullptr);
/**
diff --git a/src/utils/SkShadowTessellator.cpp b/src/utils/SkShadowTessellator.cpp
index a43a337..6dc7a75 100644
--- a/src/utils/SkShadowTessellator.cpp
+++ b/src/utils/SkShadowTessellator.cpp
@@ -25,7 +25,7 @@
*/
class SkBaseShadowTessellator {
public:
- SkBaseShadowTessellator(const SkPoint3& zPlaneParams, bool transparent);
+ SkBaseShadowTessellator(const SkPoint3& zPlaneParams, const SkRect& bounds, bool transparent);
virtual ~SkBaseShadowTessellator() {}
sk_sp<SkVertices> releaseVertices() {
@@ -99,6 +99,7 @@
SkTDArray<SkPoint> fClipPolygon;
SkTDArray<SkVector> fClipVectors;
+ SkRect fPathBounds;
SkPoint fCentroid;
SkScalar fArea;
SkScalar fLastArea;
@@ -155,8 +156,10 @@
return v0.cross(v1);
}
-SkBaseShadowTessellator::SkBaseShadowTessellator(const SkPoint3& zPlaneParams, bool transparent)
+SkBaseShadowTessellator::SkBaseShadowTessellator(const SkPoint3& zPlaneParams, const SkRect& bounds,
+ bool transparent)
: fZPlaneParams(zPlaneParams)
+ , fPathBounds(bounds)
, fCentroid({0, 0})
, fArea(0)
, fLastArea(0)
@@ -559,7 +562,7 @@
SkTDArray<SkPoint> umbraPolygon;
SkTDArray<int> umbraIndices;
umbraIndices.setReserve(fPathPolygon.count());
- if (!SkOffsetSimplePolygon(&fPathPolygon[0], fPathPolygon.count(), inset,
+ if (!SkOffsetSimplePolygon(&fPathPolygon[0], fPathPolygon.count(), fPathBounds, inset,
&umbraPolygon, &umbraIndices)) {
// TODO: figure out how to handle this case
return false;
@@ -570,7 +573,7 @@
SkTDArray<int> penumbraIndices;
penumbraPolygon.setReserve(umbraPolygon.count());
penumbraIndices.setReserve(umbraPolygon.count());
- if (!SkOffsetSimplePolygon(&fPathPolygon[0], fPathPolygon.count(), -outset,
+ if (!SkOffsetSimplePolygon(&fPathPolygon[0], fPathPolygon.count(), fPathBounds, -outset,
&penumbraPolygon, &penumbraIndices)) {
// TODO: figure out how to handle this case
return false;
@@ -904,12 +907,14 @@
const SkMatrix& ctm,
const SkPoint3& zPlaneParams,
bool transparent)
- : INHERITED(zPlaneParams, transparent) {
+ : INHERITED(zPlaneParams, path.getBounds(), transparent) {
// Set base colors
- auto baseZ = heightFunc(path.getBounds().centerX(), path.getBounds().centerY());
+ auto baseZ = heightFunc(fPathBounds.centerX(), fPathBounds.centerY());
// umbraColor is the interior value, penumbraColor the exterior value.
auto outset = SkDrawShadowMetrics::AmbientBlurRadius(baseZ);
auto inset = outset * SkDrawShadowMetrics::AmbientRecipAlpha(baseZ) - outset;
+ inset = SkScalarPin(inset, 0, SkTMin(path.getBounds().width(),
+ path.getBounds().height()));
if (!this->computePathPolygon(path, ctm)) {
return;
@@ -999,7 +1004,7 @@
const SkPoint3& zPlaneParams,
const SkPoint3& lightPos, SkScalar lightRadius,
bool transparent)
- : INHERITED(zPlaneParams, transparent) {
+ : INHERITED(zPlaneParams, path.getBounds(), transparent) {
// Compute the blur radius, scale and translation for the spot shadow.
SkMatrix shadowTransform;