Fix for saveLayer() with filters vs. the BBox Hierarchy.

src/core/SkBBoxRecord.cpp

Index: src/core/SkBBoxRecord.cpp
diff --git a/src/core/SkBBoxRecord.cpp b/src/core/SkBBoxRecord.cpp
index a40ea8ba0d27e531e997dfaa922488e0c19433a3..4a9f623dad1a256971015c024a774aaf32530a54 100644
--- a/src/core/SkBBoxRecord.cpp
+++ b/src/core/SkBBoxRecord.cpp
@@ -8,6 +8,12 @@
 
 #include "SkBBoxRecord.h"
 
+SkBBoxRecord::~SkBBoxRecord() {

[mtklein, 2014/07/14 16:43:12]

Consider just calling fSaveStack.deleteAll() ?

[Stephen White, 2014/07/14 16:55:00]

Done.

+    for (int i = fSaveStack.count() - 1; i >= 0; --i) {
+        delete fSaveStack.getAt(i);
+    }
+}
+
 void SkBBoxRecord::drawOval(const SkRect& rect, const SkPaint& paint) {
     if (this->transformBounds(rect, &paint)) {
         INHERITED::drawOval(rect, paint);
@@ -287,6 +293,27 @@ void SkBBoxRecord::onDrawPicture(const SkPicture* picture) {
     }
 }
 
+void SkBBoxRecord::willSave() {
+    *fSaveStack.append() = NULL;
+    this->INHERITED::willSave();
+}
+
+SkCanvas::SaveLayerStrategy SkBBoxRecord::willSaveLayer(const SkRect* bounds,
+                                                        const SkPaint* paint,
+                                                        SaveFlags flags) {
+    // Image filters can affect the effective bounds of primitives drawn inside saveLayer().
+    // Copy the paint so we can compute the modified bounds in transformBounds().
+    *fSaveStack.append() = paint && paint->getImageFilter() ? new SkPaint(*paint) : NULL;

[mtklein, 2014/07/14 16:43:12]

Completely fine, but consider

fSaveStack.push(paint && paint->getImageFilter() ? new SkPaint(*paint) : NULL);

[Stephen White, 2014/07/14 16:55:00]

Ha! Didn't notice those, thanks!

Done.

+    return this->INHERITED::willSaveLayer(bounds, paint, flags);
+}
+
+void SkBBoxRecord::willRestore() {
+    int last = fSaveStack.count() - 1;

[mtklein, 2014/07/14 16:43:12]

delete fSaveStack.top();
fSaveStack.pop();
?

[Stephen White, 2014/07/14 16:55:00]

Done.

+    delete fSaveStack.getAt(last);
+    fSaveStack.setCount(last);
+    this->INHERITED::willRestore();
+}
+
 bool SkBBoxRecord::transformBounds(const SkRect& bounds, const SkPaint* paint) {
     SkRect outBounds = bounds;
     outBounds.sort();
@@ -305,6 +332,14 @@ bool SkBBoxRecord::transformBounds(const SkRect& bounds, const SkPaint* paint) {
         }
     }
 
+    for (int i = fSaveStack.count() - 1; i >= 0; --i) {
+        const SkPaint* paint = fSaveStack.getAt(i);

[mtklein, 2014/07/14 16:43:12]

fSaveStack[i] ?

[Stephen White, 2014/07/14 16:55:00]

Think I'll stick with the explicit version here (operator overloads can be
misleading).

+        if (paint && paint->canComputeFastBounds()) {
+            SkRect temp;
+            outBounds = paint->computeFastBounds(outBounds, &temp);
+        }
+    }
+
     if (!outBounds.isEmpty() && !this->quickReject(outBounds)) {
         this->getTotalMatrix().mapRect(&outBounds);
         this->handleBBox(outBounds);