Fix for rounded-rect clips with filters.

gm/complexclip_blur_tiled.cpp

Index: gm/complexclip_blur_tiled.cpp
diff --git a/gm/complexclip_blur_tiled.cpp b/gm/complexclip_blur_tiled.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..aac04167b7b0a0f28c390e08c727e5550c489cc3
--- /dev/null
+++ b/gm/complexclip_blur_tiled.cpp
@@ -0,0 +1,76 @@
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "gm.h"
+#include "SkBlurImageFilter.h"
+#include "SkRRect.h"
+#include "SkSurface.h"
+
+#define WIDTH 512
+#define HEIGHT 512
+
+namespace skiagm {
+
+class ComplexClipBlurTiledGM : public GM {
+public:
+    ComplexClipBlurTiledGM() {
+    }
+
+protected:
+    SkString onShortName() override {
+        return SkString("complexclip_blur_tiled");
+    }
+
+    SkISize onISize() override {
+        return SkISize::Make(WIDTH, HEIGHT);
+    }
+
+    void onDraw(SkCanvas* canvas) override {
+        SkPaint blurPaint;
+        SkAutoTUnref<SkImageFilter> blur(SkBlurImageFilter::Create(5.0f, 5.0f));
+        blurPaint.setImageFilter(blur);
+        const SkScalar tile_size = SkIntToScalar(128);
+        SkRect bounds;
+        if (!canvas->getClipBounds(&bounds)) {
+            bounds.setEmpty();
+        }
+        int ts = SkScalarCeilToInt(tile_size);
+        SkImageInfo info = SkImageInfo::MakeN32Premul(ts, ts);
+        SkAutoTUnref<SkSurface> tileSurface(canvas->newSurface(info));
+        if (!tileSurface.get()) {
+            tileSurface.reset(SkSurface::NewRaster(info));
+        }
+        SkCanvas* tileCanvas = tileSurface->getCanvas();
+        for (SkScalar y = bounds.top(); y < bounds.bottom(); y += tile_size) {
+            for (SkScalar x = bounds.left(); x < bounds.right(); x += tile_size) {
+                tileCanvas->save();
+                tileCanvas->clear(0);
+                tileCanvas->translate(-x, -y);
+                SkRect rect = SkRect::MakeWH(WIDTH, HEIGHT);
+                tileCanvas->saveLayer(&rect, &blurPaint);
+                SkRRect rrect = SkRRect::MakeRectXY(rect.makeInset(20, 20), 25, 25);
+                tileCanvas->clipRRect(rrect, SkRegion::kDifference_Op, true);
+                SkPaint paint;
+                tileCanvas->drawRect(rect, paint);
+                tileCanvas->restore();
+                tileCanvas->restore();
+                SkAutoTUnref<SkImage> tileImage(tileSurface->newImageSnapshot());
+                canvas->drawImage(tileImage, x, y);
+            }
+        }
+    }
+
+private:
+    typedef GM INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+static GM* MyFactory1(void*) { return new ComplexClipBlurTiledGM(); }
+static GMRegistry reg1(MyFactory1);
+
+}