Fix dst bound reported by SkTileImageFilter

In the example from the bug we had the filter DAG:

color filter (table)
    0: xfermode filter (arith)
        0: tile filter [0,80,34,114] -> [0,80,800,480]
             0: color filter (table)
                 0: bitmap src 34x34 -> [0,80,34,114]
        1: color filter (table)
             0: picture filter [0, 80, 800, 480]

computeFastBounds was coming out of the DAG with a bound of [0,80,34,114] which didn't represent the pixels that would be drawn.

This CL updates SkTileImageFilter to correctly set the bound for the pixels it will hit.

BUG=493783

Review URL: https://codereview.chromium.org/1152553006

1 files changed, 76 insertions, 0 deletions

diff --git a/gm/bigtileimagefilter.cpp b/gm/bigtileimagefilter.cpp
new file mode 100644
index 0000000000..97de0d2042
--- /dev/null
+++ b/gm/bigtileimagefilter.cpp
@@ -0,0 +1,76 @@
+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkBitmapSource.h"
+#include "SkTileImageFilter.h"
+#include "gm.h"
+
+namespace skiagm {
+
+class BigTileImageFilterGM : public GM {
+public:
+    BigTileImageFilterGM() {
+        this->setBGColor(0xFF000000);
+    }
+
+protected:
+
+    SkString onShortName() override {
+        return SkString("bigtileimagefilter");
+    }
+
+    SkISize onISize() override{
+        return SkISize::Make(kWidth, kHeight);
+    }
+
+    void onOnceBeforeDraw() override {
+        fBitmap.allocN32Pixels(kBitmapSize, kBitmapSize);
+
+        SkCanvas canvas(fBitmap);
+        canvas.clear(0xFF000000);
+
+        SkPaint paint;
+        paint.setColor(SK_ColorRED);
+        paint.setStrokeWidth(3);
+        paint.setStyle(SkPaint::kStroke_Style);
+
+        canvas.drawCircle(SkScalarHalf(kBitmapSize), SkScalarHalf(kBitmapSize),
+                          SkScalarHalf(kBitmapSize), paint);
+    }
+
+    void onDraw(SkCanvas* canvas) override {
+        canvas->clear(SK_ColorBLACK);
+
+        SkPaint p;
+
+        SkAutoTUnref<SkBitmapSource> bms(SkBitmapSource::Create(fBitmap));
+        SkAutoTUnref<SkTileImageFilter> tif(SkTileImageFilter::Create(
+                            SkRect::MakeWH(SkIntToScalar(kBitmapSize), SkIntToScalar(kBitmapSize)),
+                            SkRect::MakeWH(SkIntToScalar(kWidth), SkIntToScalar(kHeight)),
+                            bms));
+        p.setImageFilter(tif);
+
+        SkRect bound = SkRect::MakeWH(SkIntToScalar(kWidth), SkIntToScalar(kHeight));
+        canvas->saveLayer(&bound, &p);
+        canvas->restore();
+    }
+
+private:
+    static const int kWidth = 512;
+    static const int kHeight = 512;
+    static const int kBitmapSize = 64;
+
+    SkBitmap fBitmap;
+
+    typedef GM INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+DEF_GM( return SkNEW(BigTileImageFilterGM); )
+
+}