Implement srcRect and dstRect functionality in SkBitmapSource. This is required for the "preserveAs…

gm/bitmapsource.cpp

Index: gm/bitmapsource.cpp
diff --git a/gm/bitmapsource.cpp b/gm/bitmapsource.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..d6e98a5bbd423a366fa13ab4e5ac522228c5909d
--- /dev/null
+++ b/gm/bitmapsource.cpp
@@ -0,0 +1,91 @@
+/*
+ * Copyright 2013 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 "SkBitmapSource.h"
+
+// This GM exercises the SkBitmapSource ImageFilter class.
+
+class BitmapSourceGM : public skiagm::GM {
+public:
+    BitmapSourceGM() {
+    }
+
+protected:
+    virtual SkString onShortName() SK_OVERRIDE {
+        return SkString("bitmapsource");
+    }
+
+    void makeBitmap() {
+        fBitmap.setConfig(SkBitmap::kARGB_8888_Config, 100, 100);
+        fBitmap.allocPixels();
+        SkBitmapDevice device(fBitmap);
+        SkCanvas canvas(&device);
+        canvas.clear(0x00000000);
+        SkPaint paint;
+        paint.setAntiAlias(true);
+        paint.setColor(0xFFFFFFFF);
+        paint.setTextSize(SkIntToScalar(96));
+        const char* str = "e";
+        canvas.drawText(str, strlen(str), SkIntToScalar(20), SkIntToScalar(70), paint);
+    }
+
+    virtual SkISize onISize() SK_OVERRIDE { return SkISize::Make(500, 150); }
+
+    virtual void onOnceBeforeDraw() SK_OVERRIDE {
+        this->makeBitmap();
+    }
+
+    static void fillRectFiltered(SkCanvas* canvas, const SkRect& clipRect, SkImageFilter* filter) {
+        SkPaint paint;
+        paint.setImageFilter(filter);
+        canvas->save();
+        canvas->clipRect(clipRect);
+        canvas->drawPaint(paint);
+        canvas->restore();
+    }
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+        canvas->clear(0x00000000);
+        {
+            SkRect srcRect = SkRect::MakeXYWH(20, 20, 30, 30);
+            SkRect dstRect = SkRect::MakeXYWH(0, 10, 60, 60);
+            SkRect clipRect = SkRect::MakeXYWH(0, 0, 100, 100);
+            SkRect bounds;
+            fBitmap.getBounds(&bounds);
+            SkAutoTUnref<SkImageFilter> bitmapSource(new SkBitmapSource(fBitmap));
+            SkAutoTUnref<SkImageFilter> bitmapSourceSrcRect(new SkBitmapSource(fBitmap, srcRect, srcRect));
+            SkAutoTUnref<SkImageFilter> bitmapSourceSrcRectDstRect(new SkBitmapSource(fBitmap, srcRect, dstRect));
+            SkAutoTUnref<SkImageFilter> bitmapSourceDstRectOnly(new SkBitmapSource(fBitmap, bounds, dstRect));
+
+            // Draw an unscaled bitmap.
+            fillRectFiltered(canvas, clipRect, bitmapSource);
+            canvas->translate(SkIntToScalar(100), 0);
+
+            // Draw an unscaled subset of the source bitmap (srcRect -> srcRect).
+            fillRectFiltered(canvas, clipRect, bitmapSourceSrcRect);
+            canvas->translate(SkIntToScalar(100), 0);
+
+            // Draw a subset of the bitmap scaled to a destination rect (srcRect -> dstRect).
+            fillRectFiltered(canvas, clipRect, bitmapSourceSrcRectDstRect);
+            canvas->translate(SkIntToScalar(100), 0);
+
+            // Draw the entire bitmap scaled to a destination rect (bounds -> dstRect).
+            fillRectFiltered(canvas, clipRect, bitmapSourceDstRectOnly);
+            canvas->translate(SkIntToScalar(100), 0);
+        }
+    }
+
+private:
+    SkBitmap fBitmap;
+    typedef GM INHERITED;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+DEF_GM( return new BitmapSourceGM; )