Add downsample from 8888 to 4444.

gm/copyTo4444.cpp

+/*
+ * 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 "SkCanvas.h"
+#include "SkImageDecoder.h"
+#include "SkOSFile.h"
+
+namespace skiagm {
+
+/**
+ *  Test copying an image from 8888 to 4444.
+ */
+class CopyTo4444GM : public GM {
+public:
+    CopyTo4444GM() {}
+
+protected:
+    virtual SkString onShortName() {
+        return SkString("copyTo4444");
+    }
+
+    virtual SkISize onISize() {
+        return make_isize(1024, 512);
+    }
+
+    virtual void onDraw(SkCanvas* canvas) {
+        SkBitmap bm, bm4444;
+        SkString filename = SkOSPath::SkPathJoin(
+                INHERITED::gResourcePath.c_str(), "mandrill_512.png");
+        if (!SkImageDecoder::DecodeFile(filename.c_str(), &bm,
+                                        SkBitmap::kARGB_8888_Config,
+                                        SkImageDecoder::kDecodePixels_Mode)) {
+            SkDebugf("Could not decode the file. Did you forget to set the "
+                     "resourcePath?\n");
+            return;
+        }
+        canvas->drawBitmap(bm, 0, 0);
+        SkAssertResult(bm.copyTo(&bm4444, SkBitmap::kARGB_4444_Config));
+        canvas->drawBitmap(bm4444, bm.width(), 0);
+    }
+
+private:
+    typedef GM INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+static GM* MyFactory(void*) { return new CopyTo4444GM; }
+static GMRegistry reg(MyFactory);
+
+}