add a GM to demo the blend bug
BUG=skia:3739
Review URL: https://codereview.chromium.org/1094863003
diff --git a/gm/blend.cpp b/gm/blend.cpp
new file mode 100644
index 0000000..90453a5
--- /dev/null
+++ b/gm/blend.cpp
@@ -0,0 +1,48 @@
+/*
+ * 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 "gm.h"
+
+DEF_SIMPLE_GM(blend, canvas, 300, 100) {
+ SkPaint p;
+
+ // All three of these blocks should be the same color.
+ canvas->save();
+ canvas->scale(100,100);
+
+ p.setColor(SK_ColorRED);
+ canvas->drawRect(SkRect::MakeXYWH(0,0,1,1), p);
+ p.setColor(0xFC008000);
+ canvas->drawRect(SkRect::MakeXYWH(0,0,1,1), p);
+
+ p.setColor(SK_ColorRED);
+ canvas->drawRect(SkRect::MakeXYWH(1,0,1,1), p);
+ canvas->saveLayer(NULL, NULL);
+ p.setColor(0xFC008000);
+ canvas->drawRect(SkRect::MakeXYWH(1,0,1,1), p);
+ canvas->restore();
+
+ p.setColor(SK_ColorRED);
+ canvas->drawRect(SkRect::MakeXYWH(2,0,1,1), p);
+ canvas->saveLayerAlpha(NULL, 0xFC);
+ p.setColor(0xFF008000);
+ canvas->drawRect(SkRect::MakeXYWH(2,0,1,1), p);
+ canvas->restore();
+ canvas->restore();
+
+ // Print out the colors in each block (if we're looking at 8888 raster).
+ if (canvas->imageInfo().colorType() == kN32_SkColorType) {
+ if (const SkPMColor* px = (const SkPMColor*)canvas->peekPixels(NULL, NULL)) {
+ p.setColor(SK_ColorWHITE);
+ for (int i = 0; i < 3; i++) {
+ SkPMColor c = px[i * 100];
+ SkString text = SkStringPrintf("0x%08x", c);
+ canvas->drawText(text.c_str(), text.size(), i * 100.0f + 20.0f, 50.0f, p);
+ }
+ }
+ }
+}