Add SkOverdrawColorFilter
Uses the value in the src alpha channel to choose how
to set the dst pixel.
This is a part of a multi-part change to detect and
display gpu overdraw on Android.
CQ_INCLUDE_TRYBOTS=master.client.skia.compile:Build-Ubuntu-GCC-x86_64-Debug-NoGPU-Trybot
BUG:32370375
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=5113
Change-Id: I07040929d8a46bbadd499dccec75eebef0e11d11
Reviewed-on: https://skia-review.googlesource.com/5113
Commit-Queue: Matt Sarett <msarett@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
diff --git a/gm/overdrawcolorfilter.cpp b/gm/overdrawcolorfilter.cpp
new file mode 100644
index 0000000..2eba228
--- /dev/null
+++ b/gm/overdrawcolorfilter.cpp
@@ -0,0 +1,68 @@
+/*
+ * 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 "SkCanvas.h"
+#include "SkOverdrawColorFilter.h"
+
+static inline void set_bitmap(SkBitmap* bitmap, uint8_t alpha) {
+ for (int y = 0; y < bitmap->height(); y++) {
+ for (int x = 0; x < bitmap->width(); x++) {
+ uint8_t* addr = bitmap->getAddr8(x, y);
+ *addr = alpha;
+ }
+ }
+
+ bitmap->notifyPixelsChanged();
+}
+
+class OverdrawColorFilter : public skiagm::GM {
+public:
+ OverdrawColorFilter() {}
+
+protected:
+ virtual SkString onShortName() override {
+ return SkString("overdrawcolorfilter");;
+ }
+
+ virtual SkISize onISize() override {
+ return SkISize::Make(200, 400);
+ }
+
+ void onDraw(SkCanvas* canvas) override {
+ static const SkPMColor colors[SkOverdrawColorFilter::kNumColors] = {
+ 0x80800000, 0x80008000, 0x80000080, 0x80808000, 0x80008080, 0x80800080,
+ };
+
+ SkPaint paint;
+ sk_sp<SkColorFilter> colorFilter = SkOverdrawColorFilter::Make(colors);
+ paint.setColorFilter(colorFilter);
+
+ SkImageInfo info = SkImageInfo::MakeA8(100, 100);
+ SkBitmap bitmap;
+ bitmap.allocPixels(info);
+ set_bitmap(&bitmap, 0);
+ canvas->drawBitmap(bitmap, 0, 0, &paint);
+ set_bitmap(&bitmap, 1);
+ canvas->drawBitmap(bitmap, 0, 100, &paint);
+ set_bitmap(&bitmap, 2);
+ canvas->drawBitmap(bitmap, 0, 200, &paint);
+ set_bitmap(&bitmap, 3);
+ canvas->drawBitmap(bitmap, 0, 300, &paint);
+ set_bitmap(&bitmap, 4);
+ canvas->drawBitmap(bitmap, 100, 0, &paint);
+ set_bitmap(&bitmap, 5);
+ canvas->drawBitmap(bitmap, 100, 100, &paint);
+ set_bitmap(&bitmap, 6);
+ canvas->drawBitmap(bitmap, 100, 200, &paint);
+ }
+
+private:
+ typedef GM INHERITED;
+};
+
+DEF_GM(return new OverdrawColorFilter;)