GPU device preserves pixel values across read/write/read of unpremul pixel values
Review URL: http://codereview.appspot.com/5695047/
git-svn-id: http://skia.googlecode.com/svn/trunk@3237 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tests/PremulAlphaRoundTripTest.cpp b/tests/PremulAlphaRoundTripTest.cpp
new file mode 100644
index 0000000..c4ec6ab
--- /dev/null
+++ b/tests/PremulAlphaRoundTripTest.cpp
@@ -0,0 +1,106 @@
+
+/*
+ * Copyright 2011 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "Test.h"
+#include "SkCanvas.h"
+#include "SkConfig8888.h"
+#include "SkGpuDevice.h"
+
+
+namespace {
+
+void fillCanvas(SkCanvas* canvas, SkCanvas::Config8888 unpremulConfig) {
+ SkBitmap bmp;
+ bmp.setConfig(SkBitmap::kARGB_8888_Config, 256, 256);
+ bmp.allocPixels();
+ SkAutoLockPixels alp(bmp);
+ uint32_t* pixels = reinterpret_cast<uint32_t*>(bmp.getPixels());
+
+ for (int a = 0; a < 256; ++a) {
+ for (int r = 0; r < 256; ++r) {
+ pixels[a * 256 + r] = SkPackConfig8888(unpremulConfig, a, r, 0, 0);
+ }
+ }
+ canvas->writePixels(bmp, 0, 0, unpremulConfig);
+}
+
+static const SkCanvas::Config8888 gUnpremulConfigs[] = {
+ SkCanvas::kNative_Unpremul_Config8888,
+/**
+ * There is a bug in Ganesh (http://code.google.com/p/skia/issues/detail?id=438)
+ * that causes the readback of pixels from BGRA canvas to an RGBA bitmap to
+ * fail. This should be removed as soon as the issue above is resolved.
+ */
+#if !defined(SK_BUILD_FOR_ANDROID)
+ SkCanvas::kBGRA_Unpremul_Config8888,
+#endif
+ SkCanvas::kRGBA_Unpremul_Config8888,
+};
+
+void PremulAlphaRoundTripTest(skiatest::Reporter* reporter,
+ GrContext* context) {
+ SkCanvas canvas;
+ for (int dtype = 0; dtype < 2; ++dtype) {
+ if (0 == dtype) {
+ canvas.setDevice(new SkDevice(SkBitmap::kARGB_8888_Config,
+ 256,
+ 256,
+ false))->unref();
+ } else {
+#if SK_SCALAR_IS_FIXED
+ // GPU device known not to work in the fixed pt build.
+ continue;
+#endif
+ canvas.setDevice(new SkGpuDevice(context,
+ SkBitmap::kARGB_8888_Config,
+ 256,
+ 256))->unref();
+ }
+
+ SkBitmap readBmp1;
+ readBmp1.setConfig(SkBitmap::kARGB_8888_Config, 256, 256);
+ readBmp1.allocPixels();
+ SkBitmap readBmp2;
+ readBmp2.setConfig(SkBitmap::kARGB_8888_Config, 256, 256);
+ readBmp2.allocPixels();
+
+ for (size_t upmaIdx = 0;
+ upmaIdx < SK_ARRAY_COUNT(gUnpremulConfigs);
+ ++upmaIdx) {
+ fillCanvas(&canvas, gUnpremulConfigs[upmaIdx]);
+ {
+ SkAutoLockPixels alp1(readBmp1);
+ SkAutoLockPixels alp2(readBmp2);
+ sk_bzero(readBmp1.getPixels(), readBmp1.getSafeSize());
+ sk_bzero(readBmp2.getPixels(), readBmp2.getSafeSize());
+ }
+
+ canvas.readPixels(&readBmp1, 0, 0, gUnpremulConfigs[upmaIdx]);
+ canvas.writePixels(readBmp1, 0, 0, gUnpremulConfigs[upmaIdx]);
+ canvas.readPixels(&readBmp2, 0, 0, gUnpremulConfigs[upmaIdx]);
+
+ SkAutoLockPixels alp1(readBmp1);
+ SkAutoLockPixels alp2(readBmp2);
+ uint32_t* pixels1 =
+ reinterpret_cast<uint32_t*>(readBmp1.getPixels());
+ uint32_t* pixels2 =
+ reinterpret_cast<uint32_t*>(readBmp2.getPixels());
+ for (int y = 0; y < 256; ++y) {
+ for (int x = 0; x < 256; ++x) {
+ int i = y * 256 + x;
+ REPORTER_ASSERT(reporter, pixels1[i] == pixels2[i]);
+ }
+ }
+ }
+ }
+}
+}
+
+#include "TestClassDef.h"
+DEFINE_GPUTESTCLASS("PremulAlphaRoundTripTest", PremulAlphaRoundTripTestClass, PremulAlphaRoundTripTest)
+