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/*
* 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 "SkCanvas.h"
#include "SkSurface.h"
#include "Test.h"
#include "sk_tool_utils.h"
#if SK_SUPPORT_GPU
#include "GrContext.h"
#endif
static uint32_t pack_unpremul_rgba(SkColor c) {
uint32_t packed;
uint8_t* byte = reinterpret_cast<uint8_t*>(&packed);
byte[0] = SkColorGetR(c);
byte[1] = SkColorGetG(c);
byte[2] = SkColorGetB(c);
byte[3] = SkColorGetA(c);
return packed;
}
static uint32_t pack_unpremul_bgra(SkColor c) {
uint32_t packed;
uint8_t* byte = reinterpret_cast<uint8_t*>(&packed);
byte[0] = SkColorGetB(c);
byte[1] = SkColorGetG(c);
byte[2] = SkColorGetR(c);
byte[3] = SkColorGetA(c);
return packed;
}
typedef uint32_t (*PackUnpremulProc)(SkColor);
const struct {
SkColorType fColorType;
PackUnpremulProc fPackProc;
} gUnpremul[] = {
{ kRGBA_8888_SkColorType, pack_unpremul_rgba },
{ kBGRA_8888_SkColorType, pack_unpremul_bgra },
};
static void fill_canvas(SkCanvas* canvas, SkColorType colorType, PackUnpremulProc proc) {
// Don't strictly need a bitmap, but its a handy way to allocate the pixels
SkBitmap bmp;
bmp.allocN32Pixels(256, 256);
for (int a = 0; a < 256; ++a) {
uint32_t* pixels = bmp.getAddr32(0, a);
for (int r = 0; r < 256; ++r) {
pixels[r] = proc(SkColorSetARGB(a, r, 0, 0));
}
}
const SkImageInfo info = SkImageInfo::Make(bmp.width(), bmp.height(),
colorType, kUnpremul_SkAlphaType);
canvas->writePixels(info, bmp.getPixels(), bmp.rowBytes(), 0, 0);
}
static void test_premul_alpha_roundtrip(skiatest::Reporter* reporter, SkSurface* surf) {
SkCanvas* canvas = surf->getCanvas();
for (size_t upmaIdx = 0; upmaIdx < SK_ARRAY_COUNT(gUnpremul); ++upmaIdx) {
fill_canvas(canvas, gUnpremul[upmaIdx].fColorType, gUnpremul[upmaIdx].fPackProc);
const SkImageInfo info = SkImageInfo::Make(256, 256, gUnpremul[upmaIdx].fColorType,
kUnpremul_SkAlphaType);
SkBitmap readBmp1;
readBmp1.allocPixels(info);
SkBitmap readBmp2;
readBmp2.allocPixels(info);
readBmp1.eraseColor(0);
readBmp2.eraseColor(0);
canvas->readPixels(readBmp1, 0, 0);
sk_tool_utils::write_pixels(canvas, readBmp1, 0, 0, gUnpremul[upmaIdx].fColorType,
kUnpremul_SkAlphaType);
canvas->readPixels(readBmp2, 0, 0);
bool success = true;
for (int y = 0; y < 256 && success; ++y) {
const uint32_t* pixels1 = readBmp1.getAddr32(0, y);
const uint32_t* pixels2 = readBmp2.getAddr32(0, y);
for (int x = 0; x < 256 && success; ++x) {
// We see sporadic failures here. May help to see where it goes wrong.
if (pixels1[x] != pixels2[x]) {
SkDebugf("%x != %x, x = %d, y = %d\n", pixels1[x], pixels2[x], x, y);
}
REPORTER_ASSERT(reporter, success = pixels1[x] == pixels2[x]);
}
}
}
}
DEF_TEST(PremulAlphaRoundTrip, reporter) {
const SkImageInfo info = SkImageInfo::MakeN32Premul(256, 256);
sk_sp<SkSurface> surf(SkSurface::MakeRaster(info));
test_premul_alpha_roundtrip(reporter, surf.get());
}
#if SK_SUPPORT_GPU
DEF_GPUTEST_FOR_RENDERING_CONTEXTS(PremulAlphaRoundTrip_Gpu, reporter, ctxInfo) {
const SkImageInfo info = SkImageInfo::MakeN32Premul(256, 256);
sk_sp<SkSurface> surf(SkSurface::MakeRenderTarget(ctxInfo.grContext(),
SkBudgeted::kNo,
info));
test_premul_alpha_roundtrip(reporter, surf.get());
}
#endif
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