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/*
* Copyright 2015 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
// This test only works with the GPU backend.
#include "gm.h"
#if SK_SUPPORT_GPU
#include "GrContext.h"
#include "GrContextPriv.h"
#include "GrGpu.h"
#include "GrTest.h"
#include "SkBitmap.h"
#include "SkGradientShader.h"
#include "SkImage.h"
namespace skiagm {
class ImageFromYUVTextures : public GM {
public:
ImageFromYUVTextures() {
this->setBGColor(0xFFFFFFFF);
}
protected:
SkString onShortName() override {
return SkString("image_from_yuv_textures");
}
SkISize onISize() override {
return SkISize::Make(50, 175);
}
void onOnceBeforeDraw() override {
// We create an RGB bitmap and then extract YUV bmps where the U and V bitmaps are
// subsampled by 2 in both dimensions.
SkPaint paint;
constexpr SkColor kColors[] =
{ SK_ColorBLUE, SK_ColorYELLOW, SK_ColorGREEN, SK_ColorWHITE };
paint.setShader(SkGradientShader::MakeRadial(SkPoint::Make(0,0), kBmpSize / 2.f, kColors,
nullptr, SK_ARRAY_COUNT(kColors),
SkShader::kMirror_TileMode));
SkBitmap rgbBmp;
rgbBmp.allocN32Pixels(kBmpSize, kBmpSize, true);
SkCanvas canvas(rgbBmp);
canvas.drawPaint(paint);
SkPMColor* rgbColors = static_cast<SkPMColor*>(rgbBmp.getPixels());
SkImageInfo yinfo = SkImageInfo::MakeA8(kBmpSize, kBmpSize);
fYUVBmps[0].allocPixels(yinfo);
SkImageInfo uinfo = SkImageInfo::MakeA8(kBmpSize / 2, kBmpSize / 2);
fYUVBmps[1].allocPixels(uinfo);
SkImageInfo vinfo = SkImageInfo::MakeA8(kBmpSize / 2, kBmpSize / 2);
fYUVBmps[2].allocPixels(vinfo);
unsigned char* yPixels;
signed char* uvPixels[2];
yPixels = static_cast<unsigned char*>(fYUVBmps[0].getPixels());
uvPixels[0] = static_cast<signed char*>(fYUVBmps[1].getPixels());
uvPixels[1] = static_cast<signed char*>(fYUVBmps[2].getPixels());
// Here we encode using the NTC encoding (even though we will draw it with all the supported
// yuv color spaces when converted back to RGB)
for (int i = 0; i < kBmpSize * kBmpSize; ++i) {
yPixels[i] = static_cast<unsigned char>(0.299f * SkGetPackedR32(rgbColors[i]) +
0.587f * SkGetPackedG32(rgbColors[i]) +
0.114f * SkGetPackedB32(rgbColors[i]));
}
for (int j = 0; j < kBmpSize / 2; ++j) {
for (int i = 0; i < kBmpSize / 2; ++i) {
// Average together 4 pixels of RGB.
int rgb[] = { 0, 0, 0 };
for (int y = 0; y < 2; ++y) {
for (int x = 0; x < 2; ++x) {
int rgbIndex = (2 * j + y) * kBmpSize + 2 * i + x;
rgb[0] += SkGetPackedR32(rgbColors[rgbIndex]);
rgb[1] += SkGetPackedG32(rgbColors[rgbIndex]);
rgb[2] += SkGetPackedB32(rgbColors[rgbIndex]);
}
}
for (int c = 0; c < 3; ++c) {
rgb[c] /= 4;
}
int uvIndex = j * kBmpSize / 2 + i;
uvPixels[0][uvIndex] = static_cast<signed char>(
((-38 * rgb[0] - 74 * rgb[1] + 112 * rgb[2] + 128) >> 8) + 128);
uvPixels[1][uvIndex] = static_cast<signed char>(
((112 * rgb[0] - 94 * rgb[1] - 18 * rgb[2] + 128) >> 8) + 128);
}
}
fRGBImage = SkImage::MakeRasterCopy(SkPixmap(rgbBmp.info(), rgbColors, rgbBmp.rowBytes()));
}
void createYUVTextures(GrContext* context, GrBackendTexture yuvTextures[3]) {
GrGpu* gpu = context->contextPriv().getGpu();
if (!gpu) {
return;
}
for (int i = 0; i < 3; ++i) {
SkASSERT(fYUVBmps[i].width() == SkToInt(fYUVBmps[i].rowBytes()));
yuvTextures[i] = gpu->createTestingOnlyBackendTexture(fYUVBmps[i].getPixels(),
fYUVBmps[i].width(),
fYUVBmps[i].height(),
kAlpha_8_GrPixelConfig,
false, GrMipMapped::kNo);
}
context->resetContext();
}
void deleteYUVTextures(GrContext* context, GrBackendTexture yuvTextures[3]) {
GrGpu* gpu = context->contextPriv().getGpu();
if (!gpu) {
return;
}
for (int i = 0; i < 3; ++i) {
if (yuvTextures[i].isValid()) {
gpu->deleteTestingOnlyBackendTexture(yuvTextures[i]);
}
}
context->resetContext();
}
void onDraw(SkCanvas* canvas) override {
GrContext* context = canvas->getGrContext();
if (!context) {
skiagm::GM::DrawGpuOnlyMessage(canvas);
return;
}
constexpr SkScalar kPad = 10.f;
SkISize sizes[] = {
{ fYUVBmps[0].width(), fYUVBmps[0].height()},
{ fYUVBmps[1].width(), fYUVBmps[1].height()},
{ fYUVBmps[2].width(), fYUVBmps[2].height()},
};
SkTArray<sk_sp<SkImage>> images;
images.push_back(fRGBImage);
for (int space = kJPEG_SkYUVColorSpace; space <= kLastEnum_SkYUVColorSpace; ++space) {
GrBackendTexture yuvTextures[3];
this->createYUVTextures(context, yuvTextures);
images.push_back(SkImage::MakeFromYUVTexturesCopy(context,
static_cast<SkYUVColorSpace>(space),
yuvTextures, sizes,
kTopLeft_GrSurfaceOrigin));
this->deleteYUVTextures(context, yuvTextures);
}
for (int i = 0; i < images.count(); ++ i) {
SkScalar y = (i + 1) * kPad + i * fYUVBmps[0].height();
SkScalar x = kPad;
canvas->drawImage(images[i].get(), x, y);
}
}
private:
sk_sp<SkImage> fRGBImage;
SkBitmap fYUVBmps[3];
static constexpr int kBmpSize = 32;
typedef GM INHERITED;
};
DEF_GM(return new ImageFromYUVTextures;)
}
#endif
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