1 /* 2 * Copyright 2015 Google Inc. 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8 // This test only works with the GPU backend. 9 10 #include "gm.h" 11 12 #if SK_SUPPORT_GPU 13 14 #include "GrContext.h" 15 #include "GrGpu.h" 16 #include "GrTest.h" 17 #include "SkBitmap.h" 18 #include "SkGradientShader.h" 19 #include "SkImage.h" 20 21 namespace skiagm { 22 class ImageFromYUVTextures : public GM { 23 public: 24 ImageFromYUVTextures() { 25 this->setBGColor(0xFFFFFFFF); 26 } 27 28 protected: 29 SkString onShortName() override { 30 return SkString("image_from_yuv_textures"); 31 } 32 33 SkISize onISize() override { 34 return SkISize::Make(50, 175); 35 } 36 37 void onOnceBeforeDraw() override { 38 // We create an RGB bitmap and then extract YUV bmps where the U and V bitmaps are 39 // subsampled by 2 in both dimensions. 40 SkPaint paint; 41 constexpr SkColor kColors[] = 42 { SK_ColorBLUE, SK_ColorYELLOW, SK_ColorGREEN, SK_ColorWHITE }; 43 paint.setShader(SkGradientShader::MakeRadial(SkPoint::Make(0,0), kBmpSize / 2.f, kColors, 44 nullptr, SK_ARRAY_COUNT(kColors), 45 SkShader::kMirror_TileMode)); 46 SkBitmap rgbBmp; 47 rgbBmp.allocN32Pixels(kBmpSize, kBmpSize, true); 48 SkCanvas canvas(rgbBmp); 49 canvas.drawPaint(paint); 50 SkPMColor* rgbColors = static_cast<SkPMColor*>(rgbBmp.getPixels()); 51 52 SkImageInfo yinfo = SkImageInfo::MakeA8(kBmpSize, kBmpSize); 53 fYUVBmps[0].allocPixels(yinfo); 54 SkImageInfo uinfo = SkImageInfo::MakeA8(kBmpSize / 2, kBmpSize / 2); 55 fYUVBmps[1].allocPixels(uinfo); 56 SkImageInfo vinfo = SkImageInfo::MakeA8(kBmpSize / 2, kBmpSize / 2); 57 fYUVBmps[2].allocPixels(vinfo); 58 unsigned char* yPixels; 59 signed char* uvPixels[2]; 60 yPixels = static_cast<unsigned char*>(fYUVBmps[0].getPixels()); 61 uvPixels[0] = static_cast<signed char*>(fYUVBmps[1].getPixels()); 62 uvPixels[1] = static_cast<signed char*>(fYUVBmps[2].getPixels()); 63 64 // Here we encode using the NTC encoding (even though we will draw it with all the supported 65 // yuv color spaces when converted back to RGB) 66 for (int i = 0; i < kBmpSize * kBmpSize; ++i) { 67 yPixels[i] = static_cast<unsigned char>(0.299f * SkGetPackedR32(rgbColors[i]) + 68 0.587f * SkGetPackedG32(rgbColors[i]) + 69 0.114f * SkGetPackedB32(rgbColors[i])); 70 } 71 for (int j = 0; j < kBmpSize / 2; ++j) { 72 for (int i = 0; i < kBmpSize / 2; ++i) { 73 // Average together 4 pixels of RGB. 74 int rgb[] = { 0, 0, 0 }; 75 for (int y = 0; y < 2; ++y) { 76 for (int x = 0; x < 2; ++x) { 77 int rgbIndex = (2 * j + y) * kBmpSize + 2 * i + x; 78 rgb[0] += SkGetPackedR32(rgbColors[rgbIndex]); 79 rgb[1] += SkGetPackedG32(rgbColors[rgbIndex]); 80 rgb[2] += SkGetPackedB32(rgbColors[rgbIndex]); 81 } 82 } 83 for (int c = 0; c < 3; ++c) { 84 rgb[c] /= 4; 85 } 86 int uvIndex = j * kBmpSize / 2 + i; 87 uvPixels[0][uvIndex] = static_cast<signed char>( 88 ((-38 * rgb[0] - 74 * rgb[1] + 112 * rgb[2] + 128) >> 8) + 128); 89 uvPixels[1][uvIndex] = static_cast<signed char>( 90 ((112 * rgb[0] - 94 * rgb[1] - 18 * rgb[2] + 128) >> 8) + 128); 91 } 92 } 93 fRGBImage = SkImage::MakeRasterCopy(SkPixmap(rgbBmp.info(), rgbColors, rgbBmp.rowBytes())); 94 } 95 96 void createYUVTextures(GrContext* context, GrBackendObject yuvHandles[3]) { 97 GrGpu* gpu = context->getGpu(); 98 if (!gpu) { 99 return; 100 } 101 102 for (int i = 0; i < 3; ++i) { 103 SkASSERT(fYUVBmps[i].width() == SkToInt(fYUVBmps[i].rowBytes())); 104 yuvHandles[i] = gpu->createTestingOnlyBackendTexture(fYUVBmps[i].getPixels(), 105 fYUVBmps[i].width(), 106 fYUVBmps[i].height(), 107 kAlpha_8_GrPixelConfig); 108 } 109 context->resetContext(); 110 } 111 112 void deleteYUVTextures(GrContext* context, const GrBackendObject yuvHandles[3]) { 113 114 GrGpu* gpu = context->getGpu(); 115 if (!gpu) { 116 return; 117 } 118 119 for (int i = 0; i < 3; ++i) { 120 gpu->deleteTestingOnlyBackendTexture(yuvHandles[i]); 121 } 122 123 context->resetContext(); 124 } 125 126 void onDraw(SkCanvas* canvas) override { 127 GrContext* context = canvas->getGrContext(); 128 if (!context) { 129 skiagm::GM::DrawGpuOnlyMessage(canvas); 130 return; 131 } 132 133 134 constexpr SkScalar kPad = 10.f; 135 136 SkISize sizes[] = { 137 { fYUVBmps[0].width(), fYUVBmps[0].height()}, 138 { fYUVBmps[1].width(), fYUVBmps[1].height()}, 139 { fYUVBmps[2].width(), fYUVBmps[2].height()}, 140 }; 141 SkTArray<sk_sp<SkImage>> images; 142 images.push_back(fRGBImage); 143 for (int space = kJPEG_SkYUVColorSpace; space <= kLastEnum_SkYUVColorSpace; ++space) { 144 GrBackendObject yuvHandles[3]; 145 this->createYUVTextures(context, yuvHandles); 146 images.push_back(SkImage::MakeFromYUVTexturesCopy(context, 147 static_cast<SkYUVColorSpace>(space), 148 yuvHandles, sizes, 149 kTopLeft_GrSurfaceOrigin)); 150 this->deleteYUVTextures(context, yuvHandles); 151 } 152 for (int i = 0; i < images.count(); ++ i) { 153 SkScalar y = (i + 1) * kPad + i * fYUVBmps[0].height(); 154 SkScalar x = kPad; 155 156 canvas->drawImage(images[i].get(), x, y); 157 } 158 } 159 160 private: 161 sk_sp<SkImage> fRGBImage; 162 SkBitmap fYUVBmps[3]; 163 164 static constexpr int kBmpSize = 32; 165 166 typedef GM INHERITED; 167 }; 168 169 DEF_GM(return new ImageFromYUVTextures;) 170 } 171 172 #endif 173
