1/* 2 * Copyright 2016 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#include <initializer_list> 9#include "Test.h" 10 11#if SK_SUPPORT_GPU 12#include "GrContext.h" 13 14#include "SkCanvas.h" 15#include "SkColorFilter.h" 16#include "SkSurface.h" 17#include "SkUtils.h" 18#include "sk_tool_utils.h" 19 20/** convert 0..1 linear value to 0..1 srgb */ 21static float linear_to_srgb(float linear) { 22 if (linear <= 0.0031308) { 23 return linear * 12.92f; 24 } else { 25 return 1.055f * powf(linear, 1.f / 2.4f) - 0.055f; 26 } 27} 28 29/** convert 0..1 srgb value to 0..1 linear */ 30static float srgb_to_linear(float srgb) { 31 if (srgb <= 0.04045f) { 32 return srgb / 12.92f; 33 } else { 34 return powf((srgb + 0.055f) / 1.055f, 2.4f); 35 } 36} 37 38bool check_gamma(uint32_t src, uint32_t dst, bool toSRGB, float error, 39 uint32_t* expected) { 40 bool result = true; 41 uint32_t expectedColor = src & 0xff000000; 42 43 // Alpha should always be exactly preserved. 44 if ((src & 0xff000000) != (dst & 0xff000000)) { 45 result = false; 46 } 47 48 for (int c = 0; c < 3; ++c) { 49 uint8_t srcComponent = (src & (0xff << (c * 8))) >> (c * 8); 50 float lower = SkTMax(0.f, (float)srcComponent - error); 51 float upper = SkTMin(255.f, (float)srcComponent + error); 52 if (toSRGB) { 53 lower = linear_to_srgb(lower / 255.f); 54 upper = linear_to_srgb(upper / 255.f); 55 } else { 56 lower = srgb_to_linear(lower / 255.f); 57 upper = srgb_to_linear(upper / 255.f); 58 } 59 SkASSERT(lower >= 0.f && lower <= 255.f); 60 SkASSERT(upper >= 0.f && upper <= 255.f); 61 uint8_t dstComponent = (dst & (0xff << (c * 8))) >> (c * 8); 62 if (dstComponent < SkScalarFloorToInt(lower * 255.f) || 63 dstComponent > SkScalarCeilToInt(upper * 255.f)) { 64 result = false; 65 } 66 uint8_t expectedComponent = SkScalarRoundToInt((lower + upper) * 127.5f); 67 expectedColor |= expectedComponent << (c * 8); 68 } 69 70 *expected = expectedColor; 71 return result; 72} 73 74DEF_GPUTEST_FOR_RENDERING_CONTEXTS(ApplyGamma, reporter, ctxInfo) { 75 GrContext* context = ctxInfo.grContext(); 76 static const int kW = 10; 77 static const int kH = 10; 78 static const size_t kRowBytes = sizeof(uint32_t) * kW; 79 80 GrSurfaceDesc baseDesc; 81 baseDesc.fConfig = kRGBA_8888_GrPixelConfig; 82 baseDesc.fWidth = kW; 83 baseDesc.fHeight = kH; 84 85 const SkImageInfo ii = SkImageInfo::MakeN32Premul(kW, kH); 86 87 SkAutoTMalloc<uint32_t> srcPixels(kW * kH); 88 for (int i = 0; i < kW * kH; ++i) { 89 srcPixels.get()[i] = i; 90 } 91 92 SkBitmap bm; 93 bm.installPixels(ii, srcPixels.get(), kRowBytes); 94 95 SkAutoTMalloc<uint32_t> read(kW * kH); 96 97 // We allow more error on GPUs with lower precision shader variables. 98 float error = context->caps()->shaderCaps()->floatPrecisionVaries() ? 1.2f : 0.5f; 99 100 for (auto toSRGB : { false, true }) { 101 sk_sp<SkSurface> dst(SkSurface::MakeRenderTarget(context, SkBudgeted::kNo, ii)); 102 103 if (!dst) { 104 ERRORF(reporter, "Could not create surfaces for copy surface test."); 105 continue; 106 } 107 108 SkCanvas* dstCanvas = dst->getCanvas(); 109 110 dstCanvas->clear(SK_ColorRED); 111 dstCanvas->flush(); 112 113 SkPaint gammaPaint; 114 gammaPaint.setBlendMode(SkBlendMode::kSrc); 115 gammaPaint.setColorFilter(toSRGB ? sk_tool_utils::MakeLinearToSRGBColorFilter() 116 : sk_tool_utils::MakeSRGBToLinearColorFilter()); 117 118 dstCanvas->drawBitmap(bm, 0, 0, &gammaPaint); 119 dstCanvas->flush(); 120 121 sk_memset32(read.get(), 0, kW * kH); 122 if (!dstCanvas->readPixels(ii, read.get(), kRowBytes, 0, 0)) { 123 ERRORF(reporter, "Error calling readPixels"); 124 continue; 125 } 126 127 bool abort = false; 128 // Validate that pixels were copied/transformed correctly. 129 for (int y = 0; y < kH && !abort; ++y) { 130 for (int x = 0; x < kW && !abort; ++x) { 131 uint32_t r = read.get()[y * kW + x]; 132 uint32_t s = srcPixels.get()[y * kW + x]; 133 uint32_t expected; 134 if (!check_gamma(s, r, toSRGB, error, &expected)) { 135 ERRORF(reporter, "Expected dst %d,%d to contain 0x%08x " 136 "from src 0x%08x and mode %s. Got %08x", x, y, expected, s, 137 toSRGB ? "ToSRGB" : "ToLinear", r); 138 abort = true; 139 break; 140 } 141 } 142 } 143 } 144} 145#endif 146