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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.
*/
#include "Test.h"
#if SK_SUPPORT_GPU
#include "SkCanvas.h"
#include "SkSurface.h"
#include "GrContextFactory.h"
#include "GrCaps.h"
// using anonymous namespace because these functions are used as template params.
namespace {
/** convert 0..1 srgb value to 0..1 linear */
float srgb_to_linear(float srgb) {
if (srgb <= 0.04045f) {
return srgb / 12.92f;
} else {
return powf((srgb + 0.055f) / 1.055f, 2.4f);
}
}
/** convert 0..1 linear value to 0..1 srgb */
float linear_to_srgb(float linear) {
if (linear <= 0.0031308) {
return linear * 12.92f;
} else {
return 1.055f * powf(linear, 1.f / 2.4f) - 0.055f;
}
}
}
/** tests a conversion with an error tolerance */
template <float (*CONVERT)(float)> static bool check_conversion(uint32_t input, uint32_t output,
float error) {
// alpha should always be exactly preserved.
if ((input & 0xff000000) != (output & 0xff000000)) {
return false;
}
for (int c = 0; c < 3; ++c) {
uint8_t inputComponent = (uint8_t) ((input & (0xff << (c*8))) >> (c*8));
float lower = SkTMax(0.f, (float) inputComponent - error);
float upper = SkTMin(255.f, (float) inputComponent + error);
lower = CONVERT(lower / 255.f);
upper = CONVERT(upper / 255.f);
SkASSERT(lower >= 0.f && lower <= 255.f);
SkASSERT(upper >= 0.f && upper <= 255.f);
uint8_t outputComponent = (output & (0xff << (c*8))) >> (c*8);
if (outputComponent < SkScalarFloorToInt(lower * 255.f) ||
outputComponent > SkScalarCeilToInt(upper * 255.f)) {
return false;
}
}
return true;
}
/** tests a forward and backward conversion with an error tolerance */
template <float (*FORWARD)(float), float (*BACKWARD)(float)>
static bool check_double_conversion(uint32_t input, uint32_t output, float error) {
// alpha should always be exactly preserved.
if ((input & 0xff000000) != (output & 0xff000000)) {
return false;
}
for (int c = 0; c < 3; ++c) {
uint8_t inputComponent = (uint8_t) ((input & (0xff << (c*8))) >> (c*8));
float lower = SkTMax(0.f, (float) inputComponent - error);
float upper = SkTMin(255.f, (float) inputComponent + error);
lower = FORWARD(lower / 255.f);
upper = FORWARD(upper / 255.f);
SkASSERT(lower >= 0.f && lower <= 255.f);
SkASSERT(upper >= 0.f && upper <= 255.f);
uint8_t upperComponent = SkScalarCeilToInt(upper * 255.f);
uint8_t lowerComponent = SkScalarFloorToInt(lower * 255.f);
lower = SkTMax(0.f, (float) lowerComponent - error);
upper = SkTMin(255.f, (float) upperComponent + error);
lower = BACKWARD(lowerComponent / 255.f);
upper = BACKWARD(upperComponent / 255.f);
SkASSERT(lower >= 0.f && lower <= 255.f);
SkASSERT(upper >= 0.f && upper <= 255.f);
upperComponent = SkScalarCeilToInt(upper * 255.f);
lowerComponent = SkScalarFloorToInt(lower * 255.f);
uint8_t outputComponent = (output & (0xff << (c*8))) >> (c*8);
if (outputComponent < lowerComponent || outputComponent > upperComponent) {
return false;
}
}
return true;
}
static bool check_srgb_to_linear_conversion(uint32_t srgb, uint32_t linear, float error) {
return check_conversion<srgb_to_linear>(srgb, linear, error);
}
static bool check_linear_to_srgb_conversion(uint32_t linear, uint32_t srgb, float error) {
return check_conversion<linear_to_srgb>(linear, srgb, error);
}
static bool check_linear_to_srgb_to_linear_conversion(uint32_t input, uint32_t output, float error) {
return check_double_conversion<linear_to_srgb, srgb_to_linear>(input, output, error);
}
static bool check_srgb_to_linear_to_srgb_conversion(uint32_t input, uint32_t output, float error) {
return check_double_conversion<srgb_to_linear, linear_to_srgb>(input, output, error);
}
typedef bool (*CheckFn) (uint32_t orig, uint32_t actual, float error);
void read_and_check_pixels(skiatest::Reporter* reporter, GrTexture* texture, uint32_t* origData,
GrPixelConfig readConfig, CheckFn checker, float error,
const char* subtestName) {
int w = texture->width();
int h = texture->height();
SkAutoTMalloc<uint32_t> readData(w * h);
memset(readData.get(), 0, sizeof(uint32_t) * w * h);
if (!texture->readPixels(0, 0, w, h, readConfig, readData.get())) {
ERRORF(reporter, "Could not read pixels for %s.", subtestName);
return;
}
for (int j = 0; j < h; ++j) {
for (int i = 0; i < w; ++i) {
uint32_t orig = origData[j * w + i];
uint32_t read = readData[j * w + i];
if (!checker(orig, read, error)) {
ERRORF(reporter, "Expected 0x%08x, read back as 0x%08x in %s at %d, %d).",
orig, read, subtestName, i, j);
return;
}
}
}
}
// TODO: Add tests for copySurface between srgb/linear textures. Add tests for unpremul/premul
// conversion during read/write along with srgb/linear conversions.
DEF_GPUTEST(SRGBReadWritePixels, reporter, factory) {
static const int kW = 255;
static const int kH = 255;
uint32_t origData[kW * kH];
for (int j = 0; j < kH; ++j) {
for (int i = 0; i < kW; ++i) {
origData[j * kW + i] = (j << 24) | (i << 16) | (i << 8) | i;
}
}
for (int t = 0; t < GrContextFactory::kGLContextTypeCnt; ++t) {
GrContextFactory::GLContextType glType = (GrContextFactory::GLContextType) t;
GrContext* context;
// We allow more error on GPUs with lower precision shader variables.
if (!GrContextFactory::IsRenderingGLContext(glType) || !(context = factory->get(glType))) {
continue;
}
GrSurfaceDesc desc;
desc.fFlags = kRenderTarget_GrSurfaceFlag;
desc.fWidth = kW;
desc.fHeight = kH;
desc.fConfig = kSRGBA_8888_GrPixelConfig;
if (context->caps()->isConfigRenderable(desc.fConfig, false) &&
context->caps()->isConfigTexturable(desc.fConfig)) {
SkAutoTUnref<GrTexture> tex(context->textureProvider()->createTexture(desc, false));
if (!tex) {
ERRORF(reporter, "Could not create SRGBA texture.");
continue;
}
float error = context->caps()->shaderCaps()->floatPrecisionVaries() ? 1.2f : 0.5f;
// Write srgba data and read as srgba and then as rgba
if (tex->writePixels(0, 0, kW, kH, kSRGBA_8888_GrPixelConfig, origData)) {
// For the all-srgba case, we allow a small error only for devices that have
// precision variation because the srgba data gets converted to linear and back in
// the shader.
float smallError = context->caps()->shaderCaps()->floatPrecisionVaries() ? 1.f :
0.0f;
read_and_check_pixels(reporter, tex, origData, kSRGBA_8888_GrPixelConfig,
check_srgb_to_linear_to_srgb_conversion, smallError,
"write/read srgba to srgba texture");
read_and_check_pixels(reporter, tex, origData, kRGBA_8888_GrPixelConfig,
check_srgb_to_linear_conversion, error,
"write srgba/read rgba with srgba texture");
} else {
ERRORF(reporter, "Could not write srgba data to srgba texture.");
}
// Now verify that we can write linear data
if (tex->writePixels(0, 0, kW, kH, kRGBA_8888_GrPixelConfig, origData)) {
// We allow more error on GPUs with lower precision shader variables.
read_and_check_pixels(reporter, tex, origData, kSRGBA_8888_GrPixelConfig,
check_linear_to_srgb_conversion, error,
"write rgba/read srgba with srgba texture");
read_and_check_pixels(reporter, tex, origData, kRGBA_8888_GrPixelConfig,
check_linear_to_srgb_to_linear_conversion, error,
"write/read rgba with srgba texture");
} else {
ERRORF(reporter, "Could not write rgba data to srgba texture.");
}
desc.fConfig = kRGBA_8888_GrPixelConfig;
tex.reset(context->textureProvider()->createTexture(desc, false));
if (!tex) {
ERRORF(reporter, "Could not create RGBA texture.");
continue;
}
// Write srgba data to a rgba texture and read back as srgba and rgba
if (tex->writePixels(0, 0, kW, kH, kSRGBA_8888_GrPixelConfig, origData)) {
read_and_check_pixels(reporter, tex, origData, kSRGBA_8888_GrPixelConfig,
check_srgb_to_linear_to_srgb_conversion, error,
"write/read srgba to rgba texture");
read_and_check_pixels(reporter, tex, origData, kRGBA_8888_GrPixelConfig,
check_srgb_to_linear_conversion, error,
"write srgba/read rgba to rgba texture");
} else {
ERRORF(reporter, "Could not write srgba data to rgba texture.");
}
// Write rgba data to a rgba texture and read back as srgba
if (tex->writePixels(0, 0, kW, kH, kRGBA_8888_GrPixelConfig, origData)) {
read_and_check_pixels(reporter, tex, origData, kSRGBA_8888_GrPixelConfig,
check_linear_to_srgb_conversion, 1.2f,
"write rgba/read srgba to rgba texture");
} else {
ERRORF(reporter, "Could not write rgba data to rgba texture.");
}
}
}
}
#endif
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