Make A8 readbacks work from non-A8 surfaces

Expand testing of A8 readbacks.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1613903005

Review URL: https://codereview.chromium.org/1613903005
This commit is contained in:
bsalomon 2016-01-25 14:33:25 -08:00 committed by Commit bot
parent 64b0f5f957
commit e9573317d3
3 changed files with 258 additions and 96 deletions

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@ -643,7 +643,11 @@ bool GrGLCaps::readPixelsSupported(GrPixelConfig rtConfig,
GrPixelConfig readConfig,
std::function<void (GrGLenum, GrGLint*)> getIntegerv,
std::function<bool ()> bindRenderTarget) const {
SkASSERT(this->isConfigRenderable(rtConfig, false));
// If it's not possible to even have a render target of rtConfig then read pixels is
// not supported regardless of readConfig.
if (!this->isConfigRenderable(rtConfig, false)) {
return false;
}
GrGLenum readFormat;
GrGLenum readType;
@ -652,7 +656,22 @@ bool GrGLCaps::readPixelsSupported(GrPixelConfig rtConfig,
}
if (kGL_GrGLStandard == fStandard) {
// All of our renderable configs can be converted to each other by glReadPixels in OpenGL.
// Some OpenGL implementations allow GL_ALPHA as a format to glReadPixels. However,
// the manual (https://www.opengl.org/sdk/docs/man/) says only these formats are allowed:
// GL_STENCIL_INDEX, GL_DEPTH_COMPONENT, GL_DEPTH_STENCIL, GL_RED, GL_GREEN, GL_BLUE,
// GL_RGB, GL_BGR, GL_RGBA, and GL_BGRA. We check for the subset that we would use.
if (readFormat != GR_GL_RED && readFormat != GR_GL_RGB && readFormat != GR_GL_RGBA &&
readFormat != GR_GL_BGRA) {
return false;
}
// There is also a set of allowed types, but all the types we use are in the set:
// GL_UNSIGNED_BYTE, GL_BYTE, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT,
// GL_HALF_FLOAT, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV,
// GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4,
// GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV,
// GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV,GL_UNSIGNED_INT_10_10_10_2,
// GL_UNSIGNED_INT_2_10_10_10_REV, GL_UNSIGNED_INT_24_8, GL_UNSIGNED_INT_10F_11F_11F_REV,
// GL_UNSIGNED_INT_5_9_9_9_REV, or GL_FLOAT_32_UNSIGNED_INT_24_8_REV.
return true;
}
@ -1070,6 +1089,17 @@ bool GrGLCaps::getExternalFormat(GrPixelConfig surfaceConfig, GrPixelConfig memo
*externalFormat = fConfigTable[memoryConfig].fFormats.fExternalFormat[usage];
*externalType = fConfigTable[memoryConfig].fFormats.fExternalType;
// When GL_RED is supported as a texture format, our alpha-only textures are stored using
// GL_RED and we swizzle in order to map all components to 'r'. However, in this case the
// surface is not alpha-only and we want alpha to really mean the alpha component of the
// texture, not the red component.
if (memoryIsAlphaOnly && !surfaceIsAlphaOnly) {
if (this->textureRedSupport()) {
SkASSERT(GR_GL_RED == *externalFormat);
*externalFormat = GR_GL_ALPHA;
}
}
return true;
}

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@ -2004,26 +2004,21 @@ bool GrGLGpu::readPixelsSupported(GrSurface* surfaceForConfig, GrPixelConfig rea
}
}
static bool requires_srgb_conversion(GrPixelConfig a, GrPixelConfig b) {
if (GrPixelConfigIsSRGB(a)) {
return !GrPixelConfigIsSRGB(b) && !GrPixelConfigIsAlphaOnly(b);
} else if (GrPixelConfigIsSRGB(b)) {
return !GrPixelConfigIsSRGB(a) && !GrPixelConfigIsAlphaOnly(a);
}
return false;
}
bool GrGLGpu::onGetReadPixelsInfo(GrSurface* srcSurface, int width, int height, size_t rowBytes,
GrPixelConfig readConfig, DrawPreference* drawPreference,
ReadPixelTempDrawInfo* tempDrawInfo) {
GrRenderTarget* srcAsRT = srcSurface->asRenderTarget();
GrPixelConfig srcConfig = srcSurface->config();
// This subclass can only read pixels from a render target. We could use glTexSubImage2D on
// GL versions that support it but we don't today.
if (!srcAsRT) {
ElevateDrawPreference(drawPreference, kRequireDraw_DrawPreference);
}
if (GrPixelConfigIsSRGB(srcSurface->config()) != GrPixelConfigIsSRGB(readConfig)) {
ElevateDrawPreference(drawPreference, kRequireDraw_DrawPreference);
}
tempDrawInfo->fSwizzle = GrSwizzle::RGBA();
tempDrawInfo->fReadConfig = readConfig;
// These settings we will always want if a temp draw is performed. The config is set below
// depending on whether we want to do a R/B swap or not.
// These settings we will always want if a temp draw is performed.
tempDrawInfo->fTempSurfaceDesc.fFlags = kRenderTarget_GrSurfaceFlag;
tempDrawInfo->fTempSurfaceDesc.fWidth = width;
tempDrawInfo->fTempSurfaceDesc.fHeight = height;
@ -2031,10 +2026,33 @@ bool GrGLGpu::onGetReadPixelsInfo(GrSurface* srcSurface, int width, int height,
tempDrawInfo->fTempSurfaceDesc.fOrigin = kTopLeft_GrSurfaceOrigin; // no CPU y-flip for TL.
tempDrawInfo->fUseExactScratch = this->glCaps().partialFBOReadIsSlow();
// Start off assuming that any temp draw should be to the readConfig, then check if that will
// be inefficient.
GrPixelConfig srcConfig = srcSurface->config();
tempDrawInfo->fTempSurfaceDesc.fConfig = readConfig;
// For now assume no swizzling, we may change that below.
tempDrawInfo->fSwizzle = GrSwizzle::RGBA();
// Depends on why we need/want a temp draw. Start off assuming no change, the surface we read
// from will be srcConfig and we will read readConfig pixels from it.
// Not that if we require a draw and return a non-renderable format for the temp surface the
// base class will fail for us.
tempDrawInfo->fTempSurfaceDesc.fConfig = srcConfig;
tempDrawInfo->fReadConfig = readConfig;
if (requires_srgb_conversion(srcConfig, readConfig)) {
if (!this->readPixelsSupported(readConfig, readConfig)) {
return false;
}
// Draw to do srgb to linear conversion or vice versa.
ElevateDrawPreference(drawPreference, kRequireDraw_DrawPreference);
tempDrawInfo->fTempSurfaceDesc.fConfig = readConfig;
tempDrawInfo->fReadConfig = readConfig;
return true;
}
GrRenderTarget* srcAsRT = srcSurface->asRenderTarget();
if (!srcAsRT) {
// For now keep assuming the draw is not a format transformation, just a draw to get to a
// RT. We may add additional transformations below.
ElevateDrawPreference(drawPreference, kRequireDraw_DrawPreference);
}
if (this->glCaps().rgba8888PixelsOpsAreSlow() && kRGBA_8888_GrPixelConfig == readConfig &&
this->readPixelsSupported(kBGRA_8888_GrPixelConfig, kBGRA_8888_GrPixelConfig)) {
@ -2056,11 +2074,35 @@ bool GrGLGpu::onGetReadPixelsInfo(GrSurface* srcSurface, int width, int height,
if (readConfig == kBGRA_8888_GrPixelConfig &&
this->glCaps().isConfigRenderable(kRGBA_8888_GrPixelConfig, false) &&
this->readPixelsSupported(kRGBA_8888_GrPixelConfig, kRGBA_8888_GrPixelConfig)) {
// We're trying to read BGRA but it's not supported. If RGBA is renderable and
// we can read it back, then do a swizzling draw to a RGBA and read it back (which
// will effectively be BGRA).
tempDrawInfo->fTempSurfaceDesc.fConfig = kRGBA_8888_GrPixelConfig;
tempDrawInfo->fSwizzle = GrSwizzle::BGRA();
tempDrawInfo->fReadConfig = kRGBA_8888_GrPixelConfig;
ElevateDrawPreference(drawPreference, kRequireDraw_DrawPreference);
} else if (readConfig == kAlpha_8_GrPixelConfig) {
// onReadPixels implements a fallback for cases where we are want to read kAlpha_8,
// it's unsupported, but 32bit RGBA reads are supported.
// Don't attempt to do any srgb conversions since we only care about alpha.
GrPixelConfig cpuTempConfig = kRGBA_8888_GrPixelConfig;
if (GrPixelConfigIsSRGB(srcSurface->config())) {
cpuTempConfig = kSRGBA_8888_GrPixelConfig;
}
if (!this->readPixelsSupported(srcSurface, cpuTempConfig)) {
// If we can't read RGBA from the src try to draw to a kRGBA_8888 (or kSRGBA_8888)
// first and then onReadPixels will read that to a 32bit temporary buffer.
if (this->caps()->isConfigRenderable(cpuTempConfig, false)) {
ElevateDrawPreference(drawPreference, kRequireDraw_DrawPreference);
tempDrawInfo->fTempSurfaceDesc.fConfig = cpuTempConfig;
tempDrawInfo->fReadConfig = kAlpha_8_GrPixelConfig;
} else {
return false;
}
} else {
SkASSERT(tempDrawInfo->fTempSurfaceDesc.fConfig == srcConfig);
SkASSERT(tempDrawInfo->fReadConfig == kAlpha_8_GrPixelConfig);
}
} else {
return false;
}
@ -2082,46 +2124,71 @@ bool GrGLGpu::onReadPixels(GrSurface* surface,
size_t rowBytes) {
SkASSERT(surface);
GrGLRenderTarget* tgt = static_cast<GrGLRenderTarget*>(surface->asRenderTarget());
if (!tgt) {
GrGLRenderTarget* renderTarget = static_cast<GrGLRenderTarget*>(surface->asRenderTarget());
if (!renderTarget) {
return false;
}
// OpenGL doesn't do sRGB <-> linear conversions when reading and writing pixels.
if (GrPixelConfigIsSRGB(surface->config()) != GrPixelConfigIsSRGB(config)) {
if (requires_srgb_conversion(surface->config(), config)) {
return false;
}
// We have a special case fallback for reading eight bit alpha. We will read back all four 8
// bit channels as RGBA and then extract A.
if (!this->readPixelsSupported(renderTarget, config)) {
// Don't attempt to do any srgb conversions since we only care about alpha.
GrPixelConfig tempConfig = kRGBA_8888_GrPixelConfig;
if (GrPixelConfigIsSRGB(renderTarget->config())) {
tempConfig = kSRGBA_8888_GrPixelConfig;
}
if (kAlpha_8_GrPixelConfig == config &&
this->readPixelsSupported(renderTarget, tempConfig)) {
SkAutoTDeleteArray<uint32_t> temp(new uint32_t[width * height * 4]);
if (this->onReadPixels(renderTarget, left, top, width, height, tempConfig, temp.get(),
width*4)) {
uint8_t* dst = reinterpret_cast<uint8_t*>(buffer);
for (int j = 0; j < height; ++j) {
for (int i = 0; i < width; ++i) {
dst[j*rowBytes + i] = (0xFF000000U & temp[j*width+i]) >> 24;
}
}
return true;
}
}
return false;
}
GrGLenum externalFormat;
GrGLenum externalType;
if (!this->glCaps().getReadPixelsFormat(surface->config(), config, &externalFormat,
if (!this->glCaps().getReadPixelsFormat(renderTarget->config(), config, &externalFormat,
&externalType)) {
return false;
}
bool flipY = kBottomLeft_GrSurfaceOrigin == surface->origin();
// resolve the render target if necessary
switch (tgt->getResolveType()) {
switch (renderTarget->getResolveType()) {
case GrGLRenderTarget::kCantResolve_ResolveType:
return false;
case GrGLRenderTarget::kAutoResolves_ResolveType:
this->flushRenderTarget(tgt, &SkIRect::EmptyIRect());
this->flushRenderTarget(renderTarget, &SkIRect::EmptyIRect());
break;
case GrGLRenderTarget::kCanResolve_ResolveType:
this->onResolveRenderTarget(tgt);
this->onResolveRenderTarget(renderTarget);
// we don't track the state of the READ FBO ID.
fStats.incRenderTargetBinds();
GL_CALL(BindFramebuffer(GR_GL_READ_FRAMEBUFFER, tgt->textureFBOID()));
GL_CALL(BindFramebuffer(GR_GL_READ_FRAMEBUFFER, renderTarget->textureFBOID()));
break;
default:
SkFAIL("Unknown resolve type");
}
const GrGLIRect& glvp = tgt->getViewport();
const GrGLIRect& glvp = renderTarget->getViewport();
// the read rect is viewport-relative
GrGLIRect readRect;
readRect.setRelativeTo(glvp, left, top, width, height, tgt->origin());
readRect.setRelativeTo(glvp, left, top, width, height, renderTarget->origin());
size_t tightRowBytes = GrBytesPerPixel(config) * width;

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@ -8,7 +8,7 @@
#include "Test.h"
// This test is specific to the GPU backend.
#if SK_SUPPORT_GPU && !defined(SK_BUILD_FOR_ANDROID)
#if SK_SUPPORT_GPU
#include "GrContext.h"
#include "SkGpuDevice.h"
@ -18,88 +18,153 @@ static const int X_SIZE = 13;
static const int Y_SIZE = 13;
DEF_GPUTEST_FOR_RENDERING_CONTEXTS(ReadWriteAlpha, reporter, context) {
unsigned char textureData[X_SIZE][Y_SIZE];
unsigned char alphaData[X_SIZE][Y_SIZE];
memset(textureData, 0, X_SIZE * Y_SIZE);
GrSurfaceDesc desc;
// let Skia know we will be using this texture as a render target
desc.fFlags = kRenderTarget_GrSurfaceFlag;
// it is a single channel texture
desc.fConfig = kAlpha_8_GrPixelConfig;
desc.fWidth = X_SIZE;
desc.fHeight = Y_SIZE;
// We are initializing the texture with zeros here
GrTexture* texture = context->textureProvider()->createTexture(desc, false, textureData, 0);
if (!texture) {
return;
}
SkAutoTUnref<GrTexture> au(texture);
// create a distinctive texture
for (int y = 0; y < Y_SIZE; ++y) {
for (int x = 0; x < X_SIZE; ++x) {
textureData[x][y] = x*Y_SIZE+y;
}
}
// upload the texture
texture->writePixels(0, 0, desc.fWidth, desc.fHeight, desc.fConfig,
textureData, 0);
memset(alphaData, 0, X_SIZE * Y_SIZE);
bool match;
unsigned char readback[X_SIZE][Y_SIZE];
// clear readback to something non-zero so we can detect readback failures
memset(readback, 0x1, X_SIZE * Y_SIZE);
for (int rt = 0; rt < 2; ++rt) {
GrSurfaceDesc desc;
// let Skia know we will be using this texture as a render target
desc.fFlags = rt ? kRenderTarget_GrSurfaceFlag : kNone_GrSurfaceFlags;
// it is a single channel texture
desc.fConfig = kAlpha_8_GrPixelConfig;
desc.fWidth = X_SIZE;
desc.fHeight = Y_SIZE;
// read the texture back
texture->readPixels(0, 0, desc.fWidth, desc.fHeight, desc.fConfig,
readback, 0);
// We are initializing the texture with zeros here
SkAutoTUnref<GrTexture> texture(
context->textureProvider()->createTexture(desc, false, alphaData, 0));
if (!texture) {
if (!rt) {
ERRORF(reporter, "Could not create alpha texture.");
}
continue;
}
// make sure the original & read back versions match
bool match = true;
// create a distinctive texture
for (int y = 0; y < Y_SIZE; ++y) {
for (int x = 0; x < X_SIZE; ++x) {
alphaData[x][y] = y*X_SIZE+x;
}
}
for (int y = 0; y < Y_SIZE; ++y) {
for (int x = 0; x < X_SIZE; ++x) {
if (textureData[x][y] != readback[x][y]) {
match = false;
// upload the texture
texture->writePixels(0, 0, desc.fWidth, desc.fHeight, desc.fConfig,
alphaData, 0);
// clear readback to something non-zero so we can detect readback failures
memset(readback, 0x1, X_SIZE * Y_SIZE);
// read the texture back
texture->readPixels(0, 0, desc.fWidth, desc.fHeight, desc.fConfig,
readback, 0);
// make sure the original & read back versions match
match = true;
for (int y = 0; y < Y_SIZE && match; ++y) {
for (int x = 0; x < X_SIZE && match; ++x) {
if (alphaData[x][y] != readback[x][y]) {
SkDebugf("Failed alpha readback. Expected: 0x%02x, "
"Got: 0x%02x at (%d,%d), rt: %d", alphaData[x][y], readback[x][y], x,
y, rt);
match = false;
}
}
}
// Now try writing on the single channel texture (if we could create as a RT).
if (texture->asRenderTarget()) {
SkSurfaceProps props(SkSurfaceProps::kLegacyFontHost_InitType);
SkAutoTUnref<SkBaseDevice> device(SkGpuDevice::Create(
texture->asRenderTarget(), &props, SkGpuDevice::kUninit_InitContents));
SkCanvas canvas(device);
SkPaint paint;
const SkRect rect = SkRect::MakeLTRB(-10, -10, X_SIZE + 10, Y_SIZE + 10);
paint.setColor(SK_ColorWHITE);
canvas.drawRect(rect, paint);
texture->readPixels(0, 0, desc.fWidth, desc.fHeight, desc.fConfig, readback, 0);
match = true;
for (int y = 0; y < Y_SIZE && match; ++y) {
for (int x = 0; x < X_SIZE && match; ++x) {
if (0xFF != readback[x][y]) {
ERRORF(reporter,
"Failed alpha readback after clear. Expected: 0xFF, Got: 0x%02x at "
"(%d,%d)", readback[x][y], x, y);
match = false;
}
}
}
}
}
REPORTER_ASSERT(reporter, match);
static const GrPixelConfig kRGBAConfigs[] {
kRGBA_8888_GrPixelConfig,
kBGRA_8888_GrPixelConfig,
kSRGBA_8888_GrPixelConfig
};
// Now try writing on the single channel texture
SkSurfaceProps props(SkSurfaceProps::kLegacyFontHost_InitType);
SkAutoTUnref<SkBaseDevice> device(SkGpuDevice::Create(texture->asRenderTarget(), &props,
SkGpuDevice::kUninit_InitContents));
SkCanvas canvas(device);
// Attempt to read back just alpha from a RGBA/BGRA texture. Once with a texture-only src and
// once with a render target.
for (auto cfg : kRGBAConfigs) {
for (int rt = 0; rt < 2; ++rt) {
GrSurfaceDesc desc;
desc.fFlags = rt ? kRenderTarget_GrSurfaceFlag : kNone_GrSurfaceFlags;
desc.fConfig = cfg;
desc.fWidth = X_SIZE;
desc.fHeight = Y_SIZE;
SkPaint paint;
uint32_t rgbaData[X_SIZE][Y_SIZE];
// Make the alpha channel of the rgba texture come from alphaData.
for (int y = 0; y < Y_SIZE; ++y) {
for (int x = 0; x < X_SIZE; ++x) {
rgbaData[x][y] = GrColorPackRGBA(6, 7, 8, alphaData[x][y]);
}
}
SkAutoTUnref<GrTexture> texture(
context->textureProvider()->createTexture(desc, false, rgbaData, 0));
if (!texture) {
// We always expect to be able to create a RGBA texture
if (!rt && kRGBA_8888_GrPixelConfig == desc.fConfig) {
ERRORF(reporter, "Failed to create RGBA texture.");
}
continue;
}
const SkRect rect = SkRect::MakeLTRB(-10, -10, X_SIZE + 10, Y_SIZE + 10);
// clear readback to something non-zero so we can detect readback failures
memset(readback, 0x0, X_SIZE * Y_SIZE);
paint.setColor(SK_ColorWHITE);
// read the texture back
texture->readPixels(0, 0, desc.fWidth, desc.fHeight, kAlpha_8_GrPixelConfig, readback,
0);
canvas.drawRect(rect, paint);
match = true;
texture->readPixels(0, 0, desc.fWidth, desc.fHeight, desc.fConfig,
readback, 0);
match = true;
for (int y = 0; y < Y_SIZE; ++y) {
for (int x = 0; x < X_SIZE; ++x) {
if (0xFF != readback[x][y]) {
match = false;
for (int y = 0; y < Y_SIZE && match; ++y) {
for (int x = 0; x < X_SIZE && match; ++x) {
if (alphaData[x][y] != readback[x][y]) {
texture->readPixels(0, 0, desc.fWidth, desc.fHeight,
kAlpha_8_GrPixelConfig, readback, 0);
ERRORF(reporter,
"Failed alpha readback from cfg %d. Expected: 0x%02x, Got: 0x%02x at"
" (%d,%d), rt:%d", desc.fConfig, alphaData[x][y], readback[x][y], x,
y, rt);
match = false;
}
}
}
}
}
REPORTER_ASSERT(reporter, match);
}
#endif