diff --git a/src/gpu/gl/GrGLCaps.cpp b/src/gpu/gl/GrGLCaps.cpp index 81d0b4483b..237412a7fc 100644 --- a/src/gpu/gl/GrGLCaps.cpp +++ b/src/gpu/gl/GrGLCaps.cpp @@ -643,7 +643,11 @@ bool GrGLCaps::readPixelsSupported(GrPixelConfig rtConfig, GrPixelConfig readConfig, std::function getIntegerv, std::function 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; } diff --git a/src/gpu/gl/GrGLGpu.cpp b/src/gpu/gl/GrGLGpu.cpp index bf0b297c8c..94307a67a4 100644 --- a/src/gpu/gl/GrGLGpu.cpp +++ b/src/gpu/gl/GrGLGpu.cpp @@ -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(surface->asRenderTarget()); - if (!tgt) { + GrGLRenderTarget* renderTarget = static_cast(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 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(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; diff --git a/tests/ReadWriteAlphaTest.cpp b/tests/ReadWriteAlphaTest.cpp index 1ee6b09a99..0a8441797c 100644 --- a/tests/ReadWriteAlphaTest.cpp +++ b/tests/ReadWriteAlphaTest.cpp @@ -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 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 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 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 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 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