From b76afedf11c7fe933954d030048c3222860249e1 Mon Sep 17 00:00:00 2001 From: bsalomon Date: Wed, 13 Jan 2016 12:19:15 -0800 Subject: [PATCH] Make A8 readback work in more cases and improve testing. BUG=skia: GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1584563002 Review URL: https://codereview.chromium.org/1584563002 --- src/gpu/gl/GrGLCaps.cpp | 28 +++++- src/gpu/gl/GrGLGpu.cpp | 42 ++++++-- tests/ReadWriteAlphaTest.cpp | 187 +++++++++++++++++++++++------------ 3 files changed, 186 insertions(+), 71 deletions(-) diff --git a/src/gpu/gl/GrGLCaps.cpp b/src/gpu/gl/GrGLCaps.cpp index 678c62abb8..0c2ed73d7c 100644 --- a/src/gpu/gl/GrGLCaps.cpp +++ b/src/gpu/gl/GrGLCaps.cpp @@ -637,7 +637,22 @@ bool GrGLCaps::readPixelsSupported(const GrGLInterface* intf, } if (kGL_GrGLStandard == intf->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; } @@ -1051,6 +1066,17 @@ 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 8033ea60e5..972049aa56 100644 --- a/src/gpu/gl/GrGLGpu.cpp +++ b/src/gpu/gl/GrGLGpu.cpp @@ -1951,7 +1951,8 @@ bool GrGLGpu::onGetReadPixelsInfo(GrSurface* srcSurface, int width, int height, ReadPixelTempDrawInfo* tempDrawInfo) { // 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 (!srcSurface->asRenderTarget()) { + GrRenderTarget* srcAsRT = srcSurface->asRenderTarget(); + if (!srcAsRT) { ElevateDrawPreference(drawPreference, kRequireDraw_DrawPreference); } @@ -1992,13 +1993,20 @@ bool GrGLGpu::onGetReadPixelsInfo(GrSurface* srcSurface, int width, int height, tempDrawInfo->fTempSurfaceDesc.fConfig = kRGBA_8888_GrPixelConfig; tempDrawInfo->fSwapRAndB = true; ElevateDrawPreference(drawPreference, kRequireDraw_DrawPreference); + } else if (kRequireDraw_DrawPreference == *drawPreference && + readConfig == kAlpha_8_GrPixelConfig && + !this->caps()->isConfigRenderable(kAlpha_8_GrPixelConfig, false)) { + // On some GLs there is no renderable single channel format. In that case we fall back + // to rendering to a RGBA and then will extract the alpha from that. + if (this->caps()->isConfigRenderable(kRGBA_8888_GrPixelConfig, false)) { + tempDrawInfo->fTempSurfaceDesc.fConfig = kRGBA_8888_GrPixelConfig; + } else { + return false; + } } - GrRenderTarget* srcAsRT = srcSurface->asRenderTarget(); - if (!srcAsRT) { - ElevateDrawPreference(drawPreference, kRequireDraw_DrawPreference); - } else if (read_pixels_pays_for_y_flip(srcAsRT, this->glCaps(), width, height, readConfig, - rowBytes)) { + if (srcAsRT && read_pixels_pays_for_y_flip(srcAsRT, this->glCaps(), width, height, readConfig, + rowBytes)) { ElevateDrawPreference(drawPreference, kGpuPrefersDraw_DrawPreference); } @@ -2049,6 +2057,28 @@ bool GrGLGpu::onReadPixels(GrSurface* surface, SkFAIL("Unknown resolve type"); } + // We have a special case fallback for reading alpha from a RGBA/BGRA surface. We will read + // back all the channels as RGBA and then extract A. + // This must be called after the RT is bound as the FBO above. + if (!this->glCaps().readPixelsSupported(this->glInterface(), config, tgt->config())) { + if ((tgt->config() == kRGBA_8888_GrPixelConfig || + tgt->config() == kBGRA_8888_GrPixelConfig) && + kAlpha_8_GrPixelConfig == config) { + SkAutoTDeleteArray temp(new uint32_t[width * height * 4]); + if (this->onReadPixels(surface, left, top, width, height, kRGBA_8888_GrPixelConfig, + 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; + } + const GrGLIRect& glvp = tgt->getViewport(); // the read rect is viewport-relative diff --git a/tests/ReadWriteAlphaTest.cpp b/tests/ReadWriteAlphaTest.cpp index 1ee6b09a99..a33d57d7a9 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 +18,147 @@ 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] = x*Y_SIZE+y; + } + } - 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); + // Attempt to read back just alpha from a RGBA/BGRA texture. Once with a texture-only src and + // once with a render target. + for (int cfg = 0; cfg < 2; ++cfg) { + for (int rt = 0; rt < 2; ++rt) { + GrSurfaceDesc desc; + desc.fFlags = rt ? kRenderTarget_GrSurfaceFlag : kNone_GrSurfaceFlags; + desc.fConfig = cfg ? kBGRA_8888_GrPixelConfig : kRGBA_8888_GrPixelConfig; + desc.fWidth = X_SIZE; + desc.fHeight = Y_SIZE; - // 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); + 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; + } - SkPaint paint; + // clear readback to something non-zero so we can detect readback failures + memset(readback, 0x0, X_SIZE * Y_SIZE); - const SkRect rect = SkRect::MakeLTRB(-10, -10, X_SIZE + 10, Y_SIZE + 10); + // read the texture back + texture->readPixels(0, 0, desc.fWidth, desc.fHeight, kAlpha_8_GrPixelConfig, readback, + 0); - paint.setColor(SK_ColorWHITE); + match = true; - 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; ++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