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
This commit is contained in:
bsalomon 2016-01-13 12:19:15 -08:00 committed by Commit bot
parent c2eff2ac77
commit b76afedf11
3 changed files with 186 additions and 71 deletions

View File

@ -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;
}

View File

@ -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<uint32_t> 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<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;
}
const GrGLIRect& glvp = tgt->getViewport();
// the read rect is viewport-relative

View File

@ -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<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] = 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<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);
// 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<SkBaseDevice> 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<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;
}
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