Prefer dual source/framebuffer fetch paths for GPU LCD.
This will allow us to batch over color changes for LCD text.
BUG=skia:
Review URL: https://codereview.chromium.org/1354423002
diff --git a/src/gpu/effects/GrPorterDuffXferProcessor.cpp b/src/gpu/effects/GrPorterDuffXferProcessor.cpp
index 1312d35..e31ff65 100644
--- a/src/gpu/effects/GrPorterDuffXferProcessor.cpp
+++ b/src/gpu/effects/GrPorterDuffXferProcessor.cpp
@@ -731,7 +731,11 @@
BlendFormula blendFormula;
if (covPOI.isFourChannelOutput()) {
if (SkXfermode::kSrcOver_Mode == fXfermode &&
- kRGBA_GrColorComponentFlags == colorPOI.validFlags()) {
+ kRGBA_GrColorComponentFlags == colorPOI.validFlags() &&
+ !caps.shaderCaps()->dualSourceBlendingSupport() &&
+ !caps.shaderCaps()->dstReadInShaderSupport()) {
+ // If we don't have dual source blending or in shader dst reads, we fall back to this
+ // trick for rendering SrcOver LCD text instead of doing a dst copy.
SkASSERT(!dstTexture || !dstTexture->texture());
return PDLCDXferProcessor::Create(fXfermode, colorPOI);
}
@@ -792,7 +796,8 @@
// the XP.
if (covPOI.isFourChannelOutput()) {
if (SkXfermode::kSrcOver_Mode == fXfermode &&
- kRGBA_GrColorComponentFlags == colorPOI.validFlags()) {
+ kRGBA_GrColorComponentFlags == colorPOI.validFlags() &&
+ !caps.shaderCaps()->dstReadInShaderSupport()) {
return false;
}
return get_lcd_blend_formula(covPOI, fXfermode).hasSecondaryOutput();