Allow FPs to elevate default precision for the entire fragment program

Currently, GrConfigConversionEffect is able to round-trip on many
mobile GPUs because it uses highp for all intermediate variables
(including the texture fetch result). Separating the texture sample
into a different processor breaks that.

This is a blunt instrument, not to be used lightly.

This reverts commit dffe9827b18444d1426859d9035f9f0087201f44.

Bug: skia:
Change-Id: I940af3256c47e6672a008d516db9e55669672ca3
Reviewed-on: https://skia-review.googlesource.com/11345
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/src/gpu/GrShaderCaps.cpp b/src/gpu/GrShaderCaps.cpp
index e3e6b07361..636b955ab7 100644
--- a/src/gpu/GrShaderCaps.cpp
+++ b/src/gpu/GrShaderCaps.cpp
@@ -32,8 +32,10 @@ static const char* precision_to_string(GrSLPrecision p) {
         return "medium";
     case kHigh_GrSLPrecision:
         return "high";
+    default:
+        SkFAIL("Unexpected precision type.");
+        return "";
     }
-    return "";
 }
 
 GrShaderCaps::GrShaderCaps(const GrContextOptions& options) {
@@ -201,7 +203,7 @@ void GrShaderCaps::initSamplerPrecisionTable() {
         }
 
         uint8_t* table = fSamplerPrecisions[visibility];
-        table[kUnknown_GrPixelConfig]        = kDefault_GrSLPrecision;
+        table[kUnknown_GrPixelConfig]        = lowp;
         table[kAlpha_8_GrPixelConfig]        = lowp;
         table[kGray_8_GrPixelConfig]         = lowp;
         table[kRGB_565_GrPixelConfig]        = lowp;