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.

Bug: skia:
Change-Id: I2ab365e3da79628069e2eb727c43c2bf45bfd789
Reviewed-on: https://skia-review.googlesource.com/10162
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/private/GrGLSL.h b/include/private/GrGLSL.h
index ed33c1cf4c..66f7be84d1 100644
--- a/include/private/GrGLSL.h
+++ b/include/private/GrGLSL.h
@@ -74,6 +74,8 @@ static inline const char* GrGLSLPrecisionString(GrSLPrecision p) {
             return "mediump";
         case kHigh_GrSLPrecision:
             return "highp";
+        case kDefault_GrSLPrecision:
+            return "";
         default:
             SkFAIL("Unexpected precision type.");
             return "";