commit 47eedcc848e7712aea9607fd489abdc70bc8bcfd
author pavel <pavel@cs.unc.edu> Thu Oct 23 13:18:50 2014 -0700
committer Commit bot <commit-bot@chromium.org> Thu Oct 23 13:18:50 2014 -0700
tree a3eedb1801e401fac76f852e3e9b4ed7d926c251
parent 08fa28cd31c96b4ebd9cb532539c3a8c88803d90

Add utils to better quantize grayscale values to three bit indices while
compressing coverage masks.

Signed-off-by: Pavel Krajcevski <pavel@cs.unc.edu>

BUG=skia:

Review URL: https://codereview.chromium.org/669243003

src/utils/SkTextureCompressor_R11EAC.cpp

diff --git a/src/utils/SkTextureCompressor_R11EAC.cpp b/src/utils/SkTextureCompressor_R11EAC.cpp
index 9996eb9..43226e0 100644
--- a/src/utils/SkTextureCompressor_R11EAC.cpp
+++ b/src/utils/SkTextureCompressor_R11EAC.cpp
@@ -7,6 +7,7 @@
 
 #include "SkTextureCompressor.h"
 #include "SkTextureCompressor_Blitter.h"
+#include "SkTextureCompressor_Utils.h"
 
 #include "SkBlitter.h"
 #include "SkEndian.h"
@@ -320,7 +321,7 @@
 // Most of the voodoo in this function comes from Hacker's Delight, section 2-18
 static inline uint32_t convert_indices(uint32_t x) {
     // Take the top three bits...
-    x = (x & 0xE0E0E0E0) >> 5;
+    x = SkTextureCompressor::ConvertToThreeBitIndex(x);
 
     // Negate...
     x = ~((0x80808080 - x) ^ 0x7F7F7F7F);