Use float rather than SkFixed for gradient TileProcs.

src/effects/gradients/SkGradientShaderPriv.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkGradientShaderPriv_DEFINED
 #define SkGradientShaderPriv_DEFINED
 
+#include "math.h"
+
 #include "SkGradientBitmapCache.h"
 #include "SkGradientShader.h"
 #include "SkClampRange.h"
 #include "SkColorPriv.h"
 #include "SkReadBuffer.h"
 #include "SkWriteBuffer.h"
 #include "SkMallocPixelRef.h"
 #include "SkUtils.h"
 #include "SkShader.h"
 #include "SkOnce.h"
@@ skipping 11 matching lines @@
             }
             if (count & 1) {
                 *dst = v0;
             }
         }
     }
 }
 
 //  Clamp
 
-static inline SkFixed clamp_tileproc(SkFixed x) {
-    return SkClampMax(x, 0xFFFF);
+static inline unsigned clamp_tileproc(float x) {
+    unsigned result = (unsigned)(0xFFFF * SkTPin(x, 0.0f, 1.0f));
+    if (result > 0xFFFF) {
+      SkDebugf("clamp_tileproc: x: %f  result: %d\n", x, result);
+    }
+    return result;
 }
 
 // Repeat
 
-static inline SkFixed repeat_tileproc(SkFixed x) {
-    return x & 0xFFFF;
+static inline unsigned repeat_tileproc(float x) {
+    float modulo = fmod(x, 1.0f);
+    unsigned result = (unsigned)(0xFFFF * modulo);
+    if (result > 0xFFFF) {
+      SkDebugf("repeat_tileproc: x: %f  modulo: %f  result: %d\n", x, modulo, result);
+    }
+    return result;
 }
 
 // Mirror
 
 // Visual Studio 2010 (MSC_VER=1600) optimizes bit-shift code incorrectly.
 // See http://code.google.com/p/skia/issues/detail?id=472
 #if defined(_MSC_VER) && (_MSC_VER >= 1600)
 #pragma optimize("", off)
 #endif
 
-static inline SkFixed mirror_tileproc(SkFixed x) {
-    int s = SkLeftShift(x, 15) >> 31;
-    return (x ^ s) & 0xFFFF;
+static inline unsigned mirror_tileproc(float x) {
+    const float x_mod_2 = fmod(x, 2.0f);
+    int x_17bits = (int)(x_mod_2 * 0x10000);
+    if (x_17bits & 0x10000) {
+        x_17bits = ~x_17bits;
+    }
+    unsigned result = x_17bits & 0xFFFF;
+    if (result > 0xFFFF) {
+      SkDebugf("mirror_tileproc: x: %f  x_mod_2: %f  x_17bits: %d  result: %d\n", x, x_mod_2, x_17bits, result);
+    }
+    return result;
 }
 
 #if defined(_MSC_VER) && (_MSC_VER >= 1600)
 #pragma optimize("", on)
 #endif
 
 ///////////////////////////////////////////////////////////////////////////////
 
-typedef SkFixed (*TileProc)(SkFixed);
+typedef unsigned (*TileProc)(float);
 
 ///////////////////////////////////////////////////////////////////////////////
 
 static const TileProc gTileProcs[] = {
     clamp_tileproc,
     repeat_tileproc,
     mirror_tileproc
 };
 
 ///////////////////////////////////////////////////////////////////////////////
@@ skipping 375 matching lines @@
     GrGLSLProgramDataManager::UniformHandle fColorStartUni;
     GrGLSLProgramDataManager::UniformHandle fColorMidUni;
     GrGLSLProgramDataManager::UniformHandle fColorEndUni;
 
     typedef GrGLSLFragmentProcessor INHERITED;
 };
 
 #endif
 
 #endif