Revert "Tiling support for GrGradientEffect kTwo_ColorType/kThree_ColorType"

This reverts commit b86aaeb7b0841c2c23f7b36b0bb0520ce2fb3256.

Reason for revert: Nexus7/Tegra3 crashing on lcdblendmodes

Original change's description:
> Tiling support for GrGradientEffect kTwo_ColorType/kThree_ColorType
> 
> Currently only the hard-stop specializations support tiling.
> 
> Consolidate the tiling code and expand to kTwo_ColorType,
> kThree_ColorType also.
> 
> Change-Id: I0c04997f563a7150a486ccc03f8121099a651c0b
> Reviewed-on: https://skia-review.googlesource.com/30780
> Reviewed-by: Brian Osman <brianosman@google.com>
> Commit-Queue: Florin Malita <fmalita@chromium.org>

TBR=bsalomon@google.com,robertphillips@google.com,brianosman@google.com,fmalita@chromium.org

Change-Id: I89c89c630f206c3a330e4b31aa3834dfbc5cd9e0
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/31244
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>

1 files changed, 52 insertions, 40 deletions

diff --git a/src/shaders/gradients/SkGradientShader.cpp b/src/shaders/gradients/SkGradientShader.cpp
index 94d6c6dcd9..985e033b45 100644
--- a/src/shaders/gradients/SkGradientShader.cpp
+++ b/src/shaders/gradients/SkGradientShader.cpp
@@ -1347,11 +1347,13 @@ GrGradientEffect::ColorType GrGradientEffect::determineColorType(
         }
     }
 
-    if (2 == shader.fColorCount) {
-        return kTwo_ColorType;
-    } else if (3 == shader.fColorCount &&
-               close_to_one_half(shader.getRecs()[1].fPos)) {
-        return kThree_ColorType;
+    if (SkShader::kClamp_TileMode == shader.getTileMode()) {
+        if (2 == shader.fColorCount) {
+            return kTwo_ColorType;
+        } else if (3 == shader.fColorCount &&
+                   close_to_one_half(shader.getRecs()[1].fPos)) {
+            return kThree_ColorType;
+        }
     }
 
     return kTexture_ColorType;
@@ -1544,31 +1546,6 @@ uint32_t GrGradientEffect::GLSLProcessor::GenBaseGradientKey(const GrProcessor&
     return key;
 }
 
-static void emit_clamp_t(GrGLSLFPFragmentBuilder* fragBuilder,
-                           const char* t,
-                           SkShader::TileMode tileMode) {
-    switch (tileMode) {
-    case SkShader::kClamp_TileMode:
-        fragBuilder->codeAppendf("float clamp_t = clamp(%s, 0.0, 1.0);", t);
-        break;
-    case SkShader::kRepeat_TileMode:
-        fragBuilder->codeAppendf("float clamp_t = fract(%s);", t);
-        break;
-    case SkShader::kMirror_TileMode:
-        fragBuilder->codeAppendf("float clamp_t = %s;", t);
-        // TODO: Is this conditional really useful?  Since the client requested kMirror,
-        // t is likely outside [0,1] most of the time so we might as well always fall through.
-        fragBuilder->codeAppendf("if (%s < 0.0 || %s > 1.0) {", t, t);
-        fragBuilder->codeAppendf("    if (mod(floor(%s), 2.0) == 0.0) {", t);
-        fragBuilder->codeAppendf("        clamp_t = fract(%s);", t);
-        fragBuilder->codeAppendf("    } else {");
-        fragBuilder->codeAppendf("        clamp_t = 1.0 - fract(%s);", t);
-        fragBuilder->codeAppendf("    }");
-        fragBuilder->codeAppendf("}");
-        break;
-    }
-}
-
 void GrGradientEffect::GLSLProcessor::emitColor(GrGLSLFPFragmentBuilder* fragBuilder,
                                                 GrGLSLUniformHandler* uniformHandler,
                                                 const GrShaderCaps* shaderCaps,
@@ -1583,7 +1560,20 @@ void GrGradientEffect::GLSLProcessor::emitColor(GrGLSLFPFragmentBuilder* fragBui
             const char* colors = uniformHandler->getUniformCStr(fColorsUni);
             const char* stopT = uniformHandler->getUniformCStr(fHardStopT);
 
-            emit_clamp_t(fragBuilder, t, ge.fTileMode);
+            fragBuilder->codeAppendf("float clamp_t = clamp(%s, 0.0, 1.0);", t);
+
+            // Account for tile mode
+            if (SkShader::kRepeat_TileMode == ge.fTileMode) {
+                fragBuilder->codeAppendf("clamp_t = fract(%s);", t);
+            } else if (SkShader::kMirror_TileMode == ge.fTileMode) {
+                fragBuilder->codeAppendf("if (%s < 0.0 || %s > 1.0) {", t, t);
+                fragBuilder->codeAppendf("    if (mod(floor(%s), 2.0) == 0.0) {", t);
+                fragBuilder->codeAppendf("        clamp_t = fract(%s);", t);
+                fragBuilder->codeAppendf("    } else {");
+                fragBuilder->codeAppendf("        clamp_t = 1.0 - fract(%s);", t);
+                fragBuilder->codeAppendf("    }");
+                fragBuilder->codeAppendf("}");
+            }
 
             // Calculate color
             fragBuilder->codeAppend ("float4 start, end;");
@@ -1614,7 +1604,20 @@ void GrGradientEffect::GLSLProcessor::emitColor(GrGLSLFPFragmentBuilder* fragBui
             const char* t      = gradientTValue;
             const char* colors = uniformHandler->getUniformCStr(fColorsUni);
 
-            emit_clamp_t(fragBuilder, t, ge.fTileMode);
+            fragBuilder->codeAppendf("float clamp_t = clamp(%s, 0.0, 1.0);", t);
+
+            // Account for tile mode
+            if (SkShader::kRepeat_TileMode == ge.fTileMode) {
+                fragBuilder->codeAppendf("clamp_t = fract(%s);", t);
+            } else if (SkShader::kMirror_TileMode == ge.fTileMode) {
+                fragBuilder->codeAppendf("if (%s < 0.0 || %s > 1.0) {", t, t);
+                fragBuilder->codeAppendf("    if (mod(floor(%s), 2.0) == 0.0) {", t);
+                fragBuilder->codeAppendf("        clamp_t = fract(%s);", t);
+                fragBuilder->codeAppendf("    } else {");
+                fragBuilder->codeAppendf("        clamp_t = 1.0 - fract(%s);", t);
+                fragBuilder->codeAppendf("    }");
+                fragBuilder->codeAppendf("}");
+            }
 
             fragBuilder->codeAppendf("float4 colorTemp = mix(%s[1], %s[2], clamp_t);", colors,
                                      colors);
@@ -1639,7 +1642,20 @@ void GrGradientEffect::GLSLProcessor::emitColor(GrGLSLFPFragmentBuilder* fragBui
             const char* t      = gradientTValue;
             const char* colors = uniformHandler->getUniformCStr(fColorsUni);
 
-            emit_clamp_t(fragBuilder, t, ge.fTileMode);
+            fragBuilder->codeAppendf("float clamp_t = clamp(%s, 0.0, 1.0);", t);
+
+            // Account for tile mode
+            if (SkShader::kRepeat_TileMode == ge.fTileMode) {
+                fragBuilder->codeAppendf("clamp_t = fract(%s);", t);
+            } else if (SkShader::kMirror_TileMode == ge.fTileMode) {
+                fragBuilder->codeAppendf("if (%s < 0.0 || %s > 1.0) {", t, t);
+                fragBuilder->codeAppendf("    if (mod(floor(%s), 2.0) == 0.0) {", t);
+                fragBuilder->codeAppendf("        clamp_t = fract(%s);", t);
+                fragBuilder->codeAppendf("    } else {");
+                fragBuilder->codeAppendf("        clamp_t = 1.0 - fract(%s);", t);
+                fragBuilder->codeAppendf("    }");
+                fragBuilder->codeAppendf("}");
+            }
 
             fragBuilder->codeAppendf("float4 colorTemp = mix(%s[0], %s[1], clamp_t);", colors,
                                      colors);
@@ -1664,10 +1680,8 @@ void GrGradientEffect::GLSLProcessor::emitColor(GrGLSLFPFragmentBuilder* fragBui
             const char* t      = gradientTValue;
             const char* colors = uniformHandler->getUniformCStr(fColorsUni);
 
-            emit_clamp_t(fragBuilder, t, ge.fTileMode);
-
-            fragBuilder->codeAppendf("float4 colorTemp = mix(%s[0], %s[1], clamp_t);",
-                                     colors, colors);
+            fragBuilder->codeAppendf("float4 colorTemp = mix(%s[0], %s[1], clamp(%s, 0.0, 1.0));",
+                                     colors, colors, t);
 
             // We could skip this step if both colors are known to be opaque. Two
             // considerations:
@@ -1691,9 +1705,7 @@ void GrGradientEffect::GLSLProcessor::emitColor(GrGLSLFPFragmentBuilder* fragBui
             const char* t      = gradientTValue;
             const char* colors = uniformHandler->getUniformCStr(fColorsUni);
 
-            emit_clamp_t(fragBuilder, t, ge.fTileMode);
-
-            fragBuilder->codeAppendf("float oneMinus2t = 1.0 - (2.0 * clamp_t);");
+            fragBuilder->codeAppendf("float oneMinus2t = 1.0 - (2.0 * %s);", t);
             fragBuilder->codeAppendf("float4 colorTemp = clamp(oneMinus2t, 0.0, 1.0) * %s[0];",
                                      colors);
             if (!shaderCaps->canUseMinAndAbsTogether()) {