commit e507ff0460f4f878214b9454fb5b9ab8d64d8063
author jvanverth <jvanverth@google.com> Fri Feb 19 06:35:22 2016 -0800
committer Commit bot <commit-bot@chromium.org> Fri Feb 19 06:35:22 2016 -0800
tree 144e5f967a735ee0ec2de3e6c5d3a7cb33a213df
parent 77b798ce8e8616e8cb0e82a22ad9eb4f69eb271f

Use unorm shorts for texture coordinates when rendering text.

There are a couple of reasons for this:
- Vulkan does not guarantee conversions from integral vertex attributes
  to floating point shader variables
- This may be faster and more precise on some platforms, as it avoids
  the aforementioned conversion and changes a multiply by a very small
  value to a multiply by a medium-sized value.
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1713693002
TBR=bsalomon@google.com

Review URL: https://codereview.chromium.org/1713693002

src/gpu/effects/GrDistanceFieldGeoProc.cpp

diff --git a/src/gpu/effects/GrDistanceFieldGeoProc.cpp b/src/gpu/effects/GrDistanceFieldGeoProc.cpp
index 50e78cc..dc01b62 100644
--- a/src/gpu/effects/GrDistanceFieldGeoProc.cpp
+++ b/src/gpu/effects/GrDistanceFieldGeoProc.cpp
@@ -78,23 +78,20 @@
 
         // add varyings
         GrGLSLVertToFrag recipScale(kFloat_GrSLType);
-        GrGLSLVertToFrag st(kVec2f_GrSLType);
+        GrGLSLVertToFrag uv(kVec2f_GrSLType);
         bool isSimilarity = SkToBool(dfTexEffect.getFlags() & kSimilarity_DistanceFieldEffectFlag);
-        varyingHandler->addVarying("IntTextureCoords", &st, kHigh_GrSLPrecision);
-        vertBuilder->codeAppendf("%s = %s;", st.vsOut(), dfTexEffect.inTextureCoords()->fName);
+        varyingHandler->addVarying("TextureCoords", &uv, kHigh_GrSLPrecision);
+        vertBuilder->codeAppendf("%s = %s;", uv.vsOut(), dfTexEffect.inTextureCoords()->fName);
 
         // compute numbers to be hardcoded to convert texture coordinates from int to float
         SkASSERT(dfTexEffect.numTextures() == 1);
         GrTexture* atlas = dfTexEffect.textureAccess(0).getTexture();
         SkASSERT(atlas && SkIsPow2(atlas->width()) && SkIsPow2(atlas->height()));
-        SkScalar recipWidth = 1.0f / atlas->width();
-        SkScalar recipHeight = 1.0f / atlas->height();
 
-        GrGLSLVertToFrag uv(kVec2f_GrSLType);
-        varyingHandler->addVarying("TextureCoords", &uv, kHigh_GrSLPrecision);
-        vertBuilder->codeAppendf("%s = vec2(%.*f, %.*f) * %s;", uv.vsOut(),
-                                 GR_SIGNIFICANT_POW2_DECIMAL_DIG, recipWidth,
-                                 GR_SIGNIFICANT_POW2_DECIMAL_DIG, recipHeight,
+        GrGLSLVertToFrag st(kVec2f_GrSLType);
+        varyingHandler->addVarying("IntTextureCoords", &st, kHigh_GrSLPrecision);
+        vertBuilder->codeAppendf("%s = vec2(%d, %d) * %s;", st.vsOut(),
+                                 atlas->width(), atlas->height(),
                                  dfTexEffect.inTextureCoords()->fName);
         
         // Use highp to work around aliasing issues
@@ -224,7 +221,7 @@
                                                    kHigh_GrSLPrecision));
     fInColor = &this->addVertexAttrib(Attribute("inColor", kVec4ub_GrVertexAttribType));
     fInTextureCoords = &this->addVertexAttrib(Attribute("inTextureCoords",
-                                                          kVec2s_GrVertexAttribType));
+                                                          kVec2us_GrVertexAttribType));
     this->addTextureAccess(&fTextureAccess);
 }
 
@@ -522,22 +519,19 @@
         // set up varyings
         bool isUniformScale = SkToBool(dfTexEffect.getFlags() & kUniformScale_DistanceFieldEffectMask);
         GrGLSLVertToFrag recipScale(kFloat_GrSLType);
-        GrGLSLVertToFrag st(kVec2f_GrSLType);
-        varyingHandler->addVarying("IntTextureCoords", &st, kHigh_GrSLPrecision);
-        vertBuilder->codeAppendf("%s = %s;", st.vsOut(), dfTexEffect.inTextureCoords()->fName);
+        GrGLSLVertToFrag uv(kVec2f_GrSLType);
+        varyingHandler->addVarying("TextureCoords", &uv, kHigh_GrSLPrecision);
+        vertBuilder->codeAppendf("%s = %s;", uv.vsOut(), dfTexEffect.inTextureCoords()->fName);
 
         // compute numbers to be hardcoded to convert texture coordinates from int to float
         SkASSERT(dfTexEffect.numTextures() == 1);
         GrTexture* atlas = dfTexEffect.textureAccess(0).getTexture();
         SkASSERT(atlas && SkIsPow2(atlas->width()) && SkIsPow2(atlas->height()));
-        SkScalar recipWidth = 1.0f / atlas->width();
-        SkScalar recipHeight = 1.0f / atlas->height();
 
-        GrGLSLVertToFrag uv(kVec2f_GrSLType);
-        varyingHandler->addVarying("TextureCoords", &uv, kHigh_GrSLPrecision);
-        vertBuilder->codeAppendf("%s = vec2(%.*f, %.*f) * %s;", uv.vsOut(),
-                                 GR_SIGNIFICANT_POW2_DECIMAL_DIG, recipWidth,
-                                 GR_SIGNIFICANT_POW2_DECIMAL_DIG, recipHeight,
+        GrGLSLVertToFrag st(kVec2f_GrSLType);
+        varyingHandler->addVarying("IntTextureCoords", &st, kHigh_GrSLPrecision);
+        vertBuilder->codeAppendf("%s = vec2(%d, %d) * %s;", st.vsOut(),
+                                 atlas->width(), atlas->height(),
                                  dfTexEffect.inTextureCoords()->fName);
 
         // add frag shader code
@@ -708,7 +702,7 @@
                                                    kHigh_GrSLPrecision));
     fInColor = &this->addVertexAttrib(Attribute("inColor", kVec4ub_GrVertexAttribType));
     fInTextureCoords = &this->addVertexAttrib(Attribute("inTextureCoords",
-                                                        kVec2s_GrVertexAttribType));
+                                                        kVec2us_GrVertexAttribType));
     this->addTextureAccess(&fTextureAccess);
 }