fixup precision with configurable atlas

src/gpu/effects/GrDistanceFieldGeoProc.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrDistanceFieldGeoProc.h"
 #include "GrFontAtlasSizes.h"
 #include "GrInvariantOutput.h"
@@ skipping 62 matching lines @@
         // add varyings
         GrGLVertToFrag recipScale(kFloat_GrSLType);
         GrGLVertToFrag st(kVec2f_GrSLType);
         bool isSimilarity = SkToBool(dfTexEffect.getFlags() & kSimilarity_DistanceFieldEffectFlag);
         args.fPB->addVarying("IntTextureCoords", &st, kHigh_GrSLPrecision);
         vsBuilder->codeAppendf("%s = %s;", st.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);
+        SkASSERT(atlas && SkIsPow2(atlas->width()) && SkIsPow2(atlas->height()));
         SkScalar recipWidth = 1.0f / atlas->width();
         SkScalar recipHeight = 1.0f / atlas->height();
 
         GrGLVertToFrag uv(kVec2f_GrSLType);
         args.fPB->addVarying("TextureCoords", &uv, kHigh_GrSLPrecision);
         vsBuilder->codeAppendf("%s = vec2(%.*f, %.*f) * %s;", uv.vsOut(),
-                               SK_FLT_DECIMAL_DIG, recipWidth,
-                               SK_FLT_DECIMAL_DIG, recipHeight,
+                               GR_SIGNIFICANT_POW2_DECIMAL_DIG, recipWidth,
+                               GR_SIGNIFICANT_POW2_DECIMAL_DIG, recipHeight,
                                dfTexEffect.inTextureCoords()->fName);
         
         // Use highp to work around aliasing issues
         fsBuilder->codeAppend(GrGLShaderVar::PrecisionString(kHigh_GrSLPrecision,
                                                              pb->ctxInfo().standard()));
         fsBuilder->codeAppendf("vec2 uv = %s;\n", uv.fsIn());
 
         fsBuilder->codeAppend("\tfloat texColor = ");
         fsBuilder->appendTextureLookup(args.fSamplers[0],
                                        "uv",
@@ skipping 433 matching lines @@
         // set up varyings
         bool isUniformScale = SkToBool(dfTexEffect.getFlags() & kUniformScale_DistanceFieldEffectMask);
         GrGLVertToFrag recipScale(kFloat_GrSLType);
         GrGLVertToFrag st(kVec2f_GrSLType);
         args.fPB->addVarying("IntTextureCoords", &st, kHigh_GrSLPrecision);
         vsBuilder->codeAppendf("%s = %s;", st.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);
+        SkASSERT(atlas && SkIsPow2(atlas->width()) && SkIsPow2(atlas->height()));
         SkScalar recipWidth = 1.0f / atlas->width();
         SkScalar recipHeight = 1.0f / atlas->height();
 
         GrGLVertToFrag uv(kVec2f_GrSLType);
         args.fPB->addVarying("TextureCoords", &uv, kHigh_GrSLPrecision);
         vsBuilder->codeAppendf("%s = vec2(%.*f, %.*f) * %s;", uv.vsOut(),
-                               SK_FLT_DECIMAL_DIG, recipWidth,
-                               SK_FLT_DECIMAL_DIG, recipHeight,
+                               GR_SIGNIFICANT_POW2_DECIMAL_DIG, recipWidth,
+                               GR_SIGNIFICANT_POW2_DECIMAL_DIG, recipHeight,
                                dfTexEffect.inTextureCoords()->fName);
 
         // add frag shader code
         GrGLFragmentBuilder* fsBuilder = args.fPB->getFragmentShaderBuilder();
 
         SkAssertResult(fsBuilder->enableFeature(
                 GrGLFragmentShaderBuilder::kStandardDerivatives_GLSLFeature));
 
         // create LCD offset adjusted by inverse of transform
         // Use highp to work around aliasing issues
@@ skipping 203 matching lines @@
     uint32_t flags = kUseLCD_DistanceFieldEffectFlag;
     flags |= d->fRandom->nextBool() ? kUniformScale_DistanceFieldEffectMask : 0;
     flags |= d->fRandom->nextBool() ? kBGR_DistanceFieldEffectFlag : 0;
     return GrDistanceFieldLCDTextGeoProc::Create(GrRandomColor(d->fRandom),
                                                  GrTest::TestMatrix(d->fRandom),
                                                  d->fTextures[texIdx], params,
                                                  wa,
                                                  flags,
                                                  d->fRandom->nextBool());
 }