Break LCD and Bitmap text dependency on hardcoded atlas values

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 59 matching lines @@
         this->emitTransforms(args.fPB, gpArgs->fPositionVar, dfTexEffect.inPosition()->fName,
                              args.fTransformsIn, args.fTransformsOut);
 
         // 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);
+        SkScalar recipWidth = 1.0f / atlas->width();
+        SkScalar recipHeight = 1.0f / atlas->height();
+
         GrGLVertToFrag uv(kVec2f_GrSLType);
         args.fPB->addVarying("TextureCoords", &uv, kHigh_GrSLPrecision);
-        // this is only used with text, so our texture bounds always match the glyph atlas
-        vsBuilder->codeAppendf("%s = vec2(" GR_FONT_ATLAS_A8_RECIP_WIDTH ", "
-                               GR_FONT_ATLAS_RECIP_HEIGHT ")*%s;", uv.vsOut(),
+        vsBuilder->codeAppendf("%s = vec2(%.*f, %.*f) * %s;", uv.vsOut(),
+                               SK_FLT_DECIMAL_DIG, recipWidth,
+                               SK_FLT_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 74 matching lines @@
     static inline void GenKey(const GrGeometryProcessor& gp,
                               const GrBatchTracker& bt,
                               const GrGLSLCaps&,
                               GrProcessorKeyBuilder* b) {
         const GrDistanceFieldA8TextGeoProc& dfTexEffect = gp.cast<GrDistanceFieldA8TextGeoProc>();
         uint32_t key = dfTexEffect.getFlags();
         key |= dfTexEffect.hasVertexColor() << 16;
         key |= dfTexEffect.colorIgnored() << 17;
         key |= ComputePosKey(dfTexEffect.viewMatrix()) << 25;
         b->add32(key);
+
+        // Currently we hardcode numbers to convert atlas coordinates to normalized floating point
+        SkASSERT(gp.numTextures() == 1);
+        GrTexture* atlas = gp.textureAccess(0).getTexture();
+        SkASSERT(atlas);
+        b->add32(atlas->width());
+        b->add32(atlas->height());
     }
 
 private:
     SkMatrix      fViewMatrix;
     GrColor       fColor;
     UniformHandle fColorUniform;
     UniformHandle fViewMatrixUniform;
 #ifdef SK_GAMMA_APPLY_TO_A8
     float         fDistanceAdjust;
     UniformHandle fDistanceAdjustUni;
@@ skipping 329 matching lines @@
         this->emitTransforms(args.fPB, gpArgs->fPositionVar, dfTexEffect.inPosition()->fName,
                              args.fTransformsIn, args.fTransformsOut);
 
         // 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);
+        SkScalar recipWidth = 1.0f / atlas->width();
+        SkScalar recipHeight = 1.0f / atlas->height();
+
         GrGLVertToFrag uv(kVec2f_GrSLType);
         args.fPB->addVarying("TextureCoords", &uv, kHigh_GrSLPrecision);
-        // this is only used with text, so our texture bounds always match the glyph atlas
-        vsBuilder->codeAppendf("%s = vec2(" GR_FONT_ATLAS_A8_RECIP_WIDTH ", "
-                               GR_FONT_ATLAS_RECIP_HEIGHT ")*%s;", uv.vsOut(),
+        vsBuilder->codeAppendf("%s = vec2(%.*f, %.*f) * %s;", uv.vsOut(),
+                               SK_FLT_DECIMAL_DIG, recipWidth,
+                               SK_FLT_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
         fsBuilder->codeAppend(GrGLShaderVar::PrecisionString(kHigh_GrSLPrecision,
                                                              pb->ctxInfo().standard()));
         fsBuilder->codeAppendf("vec2 uv = %s;\n", uv.fsIn());
         fsBuilder->codeAppend(GrGLShaderVar::PrecisionString(kHigh_GrSLPrecision,
                                                              pb->ctxInfo().standard()));
+
+        SkScalar lcdDelta = 1.0f / (3.0f * atlas->width());
         if (dfTexEffect.getFlags() & kBGR_DistanceFieldEffectFlag) {
-            fsBuilder->codeAppend("float delta = -" GR_FONT_ATLAS_LCD_DELTA ";\n");
+            fsBuilder->codeAppendf("float delta = -%.*f;\n", SK_FLT_DECIMAL_DIG, lcdDelta);
         } else {
-            fsBuilder->codeAppend("float delta = " GR_FONT_ATLAS_LCD_DELTA ";\n");
+            fsBuilder->codeAppendf("float delta = %.*f;\n", SK_FLT_DECIMAL_DIG, lcdDelta);
         }
         if (isUniformScale) {
             fsBuilder->codeAppendf("float dy = abs(dFdy(%s.y));", st.fsIn());
             fsBuilder->codeAppend("vec2 offset = vec2(dy*delta, 0.0);");
         } else {
             fsBuilder->codeAppendf("vec2 st = %s;\n", st.fsIn());
 
             fsBuilder->codeAppend("vec2 Jdx = dFdx(st);");
             fsBuilder->codeAppend("vec2 Jdy = dFdy(st);");
             fsBuilder->codeAppend("vec2 offset = delta*Jdx;");
@@ skipping 99 matching lines @@
     static inline void GenKey(const GrGeometryProcessor& gp,
                               const GrBatchTracker& bt,
                               const GrGLSLCaps&,
                               GrProcessorKeyBuilder* b) {
         const GrDistanceFieldLCDTextGeoProc& dfTexEffect = gp.cast<GrDistanceFieldLCDTextGeoProc>();
 
         uint32_t key = dfTexEffect.getFlags();
         key |= dfTexEffect.colorIgnored() << 16;
         key |= ComputePosKey(dfTexEffect.viewMatrix()) << 25;
         b->add32(key);
+
+        // Currently we hardcode numbers to convert atlas coordinates to normalized floating point
+        SkASSERT(gp.numTextures() == 1);
+        GrTexture* atlas = gp.textureAccess(0).getTexture();
+        SkASSERT(atlas);
+        b->add32(atlas->width());
+        b->add32(atlas->height());
     }
 
 private:
     SkMatrix                                     fViewMatrix;
     GrColor                                      fColor;
     UniformHandle                                fViewMatrixUniform;
     UniformHandle                                fColorUniform;
     GrDistanceFieldLCDTextGeoProc::DistanceAdjust fDistanceAdjust;
     UniformHandle                                fDistanceAdjustUni;
 
@@ skipping 56 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());
 }