Implement color filter as GrGLEffect

src/gpu/gl/GrGLProgram.cpp

Index: src/gpu/gl/GrGLProgram.cpp
diff --git a/src/gpu/gl/GrGLProgram.cpp b/src/gpu/gl/GrGLProgram.cpp
index 6fc43a6e657aa28eaa660b93a6b29e0380206c86..7d7b0a4e477d70936f18fd8597c9e46993469935 100644
--- a/src/gpu/gl/GrGLProgram.cpp
+++ b/src/gpu/gl/GrGLProgram.cpp
@@ -45,7 +45,6 @@ GrGLProgram::GrGLProgram(GrGpuGL* gpu,
     fDstCopyTexUnit = -1;
 
     fColor = GrColor_ILLEGAL;
-    fColorFilterColor = GrColor_ILLEGAL;
 
     fColorEffects.reset(desc.numColorEffects());
     fCoverageEffects.reset(desc.numCoverageEffects());
@@ -85,117 +84,6 @@ void GrGLProgram::overrideBlend(GrBlendCoeff* srcCoeff,
     }
 }
 
-namespace {
-// given two blend coefficients determine whether the src
-// and/or dst computation can be omitted.
-inline void need_blend_inputs(SkXfermode::Coeff srcCoeff,
-                              SkXfermode::Coeff dstCoeff,
-                              bool* needSrcValue,
-                              bool* needDstValue) {
-    if (SkXfermode::kZero_Coeff == srcCoeff) {
-        switch (dstCoeff) {
-            // these all read the src
-            case SkXfermode::kSC_Coeff:
-            case SkXfermode::kISC_Coeff:
-            case SkXfermode::kSA_Coeff:
-            case SkXfermode::kISA_Coeff:
-                *needSrcValue = true;
-                break;
-            default:
-                *needSrcValue = false;
-                break;
-        }
-    } else {
-        *needSrcValue = true;
-    }
-    if (SkXfermode::kZero_Coeff == dstCoeff) {
-        switch (srcCoeff) {
-            // these all read the dst
-            case SkXfermode::kDC_Coeff:
-            case SkXfermode::kIDC_Coeff:
-            case SkXfermode::kDA_Coeff:
-            case SkXfermode::kIDA_Coeff:
-                *needDstValue = true;
-                break;
-            default:
-                *needDstValue = false;
-                break;
-        }
-    } else {
-        *needDstValue = true;
-    }
-}
-
-/**
- * Create a blend_coeff * value string to be used in shader code. Sets empty
- * string if result is trivially zero.
- */
-inline void blend_term_string(SkString* str, SkXfermode::Coeff coeff,
-                       const char* src, const char* dst,
-                       const char* value) {
-    switch (coeff) {
-    case SkXfermode::kZero_Coeff:    /** 0 */
-        *str = "";
-        break;
-    case SkXfermode::kOne_Coeff:     /** 1 */
-        *str = value;
-        break;
-    case SkXfermode::kSC_Coeff:
-        str->printf("(%s * %s)", src, value);
-        break;
-    case SkXfermode::kISC_Coeff:
-        str->printf("((%s - %s) * %s)", GrGLSLExpr<4>(1).c_str(), src, value);
-        break;
-    case SkXfermode::kDC_Coeff:
-        str->printf("(%s * %s)", dst, value);
-        break;
-    case SkXfermode::kIDC_Coeff:
-        str->printf("((%s - %s) * %s)", GrGLSLExpr<4>(1).c_str(), dst, value);
-        break;
-    case SkXfermode::kSA_Coeff:      /** src alpha */
-        str->printf("(%s.a * %s)", src, value);
-        break;
-    case SkXfermode::kISA_Coeff:     /** inverse src alpha (i.e. 1 - sa) */
-        str->printf("((1.0 - %s.a) * %s)", src, value);
-        break;
-    case SkXfermode::kDA_Coeff:      /** dst alpha */
-        str->printf("(%s.a * %s)", dst, value);
-        break;
-    case SkXfermode::kIDA_Coeff:     /** inverse dst alpha (i.e. 1 - da) */
-        str->printf("((1.0 - %s.a) * %s)", dst, value);
-        break;
-    default:
-        GrCrash("Unexpected xfer coeff.");
-        break;
-    }
-}
-/**
- * Adds a line to the fragment shader code which modifies the color by
- * the specified color filter.
- */
-void add_color_filter(GrGLShaderBuilder* builder,
-                      const char * outputVar,
-                      SkXfermode::Coeff uniformCoeff,
-                      SkXfermode::Coeff colorCoeff,
-                      const char* filterColor,
-                      const char* inColor) {
-    SkString colorStr, constStr;
-    blend_term_string(&colorStr, colorCoeff, filterColor, inColor, inColor);
-    blend_term_string(&constStr, uniformCoeff, filterColor, inColor, filterColor);
-    GrGLSLExpr<4> sum;
-    if (colorStr.isEmpty() && constStr.isEmpty()) {
-        sum = GrGLSLExpr<4>(0);
-    } else if (colorStr.isEmpty()) {
-        sum = constStr;
-    } else if (constStr.isEmpty()) {
-        sum = colorStr;
-    } else {
-        sum = GrGLSLExpr<4>(colorStr) + GrGLSLExpr<4>(constStr);
-    }
-    builder->fsCodeAppendf("\t%s = %s;\n", outputVar, sum.c_str());
-}
-}
-
 bool GrGLProgram::genProgram(const GrEffectStage* colorStages[],
                              const GrEffectStage* coverageStages[]) {
     SkASSERT(0 == fProgramID);
@@ -212,23 +100,13 @@ bool GrGLProgram::genProgram(const GrEffectStage* colorStages[],
     // incoming color to current stage being processed.
     GrGLSLExpr<4> inColor = builder.getInputColor();
 
-    // Get the coeffs for the Mode-based color filter, determine if color is needed.
-    SkXfermode::Coeff colorCoeff;
-    SkXfermode::Coeff filterColorCoeff;
-    SkAssertResult(
-        SkXfermode::ModeAsCoeff(static_cast<SkXfermode::Mode>(header.fColorFilterXfermode),
-                                &filterColorCoeff,
-                                &colorCoeff));
-    bool needColor, needFilterColor;
-    need_blend_inputs(filterColorCoeff, colorCoeff, &needFilterColor, &needColor);
-
     // used in order for builder to return the per-stage uniform handles.
     typedef SkTArray<GrGLUniformManager::UniformHandle, true>* UniHandleArrayPtr;
     int maxColorOrCovEffectCnt = GrMax(fDesc.numColorEffects(), fDesc.numCoverageEffects());
     SkAutoTArray<UniHandleArrayPtr> effectUniformArrays(maxColorOrCovEffectCnt);
     SkAutoTArray<GrGLEffect*> glEffects(maxColorOrCovEffectCnt);
 
-    if (needColor) {
+    if (fDesc.numColorEffects()) {
         for (int e = 0; e < fDesc.numColorEffects(); ++e) {
             effectUniformArrays[e] = &fColorEffects[e].fSamplerUnis;
         }
@@ -245,19 +123,6 @@ bool GrGLProgram::genProgram(const GrEffectStage* colorStages[],
         }
     }
 
-    // Insert the color filter. This will soon be replaced by a color effect.
-    if (SkXfermode::kDst_Mode != header.fColorFilterXfermode) {
-        const char* colorFilterColorUniName = NULL;
-        fUniformHandles.fColorFilterUni = builder.addUniform(GrGLShaderBuilder::kFragment_Visibility,
-                                                             kVec4f_GrSLType, "FilterColor",
-                                                             &colorFilterColorUniName);
-
-        builder.fsCodeAppend("\tvec4 filteredColor;\n");
-        add_color_filter(&builder, "filteredColor", filterColorCoeff,
-                         colorCoeff, colorFilterColorUniName, inColor.c_str());
-        inColor = "filteredColor";
-    }
-
     ///////////////////////////////////////////////////////////////////////////
     // compute the partial coverage
     GrGLSLExpr<4> inCoverage = builder.getInputCoverage();
@@ -413,15 +278,6 @@ void GrGLProgram::setData(GrDrawState::BlendOptFlags blendOpts,
     this->setCoverage(drawState, coverage, sharedState);
     this->setMatrixAndRenderTargetHeight(drawState);
 
-    // Setup the SkXfermode::Mode-based colorfilter uniform if necessary
-    if (fUniformHandles.fColorFilterUni.isValid() &&
-        fColorFilterColor != drawState.getColorFilterColor()) {
-        GrGLfloat c[4];
-        GrColorToRGBAFloat(drawState.getColorFilterColor(), c);
-        fUniformManager.set4fv(fUniformHandles.fColorFilterUni, 0, 1, c);
-        fColorFilterColor = drawState.getColorFilterColor();
-    }
-
     if (NULL != dstCopy) {
         if (fUniformHandles.fDstCopyTopLeftUni.isValid()) {
             fUniformManager.set2f(fUniformHandles.fDstCopyTopLeftUni,
@@ -444,17 +300,13 @@ void GrGLProgram::setData(GrDrawState::BlendOptFlags blendOpts,
     }
 
     for (int e = 0; e < fColorEffects.count(); ++e) {
-        // We may have omitted the GrGLEffect because of the color filter logic in genProgram.
-        // This can be removed when the color filter is an effect.
-        if (NULL != fColorEffects[e].fGLEffect) {
-            this->setEffectData(*colorStages[e], fColorEffects[e]);
-        }
+        SkASSERT(NULL != fColorEffects[e].fGLEffect);
+        this->setEffectData(*colorStages[e], fColorEffects[e]);
     }
 
     for (int e = 0; e < fCoverageEffects.count(); ++e) {
-        if (NULL != fCoverageEffects[e].fGLEffect) {
-            this->setEffectData(*coverageStages[e], fCoverageEffects[e]);
-        }
+        SkASSERT(NULL != fCoverageEffects[e].fGLEffect);
+        this->setEffectData(*coverageStages[e], fCoverageEffects[e]);
     }
 }
 
@@ -477,7 +329,7 @@ void GrGLProgram::setColor(const GrDrawState& drawState,
                 }
                 break;
             case GrGLProgramDesc::kUniform_ColorInput:
-                if (fColor != color) {
+                if (fColor != color && fUniformHandles.fColorUni.isValid()) {
                     // OpenGL ES doesn't support unsigned byte varieties of glUniform
                     GrGLfloat c[4];
                     GrColorToRGBAFloat(color, c);