Refactor GrColorSpaceXformHelper

Nonlinear blending mode is going to (sometimes) require additional
uniforms and shader code for color space transformation.

This change just alters the usage of the helper struct so that we can
hide any new logic (without having to change all the FPs that use it).

BUG=skia:

Change-Id: I913478a387973f5bad5aa09a29f85d21daacab94
Reviewed-on: https://skia-review.googlesource.com/9414
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>

10 files changed, 52 insertions, 56 deletions

diff --git a/src/effects/GrAlphaThresholdFragmentProcessor.cpp b/src/effects/GrAlphaThresholdFragmentProcessor.cpp
index 897d44768f..12933ee3c2 100644
--- a/src/effects/GrAlphaThresholdFragmentProcessor.cpp
+++ b/src/effects/GrAlphaThresholdFragmentProcessor.cpp
@@ -79,7 +79,7 @@ protected:
 private:
     GrGLSLProgramDataManager::UniformHandle fInnerThresholdVar;
     GrGLSLProgramDataManager::UniformHandle fOuterThresholdVar;
-    GrGLSLProgramDataManager::UniformHandle fColorSpaceXformVar;
+    GrGLSLColorSpaceXformHelper fColorSpaceHelper;
     typedef GrGLSLFragmentProcessor INHERITED;
 };
 
@@ -94,8 +94,7 @@ void GrGLAlphaThresholdFragmentProcessor::emitCode(EmitArgs& args) {
 
     const GrAlphaThresholdFragmentProcessor& atfp =
         args.fFp.cast<GrAlphaThresholdFragmentProcessor>();
-    GrGLSLColorSpaceXformHelper colorSpaceHelper(uniformHandler, atfp.colorSpaceXform(),
-                                                 &fColorSpaceXformVar);
+    fColorSpaceHelper.emitCode(uniformHandler, atfp.colorSpaceXform());
 
     GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
     SkString coords2D = fragBuilder->ensureCoords2D(args.fTransformedCoords[0]);
@@ -105,7 +104,7 @@ void GrGLAlphaThresholdFragmentProcessor::emitCode(EmitArgs& args) {
     fragBuilder->codeAppendf("vec2 mask_coord = %s;", maskCoords2D.c_str());
     fragBuilder->codeAppend("vec4 input_color = ");
     fragBuilder->appendTextureLookup(args.fTexSamplers[0], "coord", kVec2f_GrSLType,
-                                     &colorSpaceHelper);
+                                     &fColorSpaceHelper);
     fragBuilder->codeAppend(";");
     fragBuilder->codeAppend("vec4 mask_color = ");
     fragBuilder->appendTextureLookup(args.fTexSamplers[1], "mask_coord");
@@ -140,7 +139,7 @@ void GrGLAlphaThresholdFragmentProcessor::onSetData(const GrGLSLProgramDataManag
     pdman.set1f(fInnerThresholdVar, atfp.innerThreshold());
     pdman.set1f(fOuterThresholdVar, atfp.outerThreshold());
     if (SkToBool(atfp.colorSpaceXform())) {
-        pdman.setSkMatrix44(fColorSpaceXformVar, atfp.colorSpaceXform()->srcToDst());
+        fColorSpaceHelper.setData(pdman, atfp.colorSpaceXform());
     }
 }
 
diff --git a/src/effects/SkDisplacementMapEffect.cpp b/src/effects/SkDisplacementMapEffect.cpp
index 00059817dd..8384058370 100644
--- a/src/effects/SkDisplacementMapEffect.cpp
+++ b/src/effects/SkDisplacementMapEffect.cpp
@@ -467,7 +467,7 @@ private:
     typedef GrGLSLProgramDataManager::UniformHandle UniformHandle;
 
     UniformHandle fScaleUni;
-    UniformHandle fColorSpaceXformUni;
+    GrGLSLColorSpaceXformHelper fColorSpaceHelper;
     GrTextureDomain::GLDomain fGLDomain;
 
     typedef GrGLSLFragmentProcessor INHERITED;
@@ -571,9 +571,7 @@ void GrGLDisplacementMapEffect::emitCode(EmitArgs& args) {
                                    // a number smaller than that to approximate 0, but
                                    // leave room for 32-bit float GPU rounding errors.
 
-    GrGLSLColorSpaceXformHelper colorSpaceHelper(args.fUniformHandler,
-                                                 displacementMap.colorSpaceXform(),
-                                                 &fColorSpaceXformUni);
+    fColorSpaceHelper.emitCode(args.fUniformHandler, displacementMap.colorSpaceXform());
 
     GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
     fragBuilder->codeAppendf("\t\tvec4 %s = ", dColor);
@@ -634,7 +632,7 @@ void GrGLDisplacementMapEffect::emitCode(EmitArgs& args) {
                             SkString(cCoords),
                             args.fTexSamplers[1],
                             nullptr,
-                            &colorSpaceHelper);
+                            &fColorSpaceHelper);
     fragBuilder->codeAppend(";\n");
 }
 
@@ -649,7 +647,7 @@ void GrGLDisplacementMapEffect::onSetData(const GrGLSLProgramDataManager& pdman,
                 SkScalarToFloat(scaleY) : SkScalarToFloat(-scaleY));
     fGLDomain.setData(pdman, displacementMap.domain(), colorTex);
     if (SkToBool(displacementMap.colorSpaceXform())) {
-        pdman.setSkMatrix44(fColorSpaceXformUni, displacementMap.colorSpaceXform()->srcToDst());
+        fColorSpaceHelper.setData(pdman, displacementMap.colorSpaceXform());
     }
 }
 
diff --git a/src/effects/SkMagnifierImageFilter.cpp b/src/effects/SkMagnifierImageFilter.cpp
index a78f2235ab..4312fb714e 100644
--- a/src/effects/SkMagnifierImageFilter.cpp
+++ b/src/effects/SkMagnifierImageFilter.cpp
@@ -143,7 +143,7 @@ private:
     UniformHandle       fInvZoomVar;
     UniformHandle       fInvInsetVar;
     UniformHandle       fBoundsVar;
-    UniformHandle       fColorSpaceXformVar;
+    GrGLSLColorSpaceXformHelper fColorSpaceHelper;
 
     typedef GrGLSLFragmentProcessor INHERITED;
 };
@@ -164,8 +164,7 @@ void GrGLMagnifierEffect::emitCode(EmitArgs& args) {
                                             "Bounds");
 
     const GrMagnifierEffect& zoom = args.fFp.cast<GrMagnifierEffect>();
-    GrGLSLColorSpaceXformHelper colorSpaceHelper(uniformHandler, zoom.colorSpaceXform(),
-                                                 &fColorSpaceXformVar);
+    fColorSpaceHelper.emitCode(uniformHandler, zoom.colorSpaceXform());
 
     GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
     SkString coords2D = fragBuilder->ensureCoords2D(args.fTransformedCoords[0]);
@@ -194,7 +193,7 @@ void GrGLMagnifierEffect::emitCode(EmitArgs& args) {
     fragBuilder->codeAppend("\t\tvec2 mix_coord = mix(coord, zoom_coord, weight);\n");
     fragBuilder->codeAppend("\t\tvec4 output_color = ");
     fragBuilder->appendTextureLookup(args.fTexSamplers[0], "mix_coord", kVec2f_GrSLType,
-                                     &colorSpaceHelper);
+                                     &fColorSpaceHelper);
     fragBuilder->codeAppend(";\n");
 
     fragBuilder->codeAppendf("\t\t%s = output_color;", args.fOutputColor);
@@ -239,7 +238,7 @@ void GrGLMagnifierEffect::onSetData(const GrGLSLProgramDataManager& pdman,
     }
 
     if (SkToBool(zoom.colorSpaceXform())) {
-        pdman.setSkMatrix44(fColorSpaceXformVar, zoom.colorSpaceXform()->srcToDst());
+        fColorSpaceHelper.setData(pdman, zoom.colorSpaceXform());
     }
 }
 
diff --git a/src/effects/gradients/SkGradientShader.cpp b/src/effects/gradients/SkGradientShader.cpp
index bba9f857cd..8538ddd7fe 100644
--- a/src/effects/gradients/SkGradientShader.cpp
+++ b/src/effects/gradients/SkGradientShader.cpp
@@ -1345,7 +1345,7 @@ void GrGradientEffect::GLSLProcessor::onSetData(const GrGLSLProgramDataManager&
                 fCachedYCoord = yCoord;
             }
             if (SkToBool(e.fColorSpaceXform)) {
-                pdman.setSkMatrix44(fColorSpaceXformUni, e.fColorSpaceXform->srcToDst());
+                fColorSpaceHelper.setData(pdman, e.fColorSpaceXform.get());
             }
             break;
         }
@@ -1583,15 +1583,14 @@ void GrGradientEffect::GLSLProcessor::emitColor(GrGLSLFPFragmentBuilder* fragBui
         }
 
         case kTexture_ColorType: {
-            GrGLSLColorSpaceXformHelper colorSpaceHelper(uniformHandler, ge.fColorSpaceXform.get(),
-                                                         &fColorSpaceXformUni);
+            fColorSpaceHelper.emitCode(uniformHandler, ge.fColorSpaceXform.get());
 
             const char* fsyuni = uniformHandler->getUniformCStr(fFSYUni);
 
             fragBuilder->codeAppendf("vec2 coord = vec2(%s, %s);", gradientTValue, fsyuni);
             fragBuilder->codeAppendf("%s = ", outputColor);
             fragBuilder->appendTextureLookupAndModulate(inputColor, texSamplers[0], "coord",
-                                                        kVec2f_GrSLType, &colorSpaceHelper);
+                                                        kVec2f_GrSLType, &fColorSpaceHelper);
             fragBuilder->codeAppend(";");
 
             break;
diff --git a/src/effects/gradients/SkGradientShaderPriv.h b/src/effects/gradients/SkGradientShaderPriv.h
index 1e3415371e..7f1f5f8c88 100644
--- a/src/effects/gradients/SkGradientShaderPriv.h
+++ b/src/effects/gradients/SkGradientShaderPriv.h
@@ -295,6 +295,7 @@ static inline int next_dither_toggle(int toggle) {
 #include "GrColorSpaceXform.h"
 #include "GrCoordTransform.h"
 #include "GrFragmentProcessor.h"
+#include "glsl/GrGLSLColorSpaceXformHelper.h"
 #include "glsl/GrGLSLFragmentProcessor.h"
 #include "glsl/GrGLSLProgramDataManager.h"
 
@@ -520,7 +521,7 @@ private:
     GrGLSLProgramDataManager::UniformHandle fColorsUni;
     GrGLSLProgramDataManager::UniformHandle fHardStopT;
     GrGLSLProgramDataManager::UniformHandle fFSYUni;
-    GrGLSLProgramDataManager::UniformHandle fColorSpaceXformUni;
+    GrGLSLColorSpaceXformHelper             fColorSpaceHelper;
 
     typedef GrGLSLFragmentProcessor INHERITED;
 };
diff --git a/src/gpu/effects/GrBicubicEffect.cpp b/src/gpu/effects/GrBicubicEffect.cpp
index 5f06fc166a..ec7ad79475 100644
--- a/src/gpu/effects/GrBicubicEffect.cpp
+++ b/src/gpu/effects/GrBicubicEffect.cpp
@@ -32,7 +32,7 @@ private:
     typedef GrGLSLProgramDataManager::UniformHandle UniformHandle;
 
     UniformHandle               fImageIncrementUni;
-    UniformHandle               fColorSpaceXformUni;
+    GrGLSLColorSpaceXformHelper fColorSpaceHelper;
     GrTextureDomain::GLDomain   fDomain;
 
     typedef GrGLSLFragmentProcessor INHERITED;
@@ -48,8 +48,7 @@ void GrGLBicubicEffect::emitCode(EmitArgs& args) {
 
     const char* imgInc = uniformHandler->getUniformCStr(fImageIncrementUni);
 
-    GrGLSLColorSpaceXformHelper colorSpaceHelper(uniformHandler, bicubicEffect.colorSpaceXform(),
-                                                 &fColorSpaceXformUni);
+    fColorSpaceHelper.emitCode(uniformHandler, bicubicEffect.colorSpaceXform());
 
     GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
     SkString coords2D = fragBuilder->ensureCoords2D(args.fTransformedCoords[0]);
@@ -107,9 +106,9 @@ void GrGLBicubicEffect::emitCode(EmitArgs& args) {
             y);
     }
     SkString bicubicColor("(wy.x * s0 + wy.y * s1 + wy.z * s2 + wy.w * s3)");
-    if (colorSpaceHelper.getXformMatrix()) {
+    if (fColorSpaceHelper.isValid()) {
         SkString xformedColor;
-        fragBuilder->appendColorGamutXform(&xformedColor, bicubicColor.c_str(), &colorSpaceHelper);
+        fragBuilder->appendColorGamutXform(&xformedColor, bicubicColor.c_str(), &fColorSpaceHelper);
         bicubicColor.swap(xformedColor);
     }
     fragBuilder->codeAppendf("%s = %s;",
@@ -127,7 +126,7 @@ void GrGLBicubicEffect::onSetData(const GrGLSLProgramDataManager& pdman,
     pdman.set2fv(fImageIncrementUni, 1, imageIncrement);
     fDomain.setData(pdman, bicubicEffect.domain(), texture);
     if (SkToBool(bicubicEffect.colorSpaceXform())) {
-        pdman.setSkMatrix44(fColorSpaceXformUni, bicubicEffect.colorSpaceXform()->srcToDst());
+        fColorSpaceHelper.setData(pdman, bicubicEffect.colorSpaceXform());
     }
 }
 
diff --git a/src/gpu/effects/GrSimpleTextureEffect.cpp b/src/gpu/effects/GrSimpleTextureEffect.cpp
index bd4e7206f8..8492f5b80b 100644
--- a/src/gpu/effects/GrSimpleTextureEffect.cpp
+++ b/src/gpu/effects/GrSimpleTextureEffect.cpp
@@ -42,9 +42,7 @@ class GrGLSimpleTextureEffect : public GrGLSLFragmentProcessor {
 public:
     void emitCode(EmitArgs& args) override {
         const GrSimpleTextureEffect& textureEffect = args.fFp.cast<GrSimpleTextureEffect>();
-        GrGLSLColorSpaceXformHelper colorSpaceHelper(args.fUniformHandler,
-                                                     textureEffect.colorSpaceXform(),
-                                                     &fColorSpaceXformUni);
+        fColorSpaceHelper.emitCode(args.fUniformHandler, textureEffect.colorSpaceXform());
 
         GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
         fragBuilder->codeAppendf("%s = ", args.fOutputColor);
@@ -52,7 +50,7 @@ public:
                                                     args.fTexSamplers[0],
                                                     args.fTransformedCoords[0].c_str(),
                                                     args.fTransformedCoords[0].getType(),
-                                                    &colorSpaceHelper);
+                                                    &fColorSpaceHelper);
         fragBuilder->codeAppend(";");
     }
 
@@ -66,14 +64,14 @@ protected:
     void onSetData(const GrGLSLProgramDataManager& pdman, const GrProcessor& processor) override {
         const GrSimpleTextureEffect& textureEffect = processor.cast<GrSimpleTextureEffect>();
         if (SkToBool(textureEffect.colorSpaceXform())) {
-            pdman.setSkMatrix44(fColorSpaceXformUni, textureEffect.colorSpaceXform()->srcToDst());
+            fColorSpaceHelper.setData(pdman, textureEffect.colorSpaceXform());
         }
     }
 
 private:
     typedef GrGLSLFragmentProcessor INHERITED;
 
-    UniformHandle fColorSpaceXformUni;
+    GrGLSLColorSpaceXformHelper fColorSpaceHelper;
 };
 
 ///////////////////////////////////////////////////////////////////////////////
diff --git a/src/gpu/effects/GrTextureDomain.cpp b/src/gpu/effects/GrTextureDomain.cpp
index 2ac6af8375..7a43328bc1 100644
--- a/src/gpu/effects/GrTextureDomain.cpp
+++ b/src/gpu/effects/GrTextureDomain.cpp
@@ -321,9 +321,7 @@ GrGLSLFragmentProcessor* GrTextureDomainEffect::onCreateGLSLInstance() const  {
             GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
             SkString coords2D = fragBuilder->ensureCoords2D(args.fTransformedCoords[0]);
 
-            GrGLSLColorSpaceXformHelper colorSpaceHelper(args.fUniformHandler,
-                                                         tde.colorSpaceXform(),
-                                                         &fColorSpaceXformUni);
+            fColorSpaceHelper.emitCode(args.fUniformHandler, tde.colorSpaceXform());
             fGLDomain.sampleTexture(fragBuilder,
                                     args.fUniformHandler,
                                     args.fShaderCaps,
@@ -332,7 +330,7 @@ GrGLSLFragmentProcessor* GrTextureDomainEffect::onCreateGLSLInstance() const  {
                                     coords2D,
                                     args.fTexSamplers[0],
                                     args.fInputColor,
-                                    &colorSpaceHelper);
+                                    &fColorSpaceHelper);
         }
 
     protected:
@@ -341,13 +339,13 @@ GrGLSLFragmentProcessor* GrTextureDomainEffect::onCreateGLSLInstance() const  {
             const GrTextureDomain& domain = tde.fTextureDomain;
             fGLDomain.setData(pdman, domain, tde.textureSampler(0).texture());
             if (SkToBool(tde.colorSpaceXform())) {
-                pdman.setSkMatrix44(fColorSpaceXformUni, tde.colorSpaceXform()->srcToDst());
+                fColorSpaceHelper.setData(pdman, tde.colorSpaceXform());
             }
         }
 
     private:
         GrTextureDomain::GLDomain         fGLDomain;
-        UniformHandle                     fColorSpaceXformUni;
+        GrGLSLColorSpaceXformHelper       fColorSpaceHelper;
     };
 
     return new GLSLProcessor;
diff --git a/src/gpu/glsl/GrGLSLColorSpaceXformHelper.h b/src/gpu/glsl/GrGLSLColorSpaceXformHelper.h
index 5e112f9f91..1571b06231 100644
--- a/src/gpu/glsl/GrGLSLColorSpaceXformHelper.h
+++ b/src/gpu/glsl/GrGLSLColorSpaceXformHelper.h
@@ -12,29 +12,33 @@
 #include "GrGLSLUniformHandler.h"
 
 /**
- * Stack helper class to assist with using GrColorSpaceXform within an FP's emitCode function.
- * This injects the uniform declaration, and stores the information needed to generate correct
- * gamut-transformation shader code.
+ * Helper class to assist with using GrColorSpaceXform within an FP. This manages all of the
+ * uniforms needed, and can be passed to shader builder functions to automatically generate the
+ * correct color space transformation code.
  */
 class GrGLSLColorSpaceXformHelper : public SkNoncopyable {
 public:
-    GrGLSLColorSpaceXformHelper(GrGLSLUniformHandler* uniformHandler,
-                                GrColorSpaceXform* colorSpaceXform,
-                                GrGLSLProgramDataManager::UniformHandle* handle) {
-        SkASSERT(uniformHandler && handle);
+    GrGLSLColorSpaceXformHelper() : fValid(false) {}
+
+    void emitCode(GrGLSLUniformHandler* uniformHandler, GrColorSpaceXform* colorSpaceXform) {
+        SkASSERT(uniformHandler);
         if (colorSpaceXform) {
-            *handle = uniformHandler->addUniform(kFragment_GrShaderFlag, kMat44f_GrSLType,
-                                                 kDefault_GrSLPrecision, "ColorXform",
-                                                 &fXformMatrix);
-        } else {
-            fXformMatrix = nullptr;
+            fGamutXformVar = uniformHandler->addUniform(kFragment_GrShaderFlag, kMat44f_GrSLType,
+                                                        kDefault_GrSLPrecision, "ColorXform");
+            fValid = true;
         }
     }
 
-    const char* getXformMatrix() const { return fXformMatrix; }
+    void setData(const GrGLSLProgramDataManager& pdman, GrColorSpaceXform* colorSpaceXform) {
+        pdman.setSkMatrix44(fGamutXformVar, colorSpaceXform->srcToDst());
+    }
+
+    bool isValid() const { return fValid; }
+    GrGLSLProgramDataManager::UniformHandle const gamutXformUniform() { return fGamutXformVar; }
 
 private:
-    const char* fXformMatrix;
+    GrGLSLProgramDataManager::UniformHandle fGamutXformVar;
+    bool fValid;
 };
 
 #endif
diff --git a/src/gpu/glsl/GrGLSLShaderBuilder.cpp b/src/gpu/glsl/GrGLSLShaderBuilder.cpp
index 17f7f10287..865876611a 100644
--- a/src/gpu/glsl/GrGLSLShaderBuilder.cpp
+++ b/src/gpu/glsl/GrGLSLShaderBuilder.cpp
@@ -91,7 +91,7 @@ void GrGLSLShaderBuilder::appendTextureLookup(SamplerHandle samplerHandle,
                                               const char* coordName,
                                               GrSLType varyingType,
                                               GrGLSLColorSpaceXformHelper* colorXformHelper) {
-    if (colorXformHelper && colorXformHelper->getXformMatrix()) {
+    if (colorXformHelper && colorXformHelper->isValid()) {
         // With a color gamut transform, we need to wrap the lookup in another function call
         SkString lookup;
         this->appendTextureLookup(&lookup, samplerHandle, coordName, varyingType);
@@ -109,7 +109,7 @@ void GrGLSLShaderBuilder::appendTextureLookupAndModulate(
                                                     GrGLSLColorSpaceXformHelper* colorXformHelper) {
     SkString lookup;
     this->appendTextureLookup(&lookup, samplerHandle, coordName, varyingType);
-    if (colorXformHelper && colorXformHelper->getXformMatrix()) {
+    if (colorXformHelper && colorXformHelper->isValid()) {
         SkString xform;
         this->appendColorGamutXform(&xform, lookup.c_str(), colorXformHelper);
         this->codeAppend((GrGLSLExpr4(modulation) * GrGLSLExpr4(xform)).c_str());
@@ -141,8 +141,9 @@ void GrGLSLShaderBuilder::appendColorGamutXform(SkString* out,
                        functionBody.c_str(),
                        &colorGamutXformFuncName);
 
+    GrGLSLUniformHandler* uniformHandler = fProgramBuilder->uniformHandler();
     out->appendf("%s(%s, %s)", colorGamutXformFuncName.c_str(), srcColor,
-                 colorXformHelper->getXformMatrix());
+                 uniformHandler->getUniformCStr(colorXformHelper->gamutXformUniform()));
 }
 
 void GrGLSLShaderBuilder::appendColorGamutXform(const char* srcColor,