Refactoring of GPU NormalMap handling out into its own class

src/core/SkLightingShader.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmapProcState.h"
 #include "SkColor.h"
 #include "SkEmptyShader.h"
 #include "SkErrorInternals.h"
 #include "SkLightingShader.h"
 #include "SkMathPriv.h"
 #include "SkPoint3.h"
 #include "SkReadBuffer.h"
 #include "SkWriteBuffer.h"
+#include "SkNormalSourceImpl.h"

[egdaniel, 2016/06/09 16:56:37]

we place include in alphabetical order, so move this up between SkMathPriv and
SkPoint3

[dvonbeck, 2016/06/09 18:51:29]

Done.

 
 ////////////////////////////////////////////////////////////////////////////
 
 /*
    SkLightingShader TODOs:
         support other than clamp mode
         allow 'diffuse' & 'normal' to be of different dimensions?
         support different light types
         support multiple lights
         enforce normal map is 4 channel
@@ skipping 33 matching lines @@
         , fInvNormRotation(invNormRotation) {
 
         if (normLocalM) {
             fNormLocalMatrix = *normLocalM;
         } else {
             fNormLocalMatrix.reset();
         }
         // Pre-cache so future calls to fNormLocalMatrix.getType() are threadsafe.
         (void)fNormLocalMatrix.getType();
 
+        fNormalSource = NormalMapSource::Make(fNormalMap, fInvNormRotation, &fNormLocalMatrix);
     }
 
     bool isOpaque() const override;
 
 #if SK_SUPPORT_GPU
     const GrFragmentProcessor* asFragmentProcessor(GrContext*,
                                                    const SkMatrix& viewM,
                                                    const SkMatrix* localMatrix,
                                                    SkFilterQuality,
                                                    SkSourceGammaTreatment) const override;
@@ skipping 32 matching lines @@
     SkBitmap        fDiffuseMap;
     SkBitmap        fNormalMap;
 
     sk_sp<SkLights> fLights;
 
     SkMatrix        fNormLocalMatrix;
     SkVector        fInvNormRotation;
 
     friend class SkLightingShader;
 
+    sk_sp<NormalSource> fNormalSource;
+
     typedef SkShader INHERITED;
 };
 
 ////////////////////////////////////////////////////////////////////////////
 
 #if SK_SUPPORT_GPU
 
 #include "GrCoordTransform.h"
 #include "GrFragmentProcessor.h"
 #include "GrInvariantOutput.h"
 #include "GrTextureAccess.h"
 #include "glsl/GrGLSLFragmentProcessor.h"
 #include "glsl/GrGLSLFragmentShaderBuilder.h"
 #include "glsl/GrGLSLProgramDataManager.h"
 #include "glsl/GrGLSLUniformHandler.h"
 #include "SkGr.h"
 #include "SkGrPriv.h"
 
 class LightingFP : public GrFragmentProcessor {
 public:
-    LightingFP(GrTexture* diffuse, GrTexture* normal, const SkMatrix& diffMatrix,
-               const SkMatrix& normMatrix, const GrTextureParams& diffParams,
-               const GrTextureParams& normParams, sk_sp<SkLights> lights,
-               const SkVector& invNormRotation)
+    LightingFP(GrTexture* diffuse, const SkMatrix& diffMatrix, const GrTextureParams& diffParams,
+               sk_sp<SkLights> lights, const GrFragmentProcessor* normalFP)
         : fDiffDeviceTransform(kLocal_GrCoordSet, diffMatrix, diffuse, diffParams.filterMode())
-        , fNormDeviceTransform(kLocal_GrCoordSet, normMatrix, normal, normParams.filterMode())
-        , fDiffuseTextureAccess(diffuse, diffParams)
-        , fNormalTextureAccess(normal, normParams)
-        , fInvNormRotation(invNormRotation) {
+        , fDiffuseTextureAccess(diffuse, diffParams) {
         this->addCoordTransform(&fDiffDeviceTransform);
-        this->addCoordTransform(&fNormDeviceTransform);
         this->addTextureAccess(&fDiffuseTextureAccess);
-        this->addTextureAccess(&fNormalTextureAccess);
 
         // fuse all ambient lights into a single one
         fAmbientColor.set(0.0f, 0.0f, 0.0f);
         for (int i = 0; i < lights->numLights(); ++i) {
             if (SkLights::Light::kAmbient_LightType == lights->light(i).type()) {
                 fAmbientColor += lights->light(i).color();
             } else {
                 // TODO: handle more than one of these
                 fLightColor = lights->light(i).color();
                 fLightDir = lights->light(i).dir();
             }
         }
 
+        this->registerChildProcessor(normalFP);
         this->initClassID<LightingFP>();
     }
 
     class LightingGLFP : public GrGLSLFragmentProcessor {
     public:
         LightingGLFP() {
             fLightDir.fX = 10000.0f;
             fLightColor.fX = 0.0f;
             fAmbientColor.fX = 0.0f;
-            fInvNormRotation.set(0.0f, 0.0f);
         }
 
         void emitCode(EmitArgs& args) override {
 
             GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
             GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
 
             // add uniforms
             const char* lightDirUniName = nullptr;
             fLightDirUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
                                                       kVec3f_GrSLType, kDefault_GrSLPrecision,
                                                       "LightDir", &lightDirUniName);
 
             const char* lightColorUniName = nullptr;
             fLightColorUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
                                                         kVec3f_GrSLType, kDefault_GrSLPrecision,
                                                         "LightColor", &lightColorUniName);
 
             const char* ambientColorUniName = nullptr;
             fAmbientColorUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
                                                           kVec3f_GrSLType, kDefault_GrSLPrecision,
                                                           "AmbientColor", &ambientColorUniName);
 
-            const char* xformUniName = nullptr;
-            fXformUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
-                                                   kVec2f_GrSLType, kDefault_GrSLPrecision,
-                                                   "Xform", &xformUniName);
-
             fragBuilder->codeAppend("vec4 diffuseColor = ");
             fragBuilder->appendTextureLookupAndModulate(args.fInputColor, args.fTexSamplers[0],
                                                 args.fCoords[0].c_str(),
                                                 args.fCoords[0].getType());
             fragBuilder->codeAppend(";");
 
-            fragBuilder->codeAppend("vec4 normalColor = ");
-            fragBuilder->appendTextureLookup(args.fTexSamplers[1],
-                                     args.fCoords[1].c_str(),
-                                     args.fCoords[1].getType());
-            fragBuilder->codeAppend(";");
+            SkString dstNormalName("dstNormal");
+            this->emitChild(0, nullptr, &dstNormalName, args);
 
-            fragBuilder->codeAppend("vec3 normal = normalColor.rgb - vec3(0.5);");
-
-            fragBuilder->codeAppendf(
-                                 "mat3 m = mat3(%s.x, -%s.y, 0.0, %s.y, %s.x, 0.0, 0.0, 0.0, 1.0);",
-                                 xformUniName, xformUniName, xformUniName, xformUniName);
-
-            // TODO: inverse map the light direction vectors in the vertex shader rather than
-            // transforming all the normals here!
-            fragBuilder->codeAppend("normal = normalize(m*normal);");
-
+            fragBuilder->codeAppendf("vec3 normal = %s.xyz;", dstNormalName.c_str());
             fragBuilder->codeAppendf("float NdotL = clamp(dot(normal, %s), 0.0, 1.0);",
                                      lightDirUniName);
             // diffuse light
             fragBuilder->codeAppendf("vec3 result = %s*diffuseColor.rgb*NdotL;", lightColorUniName);
             // ambient light
             fragBuilder->codeAppendf("result += %s;", ambientColorUniName);
             fragBuilder->codeAppendf("%s = vec4(result.rgb, diffuseColor.a);", args.fOutputColor);
         }
 
+        // TODO does this need changing now?

[egdaniel, 2016/06/09 16:56:37]

It shouldn't need to. The parent and child processors emit their own keys
independent of each other.

[dvonbeck, 2016/06/09 18:51:28]

Done.

         static void GenKey(const GrProcessor& proc, const GrGLSLCaps&,
                            GrProcessorKeyBuilder* b) {
 //            const LightingFP& lightingFP = proc.cast<LightingFP>();
             // only one shader generated currently
             b->add32(0x0);
         }
 
     protected:
         void onSetData(const GrGLSLProgramDataManager& pdman, const GrProcessor& proc) override {
             const LightingFP& lightingFP = proc.cast<LightingFP>();
 
             const SkVector3& lightDir = lightingFP.lightDir();
             if (lightDir != fLightDir) {
                 pdman.set3fv(fLightDirUni, 1, &lightDir.fX);
                 fLightDir = lightDir;
             }
 
             const SkColor3f& lightColor = lightingFP.lightColor();
             if (lightColor != fLightColor) {
                 pdman.set3fv(fLightColorUni, 1, &lightColor.fX);
                 fLightColor = lightColor;
             }
 
             const SkColor3f& ambientColor = lightingFP.ambientColor();
             if (ambientColor != fAmbientColor) {
                 pdman.set3fv(fAmbientColorUni, 1, &ambientColor.fX);
                 fAmbientColor = ambientColor;
             }
-
-            const SkVector& invNormRotation = lightingFP.invNormRotation();
-            if (invNormRotation != fInvNormRotation) {
-                pdman.set2fv(fXformUni, 1, &invNormRotation.fX);
-                fInvNormRotation = invNormRotation;
-            }
         }
 
     private:
         SkVector3 fLightDir;
         GrGLSLProgramDataManager::UniformHandle fLightDirUni;
 
         SkColor3f fLightColor;
         GrGLSLProgramDataManager::UniformHandle fLightColorUni;
 
         SkColor3f fAmbientColor;
         GrGLSLProgramDataManager::UniformHandle fAmbientColorUni;
-
-        SkVector fInvNormRotation;
-        GrGLSLProgramDataManager::UniformHandle fXformUni;
     };
 
     void onGetGLSLProcessorKey(const GrGLSLCaps& caps, GrProcessorKeyBuilder* b) const override {
         LightingGLFP::GenKey(*this, caps, b);
     }
 
     const char* name() const override { return "LightingFP"; }
 
     void onComputeInvariantOutput(GrInvariantOutput* inout) const override {
         inout->mulByUnknownFourComponents();
     }
 
     const SkVector3& lightDir() const { return fLightDir; }
     const SkColor3f& lightColor() const { return fLightColor; }
     const SkColor3f& ambientColor() const { return fAmbientColor; }
-    const SkVector& invNormRotation() const { return fInvNormRotation; }
 
 private:
     GrGLSLFragmentProcessor* onCreateGLSLInstance() const override { return new LightingGLFP; }
 
     bool onIsEqual(const GrFragmentProcessor& proc) const override {
         const LightingFP& lightingFP = proc.cast<LightingFP>();
         return fDiffDeviceTransform == lightingFP.fDiffDeviceTransform &&
-               fNormDeviceTransform == lightingFP.fNormDeviceTransform &&
                fDiffuseTextureAccess == lightingFP.fDiffuseTextureAccess &&
-               fNormalTextureAccess == lightingFP.fNormalTextureAccess &&
                fLightDir == lightingFP.fLightDir &&
                fLightColor == lightingFP.fLightColor &&
-               fAmbientColor == lightingFP.fAmbientColor &&
-               fInvNormRotation == lightingFP.fInvNormRotation;
+               fAmbientColor == lightingFP.fAmbientColor;
     }
 
     GrCoordTransform fDiffDeviceTransform;
-    GrCoordTransform fNormDeviceTransform;
     GrTextureAccess  fDiffuseTextureAccess;
-    GrTextureAccess  fNormalTextureAccess;
     SkVector3        fLightDir;
     SkColor3f        fLightColor;
     SkColor3f        fAmbientColor;
-
-    SkVector         fInvNormRotation;
 };
 
 ////////////////////////////////////////////////////////////////////////////
 
 static bool make_mat(const SkBitmap& bm,
                      const SkMatrix& localMatrix1,
                      const SkMatrix* localMatrix2,
                      SkMatrix* result) {
 
     result->setIDiv(bm.width(), bm.height());
 
     SkMatrix lmInverse;
     if (!localMatrix1.invert(&lmInverse)) {
         return false;
     }
     if (localMatrix2) {
         SkMatrix inv;
         if (!localMatrix2->invert(&inv)) {
             return false;
         }
         lmInverse.postConcat(inv);
     }
     result->preConcat(lmInverse);
 
     return true;
 }
 
+//const GrFragmentProcessor*
+
 const GrFragmentProcessor* SkLightingShaderImpl::asFragmentProcessor(
                                                      GrContext* context,
                                                      const SkMatrix& viewM,
                                                      const SkMatrix* localMatrix,
                                                      SkFilterQuality filterQuality,
                                                      SkSourceGammaTreatment gammaTreatment) const {
     // we assume diffuse and normal maps have same width and height
     // TODO: support different sizes
     SkASSERT(fDiffuseMap.width() == fNormalMap.width() &&
              fDiffuseMap.height() == fNormalMap.height());
-    SkMatrix diffM, normM;
+    SkMatrix diffM;
 
     if (!make_mat(fDiffuseMap, this->getLocalMatrix(), localMatrix, &diffM)) {
         return nullptr;
     }
 
-    if (!make_mat(fNormalMap, fNormLocalMatrix, localMatrix, &normM)) {
-        return nullptr;
-    }
-
     bool doBicubic;
     GrTextureParams::FilterMode diffFilterMode = GrSkFilterQualityToGrFilterMode(
                                         SkTMin(filterQuality, kMedium_SkFilterQuality),
                                         viewM,
                                         this->getLocalMatrix(),
                                         &doBicubic);
     SkASSERT(!doBicubic);
 
-    GrTextureParams::FilterMode normFilterMode = GrSkFilterQualityToGrFilterMode(
-                                        SkTMin(filterQuality, kMedium_SkFilterQuality),
-                                        viewM,
-                                        fNormLocalMatrix,
-                                        &doBicubic);
-    SkASSERT(!doBicubic);
-
     // TODO: support other tile modes
     GrTextureParams diffParams(kClamp_TileMode, diffFilterMode);
     SkAutoTUnref<GrTexture> diffuseTexture(GrRefCachedBitmapTexture(context,
                                                                     fDiffuseMap, diffParams,
                                                                     gammaTreatment));
     if (!diffuseTexture) {
         SkErrorInternals::SetError(kInternalError_SkError, "Couldn't convert bitmap to texture.");
         return nullptr;
     }
 
-    GrTextureParams normParams(kClamp_TileMode, normFilterMode);
-    SkAutoTUnref<GrTexture> normalTexture(GrRefCachedBitmapTexture(context,
-                                                                   fNormalMap, normParams,
-                                                                   gammaTreatment));
-    if (!normalTexture) {
-        SkErrorInternals::SetError(kInternalError_SkError, "Couldn't convert bitmap to texture.");
-        return nullptr;
-    }
-
+    // TODO is this correct memory handling?

[egdaniel, 2016/06/09 16:56:37]

should work. When you pass it into LightingFP and you call registerChild it
should ref it there. Thus you want to then remove your ref from this version.

[dvonbeck, 2016/06/09 18:51:28]

The master upstream changed and asFragmentProcessor() now returns an sk_sp<>. I
assume the memory handling is still correct since it will unref when the sk_sp
goes out of scope.

+    SkAutoTUnref<const GrFragmentProcessor> normalFP(
+            fNormalSource->asFragmentProcessor(context, viewM, localMatrix, filterQuality,
+                                               gammaTreatment)
+    );
     SkAutoTUnref<const GrFragmentProcessor> inner (
-        new LightingFP(diffuseTexture, normalTexture, diffM, normM, diffParams, normParams, fLights,
-                       fInvNormRotation));
+        new LightingFP(diffuseTexture, diffM, diffParams, fLights, normalFP));
     return GrFragmentProcessor::MulOutputByInputAlpha(inner);
 }
 
 #endif
 
 ////////////////////////////////////////////////////////////////////////////
 
 bool SkLightingShaderImpl::isOpaque() const {
     return fDiffuseMap.isOpaque();
 }
@@ skipping 306 matching lines @@
                                             invNormRotation, diffLocalM, normLocalM);
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(SkLightingShader)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkLightingShaderImpl)
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END
 
 ///////////////////////////////////////////////////////////////////////////////