Refactoring of CPU NormalMap handling out into its own class

src/core/SkLightingShader_NormalSource.cpp

Index: src/core/SkLightingShader_NormalSource.cpp
diff --git a/src/core/SkLightingShader_NormalSource.cpp b/src/core/SkLightingShader_NormalSource.cpp
deleted file mode 100644
index b96b1bf083c314b4f6e33f94bb21b5c0c5c0fb59..0000000000000000000000000000000000000000
--- a/src/core/SkLightingShader_NormalSource.cpp
+++ /dev/null
@@ -1,290 +0,0 @@
-/*
- * Copyright 2016 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#include "SkBitmapProcShader.h"
-#include "SkError.h"
-#include "SkErrorInternals.h"
-#include "SkLightingShader.h"
-#include "SkReadBuffer.h"
-#include "SkWriteBuffer.h"
-
-// Genretating vtable
-SkLightingShader::NormalSource::~NormalSource() {}
-
-///////////////////////////////////////////////////////////////////////////////
-
-class NormalMapSourceImpl : public SkLightingShader::NormalSource {
-public:
-    NormalMapSourceImpl(const SkBitmap &normal, const SkVector &invNormRotation,
-                        const SkMatrix *normLocalM)
-        : fNormalMap(normal)
-        , fInvNormRotation(invNormRotation) {
-
-        if (normLocalM) {
-            fNormLocalMatrix = *normLocalM;
-        } else {
-            fNormLocalMatrix.reset();
-        }
-        // Pre-cache so future calls to fNormLocalMatrix.getType() are threadsafe.
-        (void)fNormLocalMatrix.getType();
-    }
-
-#if SK_SUPPORT_GPU
-    sk_sp<GrFragmentProcessor> asFragmentProcessor(GrContext*,
-                                                   const SkMatrix& viewM,
-                                                   const SkMatrix* localMatrix,
-                                                   SkFilterQuality,
-                                                   SkSourceGammaTreatment) const override;
-#endif
-
-    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(NormalMapSourceImpl)
-
-protected:
-    void flatten(SkWriteBuffer& buf) const override;
-
-private:
-    SkBitmap        fNormalMap;
-    SkMatrix        fNormLocalMatrix;
-    SkVector        fInvNormRotation;
-
-    friend class SkLightingShader::NormalSource;
-
-    typedef SkLightingShader::NormalSource INHERITED;
-};
-
-////////////////////////////////////////////////////////////////////////////
-
-#if SK_SUPPORT_GPU
-
-#include "GrCoordTransform.h"
-#include "GrInvariantOutput.h"
-#include "GrTextureParams.h"
-#include "glsl/GrGLSLFragmentProcessor.h"
-#include "glsl/GrGLSLFragmentShaderBuilder.h"
-#include "SkGr.h"
-
-class NormalMapFP : public GrFragmentProcessor {
-public:
-    NormalMapFP(GrTexture* normal, const SkMatrix& normMatrix, const GrTextureParams& normParams,
-                const SkVector& invNormRotation)
-        : fNormDeviceTransform(kLocal_GrCoordSet, normMatrix, normal, normParams.filterMode())
-        , fNormalTextureAccess(normal, normParams)
-        , fInvNormRotation(invNormRotation) {
-        this->addCoordTransform(&fNormDeviceTransform);
-        this->addTextureAccess(&fNormalTextureAccess);
-
-        this->initClassID<NormalMapFP>();
-    }
-
-    class GLSLNormalMapFP : public GrGLSLFragmentProcessor {
-    public:
-        GLSLNormalMapFP() {
-            fInvNormRotation.set(0.0f, 0.0f);
-        }
-
-        void emitCode(EmitArgs& args) override {
-
-            GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
-            GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
-
-            // add uniform
-            const char* xformUniName = nullptr;
-            fXformUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
-                                                   kVec2f_GrSLType, kDefault_GrSLPrecision,
-                                                   "Xform", &xformUniName);
-
-            fragBuilder->codeAppend("vec4 normalColor = ");
-            fragBuilder->appendTextureLookup(args.fTexSamplers[0],
-                                             args.fCoords[0].c_str(),
-                                             args.fCoords[0].getType());
-            fragBuilder->codeAppend(";");
-
-            fragBuilder->codeAppend("vec3 normal = normalColor.rgb - vec3(0.5);");
-
-            // TODO: inverse map the light direction vectors in the vertex shader rather than
-            // transforming all the normals here!
-            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);
-
-            fragBuilder->codeAppend("normal = normalize(m*normal);");
-            fragBuilder->codeAppendf("%s = vec4(normal, 0);", args.fOutputColor);
-        }
-
-        static void GenKey(const GrProcessor& proc, const GrGLSLCaps&,
-                           GrProcessorKeyBuilder* b) {
-            b->add32(0x0);
-        }
-
-    protected:
-        void onSetData(const GrGLSLProgramDataManager& pdman, const GrProcessor& proc) override {
-            const NormalMapFP& normalMapFP = proc.cast<NormalMapFP>();
-
-            const SkVector& invNormRotation = normalMapFP.invNormRotation();
-            if (invNormRotation != fInvNormRotation) {
-                pdman.set2fv(fXformUni, 1, &invNormRotation.fX);
-                fInvNormRotation = invNormRotation;
-            }
-        }
-
-    private:
-        SkVector fInvNormRotation;
-        GrGLSLProgramDataManager::UniformHandle fXformUni;
-    };
-
-    void onGetGLSLProcessorKey(const GrGLSLCaps& caps, GrProcessorKeyBuilder* b) const override {
-        GLSLNormalMapFP::GenKey(*this, caps, b);
-    }
-
-    const char* name() const override { return "NormalMapFP"; }
-
-    void onComputeInvariantOutput(GrInvariantOutput* inout) const override {
-        inout->setToUnknown(GrInvariantOutput::ReadInput::kWillNot_ReadInput);
-    }
-
-    const SkVector& invNormRotation() const { return fInvNormRotation; }
-
-private:
-    GrGLSLFragmentProcessor* onCreateGLSLInstance() const override { return new GLSLNormalMapFP; }
-
-    bool onIsEqual(const GrFragmentProcessor& proc) const override {
-        const NormalMapFP& normalMapFP = proc.cast<NormalMapFP>();
-        return fNormDeviceTransform == normalMapFP.fNormDeviceTransform &&
-               fNormalTextureAccess == normalMapFP.fNormalTextureAccess &&
-               fInvNormRotation     == normalMapFP.fInvNormRotation;
-    }
-
-    GrCoordTransform fNormDeviceTransform;
-    GrTextureAccess  fNormalTextureAccess;
-    SkVector         fInvNormRotation;
-};
-
-// TODO same code at SkLightingShader.cpp. Refactor to common source!
-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;
-}
-
-sk_sp<GrFragmentProcessor> NormalMapSourceImpl::asFragmentProcessor(
-                                                     GrContext *context,
-                                                     const SkMatrix &viewM,
-                                                     const SkMatrix *localMatrix,
-                                                     SkFilterQuality filterQuality,
-                                                     SkSourceGammaTreatment gammaTreatment) const {
-
-    // TODO Here, the old code was checking that diffuse map and normal map are same size, that
-    //      will be addressed when diffuse maps are factored out of SkLightingShader in a future CL
-
-    SkMatrix normM;
-    if (!make_mat(fNormalMap, fNormLocalMatrix, localMatrix, &normM)) {
-        return nullptr;
-    }
-
-    bool doBicubic;
-    GrTextureParams::FilterMode normFilterMode = GrSkFilterQualityToGrFilterMode(
-            SkTMin(filterQuality, kMedium_SkFilterQuality),
-            viewM,
-            fNormLocalMatrix,
-            &doBicubic);
-    SkASSERT(!doBicubic);
-
-    // TODO: support other tile modes
-    GrTextureParams normParams(SkShader::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;
-    }
-
-    return sk_make_sp<NormalMapFP>(normalTexture, normM, normParams, fInvNormRotation);
-}
-
-#endif // SK_SUPPORT_GPU
-
-////////////////////////////////////////////////////////////////////////////
-
-sk_sp<SkFlattenable> NormalMapSourceImpl::CreateProc(SkReadBuffer& buf) {
-
-    SkMatrix normLocalM;
-    bool hasNormLocalM = buf.readBool();
-    if (hasNormLocalM) {
-        buf.readMatrix(&normLocalM);
-    } else {
-        normLocalM.reset();
-    }
-
-    SkBitmap normal;
-    if (!buf.readBitmap(&normal)) {
-        return nullptr;
-    }
-    normal.setImmutable();
-
-    SkVector invNormRotation = {1,0};
-    if (!buf.isVersionLT(SkReadBuffer::kLightingShaderWritesInvNormRotation)) {
-        invNormRotation = buf.readPoint();
-    }
-
-    return sk_make_sp<NormalMapSourceImpl>(normal, invNormRotation, &normLocalM);
-}
-
-void NormalMapSourceImpl::flatten(SkWriteBuffer& buf) const {
-    this->INHERITED::flatten(buf);
-
-    bool hasNormLocalM = !fNormLocalMatrix.isIdentity();
-    buf.writeBool(hasNormLocalM);
-    if (hasNormLocalM) {
-        buf.writeMatrix(fNormLocalMatrix);
-    }
-
-    buf.writeBitmap(fNormalMap);
-    buf.writePoint(fInvNormRotation);
-}
-
-////////////////////////////////////////////////////////////////////////////
-
-sk_sp<SkLightingShader::NormalSource> SkLightingShader::NormalSource::MakeMap(
-        const SkBitmap &normal, const SkVector &invNormRotation, const SkMatrix *normLocalM) {
-
-    // TODO not checking normal and diffuse maps to be same size, will be addressed when diffuse
-    //      maps are factored out of SkLightingShader in a future CL
-    if (normal.isNull() || SkBitmapProcShader::BitmapIsTooBig(normal)) {
-        return nullptr;
-    }
-
-    SkASSERT(SkScalarNearlyEqual(invNormRotation.lengthSqd(), SK_Scalar1));
-
-    return sk_make_sp<NormalMapSourceImpl>(normal, invNormRotation, normLocalM);
-}
-
-////////////////////////////////////////////////////////////////////////////
-
-SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(SkLightingShader::NormalSource)
-    SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(NormalMapSourceImpl)
-SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END
-
-////////////////////////////////////////////////////////////////////////////