Move SkColorMatrixFilter implementation to core.

src/effects/SkColorMatrixFilter.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkColorMatrixFilter.h"
-#include "SkColorMatrix.h"
-#include "SkColorPriv.h"
-#include "SkNx.h"
-#include "SkReadBuffer.h"
-#include "SkWriteBuffer.h"
-#include "SkUnPreMultiply.h"
-#include "SkString.h"
-
-#define SK_PMORDER_INDEX_A  (SK_A32_SHIFT / 8)
-#define SK_PMORDER_INDEX_R  (SK_R32_SHIFT / 8)
-#define SK_PMORDER_INDEX_G  (SK_G32_SHIFT / 8)
-#define SK_PMORDER_INDEX_B  (SK_B32_SHIFT / 8)
-
-static void transpose_to_pmorder(float dst[20], const float src[20]) {
-    const float* srcR = src + 0;
-    const float* srcG = src + 5;
-    const float* srcB = src + 10;
-    const float* srcA = src + 15;
-
-    for (int i = 0; i < 20; i += 4) {
-        dst[i + SK_PMORDER_INDEX_A] = *srcA++;
-        dst[i + SK_PMORDER_INDEX_R] = *srcR++;
-        dst[i + SK_PMORDER_INDEX_G] = *srcG++;
-        dst[i + SK_PMORDER_INDEX_B] = *srcB++;
-    }
-}
-
-// src is [20] but some compilers won't accept __restrict__ on anything
-// but an raw pointer or reference
-void SkColorMatrixFilter::initState(const SkScalar* SK_RESTRICT src) {
-    transpose_to_pmorder(fTranspose, src);
-
-    const float* array = fMatrix.fMat;
-
-    // check if we have to munge Alpha
-    bool changesAlpha = (array[15] || array[16] || array[17] || (array[18] - 1) || array[19]);
-    bool usesAlpha = (array[3] || array[8] || array[13]);
-
-    if (changesAlpha || usesAlpha) {
-        fFlags = changesAlpha ? 0 : kAlphaUnchanged_Flag;
-    } else {
-        fFlags = kAlphaUnchanged_Flag;
-    }
-    fFlags |= kSupports4f_Flag;
-}
-
-///////////////////////////////////////////////////////////////////////////////
-
-SkColorMatrixFilter::SkColorMatrixFilter(const SkColorMatrix& cm) : fMatrix(cm) {
-    this->initState(cm.fMat);
-}
-
-SkColorMatrixFilter::SkColorMatrixFilter(const SkScalar array[20]) {
-    memcpy(fMatrix.fMat, array, 20 * sizeof(SkScalar));
-    this->initState(array);
-}
-
-uint32_t SkColorMatrixFilter::getFlags() const {
-    return this->INHERITED::getFlags() | fFlags;
-}
-
-static Sk4f scale_rgb(float scale) {
-    static_assert(SkPM4f::A == 3, "Alpha is lane 3");
-    return Sk4f(scale, scale, scale, 1);
-}
-
-static Sk4f premul(const Sk4f& x) {
-    return x * scale_rgb(x.kth<SkPM4f::A>());
-}
-
-static Sk4f unpremul(const Sk4f& x) {
-    return x * scale_rgb(1 / x.kth<SkPM4f::A>());  // TODO: fast/approx invert?
-}
-
-static Sk4f clamp_0_1(const Sk4f& x) {
-    return Sk4f::Max(Sk4f::Min(x, Sk4f(1)), Sk4f(0));
-}
-
-static SkPMColor round(const Sk4f& x) {
-    SkPMColor c;
-    SkNx_cast<uint8_t>(x * Sk4f(255) + Sk4f(0.5f)).store(&c);
-    return c;
-}
-
-template <typename Adaptor, typename T>
-void filter_span(const float array[], const T src[], int count, T dst[]) {
-    // c0-c3 are already in [0,1].
-    const Sk4f c0 = Sk4f::Load(array + 0);
-    const Sk4f c1 = Sk4f::Load(array + 4);
-    const Sk4f c2 = Sk4f::Load(array + 8);
-    const Sk4f c3 = Sk4f::Load(array + 12);
-    // c4 (the translate vector) is in [0, 255].  Bring it back to [0,1].
-    const Sk4f c4 = Sk4f::Load(array + 16)*Sk4f(1.0f/255);
-
-    // todo: we could cache this in the constructor...
-    T matrix_translate_pmcolor = Adaptor::From4f(premul(clamp_0_1(c4)));
-
-    for (int i = 0; i < count; i++) {
-        Sk4f srcf = Adaptor::To4f(src[i]);
-        float srcA = srcf.kth<SkPM4f::A>();
-
-        if (0 == srcA) {
-            dst[i] = matrix_translate_pmcolor;
-            continue;
-        }
-        if (1 != srcA) {
-            srcf = unpremul(srcf);
-        }
-
-        Sk4f r4 = SkNx_dup<SK_R32_SHIFT/8>(srcf);
-        Sk4f g4 = SkNx_dup<SK_G32_SHIFT/8>(srcf);
-        Sk4f b4 = SkNx_dup<SK_B32_SHIFT/8>(srcf);
-        Sk4f a4 = SkNx_dup<SK_A32_SHIFT/8>(srcf);
-
-        // apply matrix
-        Sk4f dst4 = c0 * r4 + c1 * g4 + c2 * b4 + c3 * a4 + c4;
-
-        dst[i] = Adaptor::From4f(premul(clamp_0_1(dst4)));
-    }
-}
-
-struct SkPMColorAdaptor {
-    static SkPMColor From4f(const Sk4f& c4) {
-        return round(c4);
-    }
-    static Sk4f To4f(SkPMColor c) {
-        return SkNx_cast<float>(Sk4b::Load(&c)) * Sk4f(1.0f/255);
-    }
-};
-void SkColorMatrixFilter::filterSpan(const SkPMColor src[], int count, SkPMColor dst[]) const {
-    filter_span<SkPMColorAdaptor>(fTranspose, src, count, dst);
-}
-
-struct SkPM4fAdaptor {
-    static SkPM4f From4f(const Sk4f& c4) {
-        SkPM4f c;
-        c4.store(&c);
-        return c;
-    }
-    static Sk4f To4f(const SkPM4f& c) {
-        return Sk4f::Load(&c);
-    }
-};
-void SkColorMatrixFilter::filterSpan4f(const SkPM4f src[], int count, SkPM4f dst[]) const {
-    filter_span<SkPM4fAdaptor>(fTranspose, src, count, dst);
-}
-
-///////////////////////////////////////////////////////////////////////////////
-
-void SkColorMatrixFilter::flatten(SkWriteBuffer& buffer) const {
-    SkASSERT(sizeof(fMatrix.fMat)/sizeof(SkScalar) == 20);
-    buffer.writeScalarArray(fMatrix.fMat, 20);
-}
-
-SkFlattenable* SkColorMatrixFilter::CreateProc(SkReadBuffer& buffer) {
-    SkColorMatrix matrix;
-    if (buffer.readScalarArray(matrix.fMat, 20)) {
-        return Create(matrix);
-    }
-    return nullptr;
-}
-
-bool SkColorMatrixFilter::asColorMatrix(SkScalar matrix[20]) const {
-    if (matrix) {
-        memcpy(matrix, fMatrix.fMat, 20 * sizeof(SkScalar));
-    }
-    return true;
-}
-
-SkColorFilter* SkColorMatrixFilter::newComposed(const SkColorFilter* innerFilter) const {
-    SkScalar innerMatrix[20];
-    if (innerFilter->asColorMatrix(innerMatrix) && !SkColorMatrix::NeedsClamping(innerMatrix)) {
-        SkScalar concat[20];
-        SkColorMatrix::SetConcat(concat, fMatrix.fMat, innerMatrix);
-        return SkColorMatrixFilter::Create(concat);
-    }
-    return nullptr;
-}
-
-#if SK_SUPPORT_GPU
-#include "GrFragmentProcessor.h"
-#include "GrInvariantOutput.h"
-#include "glsl/GrGLSLFragmentProcessor.h"
-#include "glsl/GrGLSLFragmentShaderBuilder.h"
-#include "glsl/GrGLSLProgramDataManager.h"
-#include "glsl/GrGLSLUniformHandler.h"
-
-class ColorMatrixEffect : public GrFragmentProcessor {
-public:
-    static const GrFragmentProcessor* Create(const SkColorMatrix& matrix) {
-        return new ColorMatrixEffect(matrix);
-    }
-
-    const char* name() const override { return "Color Matrix"; }
-
-    GR_DECLARE_FRAGMENT_PROCESSOR_TEST;
-
-    class GLSLProcessor : public GrGLSLFragmentProcessor {
-    public:
-        // this class always generates the same code.
-        static void GenKey(const GrProcessor&, const GrGLSLCaps&, GrProcessorKeyBuilder* b) {}
-
-        GLSLProcessor(const GrProcessor&) {}
-
-        virtual void emitCode(EmitArgs& args) override {
-            GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
-            fMatrixHandle = uniformHandler->addUniform(GrGLSLUniformHandler::kFragment_Visibility,
-                                                       kMat44f_GrSLType, kDefault_GrSLPrecision,
-                                                       "ColorMatrix");
-            fVectorHandle = uniformHandler->addUniform(GrGLSLUniformHandler::kFragment_Visibility,
-                                                       kVec4f_GrSLType, kDefault_GrSLPrecision,
-                                                       "ColorMatrixVector");
-
-            if (nullptr == args.fInputColor) {
-                // could optimize this case, but we aren't for now.
-                args.fInputColor = "vec4(1)";
-            }
-            GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
-            // The max() is to guard against 0 / 0 during unpremul when the incoming color is
-            // transparent black.
-            fragBuilder->codeAppendf("\tfloat nonZeroAlpha = max(%s.a, 0.00001);\n",
-                                     args.fInputColor);
-            fragBuilder->codeAppendf("\t%s = %s * vec4(%s.rgb / nonZeroAlpha, nonZeroAlpha) + %s;\n",
-                                     args.fOutputColor,
-                                     uniformHandler->getUniformCStr(fMatrixHandle),
-                                     args.fInputColor,
-                                     uniformHandler->getUniformCStr(fVectorHandle));
-            fragBuilder->codeAppendf("\t%s = clamp(%s, 0.0, 1.0);\n",
-                                     args.fOutputColor, args.fOutputColor);
-            fragBuilder->codeAppendf("\t%s.rgb *= %s.a;\n", args.fOutputColor, args.fOutputColor);
-        }
-
-    protected:
-        virtual void onSetData(const GrGLSLProgramDataManager& uniManager,
-                               const GrProcessor& proc) override {
-            const ColorMatrixEffect& cme = proc.cast<ColorMatrixEffect>();
-            const float* m = cme.fMatrix.fMat;
-            // The GL matrix is transposed from SkColorMatrix.
-            float mt[]  = {
-                m[0], m[5], m[10], m[15],
-                m[1], m[6], m[11], m[16],
-                m[2], m[7], m[12], m[17],
-                m[3], m[8], m[13], m[18],
-            };
-            static const float kScale = 1.0f / 255.0f;
-            float vec[] = {
-                m[4] * kScale, m[9] * kScale, m[14] * kScale, m[19] * kScale,
-            };
-            uniManager.setMatrix4fv(fMatrixHandle, 1, mt);
-            uniManager.set4fv(fVectorHandle, 1, vec);
-        }
-
-    private:
-        GrGLSLProgramDataManager::UniformHandle fMatrixHandle;
-        GrGLSLProgramDataManager::UniformHandle fVectorHandle;
-
-        typedef GrGLSLFragmentProcessor INHERITED;
-    };
-
-private:
-    ColorMatrixEffect(const SkColorMatrix& matrix) : fMatrix(matrix) {
-        this->initClassID<ColorMatrixEffect>();
-    }
-
-    GrGLSLFragmentProcessor* onCreateGLSLInstance() const override {
-        return new GLSLProcessor(*this);
-    }
-
-    virtual void onGetGLSLProcessorKey(const GrGLSLCaps& caps,
-                                       GrProcessorKeyBuilder* b) const override {
-        GLSLProcessor::GenKey(*this, caps, b);
-    }
-
-    bool onIsEqual(const GrFragmentProcessor& s) const override {
-        const ColorMatrixEffect& cme = s.cast<ColorMatrixEffect>();
-        return cme.fMatrix == fMatrix;
-    }
-
-    void onComputeInvariantOutput(GrInvariantOutput* inout) const override {
-        // We only bother to check whether the alpha channel will be constant. If SkColorMatrix had
-        // type flags it might be worth checking the other components.
-
-        // The matrix is defined such the 4th row determines the output alpha. The first four
-        // columns of that row multiply the input r, g, b, and a, respectively, and the last column
-        // is the "translation".
-        static const uint32_t kRGBAFlags[] = {
-            kR_GrColorComponentFlag,
-            kG_GrColorComponentFlag,
-            kB_GrColorComponentFlag,
-            kA_GrColorComponentFlag
-        };
-        static const int kShifts[] = {
-            GrColor_SHIFT_R, GrColor_SHIFT_G, GrColor_SHIFT_B, GrColor_SHIFT_A,
-        };
-        enum {
-            kAlphaRowStartIdx = 15,
-            kAlphaRowTranslateIdx = 19,
-        };
-
-        SkScalar outputA = 0;
-        for (int i = 0; i < 4; ++i) {
-            // If any relevant component of the color to be passed through the matrix is non-const
-            // then we can't know the final result.
-            if (0 != fMatrix.fMat[kAlphaRowStartIdx + i]) {
-                if (!(inout->validFlags() & kRGBAFlags[i])) {
-                    inout->setToUnknown(GrInvariantOutput::kWill_ReadInput);
-                    return;
-                } else {
-                    uint32_t component = (inout->color() >> kShifts[i]) & 0xFF;
-                    outputA += fMatrix.fMat[kAlphaRowStartIdx + i] * component;
-                }
-            }
-        }
-        outputA += fMatrix.fMat[kAlphaRowTranslateIdx];
-        // We pin the color to [0,1]. This would happen to the *final* color output from the frag
-        // shader but currently the effect does not pin its own output. So in the case of over/
-        // underflow this may deviate from the actual result. Maybe the effect should pin its
-        // result if the matrix could over/underflow for any component?
-        inout->setToOther(kA_GrColorComponentFlag,
-                          static_cast<uint8_t>(SkScalarPin(outputA, 0, 255)) << GrColor_SHIFT_A,
-                          GrInvariantOutput::kWill_ReadInput);
-    }
-
-    SkColorMatrix fMatrix;
-
-    typedef GrFragmentProcessor INHERITED;
-};
-
-GR_DEFINE_FRAGMENT_PROCESSOR_TEST(ColorMatrixEffect);
-
-const GrFragmentProcessor* ColorMatrixEffect::TestCreate(GrProcessorTestData* d) {
-    SkColorMatrix colorMatrix;
-    for (size_t i = 0; i < SK_ARRAY_COUNT(colorMatrix.fMat); ++i) {
-        colorMatrix.fMat[i] = d->fRandom->nextSScalar1();
-    }
-    return ColorMatrixEffect::Create(colorMatrix);
-}
-
-const GrFragmentProcessor* SkColorMatrixFilter::asFragmentProcessor(GrContext*) const {
-    return ColorMatrixEffect::Create(fMatrix);
-}
-
-#endif
-
-#ifndef SK_IGNORE_TO_STRING
-void SkColorMatrixFilter::toString(SkString* str) const {
-    str->append("SkColorMatrixFilter: ");
-
-    str->append("matrix: (");
-    for (int i = 0; i < 20; ++i) {
-        str->appendScalar(fMatrix.fMat[i]);
-        if (i < 19) {
-            str->append(", ");
-        }
-    }
-    str->append(")");
-}
-#endif
-
-///////////////////////////////////////////////////////////////////////////////
 
 static SkScalar byte_to_scale(U8CPU byte) {
     if (0xFF == byte) {
         // want to get this exact
         return 1;
     } else {
         return byte * 0.00392156862745f;
     }
 }
 
 SkColorFilter* SkColorMatrixFilter::CreateLightingFilter(SkColor mul, SkColor add) {
     SkColorMatrix matrix;
     matrix.setScale(byte_to_scale(SkColorGetR(mul)),
                     byte_to_scale(SkColorGetG(mul)),
                     byte_to_scale(SkColorGetB(mul)),
                     1);
     matrix.postTranslate(SkIntToScalar(SkColorGetR(add)),
                          SkIntToScalar(SkColorGetG(add)),
                          SkIntToScalar(SkColorGetB(add)),
                          0);
     return SkColorMatrixFilter::Create(matrix);
 }