Adding 3D lut color filter

src/effects/SkColorCubeFilter.cpp

+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkColorCubeFilter.h"
+#include "SkColorPriv.h"
+#include "SkOnce.h"
+#include "SkReadBuffer.h"
+#include "SkUnPreMultiply.h"
+#include "SkWriteBuffer.h"
+#if SK_SUPPORT_GPU
+#include "GrContext.h"
+#include "GrCoordTransform.h"
+#include "gl/GrGLProcessor.h"
+#include "gl/builders/GrGLProgramBuilder.h"
+#include "GrTBackendProcessorFactory.h"
+#include "GrTexturePriv.h"
+#include "SkGr.h"
+#endif
+
+///////////////////////////////////////////////////////////////////////////////
+namespace {
+
+int32_t SkNextColorProfileUniqueID() {
+    static int32_t gColorProfileUniqueID;
+    // do a loop in case our global wraps around, as we never want to return a 0
+    int32_t genID;
+    do {
+        genID = sk_atomic_inc(&gColorProfileUniqueID) + 1;
+    } while (0 == genID);
+    return genID;
+}
+
+} // end namespace
+
+static const int MIN_CUBE_SIZE = 4;
+static const int MAX_CUBE_SIZE = 64;
+
+static bool is_valid_3D_lut(SkData* cubeData, int cubeDimension) {
+    size_t minMemorySize = sizeof(uint8_t) * 4 * cubeDimension * cubeDimension * cubeDimension;
+    return (cubeDimension >= MIN_CUBE_SIZE) && (cubeDimension <= MAX_CUBE_SIZE) &&
+           (NULL != cubeData) && (cubeData->size() >= minMemorySize);
+}
+
+SkColorFilter* SkColorCubeFilter::Create(SkData* cubeData, int cubeDimension) {
+    if (!is_valid_3D_lut(cubeData, cubeDimension)) {
+        return NULL;
+    }
+
+    return SkNEW_ARGS(SkColorCubeFilter, (cubeData, cubeDimension));
+}
+
+SkColorCubeFilter::SkColorCubeFilter(SkData* cubeData, int cubeDimension)
+  : fCubeData(SkRef(cubeData))
+  , fUniqueID(SkNextColorProfileUniqueID())
+  , fCache(cubeDimension) {
+}
+
+uint32_t SkColorCubeFilter::getFlags() const {
+    return this->INHERITED::getFlags() | kAlphaUnchanged_Flag;
+}
+
+SkColorCubeFilter::ColorCubeProcesingCache::ColorCubeProcesingCache(int cubeDimension)
+  : fCubeDimension(cubeDimension)
+  , fLutsInited(false) {
+    fColorToIndex[0] = fColorToIndex[1] = NULL;
+    fColorToFactors[0] = fColorToFactors[1] = NULL;
+    fColorToScalar = NULL;
+}
+
+void SkColorCubeFilter::ColorCubeProcesingCache::getProcessingLuts(
+    const int* (*colorToIndex)[2], const SkScalar* (*colorToFactors)[2],
+    const SkScalar** colorToScalar) {
+    SkOnce(&fLutsInited, &fLutsMutex,
+           SkColorCubeFilter::ColorCubeProcesingCache::initProcessingLuts, this);
+    SkASSERT((fColorToIndex[0] != NULL) &&
+             (fColorToIndex[1] != NULL) &&
+             (fColorToFactors[0] != NULL) &&
+             (fColorToFactors[1] != NULL) &&
+             (fColorToScalar != NULL));
+    (*colorToIndex)[0] = fColorToIndex[0];
+    (*colorToIndex)[1] = fColorToIndex[1];
+    (*colorToFactors)[0] = fColorToFactors[0];
+    (*colorToFactors)[1] = fColorToFactors[1];
+    (*colorToScalar) = fColorToScalar;
+}
+
+void SkColorCubeFilter::ColorCubeProcesingCache::initProcessingLuts(
+    SkColorCubeFilter::ColorCubeProcesingCache* cache) {
+    static const SkScalar inv8bit = SkScalarInvert(SkIntToScalar(255));
+
+    // We need 256 int * 2 for fColorToIndex, so a total of 512 int.
+    // We need 256 SkScalar * 2 for fColorToFactors and 256 SkScalar
+    // for fColorToScalar, so a total of 768 SkScalar.
+    cache->fLutStorage.reset(512 * sizeof(int) + 768 * sizeof(SkScalar));
+    uint8_t* storage = (uint8_t*)cache->fLutStorage.get();
+    cache->fColorToIndex[0] = (int*)storage;
+    cache->fColorToIndex[1] = cache->fColorToIndex[0] + 256;
+    cache->fColorToFactors[0] = (SkScalar*)(storage + (512 * sizeof(int)));
+    cache->fColorToFactors[1] = cache->fColorToFactors[0] + 256;
+    cache->fColorToScalar = cache->fColorToFactors[1] + 256;
+
+    SkScalar size = SkIntToScalar(cache->fCubeDimension);
+    SkScalar scale = (size - SK_Scalar1) * inv8bit;
+
+    for (int i = 0; i < 256; ++i) {
+        SkScalar index = scale * i;
+        cache->fColorToIndex[0][i] = SkScalarFloorToInt(index);
+        cache->fColorToIndex[1][i] = cache->fColorToIndex[0][i] + 1;
+        cache->fColorToScalar[i] = inv8bit * i;
+        if (cache->fColorToIndex[1][i] < cache->fCubeDimension) {
+            cache->fColorToFactors[1][i] = index - SkIntToScalar(cache->fColorToIndex[0][i]);
+            cache->fColorToFactors[0][i] = SK_Scalar1 - cache->fColorToFactors[1][i];
+        } else {
+            cache->fColorToIndex[1][i] = cache->fColorToIndex[0][i];
+            cache->fColorToFactors[0][i] = SK_Scalar1;
+            cache->fColorToFactors[1][i] = 0;
+        }
+    }
+}
+
+void SkColorCubeFilter::filterSpan(const SkPMColor src[], int count, SkPMColor dst[]) const {
+    const int* colorToIndex[2];
+    const SkScalar* colorToFactors[2];
+    const SkScalar* colorToScalar;
+    fCache.getProcessingLuts(&colorToIndex, &colorToFactors, &colorToScalar);
+
+    const int dim = fCache.cubeDimension();
+    SkColor* colorCube = (SkColor*)fCubeData->data();
+    for (int i = 0; i < count; ++i) {
+        SkColor inputColor = SkUnPreMultiply::PMColorToColor(src[i]);
+        uint8_t r = SkColorGetR(inputColor);
+        uint8_t g = SkColorGetG(inputColor);
+        uint8_t b = SkColorGetB(inputColor);
+        uint8_t a = SkColorGetA(inputColor);
+        SkScalar rOut(0), gOut(0), bOut(0);
+        for (int x = 0; x < 2; ++x) {
+            for (int y = 0; y < 2; ++y) {
+                for (int z = 0; z < 2; ++z) {
+                    SkColor lutColor = colorCube[colorToIndex[x][r] +
+                                                (colorToIndex[y][g] +
+                                                 colorToIndex[z][b] * dim) * dim];
+                    SkScalar factor = colorToFactors[x][r] *
+                                      colorToFactors[y][g] *
+                                      colorToFactors[z][b];
+                    rOut += colorToScalar[SkColorGetR(lutColor)] * factor;
+                    gOut += colorToScalar[SkColorGetG(lutColor)] * factor;
+                    bOut += colorToScalar[SkColorGetB(lutColor)] * factor;
+                }
+            }
+        }
+        const SkScalar aOut = SkIntToScalar(a);
+        dst[i] = SkPackARGB32(a,
+            SkScalarRoundToInt(rOut * aOut),
+            SkScalarRoundToInt(gOut * aOut),
+            SkScalarRoundToInt(bOut * aOut));
+    }
+}
+
+#ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
+SkColorCubeFilter::SkColorCubeFilter(SkReadBuffer& buffer)
+  : fCache(buffer.readInt()) {
+    fCubeData.reset(buffer.readByteArrayAsData());
+    buffer.validate(is_valid_3D_lut(fCubeData, fCache.cubeDimension()));
+    fUniqueID = SkNextColorProfileUniqueID();
+}
+#endif
+
+SkFlattenable* SkColorCubeFilter::CreateProc(SkReadBuffer& buffer) {
+    int cubeDimension = buffer.readInt();
+    SkData* cubeData = buffer.readByteArrayAsData();
+    if (!buffer.validate(is_valid_3D_lut(cubeData, cubeDimension))) {
+        SkSafeUnref(cubeData);
+        return NULL;
+    }
+    return Create(cubeData, cubeDimension);
+}
+
+void SkColorCubeFilter::flatten(SkWriteBuffer& buffer) const {
+    this->INHERITED::flatten(buffer);
+    buffer.writeInt(fCache.cubeDimension());
+    buffer.writeDataAsByteArray(fCubeData);
+}
+
+#ifndef SK_IGNORE_TO_STRING
+void SkColorCubeFilter::toString(SkString* str) const {
+    str->append("SkColorCubeFilter ");
+}
+#endif
+
+///////////////////////////////////////////////////////////////////////////////
+#if SK_SUPPORT_GPU
+class GrColorProfileEffect : public GrFragmentProcessor {
+public:
+    static GrFragmentProcessor* Create(GrTexture* colorCube) {
+        return (NULL != colorCube) ? SkNEW_ARGS(GrColorProfileEffect, (colorCube)) : NULL;
+    }
+
+    virtual ~GrColorProfileEffect();
+
+    virtual const GrBackendFragmentProcessorFactory& getFactory() const SK_OVERRIDE;
+    int colorCubeSize() const { return fColorCubeAccess.getTexture()->width(); }
+
+    static const char* Name() { return "ColorProfile"; }
+
+    virtual void onComputeInvariantOutput(GrProcessor::InvariantOutput*) const SK_OVERRIDE;
+
+    class GLProcessor : public GrGLFragmentProcessor {
+    public:
+        GLProcessor(const GrBackendProcessorFactory& factory, const GrProcessor&);
+        virtual ~GLProcessor();
+
+        virtual void emitCode(GrGLProgramBuilder*,
+                              const GrFragmentProcessor&,
+                              const GrProcessorKey&,
+                              const char* outputColor,
+                              const char* inputColor,
+                              const TransformedCoordsArray&,
+                              const TextureSamplerArray&) SK_OVERRIDE;
+
+        static inline void GenKey(const GrProcessor&, const GrGLCaps&, GrProcessorKeyBuilder*);
+
+        virtual void setData(const GrGLProgramDataManager&, const GrProcessor&) SK_OVERRIDE;
+
+    private:
+        GrGLProgramDataManager::UniformHandle fColorCubeSizeUni;
+        GrGLProgramDataManager::UniformHandle fColorCubeInvSizeUni;
+
+        typedef GrGLFragmentProcessor INHERITED;
+    };
+
+private:
+    virtual bool onIsEqual(const GrProcessor&) const SK_OVERRIDE;
+
+    GrColorProfileEffect(GrTexture* colorCube);
+
+    GrCoordTransform    fColorCubeTransform;
+    GrTextureAccess     fColorCubeAccess;
+
+    typedef GrFragmentProcessor INHERITED;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+GrColorProfileEffect::GrColorProfileEffect(GrTexture* colorCube)
+    : fColorCubeTransform(kLocal_GrCoordSet, colorCube)
+    , fColorCubeAccess(colorCube, "bgra", GrTextureParams::kBilerp_FilterMode) {
+    this->addCoordTransform(&fColorCubeTransform);
+    this->addTextureAccess(&fColorCubeAccess);
+}
+
+GrColorProfileEffect::~GrColorProfileEffect() {
+}
+
+bool GrColorProfileEffect::onIsEqual(const GrProcessor& sBase) const {
+    const GrColorProfileEffect& s = sBase.cast<GrColorProfileEffect>();
+    return fColorCubeAccess.getTexture() == s.fColorCubeAccess.getTexture();
+}
+
+const GrBackendFragmentProcessorFactory& GrColorProfileEffect::getFactory() const {
+    return GrTBackendFragmentProcessorFactory<GrColorProfileEffect>::getInstance();
+}
+
+void GrColorProfileEffect::onComputeInvariantOutput(InvariantOutput* inout) const {
+    inout->fValidFlags = 0;
+    inout->fIsSingleComponent = false;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+GrColorProfileEffect::GLProcessor::GLProcessor(const GrBackendProcessorFactory& factory,
+                                               const GrProcessor&)
+    : INHERITED(factory) {
+}
+
+GrColorProfileEffect::GLProcessor::~GLProcessor() {
+}
+
+void GrColorProfileEffect::GLProcessor::emitCode(GrGLProgramBuilder* builder,
+                                                 const GrFragmentProcessor&,
+                                                 const GrProcessorKey&,
+                                                 const char* outputColor,
+                                                 const char* inputColor,
+                                                 const TransformedCoordsArray& coords,
+                                                 const TextureSamplerArray& samplers) {
+    if (NULL == inputColor) {
+        inputColor = "vec4(1)";
+    }
+
+    fColorCubeSizeUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
+                                            kFloat_GrSLType, "Size");
+    const char* colorCubeSizeUni = builder->getUniformCStr(fColorCubeSizeUni);
+    fColorCubeInvSizeUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
+                                               kFloat_GrSLType, "InvSize");
+    const char* colorCubeInvSizeUni = builder->getUniformCStr(fColorCubeInvSizeUni);
+
+    const char* nonZeroAlpha = "nonZeroAlpha";
+    const char* unPMColor = "unPMColor";
+    const char* cubeIdx = "cubeIdx";
+    const char* cCoords1 = "cCoords1";
+    const char* cCoords2 = "cCoords2";
+
+    // Note: if implemented using texture3D in OpenGL ES older than OpenGL ES 3.0,
+    //       the shader might need "#extension GL_OES_texture_3D : enable".
+
+    GrGLFragmentShaderBuilder* fsBuilder = builder->getFragmentShaderBuilder();
+
+    // Unpremultiply color
+    fsBuilder->codeAppendf("\tfloat %s = max(%s.a, 0.00001);\n", nonZeroAlpha, inputColor);
+    fsBuilder->codeAppendf("\tvec4 %s = vec4(%s.rgb / %s, %s);\n",
+                           unPMColor, inputColor, nonZeroAlpha, nonZeroAlpha);
+
+    // Fit input color into the cube.
+    fsBuilder->codeAppendf(
+        "vec3 %s = vec3(%s.rg * vec2((%s - 1.0) * %s) + vec2(0.5 * %s), %s.b * (%s - 1.0));\n",
+        cubeIdx, unPMColor, colorCubeSizeUni, colorCubeInvSizeUni, colorCubeInvSizeUni,
+        unPMColor, colorCubeSizeUni);
+
+    // Compute y coord for for texture fetches.
+    fsBuilder->codeAppendf("vec2 %s = vec2(%s.r, (floor(%s.b) + %s.g) * %s);\n",
+                           cCoords1, cubeIdx, cubeIdx, cubeIdx, colorCubeInvSizeUni);
+    fsBuilder->codeAppendf("vec2 %s = vec2(%s.r, (ceil(%s.b) + %s.g) * %s);\n",
+                           cCoords2, cubeIdx, cubeIdx, cubeIdx, colorCubeInvSizeUni);
+
+    // Apply the cube.
+    fsBuilder->codeAppendf("%s = vec4(mix(", outputColor);
+    fsBuilder->appendTextureLookup(samplers[0], cCoords1, coords[0].getType());
+    fsBuilder->codeAppend(".rgb, ");
+    fsBuilder->appendTextureLookup(samplers[0], cCoords2, coords[0].getType());
+
+    // Premultiply color by alpha. Note that the input alpha is not modified by this shader.
+    fsBuilder->codeAppendf(".rgb, fract(%s.b)) * vec3(%s), %s.a);\n",
+                           cubeIdx, nonZeroAlpha, inputColor);
+}
+
+void GrColorProfileEffect::GLProcessor::setData(const GrGLProgramDataManager& pdman,
+                                                const GrProcessor& proc) {
+    const GrColorProfileEffect& colorProfile = proc.cast<GrColorProfileEffect>();
+    SkScalar size = SkIntToScalar(colorProfile.colorCubeSize());
+    pdman.set1f(fColorCubeSizeUni, SkScalarToFloat(size));
+    pdman.set1f(fColorCubeInvSizeUni, SkScalarToFloat(SkScalarInvert(size)));
+}
+
+void GrColorProfileEffect::GLProcessor::GenKey(const GrProcessor& proc,
+                                               const GrGLCaps&, GrProcessorKeyBuilder* b) {
+    b->add32(1); // Always same shader for now
+}
+
+GrFragmentProcessor* SkColorCubeFilter::asFragmentProcessor(GrContext* context) const {
+    static const GrCacheID::Domain gCubeDomain = GrCacheID::GenerateDomain();
+
+    GrCacheID::Key key;
+    key.fData32[0] = fUniqueID;
+    key.fData32[1] = fCache.cubeDimension();
+    key.fData64[1] = 0;
+    GrCacheID cacheID(gCubeDomain, key);
+
+    GrTextureDesc desc;
+    desc.fWidth = fCache.cubeDimension();
+    desc.fHeight = fCache.cubeDimension() * fCache.cubeDimension();
+    desc.fConfig = kRGBA_8888_GrPixelConfig;
+
+    SkAutoTUnref<GrTexture> textureCube(
+        static_cast<GrTexture*>(context->findAndRefCachedResource(
+            GrTexturePriv::ComputeKey(context->getGpu(), NULL, desc, cacheID))));
+
+    if (!textureCube) {
+        textureCube.reset(context->createTexture(NULL, desc, cacheID, fCubeData->data(), 0));
+    }
+
+    return textureCube ? GrColorProfileEffect::Create(textureCube) : NULL;
+}
+#endif