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      1 /*
      2  * Copyright (C) 2010 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #ifndef ANDROID_HWUI_SKIA_COLOR_FILTER_H
     18 #define ANDROID_HWUI_SKIA_COLOR_FILTER_H
     19 
     20 #include <GLES2/gl2.h>
     21 #include <SkColorFilter.h>
     22 
     23 #include <cutils/compiler.h>
     24 
     25 #include "ProgramCache.h"
     26 #include "Extensions.h"
     27 
     28 namespace android {
     29 namespace uirenderer {
     30 
     31 ///////////////////////////////////////////////////////////////////////////////
     32 // Base color filter
     33 ///////////////////////////////////////////////////////////////////////////////
     34 
     35 /**
     36  * Represents a Skia color filter. A color filter modifies a ProgramDescription
     37  * and sets uniforms on the resulting shaders.
     38  */
     39 struct SkiaColorFilter {
     40     /**
     41      * Type of Skia color filter in use.
     42      */
     43     enum Type {
     44         kNone,
     45         kColorMatrix,
     46         kLighting,
     47         kBlend,
     48     };
     49 
     50     ANDROID_API SkiaColorFilter(SkColorFilter *skFilter, Type type, bool blend);
     51     virtual ~SkiaColorFilter();
     52 
     53     virtual void describe(ProgramDescription& description, const Extensions& extensions) = 0;
     54     virtual void setupProgram(Program* program) = 0;
     55 
     56     inline bool blend() const {
     57         return mBlend;
     58     }
     59 
     60     Type type() const {
     61         return mType;
     62     }
     63 
     64     SkColorFilter* getSkColorFilter() {
     65         return mSkFilter;
     66     }
     67 
     68 protected:
     69     Type mType;
     70     bool mBlend;
     71 
     72 private:
     73     SkColorFilter *mSkFilter;
     74 }; // struct SkiaColorFilter
     75 
     76 ///////////////////////////////////////////////////////////////////////////////
     77 // Implementations
     78 ///////////////////////////////////////////////////////////////////////////////
     79 
     80 /**
     81  * A color filter that multiplies the source color with a matrix and adds a vector.
     82  */
     83 struct SkiaColorMatrixFilter: public SkiaColorFilter {
     84     ANDROID_API SkiaColorMatrixFilter(SkColorFilter *skFilter, float* matrix, float* vector);
     85     ~SkiaColorMatrixFilter();
     86 
     87     void describe(ProgramDescription& description, const Extensions& extensions);
     88     void setupProgram(Program* program);
     89 
     90 private:
     91     float* mMatrix;
     92     float* mVector;
     93 }; // struct SkiaColorMatrixFilter
     94 
     95 /**
     96  * A color filters that multiplies the source color with a fixed value and adds
     97  * another fixed value. Ignores the alpha channel of both arguments.
     98  */
     99 struct SkiaLightingFilter: public SkiaColorFilter {
    100     ANDROID_API SkiaLightingFilter(SkColorFilter *skFilter, int multiply, int add);
    101 
    102     void describe(ProgramDescription& description, const Extensions& extensions);
    103     void setupProgram(Program* program);
    104 
    105 private:
    106     GLfloat mMulR, mMulG, mMulB;
    107     GLfloat mAddR, mAddG, mAddB;
    108 }; // struct SkiaLightingFilter
    109 
    110 /**
    111  * A color filters that blends the source color with a specified destination color
    112  * and PorterDuff blending mode.
    113  */
    114 struct SkiaBlendFilter: public SkiaColorFilter {
    115     ANDROID_API SkiaBlendFilter(SkColorFilter *skFilter, int color, SkXfermode::Mode mode);
    116 
    117     void describe(ProgramDescription& description, const Extensions& extensions);
    118     void setupProgram(Program* program);
    119 
    120 private:
    121     SkXfermode::Mode mMode;
    122     GLfloat mR, mG, mB, mA;
    123 }; // struct SkiaBlendFilter
    124 
    125 }; // namespace uirenderer
    126 }; // namespace android
    127 
    128 #endif // ANDROID_HWUI_SKIA_COLOR_FILTER_H
    129