1 /* 2 * Copyright 2012 The Android Open Source Project 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8 #ifndef SkMatrixConvolutionImageFilter_DEFINED 9 #define SkMatrixConvolutionImageFilter_DEFINED 10 11 #include "SkImageFilter.h" 12 #include "SkScalar.h" 13 #include "SkSize.h" 14 #include "SkPoint.h" 15 16 /*! \class SkMatrixConvolutionImageFilter 17 Matrix convolution image filter. This filter applies an NxM image 18 processing kernel to a given input image. This can be used to produce 19 effects such as sharpening, blurring, edge detection, etc. 20 */ 21 22 class SK_API SkMatrixConvolutionImageFilter : public SkImageFilter { 23 public: 24 /*! \enum TileMode */ 25 enum TileMode { 26 kClamp_TileMode = 0, /*!< Clamp to the image's edge pixels. */ 27 kRepeat_TileMode, /*!< Wrap around to the image's opposite edge. */ 28 kClampToBlack_TileMode, /*!< Fill with transparent black. */ 29 kMax_TileMode = kClampToBlack_TileMode 30 }; 31 32 virtual ~SkMatrixConvolutionImageFilter(); 33 34 /** Construct a matrix convolution image filter. 35 @param kernelSize The kernel size in pixels, in each dimension (N by M). 36 @param kernel The image processing kernel. Must contain N * M 37 elements, in row order. 38 @param gain A scale factor applied to each pixel after 39 convolution. This can be used to normalize the 40 kernel, if it does not sum to 1. 41 @param bias A bias factor added to each pixel after convolution. 42 @param kernelOffset An offset applied to each pixel coordinate before 43 convolution. This can be used to center the kernel 44 over the image (e.g., a 3x3 kernel should have an 45 offset of {1, 1}). 46 @param tileMode How accesses outside the image are treated. (@see 47 TileMode). 48 @param convolveAlpha If true, all channels are convolved. If false, 49 only the RGB channels are convolved, and 50 alpha is copied from the source image. 51 @param input The input image filter. If NULL, the src bitmap 52 passed to filterImage() is used instead. 53 @param cropRect The rectangle to which the output processing will be limited. 54 */ 55 static SkMatrixConvolutionImageFilter* Create(const SkISize& kernelSize, 56 const SkScalar* kernel, 57 SkScalar gain, 58 SkScalar bias, 59 const SkIPoint& kernelOffset, 60 TileMode tileMode, 61 bool convolveAlpha, 62 SkImageFilter* input = NULL, 63 const CropRect* cropRect = NULL, 64 uint32_t uniqueID = 0); 65 66 SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkMatrixConvolutionImageFilter) 67 68 protected: 69 SkMatrixConvolutionImageFilter(const SkISize& kernelSize, 70 const SkScalar* kernel, 71 SkScalar gain, 72 SkScalar bias, 73 const SkIPoint& kernelOffset, 74 TileMode tileMode, 75 bool convolveAlpha, 76 SkImageFilter* input, 77 const CropRect* cropRect, 78 uint32_t uniqueID); 79 #ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING 80 explicit SkMatrixConvolutionImageFilter(SkReadBuffer& buffer); 81 #endif 82 virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE; 83 84 virtual bool onFilterImage(Proxy*, const SkBitmap& src, const Context&, 85 SkBitmap* result, SkIPoint* loc) const SK_OVERRIDE; 86 virtual bool onFilterBounds(const SkIRect&, const SkMatrix&, SkIRect*) const SK_OVERRIDE; 87 88 89 #if SK_SUPPORT_GPU 90 virtual bool asFragmentProcessor(GrFragmentProcessor**, GrTexture*, const SkMatrix&, 91 const SkIRect& bounds) const SK_OVERRIDE; 92 #endif 93 94 private: 95 SkISize fKernelSize; 96 SkScalar* fKernel; 97 SkScalar fGain; 98 SkScalar fBias; 99 SkIPoint fKernelOffset; 100 TileMode fTileMode; 101 bool fConvolveAlpha; 102 typedef SkImageFilter INHERITED; 103 104 template <class PixelFetcher, bool convolveAlpha> 105 void filterPixels(const SkBitmap& src, 106 SkBitmap* result, 107 const SkIRect& rect, 108 const SkIRect& bounds) const; 109 template <class PixelFetcher> 110 void filterPixels(const SkBitmap& src, 111 SkBitmap* result, 112 const SkIRect& rect, 113 const SkIRect& bounds) const; 114 void filterInteriorPixels(const SkBitmap& src, 115 SkBitmap* result, 116 const SkIRect& rect, 117 const SkIRect& bounds) const; 118 void filterBorderPixels(const SkBitmap& src, 119 SkBitmap* result, 120 const SkIRect& rect, 121 const SkIRect& bounds) const; 122 }; 123 124 #endif 125
