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 "include/core/SkImageFilter.h"
12 #include "include/core/SkPoint.h"
13 #include "include/core/SkScalar.h"
14 #include "include/core/SkSize.h"
15 
16 class SkBitmap;
17 enum class SkTileMode;
18 
19 /*! \class SkMatrixConvolutionImageFilter
20     Matrix convolution image filter.  This filter applies an NxM image
21     processing kernel to a given input image.  This can be used to produce
22     effects such as sharpening, blurring, edge detection, etc.
23 
24     DEPRECATED: Use include/effects/SkImageFilters::MatrixConvolution
25  */
26 
27 class SK_API SkMatrixConvolutionImageFilter {
28 public:
29     /*! \enum TileMode
30      * DEPRECATED: Use SkTileMode instead. */
31     enum TileMode {
32       kClamp_TileMode = 0,         /*!< Clamp to the image's edge pixels. */
33       kRepeat_TileMode,        /*!< Wrap around to the image's opposite edge. */
34       kClampToBlack_TileMode,  /*!< Fill with transparent black. */
35       kLast_TileMode = kClampToBlack_TileMode,
36 
37       // TODO: remove kMax - it is non-standard but used by Chromium!
38       kMax_TileMode = kClampToBlack_TileMode
39     };
40 
41     static sk_sp<SkImageFilter> Make(const SkISize& kernelSize,
42                                      const SkScalar* kernel,
43                                      SkScalar gain,
44                                      SkScalar bias,
45                                      const SkIPoint& kernelOffset,
46                                      TileMode tileMode,
47                                      bool convolveAlpha,
48                                      sk_sp<SkImageFilter> input,
49                                      const SkImageFilter::CropRect* cropRect = nullptr);
50 
51     /** Construct a matrix convolution image filter.
52         @param kernelSize     The kernel size in pixels, in each dimension (N by M).
53         @param kernel         The image processing kernel.  Must contain N * M
54                               elements, in row order.
55         @param gain           A scale factor applied to each pixel after
56                               convolution.  This can be used to normalize the
57                               kernel, if it does not sum to 1.
58         @param bias           A bias factor added to each pixel after convolution.
59         @param kernelOffset   An offset applied to each pixel coordinate before
60                               convolution.  This can be used to center the kernel
61                               over the image (e.g., a 3x3 kernel should have an
62                               offset of {1, 1}).
63         @param tileMode       How accesses outside the image are treated.  (@see
64                               TileMode). EXPERIMENTAL: kMirror not supported yet.
65         @param convolveAlpha  If true, all channels are convolved.  If false,
66                               only the RGB channels are convolved, and
67                               alpha is copied from the source image.
68         @param input          The input image filter.  If NULL, the src bitmap
69                               passed to filterImage() is used instead.
70         @param cropRect       The rectangle to which the output processing will be limited.
71     */
72     static sk_sp<SkImageFilter> Make(const SkISize& kernelSize,
73                                      const SkScalar* kernel,
74                                      SkScalar gain,
75                                      SkScalar bias,
76                                      const SkIPoint& kernelOffset,
77                                      SkTileMode tileMode,
78                                      bool convolveAlpha,
79                                      sk_sp<SkImageFilter> input,
80                                      const SkImageFilter::CropRect* cropRect = nullptr);
81 
82     static void RegisterFlattenables();
83 
84 private:
85     SkMatrixConvolutionImageFilter() = delete;
86 };
87 
88 #endif
89