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/*
* Copyright 2012 The Android Open Source Project
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkMatrixConvolutionImageFilter_DEFINED
#define SkMatrixConvolutionImageFilter_DEFINED
#include "SkImageFilter.h"
#include "SkScalar.h"
#include "SkSize.h"
#include "SkPoint.h"
class SkBitmap;
/*! \class SkMatrixConvolutionImageFilter
Matrix convolution image filter. This filter applies an NxM image
processing kernel to a given input image. This can be used to produce
effects such as sharpening, blurring, edge detection, etc.
*/
class SK_API SkMatrixConvolutionImageFilter : public SkImageFilter {
public:
/*! \enum TileMode */
enum TileMode {
kClamp_TileMode = 0, /*!< Clamp to the image's edge pixels. */
kRepeat_TileMode, /*!< Wrap around to the image's opposite edge. */
kClampToBlack_TileMode, /*!< Fill with transparent black. */
kLast_TileMode = kClampToBlack_TileMode,
// TODO: remove kMax - it is non-standard but used by Chromium!
kMax_TileMode = kClampToBlack_TileMode
};
~SkMatrixConvolutionImageFilter() override;
/** Construct a matrix convolution image filter.
@param kernelSize The kernel size in pixels, in each dimension (N by M).
@param kernel The image processing kernel. Must contain N * M
elements, in row order.
@param gain A scale factor applied to each pixel after
convolution. This can be used to normalize the
kernel, if it does not sum to 1.
@param bias A bias factor added to each pixel after convolution.
@param kernelOffset An offset applied to each pixel coordinate before
convolution. This can be used to center the kernel
over the image (e.g., a 3x3 kernel should have an
offset of {1, 1}).
@param tileMode How accesses outside the image are treated. (@see
TileMode).
@param convolveAlpha If true, all channels are convolved. If false,
only the RGB channels are convolved, and
alpha is copied from the source image.
@param input The input image filter. If NULL, the src bitmap
passed to filterImage() is used instead.
@param cropRect The rectangle to which the output processing will be limited.
*/
static sk_sp<SkImageFilter> Make(const SkISize& kernelSize,
const SkScalar* kernel,
SkScalar gain,
SkScalar bias,
const SkIPoint& kernelOffset,
TileMode tileMode,
bool convolveAlpha,
sk_sp<SkImageFilter> input,
const CropRect* cropRect = nullptr);
SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkMatrixConvolutionImageFilter)
protected:
SkMatrixConvolutionImageFilter(const SkISize& kernelSize,
const SkScalar* kernel,
SkScalar gain,
SkScalar bias,
const SkIPoint& kernelOffset,
TileMode tileMode,
bool convolveAlpha,
sk_sp<SkImageFilter> input,
const CropRect* cropRect);
void flatten(SkWriteBuffer&) const override;
sk_sp<SkSpecialImage> onFilterImage(SkSpecialImage* source, const Context&,
SkIPoint* offset) const override;
sk_sp<SkImageFilter> onMakeColorSpace(SkColorSpaceXformer*) const override;
SkIRect onFilterNodeBounds(const SkIRect&, const SkMatrix& ctm,
MapDirection, const SkIRect* inputRect) const override;
bool affectsTransparentBlack() const override;
private:
SkISize fKernelSize;
SkScalar* fKernel;
SkScalar fGain;
SkScalar fBias;
SkIPoint fKernelOffset;
TileMode fTileMode;
bool fConvolveAlpha;
template <class PixelFetcher, bool convolveAlpha>
void filterPixels(const SkBitmap& src,
SkBitmap* result,
SkIVector& offset,
const SkIRect& rect,
const SkIRect& bounds) const;
template <class PixelFetcher>
void filterPixels(const SkBitmap& src,
SkBitmap* result,
SkIVector& offset,
const SkIRect& rect,
const SkIRect& bounds) const;
void filterInteriorPixels(const SkBitmap& src,
SkBitmap* result,
SkIVector& offset,
const SkIRect& rect,
const SkIRect& bounds) const;
void filterBorderPixels(const SkBitmap& src,
SkBitmap* result,
SkIVector& offset,
const SkIRect& rect,
const SkIRect& bounds) const;
typedef SkImageFilter INHERITED;
};
#endif
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