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