| /* |
| * Copyright 2011 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef SkImageFilter_DEFINED |
| #define SkImageFilter_DEFINED |
| |
| #include "SkFlattenable.h" |
| #include "SkMatrix.h" |
| #include "SkRect.h" |
| |
| class SkBitmap; |
| class SkColorFilter; |
| class SkBaseDevice; |
| struct SkIPoint; |
| class GrEffect; |
| class GrTexture; |
| |
| /** |
| * Base class for image filters. If one is installed in the paint, then |
| * all drawing occurs as usual, but it is as if the drawing happened into an |
| * offscreen (before the xfermode is applied). This offscreen bitmap will |
| * then be handed to the imagefilter, who in turn creates a new bitmap which |
| * is what will finally be drawn to the device (using the original xfermode). |
| */ |
| class SK_API SkImageFilter : public SkFlattenable { |
| public: |
| SK_DECLARE_INST_COUNT(SkImageFilter) |
| |
| class CropRect { |
| public: |
| enum CropEdge { |
| kHasLeft_CropEdge = 0x01, |
| kHasTop_CropEdge = 0x02, |
| kHasRight_CropEdge = 0x04, |
| kHasBottom_CropEdge = 0x08, |
| kHasAll_CropEdge = 0x0F, |
| }; |
| CropRect() {} |
| explicit CropRect(const SkRect& rect, uint32_t flags = kHasAll_CropEdge) : fRect(rect), fFlags(flags) {} |
| uint32_t flags() const { return fFlags; } |
| const SkRect& rect() const { return fRect; } |
| private: |
| SkRect fRect; |
| uint32_t fFlags; |
| }; |
| |
| class SK_API Cache : public SkRefCnt { |
| public: |
| // By default, we cache only image filters with 2 or more children. |
| // Values less than 2 mean always cache; values greater than 2 are not supported. |
| static Cache* Create(int minChildren = 2); |
| virtual ~Cache() {} |
| virtual bool get(const SkImageFilter* key, SkBitmap* result, SkIPoint* offset) = 0; |
| virtual void set(const SkImageFilter* key, |
| const SkBitmap& result, const SkIPoint& offset) = 0; |
| virtual void remove(const SkImageFilter* key) = 0; |
| }; |
| |
| class Context { |
| public: |
| Context(const SkMatrix& ctm, const SkIRect& clipBounds, Cache* cache) : |
| fCTM(ctm), fClipBounds(clipBounds), fCache(cache) { |
| } |
| const SkMatrix& ctm() const { return fCTM; } |
| const SkIRect& clipBounds() const { return fClipBounds; } |
| Cache* cache() const { return fCache; } |
| private: |
| SkMatrix fCTM; |
| SkIRect fClipBounds; |
| Cache* fCache; |
| }; |
| |
| class Proxy { |
| public: |
| virtual ~Proxy() {}; |
| |
| virtual SkBaseDevice* createDevice(int width, int height) = 0; |
| // returns true if the proxy can handle this filter natively |
| virtual bool canHandleImageFilter(const SkImageFilter*) = 0; |
| // returns true if the proxy handled the filter itself. if this returns |
| // false then the filter's code will be called. |
| virtual bool filterImage(const SkImageFilter*, const SkBitmap& src, |
| const Context&, |
| SkBitmap* result, SkIPoint* offset) = 0; |
| }; |
| |
| /** |
| * Request a new (result) image to be created from the src image. |
| * If the src has no pixels (isNull()) then the request just wants to |
| * receive the config and width/height of the result. |
| * |
| * The matrix is the current matrix on the canvas. |
| * |
| * Offset is the amount to translate the resulting image relative to the |
| * src when it is drawn. This is an out-param. |
| * |
| * If the result image cannot be created, return false, in which case both |
| * the result and offset parameters will be ignored by the caller. |
| */ |
| bool filterImage(Proxy*, const SkBitmap& src, const Context&, |
| SkBitmap* result, SkIPoint* offset) const; |
| |
| /** |
| * Given the src bounds of an image, this returns the bounds of the result |
| * image after the filter has been applied. |
| */ |
| bool filterBounds(const SkIRect& src, const SkMatrix& ctm, SkIRect* dst) const; |
| |
| /** |
| * Returns true if the filter can be processed on the GPU. This is most |
| * often used for multi-pass effects, where intermediate results must be |
| * rendered to textures. For single-pass effects, use asNewEffect(). |
| * The default implementation returns asNewEffect(NULL, NULL, SkMatrix::I(), |
| * SkIRect()). |
| */ |
| virtual bool canFilterImageGPU() const; |
| |
| /** |
| * Process this image filter on the GPU. This is most often used for |
| * multi-pass effects, where intermediate results must be rendered to |
| * textures. For single-pass effects, use asNewEffect(). src is the |
| * source image for processing, as a texture-backed bitmap. result is |
| * the destination bitmap, which should contain a texture-backed pixelref |
| * on success. offset is the amount to translate the resulting image |
| * relative to the src when it is drawn. The default implementation does |
| * single-pass processing using asNewEffect(). |
| */ |
| virtual bool filterImageGPU(Proxy*, const SkBitmap& src, const Context&, |
| SkBitmap* result, SkIPoint* offset) const; |
| |
| /** |
| * Returns whether this image filter is a color filter and puts the color filter into the |
| * "filterPtr" parameter if it can. Does nothing otherwise. |
| * If this returns false, then the filterPtr is unchanged. |
| * If this returns true, then if filterPtr is not null, it must be set to a ref'd colorfitler |
| * (i.e. it may not be set to NULL). |
| */ |
| virtual bool asColorFilter(SkColorFilter** filterPtr) const; |
| |
| /** |
| * Returns the number of inputs this filter will accept (some inputs can |
| * be NULL). |
| */ |
| int countInputs() const { return fInputCount; } |
| |
| /** |
| * Returns the input filter at a given index, or NULL if no input is |
| * connected. The indices used are filter-specific. |
| */ |
| SkImageFilter* getInput(int i) const { |
| SkASSERT(i < fInputCount); |
| return fInputs[i]; |
| } |
| |
| /** |
| * Returns whether any edges of the crop rect have been set. The crop |
| * rect is set at construction time, and determines which pixels from the |
| * input image will be processed. The size of the crop rect should be |
| * used as the size of the destination image. The origin of this rect |
| * should be used to offset access to the input images, and should also |
| * be added to the "offset" parameter in onFilterImage and |
| * filterImageGPU(). (The latter ensures that the resulting buffer is |
| * drawn in the correct location.) |
| */ |
| bool cropRectIsSet() const { return fCropRect.flags() != 0x0; } |
| |
| // Default impl returns union of all input bounds. |
| virtual void computeFastBounds(const SkRect&, SkRect*) const; |
| |
| #ifdef SK_SUPPORT_GPU |
| /** |
| * Wrap the given texture in a texture-backed SkBitmap. |
| */ |
| static void WrapTexture(GrTexture* texture, int width, int height, SkBitmap* result); |
| |
| /** |
| * Recursively evaluate this filter on the GPU. If the filter has no GPU |
| * implementation, it will be processed in software and uploaded to the GPU. |
| */ |
| bool getInputResultGPU(SkImageFilter::Proxy* proxy, const SkBitmap& src, const Context&, |
| SkBitmap* result, SkIPoint* offset) const; |
| #endif |
| |
| /** |
| * Set an external cache to be used for all image filter processing. This |
| * will replace the default intra-frame cache. |
| */ |
| static void SetExternalCache(Cache* cache); |
| |
| /** |
| * Returns the currently-set external cache, or NULL if none is set. |
| */ |
| static Cache* GetExternalCache(); |
| |
| SK_DEFINE_FLATTENABLE_TYPE(SkImageFilter) |
| |
| protected: |
| SkImageFilter(int inputCount, SkImageFilter** inputs, const CropRect* cropRect = NULL); |
| |
| // Convenience constructor for 1-input filters. |
| explicit SkImageFilter(SkImageFilter* input, const CropRect* cropRect = NULL); |
| |
| // Convenience constructor for 2-input filters. |
| SkImageFilter(SkImageFilter* input1, SkImageFilter* input2, const CropRect* cropRect = NULL); |
| |
| virtual ~SkImageFilter(); |
| |
| /** |
| * Constructs a new SkImageFilter read from an SkReadBuffer object. |
| * |
| * @param inputCount The exact number of inputs expected for this SkImageFilter object. |
| * -1 can be used if the filter accepts any number of inputs. |
| * @param rb SkReadBuffer object from which the SkImageFilter is read. |
| */ |
| explicit SkImageFilter(int inputCount, SkReadBuffer& rb); |
| |
| virtual void flatten(SkWriteBuffer& wb) const SK_OVERRIDE; |
| |
| /** |
| * This is the virtual which should be overridden by the derived class |
| * to perform image filtering. |
| * |
| * src is the original primitive bitmap. If the filter has a connected |
| * input, it should recurse on that input and use that in place of src. |
| * |
| * The matrix is the current matrix on the canvas. |
| * |
| * Offset is the amount to translate the resulting image relative to the |
| * src when it is drawn. This is an out-param. |
| * |
| * If the result image cannot be created, this should false, in which |
| * case both the result and offset parameters will be ignored by the |
| * caller. |
| */ |
| virtual bool onFilterImage(Proxy*, const SkBitmap& src, const Context&, |
| SkBitmap* result, SkIPoint* offset) const; |
| // Given the bounds of the destination rect to be filled in device |
| // coordinates (first parameter), and the CTM, compute (conservatively) |
| // which rect of the source image would be required (third parameter). |
| // Used for clipping and temp-buffer allocations, so the result need not |
| // be exact, but should never be smaller than the real answer. The default |
| // implementation recursively unions all input bounds, or returns false if |
| // no inputs. |
| virtual bool onFilterBounds(const SkIRect&, const SkMatrix&, SkIRect*) const; |
| |
| /** Computes source bounds as the src bitmap bounds offset by srcOffset. |
| * Apply the transformed crop rect to the bounds if any of the |
| * corresponding edge flags are set. Intersects the result against the |
| * context's clipBounds, and returns the result in "bounds". If there is |
| * no intersection, returns false and leaves "bounds" unchanged. |
| */ |
| bool applyCropRect(const Context&, const SkBitmap& src, const SkIPoint& srcOffset, |
| SkIRect* bounds) const; |
| |
| /** Same as the above call, except that if the resulting crop rect is not |
| * entirely contained by the source bitmap's bounds, it creates a new |
| * bitmap in "result" and pads the edges with transparent black. In that |
| * case, the srcOffset is modified to be the same as the bounds, since no |
| * further adjustment is needed by the caller. This version should only |
| * be used by filters which are not capable of processing a smaller |
| * source bitmap into a larger destination. |
| */ |
| bool applyCropRect(const Context&, Proxy* proxy, const SkBitmap& src, SkIPoint* srcOffset, |
| SkIRect* bounds, SkBitmap* result) const; |
| |
| /** |
| * Returns true if the filter can be expressed a single-pass |
| * GrEffect, used to process this filter on the GPU, or false if |
| * not. |
| * |
| * If effect is non-NULL, a new GrEffect instance is stored |
| * in it. The caller assumes ownership of the stage, and it is up to the |
| * caller to unref it. |
| * |
| * The effect can assume its vertexCoords space maps 1-to-1 with texels |
| * in the texture. "matrix" is a transformation to apply to filter |
| * parameters before they are used in the effect. Note that this function |
| * will be called with (NULL, NULL, SkMatrix::I()) to query for support, |
| * so returning "true" indicates support for all possible matrices. |
| */ |
| virtual bool asNewEffect(GrEffect** effect, |
| GrTexture*, |
| const SkMatrix& matrix, |
| const SkIRect& bounds) const; |
| |
| private: |
| typedef SkFlattenable INHERITED; |
| int fInputCount; |
| SkImageFilter** fInputs; |
| CropRect fCropRect; |
| }; |
| |
| #endif |