SkMaskFilter.h

/*
 * Copyright 2006 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 SkMaskFilter_DEFINED
#define SkMaskFilter_DEFINED

#include "SkBlurTypes.h"
#include "SkFlattenable.h"
#include "SkMask.h"
#include "SkPaint.h"
#include "SkStrokeRec.h"

class GrClip;
class GrContext;
class GrRenderTargetContext;
class GrPaint;
class GrFragmentProcessor;
class GrRenderTarget;
class GrResourceProvider;
class GrTexture;
class GrTextureProxy;
class SkBitmap;
class SkBlitter;
class SkCachedData;
class SkMatrix;
class SkPath;
class SkRasterClip;
class SkRRect;

class SK_API SkMaskFilter : public SkFlattenable {
public:
    virtual SkMask::Format getFormat() const = 0;

    virtual bool filterMask(SkMask* dst, const SkMask& src, const SkMatrix&,
                            SkIPoint* margin) const;

#if SK_SUPPORT_GPU

    virtual bool asFragmentProcessor(GrFragmentProcessor**) const { return false; }

    virtual bool canFilterMaskGPU(const SkRRect& devRRect,
                                  const SkIRect& clipBounds,
                                  const SkMatrix& ctm,
                                  SkRect* maskRect) const;

    virtual bool directFilterMaskGPU(GrContext*,
                                     GrRenderTargetContext* renderTargetContext,
                                     GrPaint&& paint,
                                     const GrClip&,
                                     const SkMatrix& viewMatrix,
                                     const SkStrokeRec& strokeRec,
                                     const SkPath& path) const;
    virtual bool directFilterRRectMaskGPU(GrContext*,
                                          GrRenderTargetContext* renderTargetContext,
                                          GrPaint&& paint,
                                          const GrClip&,
                                          const SkMatrix& viewMatrix,
                                          const SkStrokeRec& strokeRec,
                                          const SkRRect& rrect,
                                          const SkRRect& devRRect) const;

    virtual sk_sp<GrTextureProxy> filterMaskGPU(GrContext*,
                                                sk_sp<GrTextureProxy> srcProxy,
                                                const SkMatrix& ctm,
                                                const SkIRect& maskRect) const;
#endif

    virtual void computeFastBounds(const SkRect& src, SkRect* dest) const;

    struct BlurRec {
        SkScalar        fSigma;
        SkBlurStyle     fStyle;
        SkBlurQuality   fQuality;
    };
    virtual bool asABlur(BlurRec*) const;

    SK_TO_STRING_PUREVIRT()
    SK_DEFINE_FLATTENABLE_TYPE(SkMaskFilter)

protected:
    SkMaskFilter() {}

    enum FilterReturn {
        kFalse_FilterReturn,
        kTrue_FilterReturn,
        kUnimplemented_FilterReturn
    };

    class NinePatch : ::SkNoncopyable {
    public:
        NinePatch() : fCache(nullptr) { }
        ~NinePatch();

        SkMask      fMask;      // fBounds must have [0,0] in its top-left
        SkIRect     fOuterRect; // width/height must be >= fMask.fBounds'
        SkIPoint    fCenter;    // identifies center row/col for stretching
        SkCachedData* fCache;
    };

    virtual FilterReturn filterRectsToNine(const SkRect[], int count,
                                           const SkMatrix&,
                                           const SkIRect& clipBounds,
                                           NinePatch*) const;
    virtual FilterReturn filterRRectToNine(const SkRRect&, const SkMatrix&,
                                           const SkIRect& clipBounds,
                                           NinePatch*) const;

private:
    friend class SkDraw;

    bool filterPath(const SkPath& devPath, const SkMatrix& ctm, const SkRasterClip&, SkBlitter*,
                    SkStrokeRec::InitStyle) const;

    bool filterRRect(const SkRRect& devRRect, const SkMatrix& ctm, const SkRasterClip&,
                     SkBlitter*) const;

    typedef SkFlattenable INHERITED;
};

#endif