include/effects/SkBlurMaskFilter.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 SkBlurMaskFilter_DEFINED
#define SkBlurMaskFilter_DEFINED

// we include this since our callers will need to at least be able to ref/unref
#include "SkMaskFilter.h"
#include "SkRect.h"
#include "SkScalar.h"
#include "SkBlurTypes.h"

class SkRRect;

class SK_API SkBlurMaskFilter {
public:
#ifdef SK_SUPPORT_LEGACY_BLURMASKFILTER
    enum BlurFlags {
        kNone_BlurFlag              = 0x00,
        /** The blur layer's radius is not affected by transforms */
        kIgnoreTransform_BlurFlag   = 0x01,
        /** Use a smother, higher qulity blur algorithm */
        kHighQuality_BlurFlag       = 0x02,
        /** mask for all blur flags */
        kAll_BlurFlag               = 0x03
    };

    /** Create a blur maskfilter.
     *  @param style     The SkBlurStyle to use
     *  @param sigma     Standard deviation of the Gaussian blur to apply. Must be > 0.
     *  @param occluder  The rect for which no pixels need be drawn (b.c. it will be overdrawn
     *                   with some opaque object. This is just a hint which backends are free to
     *                   ignore.
     *  @param flags     Flags to use - defaults to none
     *  @return The new blur maskfilter
     */
    static sk_sp<SkMaskFilter> Make(SkBlurStyle style, SkScalar sigma,
                                    const SkRect& occluder, uint32_t flags = kNone_BlurFlag);

    static sk_sp<SkMaskFilter> Make(SkBlurStyle style, SkScalar sigma,
                                    uint32_t flags = kNone_BlurFlag) {
        return Make(style, sigma, SkRect::MakeEmpty(), flags);
    }
#endif

#ifdef SK_SUPPORT_LEGACY_EMBOSSMASKFILTER
    /** Create an emboss maskfilter
        @param blurSigma    standard deviation of the Gaussian blur to apply
                            before applying lighting (e.g. 3)
        @param direction    array of 3 scalars [x, y, z] specifying the direction of the light source
        @param ambient      0...1 amount of ambient light
        @param specular     coefficient for specular highlights (e.g. 8)
        @return the emboss maskfilter
    */
    static sk_sp<SkMaskFilter> MakeEmboss(SkScalar blurSigma, const SkScalar direction[3],
                                          SkScalar ambient, SkScalar specular);
#endif

#ifdef SK_SUPPORT_LEGACY_BLURMASKFILTER
private:
    SkBlurMaskFilter(); // can't be instantiated
#endif
};

#endif