1/*
2 * Copyright 2006 The Android Open Source Project
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#ifndef SkBlurMaskFilter_DEFINED
9#define SkBlurMaskFilter_DEFINED
10
11// we include this since our callers will need to at least be able to ref/unref
12#include "SkMaskFilter.h"
13#include "SkScalar.h"
14#include "SkBlurTypes.h"
15
16class SK_API SkBlurMaskFilter {
17public:
18    /**
19     *  If radius > 0, return the corresponding sigma, else return 0. Use this to convert from the
20     *  (legacy) idea of specify the blur "radius" to the standard notion of specifying its sigma.
21     */
22    static SkScalar ConvertRadiusToSigma(SkScalar radius);
23
24    enum BlurFlags {
25        kNone_BlurFlag = 0x00,
26        /** The blur layer's radius is not affected by transforms */
27        kIgnoreTransform_BlurFlag   = 0x01,
28        /** Use a smother, higher qulity blur algorithm */
29        kHighQuality_BlurFlag       = 0x02,
30        /** mask for all blur flags */
31        kAll_BlurFlag = 0x03
32    };
33
34    /** Create a blur maskfilter.
35     *  @param style    The SkBlurStyle to use
36     *  @param sigma    Standard deviation of the Gaussian blur to apply. Must be > 0.
37     *  @param flags    Flags to use - defaults to none
38     *  @return The new blur maskfilter
39     */
40    static SkMaskFilter* Create(SkBlurStyle style, SkScalar sigma, uint32_t flags = kNone_BlurFlag);
41
42    /** Create an emboss maskfilter
43        @param blurSigma    standard deviation of the Gaussian blur to apply
44                            before applying lighting (e.g. 3)
45        @param direction    array of 3 scalars [x, y, z] specifying the direction of the light source
46        @param ambient      0...1 amount of ambient light
47        @param specular     coefficient for specular highlights (e.g. 8)
48        @return the emboss maskfilter
49    */
50    static SkMaskFilter* CreateEmboss(SkScalar blurSigma, const SkScalar direction[3],
51                                      SkScalar ambient, SkScalar specular);
52
53    SK_ATTR_DEPRECATED("use sigma version")
54    static SkMaskFilter* CreateEmboss(const SkScalar direction[3],
55                                      SkScalar ambient, SkScalar specular,
56                                      SkScalar blurRadius);
57
58    SK_DECLARE_FLATTENABLE_REGISTRAR_GROUP()
59
60private:
61    SkBlurMaskFilter(); // can't be instantiated
62};
63
64#endif
65