SkBlurDrawLooper.h revision 038aff623d9fd47946cd31685f74cf473f7c84f0 
1c5cede9ae108bb15f6b7a8aea21c7e1fefa2834cBen Murdoch/*
23240926e260ce088908e02ac07a6cf7b0c0cbf44Ben Murdoch * Copyright (C) 2008 The Android Open Source Project
33240926e260ce088908e02ac07a6cf7b0c0cbf44Ben Murdoch *
43240926e260ce088908e02ac07a6cf7b0c0cbf44Ben Murdoch * Licensed under the Apache License, Version 2.0 (the "License");
53240926e260ce088908e02ac07a6cf7b0c0cbf44Ben Murdoch * you may not use this file except in compliance with the License.
63240926e260ce088908e02ac07a6cf7b0c0cbf44Ben Murdoch * You may obtain a copy of the License at
73240926e260ce088908e02ac07a6cf7b0c0cbf44Ben Murdoch *
8c5cede9ae108bb15f6b7a8aea21c7e1fefa2834cBen Murdoch *      http://www.apache.org/licenses/LICENSE-2.0
9c5cede9ae108bb15f6b7a8aea21c7e1fefa2834cBen Murdoch *
103240926e260ce088908e02ac07a6cf7b0c0cbf44Ben Murdoch * Unless required by applicable law or agreed to in writing, software
113240926e260ce088908e02ac07a6cf7b0c0cbf44Ben Murdoch * distributed under the License is distributed on an "AS IS" BASIS,
123240926e260ce088908e02ac07a6cf7b0c0cbf44Ben Murdoch * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13c5cede9ae108bb15f6b7a8aea21c7e1fefa2834cBen Murdoch * See the License for the specific language governing permissions and
14c5cede9ae108bb15f6b7a8aea21c7e1fefa2834cBen Murdoch * limitations under the License.
15 */
16
17#ifndef SkBlurDrawLooper_DEFINED
18#define SkBlurDrawLooper_DEFINED
19
20#include "SkDrawLooper.h"
21#include "SkColor.h"
22
23class SkMaskFilter;
24
25/** \class SkBlurDrawLooper
26    This class draws a shadow of the object (possibly offset), and then draws
27    the original object in its original position.
28    should there be an option to just draw the shadow/blur layer? webkit?
29*/
30class SkBlurDrawLooper : public SkDrawLooper {
31public:
32    enum BlurFlags {
33        kNone_BlurFlag = 0x00,
34        /**
35            The blur layer's dx/dy/radius aren't affected by the canvas
36            transform.
37        */
38        kIgnoreTransform_BlurFlag = 0x01,
39        /** mask for all blur flags */
40        kAll_BlurFlag = 0x01
41    };
42
43    SkBlurDrawLooper(SkScalar radius, SkScalar dx, SkScalar dy, SkColor color,
44                     uint32_t flags = kNone_BlurFlag);
45    virtual ~SkBlurDrawLooper();
46
47    // overrides from SkDrawLooper
48    virtual void init(SkCanvas*, SkPaint*);
49    virtual bool next();
50    virtual void restore();
51
52    static SkFlattenable* CreateProc(SkFlattenableReadBuffer& buffer) {
53        return SkNEW_ARGS(SkBlurDrawLooper, (buffer));
54    }
55
56
57protected:
58    SkBlurDrawLooper(SkFlattenableReadBuffer&);
59    // overrides from SkFlattenable
60    virtual void flatten(SkFlattenableWriteBuffer& );
61    virtual Factory getFactory() { return CreateProc; }
62
63private:
64    SkCanvas*       fCanvas;
65    SkPaint*        fPaint;
66    SkMaskFilter*   fBlur;
67    SkScalar        fDx, fDy;
68    SkColor         fBlurColor;
69    SkColor         fSavedColor;    // remember the original
70    int             fSaveCount;
71    uint32_t        fBlurFlags;
72
73    enum State {
74        kBeforeEdge,
75        kAfterEdge,
76        kDone
77    };
78    State   fState;
79
80    typedef SkDrawLooper INHERITED;
81};
82
83#endif
84