SkTwoPointConicalGradient.h revision 0ac6af49975c54c2debf41e9200af416ecd2d973 
1
2/*
3 * Copyright 2012 Google Inc.
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9 #ifndef SkTwoPointConicalGradient_DEFINED
10 #define SkTwoPointConicalGradient_DEFINED
11
12#include "SkGradientShaderPriv.h"
13
14struct TwoPtRadial {
15    enum {
16        kDontDrawT  = 0x80000000
17    };
18
19    float   fCenterX, fCenterY;
20    float   fDCenterX, fDCenterY;
21    float   fRadius;
22    float   fDRadius;
23    float   fA;
24    float   fRadius2;
25    float   fRDR;
26
27    void init(const SkPoint& center0, SkScalar rad0,
28              const SkPoint& center1, SkScalar rad1);
29
30    // used by setup and nextT
31    float   fRelX, fRelY, fIncX, fIncY;
32    float   fB, fDB;
33
34    void setup(SkScalar fx, SkScalar fy, SkScalar dfx, SkScalar dfy);
35    SkFixed nextT();
36
37    static bool DontDrawT(SkFixed t) {
38        return kDontDrawT == (uint32_t)t;
39    }
40};
41
42
43class SkTwoPointConicalGradient : public SkGradientShaderBase {
44    TwoPtRadial fRec;
45    void init();
46
47public:
48    SkTwoPointConicalGradient(const SkPoint& start, SkScalar startRadius,
49                              const SkPoint& end, SkScalar endRadius,
50                              const SkColor colors[], const SkScalar pos[],
51                              int colorCount, SkShader::TileMode mode,
52                              SkUnitMapper* mapper);
53
54    virtual void shadeSpan(int x, int y, SkPMColor* dstCParam,
55                           int count) SK_OVERRIDE;
56    virtual bool setContext(const SkBitmap& device,
57                            const SkPaint& paint,
58                            const SkMatrix& matrix) SK_OVERRIDE;
59
60    virtual BitmapType asABitmap(SkBitmap* bitmap,
61                                 SkMatrix* matrix,
62                                 TileMode* xy) const;
63    virtual SkShader::GradientType asAGradient(GradientInfo* info) const  SK_OVERRIDE;
64    virtual GrEffectRef* asNewEffect(GrContext* context, const SkPaint& paint) const SK_OVERRIDE;
65
66    SkScalar getCenterX1() const { return SkPoint::Distance(fCenter1, fCenter2); }
67    SkScalar getStartRadius() const { return fRadius1; }
68    SkScalar getDiffRadius() const { return fRadius2 - fRadius1; }
69
70    SK_DEVELOPER_TO_STRING()
71    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkTwoPointConicalGradient)
72
73protected:
74    SkTwoPointConicalGradient(SkFlattenableReadBuffer& buffer);
75    virtual void flatten(SkFlattenableWriteBuffer& buffer) const SK_OVERRIDE;
76
77private:
78    typedef SkGradientShaderBase INHERITED;
79    const SkPoint fCenter1;
80    const SkPoint fCenter2;
81    const SkScalar fRadius1;
82    const SkScalar fRadius2;
83};
84
85#endif
86
87