SkTwoPointConicalGradient.h revision ce56d965069c1649afe14319cb239e6ad670682a 
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
14// TODO(dominikg): Worth making it truly immutable (i.e. set values in constructor)?
15// Should only be initialized once via init(). Immutable afterwards.
16struct TwoPtRadial {
17    enum {
18        kDontDrawT  = 0x80000000
19    };
20
21    float   fCenterX, fCenterY;
22    float   fDCenterX, fDCenterY;
23    float   fRadius;
24    float   fDRadius;
25    float   fA;
26    float   fRadius2;
27    float   fRDR;
28    bool    fFlipped;
29
30    void init(const SkPoint& center0, SkScalar rad0,
31              const SkPoint& center1, SkScalar rad1,
32              bool flipped);
33
34    static bool DontDrawT(SkFixed t) {
35        return kDontDrawT == (uint32_t)t;
36    }
37};
38
39
40class SkTwoPointConicalGradient : public SkGradientShaderBase {
41    TwoPtRadial fRec;
42    void init();
43
44public:
45    SkTwoPointConicalGradient(const SkPoint& start, SkScalar startRadius,
46                              const SkPoint& end, SkScalar endRadius,
47                              bool flippedGrad, const Descriptor&,
48                              const SkMatrix* localMatrix);
49
50
51    virtual size_t contextSize() const SK_OVERRIDE;
52
53    class TwoPointConicalGradientContext : public SkGradientShaderBase::GradientShaderBaseContext {
54    public:
55        TwoPointConicalGradientContext(const SkTwoPointConicalGradient&, const ContextRec&);
56        ~TwoPointConicalGradientContext() {}
57
58        virtual void shadeSpan(int x, int y, SkPMColor dstC[], int count) SK_OVERRIDE;
59
60    private:
61        typedef SkGradientShaderBase::GradientShaderBaseContext INHERITED;
62    };
63
64    virtual BitmapType asABitmap(SkBitmap* bitmap,
65                                 SkMatrix* matrix,
66                                 TileMode* xy) const;
67    virtual SkShader::GradientType asAGradient(GradientInfo* info) const  SK_OVERRIDE;
68    virtual GrEffectRef* asNewEffect(GrContext* context, const SkPaint& paint) const SK_OVERRIDE;
69    virtual bool isOpaque() const SK_OVERRIDE;
70
71    SkScalar getCenterX1() const { return SkPoint::Distance(fCenter1, fCenter2); }
72    SkScalar getStartRadius() const { return fRadius1; }
73    SkScalar getDiffRadius() const { return fRadius2 - fRadius1; }
74    const SkPoint& getStartCenter() const { return fCenter1; }
75    const SkPoint& getEndCenter() const { return fCenter2; }
76    SkScalar getEndRadius() const { return fRadius2; }
77    bool isFlippedGrad() const { return fFlippedGrad; }
78
79    SK_TO_STRING_OVERRIDE()
80    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkTwoPointConicalGradient)
81
82protected:
83    SkTwoPointConicalGradient(SkReadBuffer& buffer);
84    virtual void flatten(SkWriteBuffer& buffer) const SK_OVERRIDE;
85    virtual Context* onCreateContext(const ContextRec&, void* storage) const SK_OVERRIDE;
86
87private:
88    SkPoint fCenter1;
89    SkPoint fCenter2;
90    SkScalar fRadius1;
91    SkScalar fRadius2;
92    bool fFlippedGrad;
93
94    typedef SkGradientShaderBase INHERITED;
95};
96
97#endif
98