SkTwoPointConicalGradient.h revision aa64fbfd349789f27b3cc35c1968d9dc0612cf8e 
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 Descriptor&);
51
52    virtual void shadeSpan(int x, int y, SkPMColor* dstCParam,
53                           int count) SK_OVERRIDE;
54    virtual bool setContext(const SkBitmap& device,
55                            const SkPaint& paint,
56                            const SkMatrix& matrix) SK_OVERRIDE;
57
58    virtual BitmapType asABitmap(SkBitmap* bitmap,
59                                 SkMatrix* matrix,
60                                 TileMode* xy) const;
61    virtual SkShader::GradientType asAGradient(GradientInfo* info) const  SK_OVERRIDE;
62    virtual GrEffectRef* asNewEffect(GrContext* context, const SkPaint& paint) const SK_OVERRIDE;
63    virtual bool isOpaque() const SK_OVERRIDE;
64
65    SkScalar getCenterX1() const { return SkPoint::Distance(fCenter1, fCenter2); }
66    SkScalar getStartRadius() const { return fRadius1; }
67    SkScalar getDiffRadius() const { return fRadius2 - fRadius1; }
68
69    SK_TO_STRING_OVERRIDE()
70    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkTwoPointConicalGradient)
71
72protected:
73    SkTwoPointConicalGradient(SkReadBuffer& buffer);
74    virtual void flatten(SkWriteBuffer& buffer) const SK_OVERRIDE;
75
76private:
77    typedef SkGradientShaderBase INHERITED;
78    const SkPoint fCenter1;
79    const SkPoint fCenter2;
80    const SkScalar fRadius1;
81    const SkScalar fRadius2;
82};
83
84#endif
85