SkTwoPointConicalGradient.h revision d3b28e8847358460aeae745da44e474f6a7ab25d 
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    bool    fFlipped;
27
28    void init(const SkPoint& center0, SkScalar rad0,
29              const SkPoint& center1, SkScalar rad1,
30              bool flipped);
31
32    // used by setup and nextT
33    float   fRelX, fRelY, fIncX, fIncY;
34    float   fB, fDB;
35
36    void setup(SkScalar fx, SkScalar fy, SkScalar dfx, SkScalar dfy);
37    SkFixed nextT();
38
39    static bool DontDrawT(SkFixed t) {
40        return kDontDrawT == (uint32_t)t;
41    }
42};
43
44
45class SkTwoPointConicalGradient : public SkGradientShaderBase {
46    TwoPtRadial fRec;
47    void init();
48
49public:
50    SkTwoPointConicalGradient(const SkPoint& start, SkScalar startRadius,
51                              const SkPoint& end, SkScalar endRadius,
52                              bool flippedGrad, const Descriptor&);
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    virtual bool isOpaque() const SK_OVERRIDE;
66
67    SkScalar getCenterX1() const { return SkPoint::Distance(fCenter1, fCenter2); }
68    SkScalar getStartRadius() const { return fRadius1; }
69    SkScalar getDiffRadius() const { return fRadius2 - fRadius1; }
70    const SkPoint& getStartCenter() const { return fCenter1; }
71    const SkPoint& getEndCenter() const { return fCenter2; }
72    SkScalar getEndRadius() const { return fRadius2; }
73    bool isFlippedGrad() const { return fFlippedGrad; }
74
75    SK_TO_STRING_OVERRIDE()
76    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkTwoPointConicalGradient)
77
78protected:
79    SkTwoPointConicalGradient(SkReadBuffer& buffer);
80    virtual void flatten(SkWriteBuffer& buffer) const SK_OVERRIDE;
81
82private:
83    SkPoint fCenter1;
84    SkPoint fCenter2;
85    SkScalar fRadius1;
86    SkScalar fRadius2;
87    bool fFlippedGrad;
88
89    typedef SkGradientShaderBase INHERITED;
90};
91
92#endif
93