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.
16 struct 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 
DontDrawTTwoPtRadial34     static bool DontDrawT(SkFixed t) {
35         return kDontDrawT == (uint32_t)t;
36     }
37 };
38 
39 
40 class SkTwoPointConicalGradient : public SkGradientShaderBase {
41     TwoPtRadial fRec;
42 public:
43     SkTwoPointConicalGradient(const SkPoint& start, SkScalar startRadius,
44                               const SkPoint& end, SkScalar endRadius,
45                               bool flippedGrad, const Descriptor&);
46 
47 
48     size_t contextSize() const override;
49 
50     class TwoPointConicalGradientContext : public SkGradientShaderBase::GradientShaderBaseContext {
51     public:
52         TwoPointConicalGradientContext(const SkTwoPointConicalGradient&, const ContextRec&);
~TwoPointConicalGradientContext()53         ~TwoPointConicalGradientContext() {}
54 
55         void shadeSpan(int x, int y, SkPMColor dstC[], int count) override;
56 
57     private:
58         typedef SkGradientShaderBase::GradientShaderBaseContext INHERITED;
59     };
60 
61     virtual BitmapType asABitmap(SkBitmap* bitmap,
62                                  SkMatrix* matrix,
63                                  TileMode* xy) const override;
64     SkShader::GradientType asAGradient(GradientInfo* info) const  override;
65     virtual bool asFragmentProcessor(GrContext*, const SkPaint&, const SkMatrix&, const SkMatrix*,
66                                      GrColor*, GrFragmentProcessor**) const override;
67     bool isOpaque() const override;
68 
getCenterX1()69     SkScalar getCenterX1() const { return SkPoint::Distance(fCenter1, fCenter2); }
getStartRadius()70     SkScalar getStartRadius() const { return fRadius1; }
getDiffRadius()71     SkScalar getDiffRadius() const { return fRadius2 - fRadius1; }
getStartCenter()72     const SkPoint& getStartCenter() const { return fCenter1; }
getEndCenter()73     const SkPoint& getEndCenter() const { return fCenter2; }
getEndRadius()74     SkScalar getEndRadius() const { return fRadius2; }
isFlippedGrad()75     bool isFlippedGrad() const { return fFlippedGrad; }
76 
77     SK_TO_STRING_OVERRIDE()
78     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkTwoPointConicalGradient)
79 
80 protected:
81     SkTwoPointConicalGradient(SkReadBuffer& buffer);
82     void flatten(SkWriteBuffer& buffer) const override;
83     Context* onCreateContext(const ContextRec&, void* storage) const override;
84 
85 private:
86     SkPoint fCenter1;
87     SkPoint fCenter2;
88     SkScalar fRadius1;
89     SkScalar fRadius2;
90     bool fFlippedGrad;
91 
92     friend class SkGradientShader;
93     typedef SkGradientShaderBase INHERITED;
94 };
95 
96 #endif
97