aboutsummaryrefslogtreecommitdiffhomepage
path: root/include/effects/SkGradientShader.h
blob: 9821c4be82c1df80bff79c199b609a6264c63b1c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
/*
 * Copyright 2006 The Android Open Source Project
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef SkGradientShader_DEFINED
#define SkGradientShader_DEFINED

#include "SkShader.h"

/** \class SkGradientShader

    SkGradientShader hosts factories for creating subclasses of SkShader that
    render linear and radial gradients.
*/
class SK_API SkGradientShader {
public:
    enum Flags {
        /** By default gradients will interpolate their colors in unpremul space
         *  and then premultiply each of the results. By setting this flag, the
         *  gradients will premultiply their colors first, and then interpolate
         *  between them.
         */
        kInterpolateColorsInPremul_Flag = 1 << 0,
    };

    /** Returns a shader that generates a linear gradient between the two specified points.
        <p />
        @param  pts     The start and end points for the gradient.
        @param  colors  The array[count] of colors, to be distributed between the two points
        @param  pos     May be NULL. array[count] of SkScalars, or NULL, of the relative position of
                        each corresponding color in the colors array. If this is NULL,
                        the the colors are distributed evenly between the start and end point.
                        If this is not null, the values must begin with 0, end with 1.0, and
                        intermediate values must be strictly increasing.
        @param  count   Must be >=2. The number of colors (and pos if not NULL) entries.
        @param  mode    The tiling mode
    */
    static sk_sp<SkShader> MakeLinear(const SkPoint pts[2],
                                      const SkColor colors[], const SkScalar pos[], int count,
                                      SkShader::TileMode mode,
                                      uint32_t flags, const SkMatrix* localMatrix);
    static sk_sp<SkShader> MakeLinear(const SkPoint pts[2],
                                      const SkColor colors[], const SkScalar pos[], int count,
                                      SkShader::TileMode mode) {
        return MakeLinear(pts, colors, pos, count, mode, 0, nullptr);
    }

    /** Returns a shader that generates a linear gradient between the two specified points.
        <p />
        @param  pts     The start and end points for the gradient.
        @param  colors  The array[count] of colors, to be distributed between the two points
        @param  pos     May be NULL. array[count] of SkScalars, or NULL, of the relative position of
                        each corresponding color in the colors array. If this is NULL,
                        the the colors are distributed evenly between the start and end point.
                        If this is not null, the values must begin with 0, end with 1.0, and
                        intermediate values must be strictly increasing.
        @param  count   Must be >=2. The number of colors (and pos if not NULL) entries.
        @param  mode    The tiling mode
    */
    static sk_sp<SkShader> MakeLinear(const SkPoint pts[2],
                                      const SkColor4f colors[], sk_sp<SkColorSpace> colorSpace,
                                      const SkScalar pos[], int count, SkShader::TileMode mode,
                                      uint32_t flags, const SkMatrix* localMatrix);
    static sk_sp<SkShader> MakeLinear(const SkPoint pts[2],
                                      const SkColor4f colors[], sk_sp<SkColorSpace> colorSpace,
                                      const SkScalar pos[], int count, SkShader::TileMode mode) {
        return MakeLinear(pts, colors, std::move(colorSpace), pos, count, mode, 0, nullptr);
    }

    /** Returns a shader that generates a radial gradient given the center and radius.
        <p />
        @param  center  The center of the circle for this gradient
        @param  radius  Must be positive. The radius of the circle for this gradient
        @param  colors  The array[count] of colors, to be distributed between the center and edge of the circle
        @param  pos     May be NULL. The array[count] of SkScalars, or NULL, of the relative position of
                        each corresponding color in the colors array. If this is NULL,
                        the the colors are distributed evenly between the center and edge of the circle.
                        If this is not null, the values must begin with 0, end with 1.0, and
                        intermediate values must be strictly increasing.
        @param  count   Must be >= 2. The number of colors (and pos if not NULL) entries
        @param  mode    The tiling mode
    */
    static sk_sp<SkShader> MakeRadial(const SkPoint& center, SkScalar radius,
                                      const SkColor colors[], const SkScalar pos[], int count,
                                      SkShader::TileMode mode,
                                      uint32_t flags, const SkMatrix* localMatrix);
    static sk_sp<SkShader> MakeRadial(const SkPoint& center, SkScalar radius,
                                      const SkColor colors[], const SkScalar pos[], int count,
                                      SkShader::TileMode mode) {
        return MakeRadial(center, radius, colors, pos, count, mode, 0, nullptr);
    }

    /** Returns a shader that generates a radial gradient given the center and radius.
        <p />
        @param  center  The center of the circle for this gradient
        @param  radius  Must be positive. The radius of the circle for this gradient
        @param  colors  The array[count] of colors, to be distributed between the center and edge of the circle
        @param  pos     May be NULL. The array[count] of SkScalars, or NULL, of the relative position of
                        each corresponding color in the colors array. If this is NULL,
                        the the colors are distributed evenly between the center and edge of the circle.
                        If this is not null, the values must begin with 0, end with 1.0, and
                        intermediate values must be strictly increasing.
        @param  count   Must be >= 2. The number of colors (and pos if not NULL) entries
        @param  mode    The tiling mode
    */
    static sk_sp<SkShader> MakeRadial(const SkPoint& center, SkScalar radius,
                                      const SkColor4f colors[], sk_sp<SkColorSpace> colorSpace,
                                      const SkScalar pos[], int count, SkShader::TileMode mode,
                                      uint32_t flags, const SkMatrix* localMatrix);
    static sk_sp<SkShader> MakeRadial(const SkPoint& center, SkScalar radius,
                                      const SkColor4f colors[], sk_sp<SkColorSpace> colorSpace,
                                      const SkScalar pos[], int count, SkShader::TileMode mode) {
        return MakeRadial(center, radius, colors, std::move(colorSpace), pos, count, mode,
                          0, nullptr);
    }

    /**
     *  Returns a shader that generates a conical gradient given two circles, or
     *  returns NULL if the inputs are invalid. The gradient interprets the
     *  two circles according to the following HTML spec.
     *  http://dev.w3.org/html5/2dcontext/#dom-context-2d-createradialgradient
     */
    static sk_sp<SkShader> MakeTwoPointConical(const SkPoint& start, SkScalar startRadius,
                                               const SkPoint& end, SkScalar endRadius,
                                               const SkColor colors[], const SkScalar pos[],
                                               int count, SkShader::TileMode mode,
                                               uint32_t flags, const SkMatrix* localMatrix);
    static sk_sp<SkShader> MakeTwoPointConical(const SkPoint& start, SkScalar startRadius,
                                               const SkPoint& end, SkScalar endRadius,
                                               const SkColor colors[], const SkScalar pos[],
                                               int count, SkShader::TileMode mode) {
        return MakeTwoPointConical(start, startRadius, end, endRadius, colors, pos, count, mode,
                                   0, nullptr);
    }

    /**
     *  Returns a shader that generates a conical gradient given two circles, or
     *  returns NULL if the inputs are invalid. The gradient interprets the
     *  two circles according to the following HTML spec.
     *  http://dev.w3.org/html5/2dcontext/#dom-context-2d-createradialgradient
     */
    static sk_sp<SkShader> MakeTwoPointConical(const SkPoint& start, SkScalar startRadius,
                                               const SkPoint& end, SkScalar endRadius,
                                               const SkColor4f colors[],
                                               sk_sp<SkColorSpace> colorSpace, const SkScalar pos[],
                                               int count, SkShader::TileMode mode,
                                               uint32_t flags, const SkMatrix* localMatrix);
    static sk_sp<SkShader> MakeTwoPointConical(const SkPoint& start, SkScalar startRadius,
                                               const SkPoint& end, SkScalar endRadius,
                                               const SkColor4f colors[],
                                               sk_sp<SkColorSpace> colorSpace, const SkScalar pos[],
                                               int count, SkShader::TileMode mode) {
        return MakeTwoPointConical(start, startRadius, end, endRadius, colors,
                                   std::move(colorSpace), pos, count, mode, 0, nullptr);
    }

    /** Returns a shader that generates a sweep gradient given a center.
        <p />
        @param  cx         The X coordinate of the center of the sweep
        @param  cx         The Y coordinate of the center of the sweep
        @param  colors     The array[count] of colors, to be distributed around the center, within
                           the gradient angle range.
        @param  pos        May be NULL. The array[count] of SkScalars, or NULL, of the relative
                           position of each corresponding color in the colors array. If this is
                           NULL, then the colors are distributed evenly within the angular range.
                           If this is not null, the values must begin with 0, end with 1.0, and
                           intermediate values must be strictly increasing.
        @param  count      Must be >= 2. The number of colors (and pos if not NULL) entries
        @param  mode       Tiling mode: controls drawing outside of the gradient angular range.
        @param  startAngle Start of the angular range, corresponding to pos == 0.
        @param  endAngle   End of the angular range, corresponding to pos == 1.
    */
    static sk_sp<SkShader> MakeSweep(SkScalar cx, SkScalar cy,
                                     const SkColor colors[], const SkScalar pos[], int count,
                                     SkShader::TileMode mode,
                                     SkScalar startAngle, SkScalar endAngle,
                                     uint32_t flags, const SkMatrix* localMatrix);
    static sk_sp<SkShader> MakeSweep(SkScalar cx, SkScalar cy,
                                     const SkColor colors[], const SkScalar pos[], int count,
                                     uint32_t flags, const SkMatrix* localMatrix) {
        return MakeSweep(cx, cy, colors, pos, count, SkShader::kClamp_TileMode, 0, 360, flags,
                         localMatrix);
    }
    static sk_sp<SkShader> MakeSweep(SkScalar cx, SkScalar cy,
                                     const SkColor colors[], const SkScalar pos[], int count) {
        return MakeSweep(cx, cy, colors, pos, count, 0, nullptr);
    }

    /** Returns a shader that generates a sweep gradient given a center.
        <p />
        @param  cx         The X coordinate of the center of the sweep
        @param  cx         The Y coordinate of the center of the sweep
        @param  colors     The array[count] of colors, to be distributed around the center, within
                           the gradient angle range.
        @param  pos        May be NULL. The array[count] of SkScalars, or NULL, of the relative
                           position of each corresponding color in the colors array. If this is
                           NULL, then the colors are distributed evenly within the angular range.
                           If this is not null, the values must begin with 0, end with 1.0, and
                           intermediate values must be strictly increasing.
        @param  count      Must be >= 2. The number of colors (and pos if not NULL) entries
        @param  mode       Tiling mode: controls drawing outside of the gradient angular range.
        @param  startAngle Start of the angular range, corresponding to pos == 0.
        @param  endAngle   End of the angular range, corresponding to pos == 1.
    */
    static sk_sp<SkShader> MakeSweep(SkScalar cx, SkScalar cy,
                                     const SkColor4f colors[], sk_sp<SkColorSpace> colorSpace,
                                     const SkScalar pos[], int count,
                                     SkShader::TileMode mode,
                                     SkScalar startAngle, SkScalar endAngle,
                                     uint32_t flags, const SkMatrix* localMatrix);
    static sk_sp<SkShader> MakeSweep(SkScalar cx, SkScalar cy,
                                     const SkColor4f colors[], sk_sp<SkColorSpace> colorSpace,
                                     const SkScalar pos[], int count,
                                     uint32_t flags, const SkMatrix* localMatrix) {
        return MakeSweep(cx, cy, colors, std::move(colorSpace), pos, count,
                         SkShader::kClamp_TileMode, 0, 360, flags, localMatrix);
    }
    static sk_sp<SkShader> MakeSweep(SkScalar cx, SkScalar cy,
                                     const SkColor4f colors[], sk_sp<SkColorSpace> colorSpace,
                                     const SkScalar pos[], int count) {
        return MakeSweep(cx, cy, colors, std::move(colorSpace), pos, count, 0, nullptr);
    }

    SK_DECLARE_FLATTENABLE_REGISTRAR_GROUP()
};

#endif