aboutsummaryrefslogtreecommitdiffhomepage
path: root/include/core/SkLights.h
blob: c4262a0fc085c44e8fec4e227869be52bbef6644 (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

/*
 * Copyright 2015 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef SkLights_DEFINED
#define SkLights_DEFINED

#include "SkPoint3.h"
#include "SkRefCnt.h"
#include "../private/SkTArray.h"

class SkColorSpaceXformer;
class SkReadBuffer;
class SkWriteBuffer;

/** \class SkLights
    SkLights encapsulates a set of directional, point and ambient lights for use with the
    SkLightingShader.
*/
class SK_API SkLights  : public SkRefCnt {
public:
    class Light {
    public:
        enum LightType {
            kDirectional_LightType,
            kPoint_LightType
        };

        Light(const Light& other)
                : fType(other.fType)
                , fColor(other.fColor)
                , fDirOrPos(other.fDirOrPos)
                , fIntensity(other.fIntensity) {}

        Light(Light&& other)
                : fType(other.fType)
                , fColor(other.fColor)
                , fDirOrPos(other.fDirOrPos)
                , fIntensity(other.fIntensity) {}

        static Light MakeDirectional(const SkColor3f& color, const SkVector3& dir) {
            Light light(kDirectional_LightType, color, dir, 0.0f);
            if (!light.fDirOrPos.normalize()) {
                light.fDirOrPos.set(0.0f, 0.0f, 1.0f);
            }
            return light;
        }

        static Light MakePoint(const SkColor3f& color, const SkPoint3& pos, SkScalar intensity) {
            return Light(kPoint_LightType, color, pos, intensity);
        }

        LightType type() const { return fType; }
        const SkColor3f& color() const { return fColor; }
        const SkVector3& dir() const {
            SkASSERT(kDirectional_LightType == fType);
            return fDirOrPos;
        }
        const SkPoint3& pos() const {
            SkASSERT(kPoint_LightType == fType);
            return fDirOrPos;
        }
        SkScalar intensity() const {
            SkASSERT(kPoint_LightType == fType);
            return fIntensity;
        }

        Light& operator=(const Light& other) {
            if (this == &other) {
                return *this;
            }

            fType = other.fType;
            fColor = other.fColor;
            fDirOrPos = other.fDirOrPos;
            fIntensity = other.fIntensity;
            return *this;
        }

        bool operator==(const Light& other) {
            return (fType      == other.fType) &&
                   (fColor     == other.fColor) &&
                   (fDirOrPos  == other.fDirOrPos) &&
                   (fIntensity == other.fIntensity);
        }

        bool operator!=(const Light& other) { return !(this->operator==(other)); }

    private:
        friend class SkLights;

        Light(LightType type, const SkColor3f& color, const SkVector3& dirOrPos,
              SkScalar intensity)
                : fType(type)
                , fColor(color)
                , fDirOrPos(dirOrPos)
                , fIntensity(intensity) {}

        LightType   fType;
        SkColor3f   fColor;           // linear (unpremul) color. Range is 0..1 in each channel.

        SkVector3   fDirOrPos;        // For directional lights, holds the direction towards the
                                      // light (+Z is out of the screen).
                                      // If degenerate, it will be replaced with (0, 0, 1).
                                      // For point lights, holds location of point light

        SkScalar    fIntensity;       // For point lights, dictates the light intensity.
                                      // Simply a multiplier to the final light output value.
    };

    class Builder {
    public:
        Builder() : fLights(new SkLights) {}

        void add(const Light& light) {
            if (fLights) {
                fLights->fLights.push_back(light);
            }
        }

        void add(Light&& light) {
            if (fLights) {
                fLights->fLights.push_back(std::move(light));
            }
        }

        void setAmbientLightColor(const SkColor3f& color) {
            if (fLights) {
                fLights->fAmbientLightColor = color;
            }
        }

        sk_sp<SkLights> finish() {
            return std::move(fLights);
        }

    private:
        sk_sp<SkLights> fLights;
    };

    /** Returns number of lights not including the ambient light.

        @return number of lights not including the ambient light
    */
    int numLights() const { return fLights.count(); }

    /** Returns the index-th light.

        @param index  the index of the desired light
        @return       the index-th light
    */
    const Light& light(int index) const { return fLights[index]; }

    /** Returns the ambient light.

        @return the ambient light
    */
    const SkColor3f& ambientLightColor() const {
        return fAmbientLightColor;
    }

    /**
     *  Recreate an SkLights object that was serialized into a buffer.
     *
     *  @param  SkReadBuffer Serialized blob data.
     *  @return A new SkLights representing the serialized data, or NULL if the buffer is
     *          invalid.
     */
    static sk_sp<SkLights> MakeFromBuffer(SkReadBuffer& buf);

    /**
     *  Serialize to a buffer.
     *
     *  @param  buffer the write buffer to write out to
     */
    void flatten(SkWriteBuffer& buf) const;

private:
    friend class SkLightingShaderImpl;

    SkLights() : fAmbientLightColor(SkColor3f::Make(0.0f, 0.0f, 0.0f)) {}

    sk_sp<SkLights> makeColorSpace(SkColorSpaceXformer* xformer) const;

    SkTArray<Light> fLights;
    SkColor3f       fAmbientLightColor;

    typedef SkRefCnt INHERITED;
};

#endif