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
|
/*
* Copyright (C) 2013 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ANDROID_HWUI_RENDER_BUFFER_H
#define ANDROID_HWUI_RENDER_BUFFER_H
#include <GLES2/gl2.h>
#include <GLES2/gl2ext.h>
namespace android {
namespace uirenderer {
/**
* Represents an OpenGL render buffer. Render buffers are attached
* to layers to perform stencil work.
*/
struct RenderBuffer {
/**
* Creates a new render buffer in the specified format and dimensions.
* The format must be one of the formats allowed by glRenderbufferStorage().
*/
RenderBuffer(GLenum format, uint32_t width, uint32_t height):
mFormat(format), mWidth(width), mHeight(height), mAllocated(false) {
glGenRenderbuffers(1, &mName);
}
~RenderBuffer() {
if (mName) {
glDeleteRenderbuffers(1, &mName);
}
}
/**
* Returns the GL name of this render buffer.
*/
GLuint getName() const {
return mName;
}
/**
* Returns the format of this render buffer.
*/
GLenum getFormat() const {
return mFormat;
}
/**
* Binds this render buffer to the current GL context.
*/
void bind() const {
glBindRenderbuffer(GL_RENDERBUFFER, mName);
}
/**
* Indicates whether this render buffer has allocated its
* storage. See allocate() and resize().
*/
bool isAllocated() const {
return mAllocated;
}
/**
* Allocates this render buffer's storage if needed.
* This method doesn't do anything if isAllocated() returns true.
*/
void allocate() {
if (!mAllocated) {
glRenderbufferStorage(GL_RENDERBUFFER, mFormat, mWidth, mHeight);
mAllocated = true;
}
}
/**
* Resizes this render buffer. If the buffer was previously allocated,
* the storage is re-allocated wit the new specified dimensions. If the
* buffer wasn't previously allocated, the buffer remains unallocated.
*/
void resize(uint32_t width, uint32_t height) {
if (isAllocated() && (width != mWidth || height != mHeight)) {
glRenderbufferStorage(GL_RENDERBUFFER, mFormat, width, height);
}
mWidth = width;
mHeight = height;
}
/**
* Returns the width of the render buffer in pixels.
*/
uint32_t getWidth() const {
return mWidth;
}
/**
* Returns the height of the render buffer in pixels.
*/
uint32_t getHeight() const {
return mHeight;
}
/**
* Returns the size of this render buffer in bytes.
*/
uint32_t getSize() const {
// Round to the nearest byte
return (uint32_t) ((mWidth * mHeight * formatSize(mFormat)) / 8.0f + 0.5f);
}
/**
* Returns the number of bits per component in the specified format.
* The format must be one of the formats allowed by glRenderbufferStorage().
*/
static uint32_t formatSize(GLenum format) {
switch (format) {
case GL_STENCIL_INDEX8:
return 8;
case GL_STENCIL_INDEX1_OES:
return 1;
case GL_STENCIL_INDEX4_OES:
return 4;
case GL_DEPTH_COMPONENT16:
case GL_RGBA4:
case GL_RGB565:
case GL_RGB5_A1:
return 16;
}
return 0;
}
/**
* Indicates whether the specified format represents a stencil buffer.
*/
static bool isStencilBuffer(GLenum format) {
switch (format) {
case GL_STENCIL_INDEX8:
case GL_STENCIL_INDEX1_OES:
case GL_STENCIL_INDEX4_OES:
return true;
}
return false;
}
/**
* Returns the name of the specified render buffer format.
*/
static const char* formatName(GLenum format) {
switch (format) {
case GL_STENCIL_INDEX8:
return "STENCIL_8";
case GL_STENCIL_INDEX1_OES:
return "STENCIL_1";
case GL_STENCIL_INDEX4_OES:
return "STENCIL_4";
case GL_DEPTH_COMPONENT16:
return "DEPTH_16";
case GL_RGBA4:
return "RGBA_4444";
case GL_RGB565:
return "RGB_565";
case GL_RGB5_A1:
return "RGBA_5551";
}
return "Unknown";
}
private:
GLenum mFormat;
uint32_t mWidth;
uint32_t mHeight;
bool mAllocated;
GLuint mName;
}; // struct RenderBuffer
}; // namespace uirenderer
}; // namespace android
#endif // ANDROID_HWUI_RENDER_BUFFER_H
|
