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1 /*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 
17 #pragma once
18 
19 #include <GLES2/gl2.h>
20 #include <GLES2/gl2ext.h>
21 
22 #include "FrameworkFormats.h"
23 
24 #include <stdint.h>
25 #include <cstring>
26 #include <vector>
27 
28 namespace gfxstream {
29 namespace gl {
30 
31 enum class YUVPlane {
32     Y = 0,
33     U = 1,
34     V = 2,
35     UV = 3,
36 };
37 
38 // The purpose of YUVConverter is to use
39 // OpenGL shaders to convert YUV images to RGB
40 // images that can be displayed on screen.
41 // Doing this on the GPU can be much faster than
42 // on the CPU.
43 
44 // Usage:
45 // 0. Have a current OpenGL context working.
46 // 1. Constructing the YUVConverter object will allocate
47 //    OpenGL resources needed to convert, given the desired
48 //    |width| and |height| of the buffer.
49 // 2. To convert a given YUV buffer of |pixels|, call
50 //    the drawConvert method (with x, y, width, and height
51 //    arguments depicting the region to convert).
52 //    The RGB version of the YUV buffer will be drawn
53 //    to the current framebuffer. To retrieve
54 //    the result, if the user of the result is an OpenGL texture,
55 //    it suffices to have that texture be the color attachment
56 //    of the framebuffer object. Or, if you want the results
57 //    on the CPU, call glReadPixels() after the call to drawConvert().
58 class YUVConverter {
59 public:
60     // call ctor when creating a gralloc buffer
61     // with YUV format
62     YUVConverter(int width, int height, FrameworkFormat format);
63     // destroy when ColorBuffer is destroyed
64     ~YUVConverter();
65     // call when gralloc_unlock updates
66     // the host color buffer
67     // (rcUpdateColorBuffer)
68     void drawConvert(int x, int y, int width, int height, const char* pixels);
69     void drawConvertFromFormat(FrameworkFormat format, int x, int y, int width, int height,
70                                const char* pixels);
71 
72     uint32_t getDataSize();
73     // read YUV data into pixels, exactly pixels_size bytes;
74     // if size mismatches, will read nothing.
75     void readPixels(uint8_t* pixels, uint32_t pixels_size);
76 
77     void swapTextures(FrameworkFormat type, GLuint* textures);
78 
79     // public so other classes can call
80     static void createYUVGLTex(GLenum textureUnit,
81                                GLsizei width,
82                                GLsizei height,
83                                FrameworkFormat format,
84                                YUVPlane plane,
85                                GLuint* outTextureName);
86 private:
87     void init(int w, int h, FrameworkFormat format);
88     void reset();
89 
90     void createYUVGLShader();
91     void createYUVGLFullscreenQuad();
92 
93     // For dealing with n-pixel-aligned buffers
94     void updateCutoffs(float yWidth, float yStridePixels,
95                        float uvWidth, float uvStridePixels);
96 
97     int mWidth = 0;
98     int mHeight = 0;
99     FrameworkFormat mFormat;
100     // colorbuffer w/h/format, could be different
101     FrameworkFormat mColorBufferFormat;
102     // We need the following GL objects:
103     GLuint mProgram = 0;
104     GLuint mQuadVertexBuffer = 0;
105     GLuint mQuadIndexBuffer = 0;
106     GLuint mTextureY = 0;
107     GLuint mTextureU = 0;
108     GLuint mTextureV = 0;
109     bool mTexturesSwapped = false;
110     GLint mUniformLocYWidthCutoff = -1;
111     GLint mUniformLocUVWidthCutoff = -1;
112     GLint mUniformLocSamplerY = -1;
113     GLint mUniformLocSamplerU = -1;
114     GLint mUniformLocSamplerV = -1;
115     GLint mAttributeLocPos = -1;
116     GLint mAttributeLocTexCoord = -1;
117 
118     float mYWidthCutoff = 1.0;
119     float mUVWidthCutoff = 1.0;
120     bool mHasGlsl3Support = false;
121 
122     // YUVConverter can end up being used
123     // in a TextureDraw / subwindow context, and subsequently
124     // overwrite the previous state.
125     // This section is so YUVConverter can be used in the middle
126     // of any GL context without impacting what's
127     // already going on there, by saving/restoring the state
128     // that it is impacting.
129     void saveGLState();
130     void restoreGLState();
131     // Impacted state
132     GLfloat mCurrViewport[4] = {};
133     GLint mCurrTexUnit = 0;
134     GLint mCurrProgram = 0;
135     GLint mCurrTexBind = 0;
136     GLint mCurrVbo = 0;
137     GLint mCurrIbo = 0;
138 };
139 
140 }  // namespace gl
141 }  // namespace gfxstream
142