1 /*
2  * Copyright (C) 2015 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 #ifndef RENDERSTATE_MESHSTATE_H
17 #define RENDERSTATE_MESHSTATE_H
18 
19 #include "Vertex.h"
20 
21 #include <GLES2/gl2.h>
22 #include <GLES2/gl2ext.h>
23 #include <memory>
24 
25 namespace android {
26 namespace uirenderer {
27 
28 class Program;
29 
30 // Maximum number of quads that pre-allocated meshes can draw
31 const uint32_t kMaxNumberOfQuads = 2048;
32 
33 // This array is never used directly but used as a memcpy source in the
34 // OpenGLRenderer constructor
35 const TextureVertex kUnitQuadVertices[] = {
36         { 0, 0, 0, 0 },
37         { 1, 0, 1, 0 },
38         { 0, 1, 0, 1 },
39         { 1, 1, 1, 1 },
40 };
41 
42 const GLsizei kVertexStride = sizeof(Vertex);
43 const GLsizei kAlphaVertexStride = sizeof(AlphaVertex);
44 const GLsizei kTextureVertexStride = sizeof(TextureVertex);
45 const GLsizei kColorTextureVertexStride = sizeof(ColorTextureVertex);
46 
47 const GLsizei kMeshTextureOffset = 2 * sizeof(float);
48 const GLsizei kVertexAlphaOffset = 2 * sizeof(float);
49 const GLsizei kVertexAAWidthOffset = 2 * sizeof(float);
50 const GLsizei kVertexAALengthOffset = 3 * sizeof(float);
51 const GLsizei kUnitQuadCount = 4;
52 
53 class MeshState {
54 private:
55     friend class RenderState;
56 
57 public:
58     ~MeshState();
59     void dump();
60     ///////////////////////////////////////////////////////////////////////////////
61     // Buffer objects
62     ///////////////////////////////////////////////////////////////////////////////
63     /**
64      * Binds the VBO used to render simple textured quads.
65      */
66     bool bindMeshBuffer();
67 
68     /**
69      * Binds the specified VBO if needed. If buffer == 0, binds default simple textured quad.
70      */
71     bool bindMeshBuffer(GLuint buffer);
72 
73     /**
74      * Unbinds the VBO used to render simple textured quads.
75      */
76     bool unbindMeshBuffer();
77 
78     ///////////////////////////////////////////////////////////////////////////////
79     // Vertices
80     ///////////////////////////////////////////////////////////////////////////////
81     /**
82      * Binds an attrib to the specified float vertex pointer.
83      * Assumes a stride of gTextureVertexStride and a size of 2.
84      */
85     void bindPositionVertexPointer(bool force, const GLvoid* vertices,
86             GLsizei stride = kTextureVertexStride);
87 
88     /**
89      * Binds an attrib to the specified float vertex pointer.
90      * Assumes a stride of gTextureVertexStride and a size of 2.
91      */
92     void bindTexCoordsVertexPointer(bool force, const GLvoid* vertices,
93             GLsizei stride = kTextureVertexStride);
94 
95     /**
96      * Resets the vertex pointers.
97      */
98     void resetVertexPointers();
99     void resetTexCoordsVertexPointer();
100 
101     void enableTexCoordsVertexArray();
102     void disableTexCoordsVertexArray();
103 
104     ///////////////////////////////////////////////////////////////////////////////
105     // Indices
106     ///////////////////////////////////////////////////////////////////////////////
107     /**
108      * Binds a global indices buffer that can draw up to
109      * gMaxNumberOfQuads quads.
110      */
111     bool bindQuadIndicesBuffer();
112     bool unbindIndicesBuffer();
113 
114     ///////////////////////////////////////////////////////////////////////////////
115     // Getters - for use in Glop building
116     ///////////////////////////////////////////////////////////////////////////////
getUnitQuadVBO()117     GLuint getUnitQuadVBO() { return mUnitQuadBuffer; }
getQuadListIBO()118     GLuint getQuadListIBO() { return mQuadListIndices; }
119 private:
120     MeshState();
121     bool bindMeshBufferInternal(const GLuint buffer);
122     bool bindIndicesBufferInternal(const GLuint buffer);
123 
124     GLuint mUnitQuadBuffer;
125 
126     GLuint mCurrentBuffer;
127     GLuint mCurrentIndicesBuffer;
128     GLuint mCurrentPixelBuffer;
129 
130     const void* mCurrentPositionPointer;
131     GLsizei mCurrentPositionStride;
132     const void* mCurrentTexCoordsPointer;
133     GLsizei mCurrentTexCoordsStride;
134 
135     bool mTexCoordsArrayEnabled;
136 
137     // Global index buffer
138     GLuint mQuadListIndices;
139 };
140 
141 } /* namespace uirenderer */
142 } /* namespace android */
143 
144 #endif // RENDERSTATE_MESHSTATE_H
145