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     /**
65      * Binds the specified VBO if needed. If buffer == 0, binds default simple textured quad.
66      */
67     void bindMeshBuffer(GLuint buffer);
68 
69     /**
70      * Unbinds the current VBO if active.
71      */
72     void unbindMeshBuffer();
73 
74     void genOrUpdateMeshBuffer(GLuint* buffer, GLsizeiptr size, const void* data, GLenum usage);
75     void deleteMeshBuffer(GLuint);
76 
77     ///////////////////////////////////////////////////////////////////////////////
78     // Vertices
79     ///////////////////////////////////////////////////////////////////////////////
80     /**
81      * Binds an attrib to the specified float vertex pointer.
82      * Assumes a stride of gTextureVertexStride and a size of 2.
83      */
84     void bindPositionVertexPointer(const GLvoid* vertices,
85             GLsizei stride = kTextureVertexStride);
86 
87     /**
88      * Binds an attrib to the specified float vertex pointer.
89      * Assumes a stride of gTextureVertexStride and a size of 2.
90      */
91     void bindTexCoordsVertexPointer(const GLvoid* vertices,
92             GLsizei stride = kTextureVertexStride);
93 
94     /**
95      * Resets the vertex pointers.
96      */
97     void resetVertexPointers();
98 
99     void enableTexCoordsVertexArray();
100     void disableTexCoordsVertexArray();
101 
102     ///////////////////////////////////////////////////////////////////////////////
103     // Indices
104     ///////////////////////////////////////////////////////////////////////////////
105     void bindIndicesBuffer(const GLuint buffer);
106     void unbindIndicesBuffer();
107 
108     ///////////////////////////////////////////////////////////////////////////////
109     // Getters - for use in Glop building
110     ///////////////////////////////////////////////////////////////////////////////
getUnitQuadVBO()111     GLuint getUnitQuadVBO() { return mUnitQuadBuffer; }
getQuadListIBO()112     GLuint getQuadListIBO() { return mQuadListIndices; }
113 private:
114     MeshState();
115 
116     GLuint mUnitQuadBuffer;
117 
118     GLuint mCurrentBuffer;
119     GLuint mCurrentIndicesBuffer;
120     GLuint mCurrentPixelBuffer;
121 
122     const void* mCurrentPositionPointer;
123     GLsizei mCurrentPositionStride;
124     const void* mCurrentTexCoordsPointer;
125     GLsizei mCurrentTexCoordsStride;
126 
127     bool mTexCoordsArrayEnabled;
128 
129     // Global index buffer
130     GLuint mQuadListIndices;
131 };
132 
133 } /* namespace uirenderer */
134 } /* namespace android */
135 
136 #endif // RENDERSTATE_MESHSTATE_H
137