MeshState.h revision ef2507439c08f4e9c4c9bba1c6243ca9df2ee827 
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
25namespace android {
26namespace uirenderer {
27
28class Program;
29
30// Maximum number of quads that pre-allocated meshes can draw
31const uint32_t kMaxNumberOfQuads = 2048;
32
33// This array is never used directly but used as a memcpy source in the
34// OpenGLRenderer constructor
35const TextureVertex kUnitQuadVertices[] = {
36        { 0, 0, 0, 0 },
37        { 1, 0, 1, 0 },
38        { 0, 1, 0, 1 },
39        { 1, 1, 1, 1 },
40};
41
42const GLsizei kVertexStride = sizeof(Vertex);
43const GLsizei kAlphaVertexStride = sizeof(AlphaVertex);
44const GLsizei kTextureVertexStride = sizeof(TextureVertex);
45const GLsizei kColorTextureVertexStride = sizeof(ColorTextureVertex);
46
47const GLsizei kMeshTextureOffset = 2 * sizeof(float);
48const GLsizei kVertexAlphaOffset = 2 * sizeof(float);
49const GLsizei kVertexAAWidthOffset = 2 * sizeof(float);
50const GLsizei kVertexAALengthOffset = 3 * sizeof(float);
51const GLsizei kUnitQuadCount = 4;
52
53class MeshState {
54private:
55    friend class RenderState;
56
57public:
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    ///////////////////////////////////////////////////////////////////////////////
117    GLuint getUnitQuadVBO() { return mUnitQuadBuffer; }
118    GLuint getQuadListIBO() { return mQuadListIndices; }
119private:
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