MeshState.h revision 031888744e24b5c7243ac99ec98b78aff5db1c78 
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);
45
46const GLsizei kMeshTextureOffset = 2 * sizeof(float);
47const GLsizei kVertexAlphaOffset = 2 * sizeof(float);
48const GLsizei kVertexAAWidthOffset = 2 * sizeof(float);
49const GLsizei kVertexAALengthOffset = 3 * sizeof(float);
50const GLsizei kMeshCount = 4;
51
52class MeshState {
53private:
54    friend class RenderState;
55
56public:
57    ~MeshState();
58    ///////////////////////////////////////////////////////////////////////////////
59    // Buffer objects
60    ///////////////////////////////////////////////////////////////////////////////
61    /**
62     * Binds the VBO used to render simple textured quads.
63     */
64    bool bindMeshBuffer();
65
66    /**
67     * Binds the specified VBO if needed. If buffer == 0, binds default simple textured quad.
68     */
69    bool bindMeshBuffer(GLuint buffer);
70
71    /**
72     * Unbinds the VBO used to render simple textured quads.
73     */
74    bool unbindMeshBuffer();
75
76    ///////////////////////////////////////////////////////////////////////////////
77    // Vertices
78    ///////////////////////////////////////////////////////////////////////////////
79    /**
80     * Binds an attrib to the specified float vertex pointer.
81     * Assumes a stride of gTextureVertexStride and a size of 2.
82     */
83    void bindPositionVertexPointer(bool force, const GLvoid* vertices,
84            GLsizei stride = kTextureVertexStride);
85
86    /**
87     * Binds an attrib to the specified float vertex pointer.
88     * Assumes a stride of gTextureVertexStride and a size of 2.
89     */
90    void bindTexCoordsVertexPointer(bool force, const GLvoid* vertices,
91            GLsizei stride = kTextureVertexStride);
92
93    /**
94     * Resets the vertex pointers.
95     */
96    void resetVertexPointers();
97    void resetTexCoordsVertexPointer();
98
99    void enableTexCoordsVertexArray();
100    void disableTexCoordsVertexArray();
101
102    ///////////////////////////////////////////////////////////////////////////////
103    // Indices
104    ///////////////////////////////////////////////////////////////////////////////
105    /**
106     * Binds a global indices buffer that can draw up to
107     * gMaxNumberOfQuads quads.
108     */
109    bool bindQuadIndicesBuffer();
110    bool bindShadowIndicesBuffer();
111    bool unbindIndicesBuffer();
112
113    ///////////////////////////////////////////////////////////////////////////////
114    // Getters - for use in Glop building
115    ///////////////////////////////////////////////////////////////////////////////
116    GLuint getUnitQuadVBO() { return mUnitQuadBuffer; }
117private:
118    MeshState();
119    bool bindIndicesBufferInternal(const GLuint buffer);
120
121    // VBO to draw with
122    GLuint mUnitQuadBuffer;
123
124    GLuint mCurrentBuffer;
125    GLuint mCurrentIndicesBuffer;
126    GLuint mCurrentPixelBuffer;
127
128    const void* mCurrentPositionPointer;
129    GLsizei mCurrentPositionStride;
130    const void* mCurrentTexCoordsPointer;
131    GLsizei mCurrentTexCoordsStride;
132
133    bool mTexCoordsArrayEnabled;
134
135    // Global index buffer
136    GLuint mQuadListIndices;
137    GLuint mShadowStripsIndices;
138};
139
140} /* namespace uirenderer */
141} /* namespace android */
142
143#endif // RENDERSTATE_MESHSTATE_H
144