MeshState.h revision 2ab95d780b023152556d9f8659de734ec7b55047 
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 kUnitQuadCount = 4;
51
52class MeshState {
53private:
54    friend class RenderState;
55
56public:
57    ~MeshState();
58    void dump();
59    ///////////////////////////////////////////////////////////////////////////////
60    // Buffer objects
61    ///////////////////////////////////////////////////////////////////////////////
62    /**
63     * Binds the VBO used to render simple textured quads.
64     */
65    bool bindMeshBuffer();
66
67    /**
68     * Binds the specified VBO if needed. If buffer == 0, binds default simple textured quad.
69     */
70    bool bindMeshBuffer(GLuint buffer);
71
72    /**
73     * Unbinds the VBO used to render simple textured quads.
74     */
75    bool unbindMeshBuffer();
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(bool force, 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(bool force, const GLvoid* vertices,
92            GLsizei stride = kTextureVertexStride);
93
94    /**
95     * Resets the vertex pointers.
96     */
97    void resetVertexPointers();
98    void resetTexCoordsVertexPointer();
99
100    void enableTexCoordsVertexArray();
101    void disableTexCoordsVertexArray();
102
103    ///////////////////////////////////////////////////////////////////////////////
104    // Indices
105    ///////////////////////////////////////////////////////////////////////////////
106    /**
107     * Binds a global indices buffer that can draw up to
108     * gMaxNumberOfQuads quads.
109     */
110    bool bindQuadIndicesBuffer();
111    bool unbindIndicesBuffer();
112
113    ///////////////////////////////////////////////////////////////////////////////
114    // Getters - for use in Glop building
115    ///////////////////////////////////////////////////////////////////////////////
116    GLuint getUnitQuadVBO() { return mUnitQuadBuffer; }
117    GLuint getQuadListIBO() { return mQuadListIndices; }
118private:
119    MeshState();
120    bool bindMeshBufferInternal(const GLuint buffer);
121    bool bindIndicesBufferInternal(const GLuint buffer);
122
123    GLuint mUnitQuadBuffer;
124
125    GLuint mCurrentBuffer;
126    GLuint mCurrentIndicesBuffer;
127    GLuint mCurrentPixelBuffer;
128
129    const void* mCurrentPositionPointer;
130    GLsizei mCurrentPositionStride;
131    const void* mCurrentTexCoordsPointer;
132    GLsizei mCurrentTexCoordsStride;
133
134    bool mTexCoordsArrayEnabled;
135
136    // Global index buffer
137    GLuint mQuadListIndices;
138};
139
140} /* namespace uirenderer */
141} /* namespace android */
142
143#endif // RENDERSTATE_MESHSTATE_H
144