1/*
2 * Copyright (C) 2013 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
17package com.android.accessorydisplay.source.presentation;
18
19import java.nio.ByteBuffer;
20import java.nio.ByteOrder;
21import java.nio.IntBuffer;
22
23import javax.microedition.khronos.opengles.GL10;
24
25/**
26 * A vertex shaded cube.
27 */
28class Cube
29{
30    public Cube()
31    {
32        int one = 0x10000;
33        int vertices[] = {
34                -one, -one, -one,
35                one, -one, -one,
36                one,  one, -one,
37                -one,  one, -one,
38                -one, -one,  one,
39                one, -one,  one,
40                one,  one,  one,
41                -one,  one,  one,
42        };
43
44        int colors[] = {
45                0,    0,    0,  one,
46                one,    0,    0,  one,
47                one,  one,    0,  one,
48                0,  one,    0,  one,
49                0,    0,  one,  one,
50                one,    0,  one,  one,
51                one,  one,  one,  one,
52                0,  one,  one,  one,
53        };
54
55        byte indices[] = {
56                0, 4, 5,    0, 5, 1,
57                1, 5, 6,    1, 6, 2,
58                2, 6, 7,    2, 7, 3,
59                3, 7, 4,    3, 4, 0,
60                4, 7, 6,    4, 6, 5,
61                3, 0, 1,    3, 1, 2
62        };
63
64        // Buffers to be passed to gl*Pointer() functions
65        // must be direct, i.e., they must be placed on the
66        // native heap where the garbage collector cannot
67        // move them.
68        //
69        // Buffers with multi-byte datatypes (e.g., short, int, float)
70        // must have their byte order set to native order
71
72        ByteBuffer vbb = ByteBuffer.allocateDirect(vertices.length*4);
73        vbb.order(ByteOrder.nativeOrder());
74        mVertexBuffer = vbb.asIntBuffer();
75        mVertexBuffer.put(vertices);
76        mVertexBuffer.position(0);
77
78        ByteBuffer cbb = ByteBuffer.allocateDirect(colors.length*4);
79        cbb.order(ByteOrder.nativeOrder());
80        mColorBuffer = cbb.asIntBuffer();
81        mColorBuffer.put(colors);
82        mColorBuffer.position(0);
83
84        mIndexBuffer = ByteBuffer.allocateDirect(indices.length);
85        mIndexBuffer.put(indices);
86        mIndexBuffer.position(0);
87    }
88
89    public void draw(GL10 gl)
90    {
91        gl.glFrontFace(GL10.GL_CW);
92        gl.glVertexPointer(3, GL10.GL_FIXED, 0, mVertexBuffer);
93        gl.glColorPointer(4, GL10.GL_FIXED, 0, mColorBuffer);
94        gl.glDrawElements(GL10.GL_TRIANGLES, 36, GL10.GL_UNSIGNED_BYTE, mIndexBuffer);
95    }
96
97    private IntBuffer   mVertexBuffer;
98    private IntBuffer   mColorBuffer;
99    private ByteBuffer  mIndexBuffer;
100}
101