1 /*
2  * Copyright (C) 2007 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 
17 package com.example.android.apis.graphics;
18 
19 import javax.microedition.khronos.egl.EGLConfig;
20 import javax.microedition.khronos.opengles.GL10;
21 
22 import android.opengl.GLSurfaceView;
23 
24 /**
25  * Render a pair of tumbling cubes.
26  */
27 
28 public class CubeRenderer implements GLSurfaceView.Renderer {
CubeRenderer(boolean useTranslucentBackground)29     public CubeRenderer(boolean useTranslucentBackground) {
30         mTranslucentBackground = useTranslucentBackground;
31         mCube = new Cube();
32     }
33 
onDrawFrame(GL10 gl)34     public void onDrawFrame(GL10 gl) {
35         /*
36          * Usually, the first thing one might want to do is to clear
37          * the screen. The most efficient way of doing this is to use
38          * glClear().
39          */
40 
41         gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
42 
43         /*
44          * Now we're ready to draw some 3D objects
45          */
46 
47         gl.glMatrixMode(GL10.GL_MODELVIEW);
48         gl.glLoadIdentity();
49         gl.glTranslatef(0, 0, -3.0f);
50         gl.glRotatef(mAngle,        0, 1, 0);
51         gl.glRotatef(mAngle*0.25f,  1, 0, 0);
52 
53         gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
54         gl.glEnableClientState(GL10.GL_COLOR_ARRAY);
55 
56         mCube.draw(gl);
57 
58         gl.glRotatef(mAngle*2.0f, 0, 1, 1);
59         gl.glTranslatef(0.5f, 0.5f, 0.5f);
60 
61         mCube.draw(gl);
62 
63         mAngle += 1.2f;
64     }
65 
onSurfaceChanged(GL10 gl, int width, int height)66     public void onSurfaceChanged(GL10 gl, int width, int height) {
67          gl.glViewport(0, 0, width, height);
68 
69          /*
70           * Set our projection matrix. This doesn't have to be done
71           * each time we draw, but usually a new projection needs to
72           * be set when the viewport is resized.
73           */
74 
75          float ratio = (float) width / height;
76          gl.glMatrixMode(GL10.GL_PROJECTION);
77          gl.glLoadIdentity();
78          gl.glFrustumf(-ratio, ratio, -1, 1, 1, 10);
79     }
80 
onSurfaceCreated(GL10 gl, EGLConfig config)81     public void onSurfaceCreated(GL10 gl, EGLConfig config) {
82         /*
83          * By default, OpenGL enables features that improve quality
84          * but reduce performance. One might want to tweak that
85          * especially on software renderer.
86          */
87         gl.glDisable(GL10.GL_DITHER);
88 
89         /*
90          * Some one-time OpenGL initialization can be made here
91          * probably based on features of this particular context
92          */
93          gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT,
94                  GL10.GL_FASTEST);
95 
96          if (mTranslucentBackground) {
97              gl.glClearColor(0,0,0,0);
98          } else {
99              gl.glClearColor(1,1,1,1);
100          }
101          gl.glEnable(GL10.GL_CULL_FACE);
102          gl.glShadeModel(GL10.GL_SMOOTH);
103          gl.glEnable(GL10.GL_DEPTH_TEST);
104     }
105     private boolean mTranslucentBackground;
106     private Cube mCube;
107     private float mAngle;
108 }
109