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      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 {
     29     public CubeRenderer(boolean useTranslucentBackground) {
     30         mTranslucentBackground = useTranslucentBackground;
     31         mCube = new Cube();
     32     }
     33 
     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 
     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 
     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