Practice2- 运用OpenGL ES画点

Practice2- 使用OpenGL ES画点
public void onSurfaceCreated( GL10 gl, EGLConfig config ){
    gl.glClearColor( 0.0f, 0.0f, 0.0f, 1.0f );//

    gl.glShadeModel( GL10.GL_FLAT );//
   
    gl.glHint( GL10.GL_POINT_SMOOTH_HINT, GL10.GL_FASTEST );//
   
    gl.glEnableClientState( GL10.GL_VERTEX_ARRAY );//set for  array as vertex
    gl.glEnableClientState( GL10.GL_COLOR_ARRAY );//set for  array as color
    gl.glDisable( GL10.GL_TEXTURE_2D );//no 2D texture binded, so we disable it for fast speed
}


    //override method
    public void onDrawFrame( GL10 gl ){
    gl.glClear( GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT );
   
    int x = 0;
    int y = 0;
    int i = 0,j=0;
    int vertex[] = new int[pointNum * 2];
    int color[] = new int[pointNum * 4];

    //set each dot's position
    for( i=0 ; i<pointNum ; i++ ){
    if( dispWidth != 0 ){
    x = rand.nextInt( dispWidth );
    }
    if( dispHeight != 0 ){
    y = rand.nextInt( dispHeight );
    }
    vertex[i*2] = x * 0x10000;
    vertex[i*2+1] = y * 0x10000;
   
    for( j=0 ; j<4 ; j++ ){
    color[i*4 + j] = one;
    }
    }
drawPoint( gl, vertex, color, 10 );
    try{
    Thread.sleep( 17 );
    } catch ( InterruptedException e ){
    }
    //System.gc();uncomment this will slow down performance
    }

   
private void drawPoint( GL10 gl, int[] vertex, int[] color, int size ){
gl.glPointSize( size );
gl.glVertexPointer( 2, GL10.GL_FIXED, 0, getIntBuffer( vertex ) );
gl.glColorPointer( 4, GL10.GL_FIXED, 0, getIntBuffer( color ) );
    gl.glDrawArrays( GL10.GL_POINTS, 0, pointNum );
    }