GLRenderer.java

package com.godoro.androidopengl;

import android.opengl.*;

import javax.microedition.khronos.opengles.*;

public abstract class GLRenderer implements GLSurfaceView.Renderer {

    protected GLActivity activity;

    public GLRenderer(GLActivity activity) {
        this.activity = activity;
    }

    @Override
    public void onSurfaceCreated(GL10 gl, javax.microedition.khronos.egl.EGLConfig config) {
        gl.glClearColor(0.0f, 0.0f, 0.0f, 0.5f);

        gl.glClearDepthf(1.0f);
        gl.glEnable(GL10.GL_DEPTH_TEST);
        gl.glDepthFunc(GL10.GL_LEQUAL);

        gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT,
                GL10.GL_NICEST);

    }

    @Override
    public void onSurfaceChanged(GL10 gl, int width, int height) {
        gl.glViewport(0, 0, width, height);
        gl.glMatrixMode(GL10.GL_PROJECTION);
        gl.glLoadIdentity();
        GLU.gluPerspective(gl, 45.0f, (float) width / (float) height, 0.1f, 100.0f);
        gl.glViewport(0, 0, width, height);

        gl.glMatrixMode(GL10.GL_MODELVIEW);
        gl.glLoadIdentity();
    }

    @Override
    public void onDrawFrame(GL10 gl) {
        gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
        gl.glLoadIdentity();

        onDrawShapes(gl);

        gl.glLoadIdentity();

    }

    abstract protected void onDrawShapes(GL10 gl);
}