Mega Code Archive
Wrapper activity demonstrating the use of {@link GLSurfaceView} to display translucent 3D graphics
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/*
* Copyright (C) 2007 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package app.test;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.IntBuffer;
import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL10;
import android.app.Activity;
import android.graphics.PixelFormat;
import android.opengl.GLSurfaceView;
import android.os.Bundle;
/**
* A vertex shaded cube.
*/
class Cube {
public Cube() {
int one = 0x10000;
int vertices[] = { -one, -one, -one, one, -one, -one, one, one, -one,
-one, one, -one, -one, -one, one, one, -one, one, one, one,
one, -one, one, one, };
int colors[] = { 0, 0, 0, one, one, 0, 0, one, one, one, 0, one, 0,
one, 0, one, 0, 0, one, one, one, 0, one, one, one, one, one,
one, 0, one, one, one, };
byte indices[] = { 0, 4, 5, 0, 5, 1, 1, 5, 6, 1, 6, 2, 2, 6, 7, 2, 7,
3, 3, 7, 4, 3, 4, 0, 4, 7, 6, 4, 6, 5, 3, 0, 1, 3, 1, 2 };
// Buffers to be passed to gl*Pointer() functions
// must be direct, i.e., they must be placed on the
// native heap where the garbage collector cannot
// move them.
//
// Buffers with multi-byte datatypes (e.g., short, int, float)
// must have their byte order set to native order
ByteBuffer vbb = ByteBuffer.allocateDirect(vertices.length * 4);
vbb.order(ByteOrder.nativeOrder());
mVertexBuffer = vbb.asIntBuffer();
mVertexBuffer.put(vertices);
mVertexBuffer.position(0);
ByteBuffer cbb = ByteBuffer.allocateDirect(colors.length * 4);
cbb.order(ByteOrder.nativeOrder());
mColorBuffer = cbb.asIntBuffer();
mColorBuffer.put(colors);
mColorBuffer.position(0);
mIndexBuffer = ByteBuffer.allocateDirect(indices.length);
mIndexBuffer.put(indices);
mIndexBuffer.position(0);
}
public void draw(GL10 gl) {
gl.glFrontFace(GL10.GL_CW);
gl.glVertexPointer(3, GL10.GL_FIXED, 0, mVertexBuffer);
gl.glColorPointer(4, GL10.GL_FIXED, 0, mColorBuffer);
gl.glDrawElements(GL10.GL_TRIANGLES, 36, GL10.GL_UNSIGNED_BYTE,
mIndexBuffer);
}
private IntBuffer mVertexBuffer;
private IntBuffer mColorBuffer;
private ByteBuffer mIndexBuffer;
}
/**
* Render a pair of tumbling cubes.
*/
class CubeRenderer implements GLSurfaceView.Renderer {
public CubeRenderer(boolean useTranslucentBackground) {
mTranslucentBackground = useTranslucentBackground;
mCube = new Cube();
}
public void onDrawFrame(GL10 gl) {
/*
* Usually, the first thing one might want to do is to clear the screen.
* The most efficient way of doing this is to use glClear().
*/
gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
/*
* Now we're ready to draw some 3D objects
*/
gl.glMatrixMode(GL10.GL_MODELVIEW);
gl.glLoadIdentity();
gl.glTranslatef(0, 0, -3.0f);
gl.glRotatef(mAngle, 0, 1, 0);
gl.glRotatef(mAngle * 0.25f, 1, 0, 0);
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
gl.glEnableClientState(GL10.GL_COLOR_ARRAY);
mCube.draw(gl);
gl.glRotatef(mAngle * 2.0f, 0, 1, 1);
gl.glTranslatef(0.5f, 0.5f, 0.5f);
mCube.draw(gl);
mAngle += 1.2f;
}
public void onSurfaceChanged(GL10 gl, int width, int height) {
gl.glViewport(0, 0, width, height);
/*
* Set our projection matrix. This doesn't have to be done each time we
* draw, but usually a new projection needs to be set when the viewport
* is resized.
*/
float ratio = (float) width / height;
gl.glMatrixMode(GL10.GL_PROJECTION);
gl.glLoadIdentity();
gl.glFrustumf(-ratio, ratio, -1, 1, 1, 10);
}
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
/*
* By default, OpenGL enables features that improve quality but reduce
* performance. One might want to tweak that especially on software
* renderer.
*/
gl.glDisable(GL10.GL_DITHER);
/*
* Some one-time OpenGL initialization can be made here probably based
* on features of this particular context
*/
gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_FASTEST);
if (mTranslucentBackground) {
gl.glClearColor(0, 0, 0, 0);
} else {
gl.glClearColor(1, 1, 1, 1);
}
gl.glEnable(GL10.GL_CULL_FACE);
gl.glShadeModel(GL10.GL_SMOOTH);
gl.glEnable(GL10.GL_DEPTH_TEST);
}
private boolean mTranslucentBackground;
private Cube mCube;
private float mAngle;
}
/**
* Wrapper activity demonstrating the use of {@link GLSurfaceView} to
* display translucent 3D graphics.
*/
public class TranslucentGLSurfaceViewActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Create our Preview view and set it as the content of our
// Activity
mGLSurfaceView = new GLSurfaceView(this);
// We want an 8888 pixel format because that's required for
// a translucent window.
// And we want a depth buffer.
mGLSurfaceView.setEGLConfigChooser(8, 8, 8, 8, 16, 0);
// Tell the cube renderer that we want to render a translucent version
// of the cube:
mGLSurfaceView.setRenderer(new CubeRenderer(true));
// Use a surface format with an Alpha channel:
mGLSurfaceView.getHolder().setFormat(PixelFormat.TRANSLUCENT);
setContentView(mGLSurfaceView);
}
@Override
protected void onResume() {
super.onResume();
mGLSurfaceView.onResume();
}
@Override
protected void onPause() {
super.onPause();
mGLSurfaceView.onPause();
}
private GLSurfaceView mGLSurfaceView;
}
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