/*
* Copyright (C) 2008 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 com.example.android.apis.graphics;
import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import java.nio.ShortBuffer;
import javax.microedition.khronos.egl.EGL10;
import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL10;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.opengl.GLSurfaceView;
import android.opengl.GLU;
import android.opengl.GLUtils;
import android.os.SystemClock;
import com.example.android.apis.R;
public class TriangleRenderer implements GLSurfaceView.Renderer{
public TriangleRenderer(Context context) {
mContext = context;
mTriangle = new Triangle();
}
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);
gl.glClearColor(.5f, .5f, .5f, 1);
gl.glShadeModel(GL10.GL_SMOOTH);
gl.glEnable(GL10.GL_DEPTH_TEST);
gl.glEnable(GL10.GL_TEXTURE_2D);
/*
* Create our texture. This has to be done each time the
* surface is created.
*/
int[] textures = new int[1];
gl.glGenTextures(1, textures, 0);
mTextureID = textures[0];
gl.glBindTexture(GL10.GL_TEXTURE_2D, mTextureID);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER,
GL10.GL_NEAREST);
gl.glTexParameterf(GL10.GL_TEXTURE_2D,
GL10.GL_TEXTURE_MAG_FILTER,
GL10.GL_LINEAR);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_S,
GL10.GL_CLAMP_TO_EDGE);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_T,
GL10.GL_CLAMP_TO_EDGE);
gl.glTexEnvf(GL10.GL_TEXTURE_ENV, GL10.GL_TEXTURE_ENV_MODE,
GL10.GL_REPLACE);
InputStream is = mContext.getResources()
.openRawResource(R.drawable.robot);
Bitmap bitmap;
try {
bitmap = BitmapFactory.decodeStream(is);
} finally {
try {
is.close();
} catch(IOException e) {
// Ignore.
}
}
GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, bitmap, 0);
bitmap.recycle();
}
public void onDrawFrame(GL10 gl) {
/*
* 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);
gl.glTexEnvx(GL10.GL_TEXTURE_ENV, GL10.GL_TEXTURE_ENV_MODE,
GL10.GL_MODULATE);
/*
* 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();
GLU.gluLookAt(gl, 0, 0, -5, 0f, 0f, 0f, 0f, 1.0f, 0.0f);
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
gl.glActiveTexture(GL10.GL_TEXTURE0);
gl.glBindTexture(GL10.GL_TEXTURE_2D, mTextureID);
gl.glTexParameterx(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_S,
GL10.GL_REPEAT);
gl.glTexParameterx(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_T,
GL10.GL_REPEAT);
long time = SystemClock.uptimeMillis() % 4000L;
float angle = 0.090f * ((int) time);
gl.glRotatef(angle, 0, 0, 1.0f);
mTriangle.draw(gl);
}
public void onSurfaceChanged(GL10 gl, int w, int h) {
gl.glViewport(0, 0, w, h);
/*
* 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) w / h;
gl.glMatrixMode(GL10.GL_PROJECTION);
gl.glLoadIdentity();
gl.glFrustumf(-ratio, ratio, -1, 1, 3, 7);
}
private Context mContext;
private Triangle mTriangle;
private int mTextureID;
}
class Triangle {
public Triangle() {
// 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(VERTS * 3 * 4);
vbb.order(ByteOrder.nativeOrder());
mFVertexBuffer = vbb.asFloatBuffer();
ByteBuffer tbb = ByteBuffer.allocateDirect(VERTS * 2 * 4);
tbb.order(ByteOrder.nativeOrder());
mTexBuffer = tbb.asFloatBuffer();
ByteBuffer ibb = ByteBuffer.allocateDirect(VERTS * 2);
ibb.order(ByteOrder.nativeOrder());
mIndexBuffer = ibb.asShortBuffer();
// A unit-sided equalateral triangle centered on the origin.
float[] coords = {
// X, Y, Z
-0.5f, -0.25f, 0,
0.5f, -0.25f, 0,
0.0f, 0.559016994f, 0
};
for (int i = 0; i < VERTS; i++) {
for(int j = 0; j < 3; j++) {
mFVertexBuffer.put(coords[i*3+j] * 2.0f);
}
}
for (int i = 0; i < VERTS; i++) {
for(int j = 0; j < 2; j++) {
mTexBuffer.put(coords[i*3+j] * 2.0f + 0.5f);
}
}
for(int i = 0; i < VERTS; i++) {
mIndexBuffer.put((short) i);
}
mFVertexBuffer.position(0);
mTexBuffer.position(0);
mIndexBuffer.position(0);
}
public void draw(GL10 gl) {
gl.glFrontFace(GL10.GL_CCW);
gl.glVertexPointer(3, GL10.GL_FLOAT, 0, mFVertexBuffer);
gl.glEnable(GL10.GL_TEXTURE_2D);
gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, mTexBuffer);
gl.glDrawElements(GL10.GL_TRIANGLE_STRIP, VERTS,
GL10.GL_UNSIGNED_SHORT, mIndexBuffer);
}
private final static int VERTS = 3;
private FloatBuffer mFVertexBuffer;
private FloatBuffer mTexBuffer;
private ShortBuffer mIndexBuffer;
}