/*
* 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 static android.opengl.GLES10.*;
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.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;
/**
* A GLSurfaceView.Renderer that uses the Android-specific
* android.opengl.GLESXXX static OpenGL ES APIs. The static APIs
* expose more of the OpenGL ES features than the
* javax.microedition.khronos.opengles APIs, and also
* provide a programming model that is closer to the C OpenGL ES APIs, which
* may make it easier to reuse code and documentation written for the
* C OpenGL ES APIs.
*
*/
public class StaticTriangleRenderer implements GLSurfaceView.Renderer{
public interface TextureLoader {
/**
* Load a texture into the currently bound OpenGL texture.
*/
void load(GL10 gl);
}
public StaticTriangleRenderer(Context context) {
init(context, new RobotTextureLoader());
}
public StaticTriangleRenderer(Context context, TextureLoader loader) {
init(context, loader);
}
private void init(Context context, TextureLoader loader) {
mContext = context;
mTriangle = new Triangle();
mTextureLoader = loader;
}
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.
*/
glDisable(GL_DITHER);
/*
* Some one-time OpenGL initialization can be made here
* probably based on features of this particular context
*/
glHint(GL_PERSPECTIVE_CORRECTION_HINT,
GL_FASTEST);
glClearColor(.5f, .5f, .5f, 1);
glShadeModel(GL_SMOOTH);
glEnable(GL_DEPTH_TEST);
glEnable(GL_TEXTURE_2D);
/*
* Create our texture. This has to be done each time the
* surface is created.
*/
int[] textures = new int[1];
glGenTextures(1, textures, 0);
mTextureID = textures[0];
glBindTexture(GL_TEXTURE_2D, mTextureID);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
GL_NEAREST);
glTexParameterf(GL_TEXTURE_2D,
GL_TEXTURE_MAG_FILTER,
GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S,
GL_CLAMP_TO_EDGE);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T,
GL_CLAMP_TO_EDGE);
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE,
GL_REPLACE);
mTextureLoader.load(gl);
}
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.
*/
glDisable(GL_DITHER);
glTexEnvx(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE,
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().
*/
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
/*
* Now we're ready to draw some 3D objects
*/
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
GLU.gluLookAt(gl, 0, 0, -5, 0f, 0f, 0f, 0f, 1.0f, 0.0f);
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, mTextureID);
glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S,
GL_REPEAT);
glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T,
GL_REPEAT);
long time = SystemClock.uptimeMillis() % 4000L;
float angle = 0.090f * ((int) time);
glRotatef(angle, 0, 0, 1.0f);
mTriangle.draw(gl);
}
public void onSurfaceChanged(GL10 gl, int w, int h) {
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;
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glFrustumf(-ratio, ratio, -1, 1, 3, 7);
}
private Context mContext;
private Triangle mTriangle;
private int mTextureID;
private TextureLoader mTextureLoader;
private class RobotTextureLoader implements TextureLoader {
public void load(GL10 gl) {
InputStream is = mContext.getResources().openRawResource(
R.raw.robot);
Bitmap bitmap;
try {
bitmap = BitmapFactory.decodeStream(is);
} finally {
try {
is.close();
} catch (IOException e) {
// Ignore.
}
}
GLUtils.texImage2D(GL_TEXTURE_2D, 0, bitmap, 0);
bitmap.recycle();
}
}
static 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 equilateral 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) {
glFrontFace(GL_CCW);
glVertexPointer(3, GL_FLOAT, 0, mFVertexBuffer);
glEnable(GL_TEXTURE_2D);
glTexCoordPointer(2, GL_FLOAT, 0, mTexBuffer);
glDrawElements(GL_TRIANGLE_STRIP, VERTS,
GL_UNSIGNED_SHORT, mIndexBuffer);
}
private final static int VERTS = 3;
private FloatBuffer mFVertexBuffer;
private FloatBuffer mTexBuffer;
private ShortBuffer mIndexBuffer;
}
}