Demonstrate how to use the OES_texture_cube_map extension, available on some high-end OpenGL ES 1.x GPUs.
/*
* 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.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.CharBuffer;
import java.nio.FloatBuffer;
import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL;
import javax.microedition.khronos.opengles.GL10;
import javax.microedition.khronos.opengles.GL11;
import javax.microedition.khronos.opengles.GL11Ext;
import javax.microedition.khronos.opengles.GL11ExtensionPack;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.opengl.GLSurfaceView;
import android.opengl.GLU;
import android.opengl.GLUtils;
import android.os.Bundle;
import android.util.Log;
/**
* Demonstrate how to use the OES_texture_cube_map extension, available on some
* high-end OpenGL ES 1.x GPUs.
*/
public class CubeMapActivity extends Activity {
private GLSurfaceView mGLSurfaceView;
private class Renderer implements GLSurfaceView.Renderer {
private boolean mContextSupportsCubeMap;
private Grid mGrid;
private int mCubeMapTextureID;
private boolean mUseTexGen = false;
private float mAngle;
public void onDrawFrame(GL10 gl) {
checkGLError(gl);
if (mContextSupportsCubeMap) {
gl.glClearColor(0,0,1,0);
} else {
// Current context doesn't support cube maps.
// Indicate this by drawing a red background.
gl.glClearColor(1,0,0,0);
}
gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
gl.glEnable(GL10.GL_DEPTH_TEST);
gl.glMatrixMode(GL10.GL_MODELVIEW);
gl.glLoadIdentity();
GLU.gluLookAt(gl, 0, 0, -5, 0f, 0f, 0f, 0f, 1.0f, 0.0f);
gl.glRotatef(mAngle, 0, 1, 0);
gl.glRotatef(mAngle*0.25f, 1, 0, 0);
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
checkGLError(gl);
if (mContextSupportsCubeMap) {
gl.glActiveTexture(GL10.GL_TEXTURE0);
checkGLError(gl);
gl.glEnable(GL11ExtensionPack.GL_TEXTURE_CUBE_MAP);
checkGLError(gl);
gl.glBindTexture(GL11ExtensionPack.GL_TEXTURE_CUBE_MAP, mCubeMapTextureID);
checkGLError(gl);
GL11ExtensionPack gl11ep = (GL11ExtensionPack) gl;
gl11ep.glTexGeni(GL11ExtensionPack.GL_TEXTURE_GEN_STR,
GL11ExtensionPack.GL_TEXTURE_GEN_MODE,
GL11ExtensionPack.GL_REFLECTION_MAP);
checkGLError(gl);
gl.glEnable(GL11ExtensionPack.GL_TEXTURE_GEN_STR);
checkGLError(gl);
gl.glTexEnvx(GL10.GL_TEXTURE_ENV, GL10.GL_TEXTURE_ENV_MODE, GL10.GL_DECAL);
}
checkGLError(gl);
mGrid.draw(gl);
if (mContextSupportsCubeMap) {
gl.glDisable(GL11ExtensionPack.GL_TEXTURE_GEN_STR);
}
checkGLError(gl);
mAngle += 1.2f;
}
public void onSurfaceChanged(GL10 gl, int width, int height) {
checkGLError(gl);
gl.glViewport(0, 0, width, height);
float ratio = (float) width / height;
gl.glMatrixMode(GL10.GL_PROJECTION);
gl.glLoadIdentity();
gl.glFrustumf(-ratio, ratio, -1, 1, 1, 10);
checkGLError(gl);
}
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
checkGLError(gl);
// This test needs to be done each time a context is created,
// because different contexts may support different extensions.
mContextSupportsCubeMap = checkIfContextSupportsCubeMap(gl);
mGrid = generateTorusGrid(gl, 60, 60, 3.0f, 0.75f);
if (mContextSupportsCubeMap) {
int[] cubeMapResourceIds = new int[]{
R.raw.skycubemap0, R.raw.skycubemap1, R.raw.skycubemap2,
R.raw.skycubemap3, R.raw.skycubemap4, R.raw.skycubemap5};//jpg files
mCubeMapTextureID = generateCubeMap(gl, cubeMapResourceIds);
}
checkGLError(gl);
}
private int generateCubeMap(GL10 gl, int[] resourceIds) {
checkGLError(gl);
int[] ids = new int[1];
gl.glGenTextures(1, ids, 0);
int cubeMapTextureId = ids[0];
gl.glBindTexture(GL11ExtensionPack.GL_TEXTURE_CUBE_MAP, cubeMapTextureId);
gl.glTexParameterf(GL11ExtensionPack.GL_TEXTURE_CUBE_MAP,
GL10.GL_TEXTURE_MIN_FILTER, GL10.GL_LINEAR);
gl.glTexParameterf(GL11ExtensionPack.GL_TEXTURE_CUBE_MAP,
GL10.GL_TEXTURE_MAG_FILTER, GL10.GL_LINEAR);
for (int face = 0; face < 6; face++) {
InputStream is = getResources().openRawResource(resourceIds[face]);
Bitmap bitmap;
try {
bitmap = BitmapFactory.decodeStream(is);
} finally {
try {
is.close();
} catch(IOException e) {
Log.e("CubeMap", "Could not decode texture for face " + Integer.toString(face));
}
}
GLUtils.texImage2D(GL11ExtensionPack.GL_TEXTURE_CUBE_MAP_POSITIVE_X + face, 0,
bitmap, 0);
bitmap.recycle();
}
checkGLError(gl);
return cubeMapTextureId;
}
private Grid generateTorusGrid(GL gl, int uSteps, int vSteps, float majorRadius, float minorRadius) {
Grid grid = new Grid(uSteps + 1, vSteps + 1);
for (int j = 0; j <= vSteps; j++) {
double angleV = Math.PI * 2 * j / vSteps;
float cosV = (float) Math.cos(angleV);
float sinV = (float) Math.sin(angleV);
for (int i = 0; i <= uSteps; i++) {
double angleU = Math.PI * 2 * i / uSteps;
float cosU = (float) Math.cos(angleU);
float sinU = (float) Math.sin(angleU);
float d = majorRadius+minorRadius*cosU;
float x = d*cosV;
float y = d*(-sinV);
float z = minorRadius * sinU;
float nx = cosV * cosU;
float ny = -sinV * cosU;
float nz = sinU;
float length = (float) Math.sqrt(nx*nx + ny*ny + nz*nz);
nx /= length;
ny /= length;
nz /= length;
grid.set(i, j, x, y, z, nx, ny, nz);
}
}
grid.createBufferObjects(gl);
return grid;
}
private boolean checkIfContextSupportsCubeMap(GL10 gl) {
return checkIfContextSupportsExtension(gl, "GL_OES_texture_cube_map");
}
/**
* This is not the fastest way to check for an extension, but fine if
* we are only checking for a few extensions each time a context is created.
* @param gl
* @param extension
* @return true if the extension is present in the current context.
*/
private boolean checkIfContextSupportsExtension(GL10 gl, String extension) {
String extensions = " " + gl.glGetString(GL10.GL_EXTENSIONS) + " ";
// The extensions string is padded with spaces between extensions, but not
// necessarily at the beginning or end. For simplicity, add spaces at the
// beginning and end of the extensions string and the extension string.
// This means we can avoid special-case checks for the first or last
// extension, as well as avoid special-case checks when an extension name
// is the same as the first part of another extension name.
return extensions.indexOf(" " + extension + " ") >= 0;
}
}
/** A grid is a topologically rectangular array of vertices.
*
* This grid class is customized for the vertex data required for this
* example.
*
* The vertex and index data are held in VBO objects because on most
* GPUs VBO objects are the fastest way of rendering static vertex
* and index data.
*
*/
private static class Grid {
// Size of vertex data elements in bytes:
final static int FLOAT_SIZE = 4;
final static int CHAR_SIZE = 2;
// Vertex structure:
// float x, y, z;
// float nx, ny, nx;
final static int VERTEX_SIZE = 6 * FLOAT_SIZE;
final static int VERTEX_NORMAL_BUFFER_INDEX_OFFSET = 3;
private int mVertexBufferObjectId;
private int mElementBufferObjectId;
// These buffers are used to hold the vertex and index data while
// constructing the grid. Once createBufferObjects() is called
// the buffers are nulled out to save memory.
private ByteBuffer mVertexByteBuffer;
private FloatBuffer mVertexBuffer;
private CharBuffer mIndexBuffer;
private int mW;
private int mH;
private int mIndexCount;
public Grid(int w, int h) {
if (w < 0 || w >= 65536) {
throw new IllegalArgumentException("w");
}
if (h < 0 || h >= 65536) {
throw new IllegalArgumentException("h");
}
if (w * h >= 65536) {
throw new IllegalArgumentException("w * h >= 65536");
}
mW = w;
mH = h;
int size = w * h;
mVertexByteBuffer = ByteBuffer.allocateDirect(VERTEX_SIZE * size)
.order(ByteOrder.nativeOrder());
mVertexBuffer = mVertexByteBuffer.asFloatBuffer();
int quadW = mW - 1;
int quadH = mH - 1;
int quadCount = quadW * quadH;
int indexCount = quadCount * 6;
mIndexCount = indexCount;
mIndexBuffer = ByteBuffer.allocateDirect(CHAR_SIZE * indexCount)
.order(ByteOrder.nativeOrder()).asCharBuffer();
/*
* Initialize triangle list mesh.
*
* [0]-----[ 1] ...
* | / |
* | / |
* | / |
* [w]-----[w+1] ...
* | |
*
*/
{
int i = 0;
for (int y = 0; y < quadH; y++) {
for (int x = 0; x < quadW; x++) {
char a = (char) (y * mW + x);
char b = (char) (y * mW + x + 1);
char c = (char) ((y + 1) * mW + x);
char d = (char) ((y + 1) * mW + x + 1);
mIndexBuffer.put(i++, a);
mIndexBuffer.put(i++, c);
mIndexBuffer.put(i++, b);
mIndexBuffer.put(i++, b);
mIndexBuffer.put(i++, c);
mIndexBuffer.put(i++, d);
}
}
}
}
public void set(int i, int j, float x, float y, float z, float nx, float ny, float nz) {
if (i < 0 || i >= mW) {
throw new IllegalArgumentException("i");
}
if (j < 0 || j >= mH) {
throw new IllegalArgumentException("j");
}
int index = mW * j + i;
mVertexBuffer.position(index * VERTEX_SIZE / FLOAT_SIZE);
mVertexBuffer.put(x);
mVertexBuffer.put(y);
mVertexBuffer.put(z);
mVertexBuffer.put(nx);
mVertexBuffer.put(ny);
mVertexBuffer.put(nz);
}
public void createBufferObjects(GL gl) {
checkGLError(gl);
// Generate a the vertex and element buffer IDs
int[] vboIds = new int[2];
GL11 gl11 = (GL11) gl;
gl11.glGenBuffers(2, vboIds, 0);
mVertexBufferObjectId = vboIds[0];
mElementBufferObjectId = vboIds[1];
// Upload the vertex data
gl11.glBindBuffer(GL11.GL_ARRAY_BUFFER, mVertexBufferObjectId);
mVertexByteBuffer.position(0);
gl11.glBufferData(GL11.GL_ARRAY_BUFFER, mVertexByteBuffer.capacity(), mVertexByteBuffer, GL11.GL_STATIC_DRAW);
gl11.glBindBuffer(GL11.GL_ELEMENT_ARRAY_BUFFER, mElementBufferObjectId);
mIndexBuffer.position(0);
gl11.glBufferData(GL11.GL_ELEMENT_ARRAY_BUFFER, mIndexBuffer.capacity() * CHAR_SIZE, mIndexBuffer, GL11.GL_STATIC_DRAW);
// We don't need the in-memory data any more
mVertexBuffer = null;
mVertexByteBuffer = null;
mIndexBuffer = null;
checkGLError(gl);
}
public void draw(GL10 gl) {
checkGLError(gl);
GL11 gl11 = (GL11) gl;
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
gl11.glBindBuffer(GL11.GL_ARRAY_BUFFER, mVertexBufferObjectId);
gl11.glVertexPointer(3, GL10.GL_FLOAT, VERTEX_SIZE, 0);
gl.glEnableClientState(GL10.GL_NORMAL_ARRAY);
gl11.glNormalPointer(GL10.GL_FLOAT, VERTEX_SIZE, VERTEX_NORMAL_BUFFER_INDEX_OFFSET * FLOAT_SIZE);
gl11.glBindBuffer(GL11.GL_ELEMENT_ARRAY_BUFFER, mElementBufferObjectId);
gl11.glDrawElements(GL10.GL_TRIANGLES, mIndexCount, GL10.GL_UNSIGNED_SHORT, 0);
gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
gl.glDisableClientState(GL10.GL_NORMAL_ARRAY);
gl11.glBindBuffer(GL11.GL_ARRAY_BUFFER, 0);
gl11.glBindBuffer(GL11.GL_ELEMENT_ARRAY_BUFFER, 0);
checkGLError(gl);
}
}
static void checkGLError(GL gl) {
int error = ((GL10) gl).glGetError();
if (error != GL10.GL_NO_ERROR) {
throw new RuntimeException("GLError 0x" + Integer.toHexString(error));
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Create our surface view and set it as the content of our
// Activity
mGLSurfaceView = new GLSurfaceView(this);
mGLSurfaceView.setRenderer(new Renderer());
setContentView(mGLSurfaceView);
}
@Override
protected void onResume() {
// Ideally a game should implement onResume() and onPause()
// to take appropriate action when the activity looses focus
super.onResume();
mGLSurfaceView.onResume();
}
@Override
protected void onPause() {
// Ideally a game should implement onResume() and onPause()
// to take appropriate action when the activity looses focus
super.onPause();
mGLSurfaceView.onPause();
}
}
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