用android编写颜色立方体

小灰灰 2022-08-03 11:46 105阅读 0赞

[http://www.anddev.org/colored\_3d\_cube-t4.html][http_www.anddev.org_colored_3d_cube-t4.html]

**Colored 3D Cube**  
  
**What is this:** This tutorial shows how to create colored 3D Objects using the [OpenGL® ES][OpenGL_ ES] cross-platform API.  
  
**What you learn:** You will learn how easy it is, to create a Colored 3D Cube, using OpenGL® ES.   
  
 **Problems/Questions:** post [here][]  
  
**Difficulty:** 1.5 of 5   
  
**What it will look like:**   
![android3dcolorcube.png][]  
  
**Introduction:**  
Lets quote wikipedia first:

<table style="width: 90%;"> 
 <tbody> 
 <tr> 
 <td>Quote:</td> 
 </tr> 
 <tr> 
 <td>OpenGL ES (OpenGL for Embedded Systems) is a subset of the OpenGL 3D graphics API designed for embedded devices such as mobile phones, PDAs, and video game consoles. It is defined and promoted by the Khronos Group, a graphics hardware and software industry consortium interested in open APIs for graphics and multimedia.</td> 
 </tr> 
 </tbody> 
</table>

**Description:**  
  
What we will do is, create a custom view and using OpenGL ES in it to draw a colored cube.  
The Main steps are:

<table style="width: 90%;"> 
 <tbody> 
 <tr> 
 <td>Java:</td> 
 </tr> 
 <tr> 
 <td> 
 <div style="font-family: monospace;">
 &nbsp; &nbsp; &nbsp; &nbsp; 
 int one = 0x10000; 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 /* Every vertex got 3 values, for &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* x / y / z position in the kartesian space. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;*/ 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 int vertices 
 [ 
 ] = 
 { 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;-one, -one, -one, 
 // Vertex Zero 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; one, -one, -one, 
 // Vertex Two 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; one, &nbsp;one, -one, 
 // Vertex ... 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;-one, &nbsp;one, -one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;-one, -one, &nbsp;one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; one, -one, &nbsp;one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; one, &nbsp;one, &nbsp;one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;-one, &nbsp;one, &nbsp;one, 
 // Vertex Seven 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 }; 
 </div> </td> 
 </tr> 
 </tbody> 
</table>

That is pretty easy, each row stands for a single vertex, consisting of three values (x,y,z) which simply result in a point in the cartesian space.  
So if you think of each codeline as one vertex you get something like this:  
(**Note:** We ***only*** created the vertices, not the edges. I just added them, that the cube-structure becomes better visible.)  
(**Note2:** You will see that the blue coordinate-system is located right in the middle of the cube)   
  
![android3dcolorcube_vertices2.png][]

<table style="width: 90%;"> 
 <tbody> 
 <tr> 
 <td>Java:</td> 
 </tr> 
 <tr> 
 <td> 
 <div style="font-family: monospace;">
 &nbsp; &nbsp; &nbsp; &nbsp; 
 /* Every vertex has got its own color, described by 4 values &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* R(ed) &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* G(green) &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* B(blue) &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* A(lpha) &lt;-- Opticacy &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;*/ 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 int colors 
 [ 
 ] = 
 { 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 0, &nbsp; &nbsp; 
 0, &nbsp; &nbsp; 
 0, &nbsp;one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; one, &nbsp; &nbsp; 
 0, &nbsp; &nbsp; 
 0, &nbsp;one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; one, &nbsp;one, &nbsp; &nbsp; 
 0, &nbsp;one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 0, &nbsp;one, &nbsp; &nbsp; 
 0, &nbsp;one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 0, &nbsp; &nbsp; 
 0, &nbsp;one, &nbsp;one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; one, &nbsp; &nbsp; 
 0, &nbsp;one, &nbsp;one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; one, &nbsp;one, &nbsp;one, &nbsp;one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 0, &nbsp;one, &nbsp;one, &nbsp;one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 }; 
 </div> </td> 
 </tr> 
 </tbody> 
</table>

In this code-block the color of all the 8 vertices are described, as *'4' each*: R(ed) G(reen) B(lue) A(lpha). (Alpha means Opticacy)  
OpenGL SE will create the color-flows automatically!

<table style="width: 90%;"> 
 <tbody> 
 <tr> 
 <td>Java:</td> 
 </tr> 
 <tr> 
 <td> 
 <div style="font-family: monospace;">
 &nbsp; &nbsp; &nbsp; &nbsp; 
 /* The last thing is that we need to describe some Triangles. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* A triangle got 3 vertices. &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; * The confusing thing is, that it is important in which order &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; * the vertices of each triangle are described. &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; * So describing a triangle through the vertices: "0, 4, 5" &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; * will not result in the same triangle as: "0, 5, 4" &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; * You probably ask: Why the hell isn't that the same ??? &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; * The reason for that is the call of: "gl.glFrontFace(gl.GL_CW);" &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; * which means, that we have to describe the "visible" side of the &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; * triangles by naming its vertices in a ClockWise order! &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; * From the other side, the triangle will be 100% lookthru! &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; * You can create a kind of magic mirror with that . &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;*/ 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 byte indices 
 [ 
 ] = 
 { 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 0, 
 4, 
 5, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 0, 
 5, 
 1, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 1, 
 5, 
 6, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 1, 
 6, 
 2, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 2, 
 6, 
 7, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 2, 
 7, 
 3, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 3, 
 7, 
 4, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 3, 
 4, 
 0, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 4, 
 7, 
 6, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 4, 
 6, 
 5, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 3, 
 0, 
 1, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 3, 
 1, 
 2 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 }; 
 </div> </td> 
 </tr> 
 </tbody> 
</table>

This is the tricky part. I think that I described it good enough in them comment.  
Lets take a look at two example triangles:   
![android3dcolorcube_triangles3.png][]  
  
**The Code**  
**Original Source:**  
[code.google.com][]  
  
**Modified by:** Nicolas 'plusminus' Gramlich

<table style="width: 90%;"> 
 <tbody> 
 <tr> 
 <td>Java:</td> 
 </tr> 
 <tr> 
 <td> 
 <div style="font-family: monospace;"> 
 /* &nbsp;* Copyright (C) 2007 Google Inc. &nbsp;* &nbsp;* Licensed under the Apache License, Version 2.0 (the "License"); &nbsp;* you may not use this file except in compliance with the License. &nbsp;* You may obtain a copy of the License at &nbsp;* &nbsp;* &nbsp; &nbsp; &nbsp;http://www.apache.org/licenses/LICENSE-2.0 &nbsp;* &nbsp;* Unless required by applicable law or agreed to in writing, software &nbsp;* distributed under the License is distributed on an "AS IS" BASIS, &nbsp;* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. &nbsp;* See the License for the specific language governing permissions and &nbsp;* limitations under the License. &nbsp;*/ 
 
 
 package com. 
 google. 
 android. 
 samples. 
 graphics; 
 
 
 import android. 
 app. 
 Activity; 
 
 import android. 
 content. 
 Context; 
 
 import android. 
 graphics. 
 Canvas; 
 
 import android. 
 graphics. 
 OpenGLContext; 
 
 import android. 
 os. 
 Bundle; 
 
 import android. 
 os. 
 Handler; 
 
 import android. 
 os. 
 Message; 
 
 import android. 
 os. 
 SystemClock; 
 
 import android. 
 view. 
 View; 
 
 
 import java. 
 nio. 
 ByteBuffer; 
 
 import java. 
 nio. 
 ByteOrder; 
 
 import java. 
 nio. 
 IntBuffer; 
 
 
 import javax. 
 microedition. 
 khronos. 
 opengles. 
 GL10; 
 
 
 
 /** &nbsp;* Example of how to use OpenGL|ES in a custom view &nbsp;* &nbsp;*/ 
 
 
 public 
 class GLView1 
 extends Activity 
 { 
 
 &nbsp; &nbsp; @Override 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 protected 
 void onCreate 
 (Bundle icicle 
 ) 
 &nbsp; &nbsp; 
 { 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 super. 
 onCreate 
 (icicle 
 ); &nbsp; &nbsp; 
 &nbsp; &nbsp; &nbsp; &nbsp; setContentView 
 ( 
 new GLView 
 ( getApplication 
 ( 
 ) 
 ) 
 ); 
 &nbsp; &nbsp; 
 } 
 
 &nbsp; &nbsp; @Override 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 protected 
 void onResume 
 ( 
 ) 
 &nbsp; &nbsp; 
 { 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 super. 
 onResume 
 ( 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 //android.os.Debug.startMethodTracing("/tmp/trace/GLView1.dmtrace", 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 // &nbsp;8 * 1024 * 1024); 
 &nbsp; &nbsp; 
 } 
 
 &nbsp; &nbsp; @Override 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 protected 
 void onStop 
 ( 
 ) 
 &nbsp; &nbsp; 
 { 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 super. 
 onStop 
 ( 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 //android.os.Debug.stopMethodTracing(); 
 &nbsp; &nbsp; 
 } 
 
 } 
 
 
 class GLView 
 extends 
 View 
 
 { 
 &nbsp; &nbsp; 
 /** &nbsp; &nbsp; &nbsp;* The View constructor is a good place to allocate our OpenGL context &nbsp; &nbsp; &nbsp;*/ 
 &nbsp; &nbsp; 
 public GLView 
 ( 
 Context context 
 ) 
 &nbsp; &nbsp; 
 { 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 super 
 (context 
 ); 
 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 /* &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* Create an OpenGL|ES context. This must be done only once, an &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* OpenGL contex is a somewhat heavy object. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;*/ 
 &nbsp; &nbsp; &nbsp; &nbsp; mGLContext = 
 new OpenGLContext 
 ( 
 0 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; mCube = 
 new Cube 
 ( 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; mAnimate = 
 false; 
 &nbsp; &nbsp; 
 } 
 
 &nbsp; &nbsp; 
 /* &nbsp; &nbsp; &nbsp;* Start the animation only once we're attached to a window &nbsp; &nbsp; &nbsp;* @see android.view.View#onAttachedToWindow() &nbsp; &nbsp; &nbsp;*/ 
 &nbsp; &nbsp; @Override 
 &nbsp; &nbsp; 
 protected 
 void onAttachedToWindow 
 ( 
 ) 
 { 
 &nbsp; &nbsp; &nbsp; &nbsp; mAnimate = 
 true; 
 &nbsp; &nbsp; &nbsp; &nbsp; Message msg = mHandler. 
 obtainMessage 
 (INVALIDATE 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; mNextTime = SystemClock. 
 uptimeMillis 
 ( 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; mHandler. 
 sendMessageAtTime 
 (msg, mNextTime 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 super. 
 onAttachedToWindow 
 ( 
 ); 
 &nbsp; &nbsp; 
 } 
 
 &nbsp; &nbsp; 
 /* &nbsp; &nbsp; &nbsp;* Make sure to stop the animation when we're no longer on screen, &nbsp; &nbsp; &nbsp;* failing to do so will cause most of the view hierarchy to be &nbsp; &nbsp; &nbsp;* leaked until the current process dies. &nbsp; &nbsp; &nbsp;* @see android.view.View#onDetachedFromWindow() &nbsp; &nbsp; &nbsp;*/ 
 &nbsp; &nbsp; @Override 
 &nbsp; &nbsp; 
 protected 
 void onDetachedFromWindow 
 ( 
 ) 
 { 
 &nbsp; &nbsp; &nbsp; &nbsp; mAnimate = 
 false; 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 super. 
 onDetachedFromWindow 
 ( 
 ); 
 &nbsp; &nbsp; 
 } 
 
 &nbsp; &nbsp; 
 /** &nbsp; &nbsp; &nbsp;* Draw the view content &nbsp; &nbsp; &nbsp;* &nbsp; &nbsp; &nbsp;* @see android.view.View#onDraw(android.graphics.Canvas) &nbsp; &nbsp; &nbsp;*/ 
 &nbsp; &nbsp; @Override 
 &nbsp; &nbsp; 
 protected 
 void onDraw 
 ( 
 Canvas canvas 
 ) 
 { 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 if 
 ( 
 true 
 ) 
 { 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 /* &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* First, we need to get to the appropriate GL interface. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* This is simply done by casting the GL context to either &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* GL10 or GL11. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;*/ 
 &nbsp; &nbsp; &nbsp; &nbsp; GL10 gl = 
 (GL10 
 ) 
 (mGLContext. 
 getGL 
 ( 
 ) 
 ); 
 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 /* &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* Before we can issue GL commands, we need to make sure all &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* native drawing commands are completed. Simply call &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* waitNative() to accomplish this. Once this is done, no native &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* calls should be issued. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;*/ 
 &nbsp; &nbsp; &nbsp; &nbsp; mGLContext. 
 waitNative 
 (canvas, 
 this 
 ); 
 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 int w = getWidth 
 ( 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 int h = getHeight 
 ( 
 ); 
 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 /* &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* Set the viewport. This doesn't have to be done each time &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* draw() is called. Typically this is called when the view &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* is resized. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;*/ 
 
 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; gl. 
 glViewport 
 ( 
 0, 
 0, w, h 
 ); 
 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 /* &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* Set our projection matrix. This doesn't have to be done &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* each time we draw, but usualy a new projection needs to be set &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* when the viewport is resized. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;*/ 
 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 float ratio = 
 ( 
 float 
 )w / h; 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; gl. 
 glMatrixMode 
 (gl. 
 GL_PROJECTION 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; gl. 
 glLoadIdentity 
 ( 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; gl. 
 glFrustumf 
 (-ratio, ratio, 
 -1, 
 1, 
 2, 
 12 
 ); 
 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 /* &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* dithering is enabled by default in OpenGL, unfortunattely &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* it has a significant impact on performace in software &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* implementation. Often, it's better to just turn it off. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;*/ 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;gl. 
 glDisable 
 (gl. 
 GL_DITHER 
 ); 
 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 /* &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* Usually, the first thing one might want to do is to clear &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* the screen. The most efficient way of doing this is to use &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* glClear(). However we must make sure to set the scissor &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* correctly first. The scissor is always specified in window &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* coordinates: &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;*/ 
 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; gl. 
 glClearColor 
 ( 
 1, 
 1, 
 1, 
 1 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; gl. 
 glEnable 
 (gl. 
 GL_SCISSOR_TEST 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; gl. 
 glScissor 
 ( 
 0, 
 0, w, h 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; gl. 
 glClear 
 (gl. 
 GL_COLOR_BUFFER_BIT 
 ); 
 
 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 /* &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* Now we're ready to draw some 3D object &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;*/ 
 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; gl. 
 glMatrixMode 
 (gl. 
 GL_MODELVIEW 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; gl. 
 glLoadIdentity 
 ( 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; gl. 
 glTranslatef 
 ( 
 0, 
 0, 
 -3.0f 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; gl. 
 glScalef 
 ( 
 0.5f, 
 0.5f, 
 0.5f 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; gl. 
 glRotatef 
 (mAngle, &nbsp; &nbsp; &nbsp; &nbsp; 
 0, 
 1, 
 0 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; gl. 
 glRotatef 
 (mAngle* 
 0.25f, &nbsp; 
 1, 
 0, 
 0 
 ); 
 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; gl. 
 glColor4f 
 ( 
 0.7f, 
 0.7f, 
 0.7f, 
 1.0f 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; gl. 
 glEnableClientState 
 (gl. 
 GL_VERTEX_ARRAY 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; gl. 
 glEnableClientState 
 (gl. 
 GL_COLOR_ARRAY 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; gl. 
 glEnable 
 (gl. 
 GL_CULL_FACE 
 ); 
 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; mCube. 
 draw 
 (gl 
 ); 
 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; mAngle += 
 1.2f; 
 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 /* &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* Once we're done with GL, we need to flush all GL commands and &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* make sure they complete before we can issue more native &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* drawing commands. This is done by calling waitGL(). &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;*/ 
 &nbsp; &nbsp; &nbsp; &nbsp; mGLContext. 
 waitGL 
 ( 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 } 
 &nbsp; &nbsp; 
 } 
 
 
 &nbsp; &nbsp; 
 // ------------------------------------------------------------------------ 
 
 &nbsp; &nbsp; 
 private 
 static 
 final 
 int INVALIDATE = 
 1; 
 
 &nbsp; &nbsp; 
 private 
 final Handler mHandler = 
 new Handler 
 ( 
 ) 
 { 
 &nbsp; &nbsp; &nbsp; &nbsp; @Override 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 public 
 void handleMessage 
 (Message msg 
 ) 
 { 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 if 
 (mAnimate &amp;&amp; msg. 
 what == INVALIDATE 
 ) 
 { 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; invalidate 
 ( 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; msg = obtainMessage 
 (INVALIDATE 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 long current = SystemClock. 
 uptimeMillis 
 ( 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 if 
 (mNextTime &lt; current 
 ) 
 { 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; mNextTime = current + 
 20; 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 } 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; sendMessageAtTime 
 (msg, mNextTime 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; mNextTime += 
 20; 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 } 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 } 
 &nbsp; &nbsp; 
 }; 
 
 &nbsp; &nbsp; 
 private OpenGLContext &nbsp; mGLContext; 
 &nbsp; &nbsp; 
 private Cube &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;mCube; 
 &nbsp; &nbsp; 
 private 
 float &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; mAngle; 
 &nbsp; &nbsp; 
 private 
 long &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;mNextTime; 
 &nbsp; &nbsp; 
 private 
 boolean &nbsp; &nbsp; &nbsp; &nbsp; mAnimate; 
 
 } 
 
 
 
 class Cube 
 
 { 
 &nbsp; &nbsp; 
 public Cube 
 ( 
 ) 
 &nbsp; &nbsp; 
 { 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 int one = 0x10000; 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 /* Every vertex got 3 values, for &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* x / y / z position in the kartesian space. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;*/ 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 int vertices 
 [ 
 ] = 
 { 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;-one, -one, -one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; one, -one, -one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; one, &nbsp;one, -one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;-one, &nbsp;one, -one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;-one, -one, &nbsp;one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; one, -one, &nbsp;one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; one, &nbsp;one, &nbsp;one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;-one, &nbsp;one, &nbsp;one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 }; 
 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 /* Every vertex has got its own color, described by 4 values &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* R(ed) &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* G(green) &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* B(blue) &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* A(lpha) &lt;-- Opticacy &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;*/ 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 int colors 
 [ 
 ] = 
 { 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 0, &nbsp; &nbsp; 
 0, &nbsp; &nbsp; 
 0, &nbsp;one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; one, &nbsp; &nbsp; 
 0, &nbsp; &nbsp; 
 0, &nbsp;one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; one, &nbsp;one, &nbsp; &nbsp; 
 0, &nbsp;one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 0, &nbsp;one, &nbsp; &nbsp; 
 0, &nbsp;one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 0, &nbsp; &nbsp; 
 0, &nbsp;one, &nbsp;one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; one, &nbsp; &nbsp; 
 0, &nbsp;one, &nbsp;one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; one, &nbsp;one, &nbsp;one, &nbsp;one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 0, &nbsp;one, &nbsp;one, &nbsp;one, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 }; 
 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 /* The last thing is that we need to describe some Triangles. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* A triangle got 3 vertices. &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; * The confusing thing is, that it is important in which order &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; * the vertices of each triangle are described. &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; * So describing a triangle through the vertices: "0, 4, 5" &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; * will not result in the same triangle as: "0, 5, 4" &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; * You probably ask: Why the hell isn't that the same ??? &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; * The reason for that is the call of: "gl.glFrontFace(gl.GL_CW);" &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; * which means, that we have to describe the "visible" side of the &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; * triangles by naming its vertices in a ClockWise order! &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; * From the other side, the triangle will be 100% lookthru! &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; * You can create a kind of magic mirror with that . &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;*/ 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 byte indices 
 [ 
 ] = 
 { 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 0, 
 4, 
 5, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 0, 
 5, 
 1, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 1, 
 5, 
 6, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 1, 
 6, 
 2, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 2, 
 6, 
 7, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 2, 
 7, 
 3, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 3, 
 7, 
 4, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 3, 
 4, 
 0, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 4, 
 7, 
 6, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 4, 
 6, 
 5, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 3, 
 0, 
 1, 
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 3, 
 1, 
 2 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 }; 
 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 // Buffers to be passed to gl*Pointer() functions 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 // must be direct, i.e., they must be placed on the 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 // native heap where the garbage collector cannot 
 &nbsp; &nbsp; &nbsp; &nbsp; 
 // move them. 
 &nbsp; &nbsp; 
 // 
 &nbsp; &nbsp; 
 // Buffers with multi-byte datatypes (e.g., short, int, float) 
 &nbsp; &nbsp; 
 // must have their byte order set to native order 
 
 &nbsp; &nbsp; ByteBuffer vbb = ByteBuffer. 
 allocateDirect 
 (vertices. 
 length* 
 4 
 ); 
 &nbsp; &nbsp; vbb. 
 order 
 (ByteOrder. 
 nativeOrder 
 ( 
 ) 
 ); 
 &nbsp; &nbsp; mVertexBuffer = vbb. 
 asIntBuffer 
 ( 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; mVertexBuffer. 
 put 
 (vertices 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; mVertexBuffer. 
 position 
 ( 
 0 
 ); 
 
 &nbsp; &nbsp; ByteBuffer cbb = ByteBuffer. 
 allocateDirect 
 (colors. 
 length* 
 4 
 ); 
 &nbsp; &nbsp; cbb. 
 order 
 (ByteOrder. 
 nativeOrder 
 ( 
 ) 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; mColorBuffer = cbb. 
 asIntBuffer 
 ( 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; mColorBuffer. 
 put 
 (colors 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; mColorBuffer. 
 position 
 ( 
 0 
 ); 
 
 &nbsp; &nbsp; &nbsp; &nbsp; mIndexBuffer = ByteBuffer. 
 allocateDirect 
 (indices. 
 length 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; mIndexBuffer. 
 put 
 (indices 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; mIndexBuffer. 
 position 
 ( 
 0 
 ); 
 &nbsp; &nbsp; 
 } 
 
 &nbsp; &nbsp; 
 public 
 void draw 
 (GL10 gl 
 ) 
 &nbsp; &nbsp; 
 { 
 &nbsp; &nbsp; &nbsp; &nbsp; gl. 
 glFrontFace 
 (gl. 
 GL_CW 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; gl. 
 glVertexPointer 
 ( 
 3, gl. 
 GL_FIXED, 
 0, mVertexBuffer 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; gl. 
 glColorPointer 
 ( 
 4, gl. 
 GL_FIXED, 
 0, mColorBuffer 
 ); 
 &nbsp; &nbsp; &nbsp; &nbsp; gl. 
 glDrawElements 
 (gl. 
 GL_TRIANGLES, 
 36, gl. 
 GL_UNSIGNED_BYTE, mIndexBuffer 
 ); 
 &nbsp; &nbsp; 
 } 
 
 &nbsp; &nbsp; 
 private IntBuffer &nbsp; mVertexBuffer; 
 &nbsp; &nbsp; 
 private IntBuffer &nbsp; mColorBuffer; 
 &nbsp; &nbsp; 
 private ByteBuffer &nbsp;mIndexBuffer; 
 
 } 
 </div> </td> 
 </tr> 
 </tbody> 
</table>

I hope you succeeded and understood this tutorial.  
  
Please vote and/or leave a comment  .  
  
See you soon

*  1. Setup the view and create a cube  
    (1.1. Start/Stop the animation if we are (not) viewing it)  
    2. Do some trigonometry (rotation)  
    3. Make the Cube paint itself

**Most interesting:**  
What the heck do those values in the Cube-Constructor mean...

[http_www.anddev.org_colored_3d_cube-t4.html]: http://www.anddev.org/colored_3d_cube-t4.html
[OpenGL_ ES]: http://www.khronos.org/opengles/
[here]: http://www.anddev.org/viewtopic.php?t=13
[android3dcolorcube.png]: /images/20220731/df577bd4d3f1441480f0236ea07ea443.png
[android3dcolorcube_vertices2.png]: /images/20220731/1d9b1d4a83c5416f9ef383ae519dc2b0.png
[android3dcolorcube_triangles3.png]: /images/20220731/ec75913d6e51423182645d6f5ce170fb.png
[code.google.com]: http://code.google.com/android/samples/ApiDemos/src/com/google/android/samples/graphics/GLView1.html