openGL ES 2.0 3维物体的平移（II）

先上第一个demo，关于物体cube在空间中的平移，（理解了这个，再学习接下来的旋转和缩放，就简单的多了···）

第一个文件：ShaderUtil.java————（主要作用是，生成渲染器，再生成渲染器程序）

package com.example.sample_5_3_mine;

import java.io.ByteArrayOutputStream;
import java.io.InputStream;

import android.content.res.Resources;
import android.opengl.GLES20;
import android.util.Log;

public class ShaderUtil {

public static int loadShader(
int shaderType,
String source){
int shader = GLES20.glCreateShader(shaderType);
if(shader!=0){
GLES20.glShaderSource(shader, source);
GLES20.glCompileShader(shader);
int[] compiled = new int[1];
GLES20.glGetShaderiv(shader, GLES20.GL_COMPILE_STATUS, compiled, 0);
if(compiled[0] == 0){
Log.e("ES_ERROR","Could not compiled shader");
Log.e("ES_ERROR",GLES20.glGetShaderInfoLog(shader));
GLES20.glDeleteShader(shader);
shader = 0;
}
}

return shader;
}

public static int createProgram(
String vertexSource,
String fragmentSource){
int vertexShader = loadShader(GLES20.GL_VERTEX_SHADER,vertexSource);
if(vertexShader == 0){
return 0;
}
int pixelShader = loadShader(GLES20.GL_FRAGMENT_SHADER,fragmentSource);
if(pixelShader == 0){
return 0;
}

int program = GLES20.glCreateProgram();
if(program != 0){
GLES20.glAttachShader(program,vertexShader);
checkGlError("glAttachShader");
GLES20.glAttachShader(program, pixelShader);
checkGlError("glAttachShader");
GLES20.glLinkProgram(program);
int[] linkStatus = new int[1];
GLES20.glGetProgramiv(program, GLES20.GL_LINK_STATUS, linkStatus,0);
if(linkStatus[0] != GLES20.GL_TRUE){
Log.e("ES20_ERROR","Could not link program");
Log.e("ES_ERROR",GLES20.glGetProgramInfoLog(program));
GLES20.glDeleteProgram(program);
program = 0;
}
}
return program;
}

public static void checkGlError(String op){
int error;
while((error = GLES20.glGetError()) !=GLES20.GL_NO_ERROR){
Log.e("ES20_ERROR",op + "glError:" + error);
throw new RuntimeException(op + ":glError");
}
}

public static String loadFromAssetsFile(String fname,Resources r){
String result = null;
try{
InputStream in = r.getAssets().open(fname);
int ch = 0;
ByteArrayOutputStream baos = new ByteArrayOutputStream();
while((ch = in.read()) != -1){
baos.write(ch);
}
byte[] buff = baos.toByteArray();
baos.close();
in.close();
result = new String(buff,"UTF-8");
result = result.replaceAll("\\r\\n", "\n");
}
catch(Exception e){
e.printStackTrace();
}

return result;
}


}

ok、现在改轮到主类：MainActivity.java的编写了：

package com.example.sample_5_3_mine;


//以后像这种多个demo.java这种shen me gui!!
//应该先在LogCat中查看相应的包类，查看出来第一个出错的是哪一个.java类，
//而不是盲目的一次“比较文件”，一比较就是6个！我勒个去！6个啊！！
//相比VC++6.0来说，Eclipse的开发节省了很多细节问题，（之前出现的大小写，多一个少一个字符啊，什么的，没了）
//哈哈、好开森~~


//错误检查报告：
//1、屏幕设置方式出错   ||  2、ByteBuffer cbb = ByteBuffer.allocateDirect(colors.length*4);
import android.os.Bundle;
import android.app.Activity;
import android.content.pm.ActivityInfo;
import android.view.Menu;
import android.view.Window;
import android.view.WindowManager;

public class MainActivity extends Activity {

private MySurfaceView mGLSurfaceView;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, 
WindowManager.LayoutParams.FLAG_FULLSCREEN);
//这儿是显示不正确的第二个错误：屏幕显示方式应该为:LANFSCAPE,
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
mGLSurfaceView = new MySurfaceView(this);

setContentView(mGLSurfaceView);
mGLSurfaceView.requestFocus();
mGLSurfaceView.setFocusableInTouchMode(true);

}



@Override
protected void onPause() {
// TODO 自动生成的方法存根
super.onPause();
mGLSurfaceView.onPause();
}



@Override
protected void onResume() {
// TODO 自动生成的方法存根
super.onResume();
mGLSurfaceView.onResume();
}



@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}

}

现在是MySurfaceView.java文件的编写：

这个类的作用主要用于定义摄像机的位置参数，以及镜头的显示（宽高比等等），

package com.example.sample_5_3_mine;

import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL10;

import android.content.Context;
import android.opengl.GLES20;
import android.opengl.GLSurfaceView;

public class MySurfaceView extends GLSurfaceView{

private SceneRenderer mRenderer;
public MySurfaceView(Context context) {
super(context);
// TODO 自动生成的构造函数存根
this.setEGLContextClientVersion(2);
mRenderer = new SceneRenderer();
setRenderer(mRenderer);
setRenderMode(GLSurfaceView.RENDERMODE_CONTINUOUSLY);
}

private class SceneRenderer implements GLSurfaceView.Renderer{

Cube cube;
//下面由于三个函数：onDrawFrame()、onSurfaceChanged()、onSurfaceCreated()
//调用的时候并非按照顺序进行，而应该是：
//创建对象，打开开关->设置摄相机参数->开始绘画屏幕
//onSurfaceCreated()->onSurfaceChanged()->onDrawFrame()
@Override
public void onDrawFrame(GL10 gl) {
// TODO 自动生成的方法存根
GLES20.glClear(GLES20.GL_DEPTH_BUFFER_BIT | GLES20.GL_COLOR_BUFFER_BIT);
MatrixState.pushMatrix();
cube.drawSelf();
MatrixState.popMatrix();

MatrixState.pushMatrix();
MatrixState.translate(4,0,0);
cube.drawSelf();
MatrixState.popMatrix();
}

@Override
public void onSurfaceChanged(GL10 gl, int width, int height) {
// TODO 自动生成的方法存根
GLES20.glViewport(0, 0, width, height);
Constant.ratio = (float) width/height;
MatrixState.setProjectFrustum(-Constant.ratio*0.8f, Constant.ratio*1.2f, -1, 1, 20, 100);

MatrixState.setCamera(-16f, 8f, 45, 0f, 0f, 0f, 0f, 1.0f, 0.0f);

MatrixState.setInitStack();
}

@Override
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
// TODO 自动生成的方法存根
 GLES20.glClearColor(0.5f, 0.5f, 0.5f, 1.0f);
 cube = new Cube(MySurfaceView.this);
 GLES20.glEnable(GLES20.GL_DEPTH_TEST);
 GLES20.glEnable(GLES20.GL_CULL_FACE);
}

}
}

 

好了，现在编写MatrixState.java这个类:

这个类主要作用于：矩阵的变换，保存矩阵场景，以及如何通过举证实现物体的平移、旋转、缩放等等函数：

package com.example.sample_5_3_mine;

import java.nio.ByteBuffer;

import android.opengl.Matrix;

public class MatrixState {

private static float[] mProjMatrix = new float[16];
private static float[] mVMatrix = new float[16];
private static float[] currMatrix;

static float[][] mStack = new float[10][16];
static int stackTop = -1;

public static void setInitStack(){
currMatrix = new float[16];
Matrix.setRotateM(currMatrix, 0, 0, 1, 0, 0);
}

public static void pushMatrix(){
stackTop++;
for(int i=0;i<16;i++){
mStack[stackTop][i] = currMatrix[i];
}
}

public static void popMatrix(){
for(int i=0;i<16;i++){
currMatrix[i] = mStack[stackTop][i];
}
stackTop--;
}

public static void translate(float x,float y, float z){
Matrix.translateM(currMatrix, 0, x, y, z);
}

static ByteBuffer llbb = ByteBuffer.allocateDirect(3*4);
static float[] cameraLocation = new float[3];
public static void setCamera(
float cx,float cy, float cz,
float tx, float ty, float tz,
float upx,float upy, float upz){
Matrix.setLookAtM(mVMatrix, 0, cx, cy, cz, tx, ty, tz, upx, upy, upz);
}

public static void setProjectFrustum(float left,float right,
float bottom, float top,
float near, float far){
Matrix.frustumM(mProjMatrix, 0, left, right, bottom, top, near, far);
}
public static void setProjectOrtho(float left, float right,
float bottom, float top,
float near,float far){
Matrix.orthoM(mProjMatrix, 0, left, right, bottom, top, near, far);
}

static float[] mMVPMatrix = new float[16];
public static float[] getFinalMatrix(){
Matrix.multiplyMM(mMVPMatrix, 0, mVMatrix, 0, currMatrix, 0);
Matrix.multiplyMM(mMVPMatrix, 0, mProjMatrix, 0, mMVPMatrix, 0);
return mMVPMatrix;
}

public static float[] getMMatrix(){
return currMatrix;
}

}

嗯、对了，还有一个常量类Constan.java,,它的作用主要是：

申请定义一些常用的变量，直接定义好，一次定义，多次使用~

package com.example.sample_5_3_mine;

public class Constant {
public static final float UNIT_SIZE = 1f;

public static float ratio;
}

ok、ok、现在就剩下最后一个类Cube.jaba的定义以及编写了：

它的作用主要是：定义一个正方体Cube，定义好它的大小，位置，各个顶点等数据，同时也包含有自身的drawSelf()方法，用于在屏幕上对自身进行绘画等等，

来啦~~：

package com.example.sample_5_3_mine;


//自我总结：本次出错在Cube.java上，其中一个比较重要的原因是：不仔细，前面5个全神贯注敲打了，
//这个给漏网之鱼，一不留神就溜走了，下次记住：一定要：仔仔细细敲全部！

//还有就是！检查核对的是也没有仔细看！

import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;

import android.opengl.GLES20;

public class Cube {

int mProgram;
int muMVPMatrixHandle;
int maPositionHandle;
int maColorHandle;
String mVertexShader;
String mFragmentShader;

FloatBuffer mVertexBuffer;
FloatBuffer mColorBuffer;
int vCount = 0;

//构造函数
public Cube(MySurfaceView mv){
initVertexData();

initShader(mv);
}

public void initVertexData(){
vCount = 12*6;
float vertices[] = new float[]{

        //前面
        0,0,Constant.UNIT_SIZE,
        
        Constant.UNIT_SIZE,Constant.UNIT_SIZE,Constant.UNIT_SIZE,
        
        -Constant.UNIT_SIZE,Constant.UNIT_SIZE,Constant.UNIT_SIZE,
        
        0,0,Constant.UNIT_SIZE,
        
        -Constant.UNIT_SIZE,Constant.UNIT_SIZE,Constant.UNIT_SIZE,
        
        -Constant.UNIT_SIZE,-Constant.UNIT_SIZE,Constant.UNIT_SIZE,
        
        0,0,Constant.UNIT_SIZE,
        
        -Constant.UNIT_SIZE,-Constant.UNIT_SIZE,Constant.UNIT_SIZE,
        
        Constant.UNIT_SIZE,-Constant.UNIT_SIZE,Constant.UNIT_SIZE,
        
        0,0,Constant.UNIT_SIZE,
        
        Constant.UNIT_SIZE,-Constant.UNIT_SIZE,Constant.UNIT_SIZE,
        
        Constant.UNIT_SIZE,Constant.UNIT_SIZE,Constant.UNIT_SIZE,
        //后面
        0,0,-Constant.UNIT_SIZE,        
        Constant.UNIT_SIZE,Constant.UNIT_SIZE,-Constant.UNIT_SIZE,
        Constant.UNIT_SIZE,-Constant.UNIT_SIZE,-Constant.UNIT_SIZE,
        0,0,-Constant.UNIT_SIZE, 
        Constant.UNIT_SIZE,-Constant.UNIT_SIZE,-Constant.UNIT_SIZE,
        -Constant.UNIT_SIZE,-Constant.UNIT_SIZE,-Constant.UNIT_SIZE,
        0,0,-Constant.UNIT_SIZE, 
        -Constant.UNIT_SIZE,-Constant.UNIT_SIZE,-Constant.UNIT_SIZE,
        -Constant.UNIT_SIZE,Constant.UNIT_SIZE,-Constant.UNIT_SIZE,
        0,0,-Constant.UNIT_SIZE, 
        -Constant.UNIT_SIZE,Constant.UNIT_SIZE,-Constant.UNIT_SIZE,
        Constant.UNIT_SIZE,Constant.UNIT_SIZE,-Constant.UNIT_SIZE,
        //左面
        -Constant.UNIT_SIZE,0,0,      
        -Constant.UNIT_SIZE,Constant.UNIT_SIZE,Constant.UNIT_SIZE,
        -Constant.UNIT_SIZE,Constant.UNIT_SIZE,-Constant.UNIT_SIZE,
        -Constant.UNIT_SIZE,0,0,   
        -Constant.UNIT_SIZE,Constant.UNIT_SIZE,-Constant.UNIT_SIZE,
        -Constant.UNIT_SIZE,-Constant.UNIT_SIZE,-Constant.UNIT_SIZE,
        -Constant.UNIT_SIZE,0,0,   
        -Constant.UNIT_SIZE,-Constant.UNIT_SIZE,-Constant.UNIT_SIZE,
        -Constant.UNIT_SIZE,-Constant.UNIT_SIZE,Constant.UNIT_SIZE,
        -Constant.UNIT_SIZE,0,0,   
        -Constant.UNIT_SIZE,-Constant.UNIT_SIZE,Constant.UNIT_SIZE,
        -Constant.UNIT_SIZE,Constant.UNIT_SIZE,Constant.UNIT_SIZE,
        //右面
        Constant.UNIT_SIZE,0,0,   
        Constant.UNIT_SIZE,Constant.UNIT_SIZE,Constant.UNIT_SIZE,
        Constant.UNIT_SIZE,-Constant.UNIT_SIZE,Constant.UNIT_SIZE,
        Constant.UNIT_SIZE,0,0,   
        Constant.UNIT_SIZE,-Constant.UNIT_SIZE,Constant.UNIT_SIZE,
        Constant.UNIT_SIZE,-Constant.UNIT_SIZE,-Constant.UNIT_SIZE,
        Constant.UNIT_SIZE,0,0,   
        Constant.UNIT_SIZE,-Constant.UNIT_SIZE,-Constant.UNIT_SIZE,
        Constant.UNIT_SIZE,Constant.UNIT_SIZE,-Constant.UNIT_SIZE,
        Constant.UNIT_SIZE,0,0,  
        Constant.UNIT_SIZE,Constant.UNIT_SIZE,-Constant.UNIT_SIZE,
        Constant.UNIT_SIZE,Constant.UNIT_SIZE,Constant.UNIT_SIZE,
        //上面
        0,Constant.UNIT_SIZE,0,      
        Constant.UNIT_SIZE,Constant.UNIT_SIZE,Constant.UNIT_SIZE,
        Constant.UNIT_SIZE,Constant.UNIT_SIZE,-Constant.UNIT_SIZE,
        0,Constant.UNIT_SIZE,0,        
        Constant.UNIT_SIZE,Constant.UNIT_SIZE,-Constant.UNIT_SIZE,
        -Constant.UNIT_SIZE,Constant.UNIT_SIZE,-Constant.UNIT_SIZE,
        0,Constant.UNIT_SIZE,0,       
        -Constant.UNIT_SIZE,Constant.UNIT_SIZE,-Constant.UNIT_SIZE,
        -Constant.UNIT_SIZE,Constant.UNIT_SIZE,Constant.UNIT_SIZE, 
        0,Constant.UNIT_SIZE,0,      
        -Constant.UNIT_SIZE,Constant.UNIT_SIZE,Constant.UNIT_SIZE,
        Constant.UNIT_SIZE,Constant.UNIT_SIZE,Constant.UNIT_SIZE,  
        //下面
        0,-Constant.UNIT_SIZE,0,        
        Constant.UNIT_SIZE,-Constant.UNIT_SIZE,Constant.UNIT_SIZE,
        -Constant.UNIT_SIZE,-Constant.UNIT_SIZE,Constant.UNIT_SIZE,
        0,-Constant.UNIT_SIZE,0,  
        -Constant.UNIT_SIZE,-Constant.UNIT_SIZE,Constant.UNIT_SIZE,
        -Constant.UNIT_SIZE,-Constant.UNIT_SIZE,-Constant.UNIT_SIZE,
        0,-Constant.UNIT_SIZE,0,   
        -Constant.UNIT_SIZE,-Constant.UNIT_SIZE,-Constant.UNIT_SIZE,
        Constant.UNIT_SIZE,-Constant.UNIT_SIZE,-Constant.UNIT_SIZE,
        0,-Constant.UNIT_SIZE,0,    
        Constant.UNIT_SIZE,-Constant.UNIT_SIZE,-Constant.UNIT_SIZE,
        Constant.UNIT_SIZE,-Constant.UNIT_SIZE,Constant.UNIT_SIZE,
};

//错在这里啦！！！
ByteBuffer vbb = ByteBuffer.allocateDirect(vertices.length*4);
vbb.order(ByteOrder.nativeOrder());
mVertexBuffer = vbb.asFloatBuffer();
mVertexBuffer.put(vertices);
mVertexBuffer.position(0);

float colors[] = new float[]{
//前面        
        1,1,1,0,//中间为白色
        1,0,0,0,
        1,0,0,0,
        1,1,1,0,//中间为白色
        1,0,0,0,
        1,0,0,0,
        1,1,1,0,//中间为白色
        1,0,0,0,
        1,0,0,0,
        1,1,1,0,//中间为白色
        1,0,0,0,
        1,0,0,0,
        //后面
        1,1,1,0,//中间为白色
        0,0,1,0,
        0,0,1,0, 
        1,1,1,0,//中间为白色
        0,0,1,0,
        0,0,1,0, 
        1,1,1,0,//中间为白色
        0,0,1,0,
        0,0,1,0, 
        1,1,1,0,//中间为白色
        0,0,1,0,
        0,0,1,0, 
        //左面
        1,1,1,0,//中间为白色
        1,0,1,0,
        1,0,1,0, 
        1,1,1,0,//中间为白色
        1,0,1,0,
        1,0,1,0, 
        1,1,1,0,//中间为白色
        1,0,1,0,
        1,0,1,0, 
        1,1,1,0,//中间为白色
        1,0,1,0,
        1,0,1,0, 
        //右面
        1,1,1,0,//中间为白色
        1,1,0,0,
        1,1,0,0,
        1,1,1,0,//中间为白色
        1,1,0,0,
        1,1,0,0,
        1,1,1,0,//中间为白色
        1,1,0,0,
        1,1,0,0,
        1,1,1,0,//中间为白色
        1,1,0,0,
        1,1,0,0,
        //上面
        1,1,1,0,//中间为白色
        0,1,0,0,
        0,1,0,0,
        1,1,1,0,//中间为白色
        0,1,0,0,
        0,1,0,0,
        1,1,1,0,//中间为白色
        0,1,0,0,
        0,1,0,0,
        1,1,1,0,//中间为白色
        0,1,0,0,
        0,1,0,0,        
        //下面
        1,1,1,0,//中间为白色
        0,1,1,0,
        0,1,1,0,
        1,1,1,0,//中间为白色
        0,1,1,0,
        0,1,1,0,
        1,1,1,0,//中间为白色
        0,1,1,0,
        0,1,1,0,
        1,1,1,0,//中间为白色
        0,1,1,0,
        0,1,1,0,
};

ByteBuffer cbb = ByteBuffer.allocateDirect(colors.length*4);
cbb.order(ByteOrder.nativeOrder());
mColorBuffer = cbb.asFloatBuffer();
mColorBuffer.put(colors);
mColorBuffer.position(0);
}

public void initShader(MySurfaceView mv){
mVertexShader = ShaderUtil.loadFromAssetsFile("vertex.sh", mv.getResources());
mFragmentShader = ShaderUtil.loadFromAssetsFile("frag.sh", mv.getResources());
mProgram = ShaderUtil.createProgram(mVertexShader, mFragmentShader);

maPositionHandle = GLES20.glGetAttribLocation(mProgram, "aPosition");
maColorHandle = GLES20.glGetAttribLocation(mProgram, "aColor");
muMVPMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uMVPMatrix");
}

public void drawSelf(){
GLES20.glUseProgram(mProgram);

GLES20.glUniformMatrix4fv(muMVPMatrixHandle, 1, false, MatrixState.getFinalMatrix(),0);
//GLES20.glUniformMatrix4fv(muMV, arg1, arg2, arg3)
GLES20.glVertexAttribPointer(maPositionHandle,3,GLES20.GL_FLOAT,
false,3*4,mVertexBuffer);
GLES20.glVertexAttribPointer(maColorHandle, 4, GLES20.GL_FLOAT,
false, 4*4, mColorBuffer);

GLES20.glEnableVertexAttribArray(maPositionHandle);
GLES20.glEnableVertexAttribArray(maColorHandle);
GLES20.glDrawArrays(GLES20.GL_TRIANGLES,0,vCount);

}

}

我了个去，差点忘记了一个重要的demo:

frag.sh文件：

precision mediump float;
varying  vec4 vColor; //接收从顶点着色器过来的参数
varying vec3 vPosition;//接收从顶点着色器过来的顶点位置
void main() {  
   gl_FragColor = vColor;//给此片元颜色值
}

vertex.sh文件：

uniform mat4 uMVPMatrix; //总变换矩阵
attribute vec3 aPosition;  //顶点位置
attribute vec4 aColor;    //顶点颜色
varying  vec4 vColor;  //用于传递给片元着色器的变量
void main()  {                            
   gl_Position = uMVPMatrix * vec4(aPosition,1); //根据总变换矩阵计算此次绘制此顶点位置
   vColor = aColor;//将接收的颜色传递给片元着色器
}