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第16章 游戏开发中的物理学/Sample16_4/.classpath

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+<?xml version="1.0" encoding="UTF-8"?>
+<classpath>
+	<classpathentry kind="src" path="src"/>
+	<classpathentry kind="src" path="gen"/>
+	<classpathentry kind="con" path="com.android.ide.eclipse.adt.ANDROID_FRAMEWORK"/>
+	<classpathentry kind="output" path="bin"/>
+</classpath>

第16章 游戏开发中的物理学/Sample16_4/.project

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+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+	<name>Sample16_4</name>
+	<comment></comment>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>com.android.ide.eclipse.adt.ResourceManagerBuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+		<buildCommand>
+			<name>com.android.ide.eclipse.adt.PreCompilerBuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+		<buildCommand>
+			<name>org.eclipse.jdt.core.javabuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+		<buildCommand>
+			<name>com.android.ide.eclipse.adt.ApkBuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
+	<natures>
+		<nature>com.android.ide.eclipse.adt.AndroidNature</nature>
+		<nature>org.eclipse.jdt.core.javanature</nature>
+	</natures>
+</projectDescription>

第16章 游戏开发中的物理学/Sample16_4/.settings/org.eclipse.jdt.core.prefs

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+#Wed Jan 05 21:56:15 CST 2011
+eclipse.preferences.version=1
+org.eclipse.jdt.core.compiler.codegen.inlineJsrBytecode=enabled
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.6
+org.eclipse.jdt.core.compiler.codegen.unusedLocal=preserve
+org.eclipse.jdt.core.compiler.compliance=1.6
+org.eclipse.jdt.core.compiler.debug.lineNumber=generate
+org.eclipse.jdt.core.compiler.debug.localVariable=generate
+org.eclipse.jdt.core.compiler.debug.sourceFile=generate
+org.eclipse.jdt.core.compiler.problem.assertIdentifier=error
+org.eclipse.jdt.core.compiler.problem.enumIdentifier=error
+org.eclipse.jdt.core.compiler.source=1.6

第16章 游戏开发中的物理学/Sample16_4/AndroidManifest.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+      android:versionCode="1"
+      android:versionName="1.0" package="com.bn.Sample16_4">
+    <application android:icon="@drawable/icon" android:label="@string/app_name">
+        <activity android:name="com.bn.Sample16_4.Sample16_4Activity"
+                  android:label="@string/app_name">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+    </application>
+    <uses-sdk android:targetSdkVersion="8"></uses-sdk>
+</manifest> 

第16章 游戏开发中的物理学/Sample16_4/assets/frag_xk.sh

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+//焰火粒子着色器
+precision mediump float;
+uniform vec3 uColor;//粒子颜色
+void main()                         
+{
+  //给此片元颜色值 
+  gl_FragColor = vec4(uColor,1.0);
+}              

第16章 游戏开发中的物理学/Sample16_4/assets/vertex_xk.sh

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+//焰火粒子着色器
+uniform mat4 uMVPMatrix; //总变换矩阵
+uniform float uPointSize;//点尺寸
+attribute vec3 aPosition;  //顶点位置
+void main()     
+{     
+   //根据总变换矩阵计算此次绘制此顶点位置                         		
+   gl_Position = uMVPMatrix * vec4(aPosition,1); 
+   //设置粒子尺寸
+   gl_PointSize=uPointSize;
+}                 

第16章 游戏开发中的物理学/Sample16_4/default.properties

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+# This file is automatically generated by Android Tools.
+# Do not modify this file -- YOUR CHANGES WILL BE ERASED!
+# 
+# This file must be checked in Version Control Systems.
+# 
+# To customize properties used by the Ant build system use,
+# "build.properties", and override values to adapt the script to your
+# project structure.
+
+# Indicates whether an apk should be generated for each density.
+split.density=false
+# Project target.
+target=android-8

第16章 游戏开发中的物理学/Sample16_4/gen/com/bn/Sample16_4/R.java

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+/* AUTO-GENERATED FILE.  DO NOT MODIFY.
+ *
+ * This class was automatically generated by the
+ * aapt tool from the resource data it found.  It
+ * should not be modified by hand.
+ */
+
+package com.bn.Sample16_4;
+
+public final class R {
+    public static final class attr {
+    }
+    public static final class drawable {
+        public static final int fu=0x7f020000;
+        public static final int icon=0x7f020001;
+    }
+    public static final class string {
+        public static final int app_name=0x7f030000;
+    }
+}

第16章 游戏开发中的物理学/Sample16_4/res/values/strings.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <string name="app_name">Sample16_4</string>
+</resources>

第16章 游戏开发中的物理学/Sample16_4/src/com/bn/Sample16_4/GrainForDraw.java

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+package com.bn.Sample16_4;
+
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.nio.FloatBuffer;
+import android.opengl.GLES20;
+
+//用户绘制单个粒子的类
+public class GrainForDraw 
+{
+	private FloatBuffer   mVertexBuffer;//顶点坐标数据缓冲
+	private FloatBuffer   mColorBuffer;//顶点颜色数据缓冲
+    float scale;//星星尺寸
+    
+    String mVertexShader;//顶点着色器    	 
+    String mFragmentShader;//片元着色器
+    
+    int mProgram;//自定义渲染管线程序id 
+    int muMVPMatrixHandle;//总变换矩阵引用id
+    int maPositionHandle; //顶点位置属性引用id  
+    int uPointSizeHandle;//顶点尺寸参数引用
+    int uColorHandle;//顶点颜色参数引用
+    
+    public GrainForDraw(float scale,float red,float green,float blue,MySurfaceView mv)
+    {
+    	this.scale=scale;
+    	initVertexData(red,green,blue);
+    	initShader(mv);
+    }
+    
+    //初始化顶点坐标的方法
+    public void initVertexData(float red,float green,float blue)
+    {    	  	
+    	//顶点坐标数据的初始化   
+        float vertices[]={0,0,0};		
+        //创建顶点坐标数据缓冲
+        //vertices.length*4是因为一个Float四个字节
+        ByteBuffer vbb = ByteBuffer.allocateDirect(vertices.length*4);
+        vbb.order(ByteOrder.nativeOrder());//设置字节顺序
+        mVertexBuffer = vbb.asFloatBuffer();//转换为int型缓冲
+        mVertexBuffer.put(vertices);//向缓冲区中放入顶点坐标数据
+        mVertexBuffer.position(0);//设置缓冲区起始位置
+        
+        //顶点坐标数据的初始化
+        float colors[]={red,green,blue};		
+        //创建顶点坐标数据缓冲
+        ByteBuffer cbb = ByteBuffer.allocateDirect(colors.length*4);
+        cbb.order(ByteOrder.nativeOrder());//设置字节顺序
+        mColorBuffer = cbb.asFloatBuffer();//转换为int型缓冲
+        mColorBuffer.put(colors);//向缓冲区中放入顶点坐标数据
+        mColorBuffer.position(0);//设置缓冲区起始位置
+    }
+
+    //初始化shader
+    public void initShader(MySurfaceView mv)
+    {
+    	//加载顶点着色器的脚本内容       
+        mVertexShader=ShaderUtil.loadFromAssetsFile("vertex_xk.sh", mv.getResources());
+        //加载片元着色器的脚本内容
+        mFragmentShader=ShaderUtil.loadFromAssetsFile("frag_xk.sh", mv.getResources());  
+        //基于顶点着色器与片元着色器创建程序
+        mProgram = ShaderUtil.createProgram(mVertexShader, mFragmentShader);
+        //获取程序中顶点位置属性引用id  
+        maPositionHandle = GLES20.glGetAttribLocation(mProgram, "aPosition");        
+        //获取程序中总变换矩阵引用id
+        muMVPMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uMVPMatrix"); 
+        //获取顶点尺寸参数引用
+        uPointSizeHandle = GLES20.glGetUniformLocation(mProgram, "uPointSize"); 
+        //获取顶点颜色参数引用
+        uColorHandle = GLES20.glGetUniformLocation(mProgram, "uColor"); 
+    }
+    
+    public void drawSelf()
+    {  
+    	//指定使用某套shader程序
+   	    GLES20.glUseProgram(mProgram);
+        //将最终变换矩阵传入shader程序
+        GLES20.glUniformMatrix4fv(muMVPMatrixHandle, 1, false, MatrixState.getFinalMatrix(), 0);  
+        //将顶点尺寸传入Shader程序
+        GLES20.glUniform1f(uPointSizeHandle, scale);  
+        //将顶点颜色传入Shader程序
+        GLES20.glUniform3fv(uColorHandle, 1,mColorBuffer); 
+        //为画笔指定顶点位置数据    
+        GLES20.glVertexAttribPointer        
+        (
+        		maPositionHandle,   
+        		3, 
+        		GLES20.GL_FLOAT, 
+        		false,
+                3*4, 
+                mVertexBuffer   
+        );   
+        //允许顶点位置数据数组
+        GLES20.glEnableVertexAttribArray(maPositionHandle);         
+        //绘制星星点    
+        GLES20.glDrawArrays(GLES20.GL_POINTS, 0, 1); 
+    }
+}

第16章 游戏开发中的物理学/Sample16_4/src/com/bn/Sample16_4/GrainGroup.java

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+package com.bn.Sample16_4;
+import java.util.ArrayList;
+
+//代表粒子系统的类
+public class GrainGroup {
+	//用于绘制的粒子
+	static GrainForDraw gfd;     
+	//所有粒子的列表
+	ArrayList<SingleGrain> al=new ArrayList<SingleGrain>();
+ 	static final float SPEED_SPAN=(float) (1.5f+1.5f*Math.random());//粒子初速度
+	static final float SPEED=0.02f;//粒子移动每一步的模拟时延，也就是时间戳间隔
+	
+     public GrainGroup(MySurfaceView mv)
+     {
+    	//初始化用于绘制的六个不同颜色的粒子
+    	gfd=new GrainForDraw(4,1,1,1,mv);
+    	//随机添加粒子
+ 		for(int i=0;i<400;i++)
+ 		{
+ 			//随机产生粒子的方位角及仰角
+ 			double elevation=0.35f*Math.random()*Math.PI+Math.PI*0.15f;//仰角
+ 			double direction=Math.random()*Math.PI*2;//方位角
+ 			//计算出粒子在XYZ轴方向的速度分量
+ 			float vy=(float)(SPEED_SPAN*Math.sin(elevation));	
+ 			float vx=(float)(SPEED_SPAN*Math.cos(elevation)*Math.cos(direction));	
+ 			float vz=(float)(SPEED_SPAN*Math.cos(elevation)*Math.sin(direction));	
+ 			//创建粒子对像并添加进粒子列表
+ 			al.add(new SingleGrain(vx,vy,vz));
+ 		}
+     }
+     
+     long timeStamp=0;
+     public void drawSelf()
+     {
+    	 long currTimeStamp=System.nanoTime()/1000000;
+    	 if(currTimeStamp-timeStamp>10)
+    	 {
+    		 for(SingleGrain sp:al)
+        	 {//扫描粒子列表，并修改粒子时间戳
+        		sp.timeSpan=sp.timeSpan+SPEED;
+        		if(sp.timeSpan>10)  
+        		{
+        			sp.timeSpan=0;
+        		}
+        	 }
+    		 timeStamp=currTimeStamp;
+    	 }
+    	 
+		 int size=al.size();
+		 //循环扫描所有粒子的列表并绘制各个粒子
+		 for(int i=0;i<size;i++)
+    	 {
+			 try
+	    	 {
+    		   al.get(i).drawSelf();
+	    	 }
+			 catch(Exception e){}
+    	 } 
+     }
+}

第16章 游戏开发中的物理学/Sample16_4/src/com/bn/Sample16_4/MatrixState.java

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+package com.bn.Sample16_4;
+
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.nio.FloatBuffer;
+import java.util.*;
+import android.opengl.Matrix;
+
+//存储系统矩阵状态的类
+public class MatrixState 
+{
+	private static float[] mProjMatrix = new float[16];//4x4矩阵 投影用
+    private static float[] mVMatrix = new float[16];//摄像机位置朝向9参数矩阵   
+    private static float[] currMatrix;//当前变换矩阵   
+    public static FloatBuffer cameraFB;    
+    
+    public static Stack<float[]> mStack=new Stack<float[]>();//保护变换矩阵的栈
+    
+    public static void setInitStack()//获取不变换初始矩阵
+    {
+    	currMatrix=new float[16];
+    	Matrix.setRotateM(currMatrix, 0, 0, 1, 0, 0);
+    }
+    
+    public static void pushMatrix()//保护变换矩阵
+    {
+    	mStack.push(currMatrix.clone());
+    }
+    
+    public static void popMatrix()//恢复变换矩阵
+    {
+    	currMatrix=mStack.pop();
+    }
+    
+    public static void translate(float x,float y,float z)//设置沿xyz轴移动
+    {
+    	Matrix.translateM(currMatrix, 0, x, y, z);
+    }
+    
+    public static void rotate(float angle,float x,float y,float z)//设置绕xyz轴移动
+    {
+    	Matrix.rotateM(currMatrix,0,angle,x,y,z);
+    }
+    
+    
+    //设置摄像机
+    public static void setCamera
+    (
+    		float cx,	//摄像机位置x
+    		float cy,   //摄像机位置y
+    		float cz,   //摄像机位置z
+    		float tx,   //摄像机目标点x
+    		float ty,   //摄像机目标点y
+    		float tz,   //摄像机目标点z
+    		float upx,  //摄像机UP向量X分量
+    		float upy,  //摄像机UP向量Y分量
+    		float upz   //摄像机UP向量Z分量		
+    )
+    {
+    	Matrix.setLookAtM
+        (
+        		mVMatrix, 
+        		0, 
+        		cx,
+        		cy,
+        		cz,
+        		tx,
+        		ty,
+        		tz,
+        		upx,
+        		upy,
+        		upz
+        );
+    	
+    	float[] cameraLocation=new float[3];//摄像机位置
+    	cameraLocation[0]=cx;
+    	cameraLocation[1]=cy;
+    	cameraLocation[2]=cz;
+    	
+    	ByteBuffer llbb = ByteBuffer.allocateDirect(3*4);
+        llbb.order(ByteOrder.nativeOrder());//设置字节顺序
+        cameraFB=llbb.asFloatBuffer();
+        cameraFB.put(cameraLocation);
+        cameraFB.position(0);  
+    }
+    
+    //设置透视投影参数
+    public static void setProjectFrustum
+    (
+    	float left,		//near面的left
+    	float right,    //near面的right
+    	float bottom,   //near面的bottom
+    	float top,      //near面的top
+    	float near,		//near面距离
+    	float far       //far面距离
+    )
+    {
+    	Matrix.frustumM(mProjMatrix, 0, left, right, bottom, top, near, far);    	
+    }
+    
+    //设置正交投影参数
+    public static void setProjectOrtho
+    (
+    	float left,		//near面的left
+    	float right,    //near面的right
+    	float bottom,   //near面的bottom
+    	float top,      //near面的top
+    	float near,		//near面距离
+    	float far       //far面距离
+    )
+    {    	
+    	Matrix.orthoM(mProjMatrix, 0, left, right, bottom, top, near, far);
+    }   
+   
+    //获取具体物体的总变换矩阵
+    public static float[] getFinalMatrix()
+    {
+    	float[] mMVPMatrix=new float[16];
+    	Matrix.multiplyMM(mMVPMatrix, 0, mVMatrix, 0, currMatrix, 0);
+        Matrix.multiplyMM(mMVPMatrix, 0, mProjMatrix, 0, mMVPMatrix, 0);        
+        return mMVPMatrix;
+    }
+    
+    //获取具体物体的变换矩阵
+    public static float[] getMMatrix()
+    {       
+        return currMatrix;
+    }
+}

第16章 游戏开发中的物理学/Sample16_4/src/com/bn/Sample16_4/MySurfaceView.java

@@ -0,0 +1,66 @@
+package com.bn.Sample16_4;
+
+import android.opengl.GLSurfaceView;
+import android.opengl.GLES20;
+import android.util.Log;
+import javax.microedition.khronos.egl.EGLConfig;
+import javax.microedition.khronos.opengles.GL10;
+import android.content.Context;
+
+class MySurfaceView extends GLSurfaceView 
+{
+    private SceneRenderer mRenderer;//场景渲染器
+    long olds;
+	long currs;
+	
+	public MySurfaceView(Context context) {
+        super(context);
+        this.setEGLContextClientVersion(2); //设置使用OPENGL ES2.0
+        mRenderer = new SceneRenderer();	//创建场景渲染器
+        setRenderer(mRenderer);				//设置渲染器		        
+        setRenderMode(GLSurfaceView.RENDERMODE_CONTINUOUSLY);//设置渲染模式为主动渲染   
+    }
+
+	private class SceneRenderer implements GLSurfaceView.Renderer 
+    {
+		GrainGroup grainGroup;//焰火粒子系统
+        public void onDrawFrame(GL10 gl) 
+        { 
+        	currs=System.nanoTime();
+        	Log.d("FPS", (1000000000.0/(currs-olds)+"FPS"));
+			olds=currs;
+        	//清除深度缓冲与颜色缓冲
+            GLES20.glClear( GLES20.GL_DEPTH_BUFFER_BIT | GLES20.GL_COLOR_BUFFER_BIT);
+            //保护现场
+            MatrixState.pushMatrix();
+            MatrixState.translate(0, -2, 0);
+            grainGroup.drawSelf();
+            //恢复现场
+            MatrixState.popMatrix();
+        }  
+
+        public void onSurfaceChanged(GL10 gl, int width, int height) {
+            //设置视窗大小及位置 
+        	GLES20.glViewport(0, 0, width, height); 
+        	//计算GLSurfaceView的宽高比
+            float ratio = (float) width / height;
+            //调用此方法计算产生透视投影矩阵
+            MatrixState.setProjectFrustum(-ratio, ratio, -1, 1, 1, 100);
+            //调用此方法产生摄像机9参数位置矩阵
+            MatrixState.setCamera(0,2,7,0,0,0,0f,1.0f,0.0f);
+        }
+        
+        public void onSurfaceCreated(GL10 gl, EGLConfig config) {
+            //设置屏幕背景色RGBA
+            GLES20.glClearColor(0.0f,0.0f,0.0f,1.0f);
+            //创建焰火粒子系统
+            grainGroup=new GrainGroup(MySurfaceView.this);
+            //打开深度检测
+            GLES20.glEnable(GLES20.GL_DEPTH_TEST);
+            //关闭背面剪裁   
+            GLES20.glEnable(GLES20.GL_CULL_FACE);
+            //初始化变换矩阵
+            MatrixState.setInitStack();
+        }
+    }
+}

第16章 游戏开发中的物理学/Sample16_4/src/com/bn/Sample16_4/Sample16_4Activity.java

@@ -0,0 +1,40 @@
+package com.bn.Sample16_4;
+import android.app.Activity;
+import android.content.pm.ActivityInfo;
+import android.os.Bundle;
+import android.view.Window;
+import android.view.WindowManager;
+
+public class Sample16_4Activity extends Activity {
+	private MySurfaceView mGLSurfaceView;
+    @Override
+    protected void onCreate(Bundle savedInstanceState) 
+    {
+        super.onCreate(savedInstanceState);         
+        //设置为全屏
+        requestWindowFeature(Window.FEATURE_NO_TITLE); 
+		getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN ,  
+		              WindowManager.LayoutParams.FLAG_FULLSCREEN);
+		//设置为竖屏模式
+		setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
+		//切换到主界面
+			
+		//初始化GLSurfaceView
+        mGLSurfaceView = new MySurfaceView(this);
+        setContentView(mGLSurfaceView);	
+        mGLSurfaceView.requestFocus();//获取焦点
+        mGLSurfaceView.setFocusableInTouchMode(true);//设置为可触控  
+    }
+
+    @Override
+    protected void onResume() {
+        super.onResume();
+        mGLSurfaceView.onResume();
+    }
+
+    @Override
+    protected void onPause() {
+        super.onPause();
+        mGLSurfaceView.onPause();
+    }    
+}

第16章 游戏开发中的物理学/Sample16_4/src/com/bn/Sample16_4/ShaderUtil.java

@@ -0,0 +1,126 @@
+package com.bn.Sample16_4;
+
+import java.io.ByteArrayOutputStream;
+import java.io.InputStream;
+
+import android.content.res.Resources;
+import android.opengl.GLES20;
+import android.util.Log;
+
+//加载顶点Shader与片元Shader的工具类
+public class ShaderUtil 
+{
+   //加载制定shader的方法
+   public static int loadShader
+   (
+		 int shaderType, //shader的类型  GLES20.GL_VERTEX_SHADER   GLES20.GL_FRAGMENT_SHADER
+		 String source   //shader的脚本字符串
+   ) 
+   {
+	    //创建一个新shader
+        int shader = GLES20.glCreateShader(shaderType);
+        //若创建成功则加载shader
+        if (shader != 0) 
+        {
+        	//加载shader的源代码
+            GLES20.glShaderSource(shader, source);
+            //编译shader
+            GLES20.glCompileShader(shader);
+            //存放编译成功shader数量的数组
+            int[] compiled = new int[1];
+            //获取Shader的编译情况
+            GLES20.glGetShaderiv(shader, GLES20.GL_COMPILE_STATUS, compiled, 0);
+            if (compiled[0] == 0) 
+            {//若编译失败则显示错误日志并删除此shader
+                Log.e("ES20_ERROR", "Could not compile shader " + shaderType + ":");
+                Log.e("ES20_ERROR", GLES20.glGetShaderInfoLog(shader));
+                GLES20.glDeleteShader(shader);
+                shader = 0;      
+            }  
+        }
+        return shader;
+    }
+    
+   //创建shader程序的方法
+   public static int createProgram(String vertexSource, String fragmentSource) 
+   {
+	    //加载顶点着色器
+        int vertexShader = loadShader(GLES20.GL_VERTEX_SHADER, vertexSource);
+        if (vertexShader == 0) 
+        {
+            return 0;
+        }
+        
+        //加载片元着色器
+        int pixelShader = loadShader(GLES20.GL_FRAGMENT_SHADER, fragmentSource);
+        if (pixelShader == 0) 
+        {
+            return 0;
+        }
+
+        //创建程序
+        int program = GLES20.glCreateProgram();
+        //若程序创建成功则向程序中加入顶点着色器与片元着色器
+        if (program != 0) 
+        {
+        	//向程序中加入顶点着色器
+            GLES20.glAttachShader(program, vertexShader);
+            checkGlError("glAttachShader");
+            //向程序中加入片元着色器
+            GLES20.glAttachShader(program, pixelShader);
+            checkGlError("glAttachShader");
+            //链接程序
+            GLES20.glLinkProgram(program);
+            //存放链接成功program数量的数组
+            int[] linkStatus = new int[1];
+            //获取program的链接情况
+            GLES20.glGetProgramiv(program, GLES20.GL_LINK_STATUS, linkStatus, 0);
+            //若链接失败则报错并删除程序
+            if (linkStatus[0] != GLES20.GL_TRUE) 
+            {
+                Log.e("ES20_ERROR", "Could not link program: ");
+                Log.e("ES20_ERROR", GLES20.glGetProgramInfoLog(program));
+                GLES20.glDeleteProgram(program);
+                program = 0;
+            }
+        }
+        return program;
+    }
+    
+   //检查每一步操作是否有错误的方法 
+   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 " + error);
+        }
+   }
+   
+   //从sh脚本中加载shader内容的方法
+   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;
+   }
+}

第16章 游戏开发中的物理学/Sample16_4/src/com/bn/Sample16_4/SingleGrain.java

@@ -0,0 +1,28 @@
+package com.bn.Sample16_4;
+//存储粒子系统中的某个粒子物理信息的类
+public class SingleGrain {
+	float vx;//x轴速度分量
+	float vy;//y轴速度分量
+	float vz;//z轴速度分量
+	float timeSpan=0;//累计时间
+	
+	public SingleGrain(float vx,float vy,float vz)
+	{
+		this.vx=vx;
+		this.vy=vy;
+		this.vz=vz;		
+	}
+	
+	public void drawSelf()
+	{
+		MatrixState.pushMatrix();	
+		//根据当前时间戳计算出粒子位置
+		float x=vx*timeSpan;
+		float z=vz*timeSpan;
+		float y=vy*timeSpan-0.5f*timeSpan*timeSpan*1.5f+3.0f;		
+		MatrixState.translate(x, y, z);
+		//绘制粒子
+		GrainGroup.gfd.drawSelf();
+		MatrixState.popMatrix();
+	}
+}