剖析J2ME 3D编程的第一个3D程序(1)(2)

J2ME 3D编程的第一个3D程序源代码如下： 

//First3DMIDlet.java  
 
packagefirst3d;  
 
importjavax.microedition.midlet.*;  
 
importjavax.microedition.lcdui.*;  
 
publicclassFirst3DMIDletextendsMIDlet{  
 
privateFirst3DCanvasdisplayable=newFirst3DCanvas();  
 
 
publicvoidstartApp(){  
 
Display.getDisplay(this).setCurrent(displayable);  
 
}  
 
publicvoidpauseApp(){}  
 
publicvoiddestroyApp(booleanunconditional){}  
 
}  
 
//First3Dcanvas.java  
 
packagefirst3d;  
 
importjavax.microedition.lcdui.*;  
 
importjavax.microedition.m3g.*;  
 
importjava.util.*;  
 
/**  
 
*第一个3D程序  
 
*/  
 
publicclassFirst3DCanvas  
 
extendsCanvas  
 
implementsRunnable{  
 
/**World对象*/  
 
privateWorldmyWorld=null;  
 
/**Graphics3D对象*/  
 
privateGraphics3Dg3d=Graphics3D.getInstance();  
 
/**Camera对象*/  
 
privateCameracam=null;  
 
privateintviewport_x;  
 
privateintviewport_y;  
 
privateintviewport_width;  
 
privateintviewport_height;  
 
privatelongworldStartTime=0;  
 
//重绘时间  
 
privateintvalidity=0;  
 
publicFirst3DCanvas(){  
 
//启动重绘界面的线程  
 
Threadthread=newThread(this);  
 
thread.start();  
 
try{  
 
//导入3D图片  
 
myWorld=(World)Loader.load("/swerve.m3g")[0];  
 
viewport_x=0;  
 
viewport_y=0;  
 
viewport_width=getWidth();  
 
viewport_height=getHeight();  
 
cam=myWorld.getActiveCamera();  
 
//设置cam对象  
 
float[]params=newfloat[4];  
 
inttype=cam.getProjection(params);  
 
if(type!=Camera.GENERIC){  
 
//calculatewindowaspectratio  
 
floatwaspect=viewport_width/viewport_height;  
 
if(waspect<params[1]){  
 
floatheight=viewport_width/params[1];  
 
viewport_height=(int)height;  
 
viewport_y=(getHeight()-viewport_height)/2;  
 
}  
 
else{  
 
floatwidth=viewport_height*params[1];  
 
viewport_width=(int)width;  
 
viewport_x=(getWidth()-viewport_width)/2;  
 
}  
 
}  
 
worldStartTime=System.currentTimeMillis();  
 
}  
 
catch(Exceptione){}  
 
}  
 
protectedvoidpaint(Graphicsg){  
 
//清除背景  
 
g.setColor(0x00);  
 
g.fillRect(0,0,getWidth(),getHeight());  
 
//和3D对象绑定  
 
g3d.bindTarget(g);  
 
g3d.setViewport(viewport_x,viewport_y,
viewport_width,viewport_height);  
 
longstartTime=System.currentTimeMillis()-worldStartTime;  
 
validity=myWorld.animate((int)startTime);  
 
try{  
 
g3d.render(myWorld);  
 
}  
 
finally{  
 
g3d.releaseTarget();  
 
}  
}  
 
publicvoidrun(){  
 
try{  
 
while(true){  
 
//重绘图形  
 
repaint(viewport_x,viewport_y,
viewport_width,viewport_height);  
}  
 
}catch(Exceptione){}  
}  
}