HTML5 game development-Box2dWeb application (1)-Create various rigid bodies

At the beginning of this article, we will introduce the new functions of lufylegend-1.4.0, how to create a physical world and various rigid bodies in this physical world with box2dweb

Preparation

First you need to download the html5 open source library lufylegend-1.4.0

http://blog.csdn.net/lufy_legend/article/details /7644932

box2dweb You can download it here

http://code.google.com/p/box2dweb/downloads/list

Prepare three pictures,

are used to create circular, rectangular and triangular rigid bodies respectively.

Ready to finish, now start production.
The following is to use the LLoadManage class in lufylegend.js to read the image

init(10,"mylegend",800,400,main);
var backLayer,cLayer,wallLayer,bitmap,loadingLayer;
var imglist = {};
var imgData = new Array(
		{name:"bird1",path:"./images/bird1.png"},
		{name:"bird2",path:"./images/bird2.png"},
		{name:"stage01",path:"./images/stage01.png"}
		);
function main(){	
	LGlobal.setDebug(true);	
	backLayer = new LSprite();	
	addChild(backLayer);	
	
	
	loadingLayer = new LoadingSample3();
	backLayer.addChild(loadingLayer);	
	LLoadManage.load(
		imgData,
		function(progress){
			loadingLayer.setProgress(progress);
		},
		function(result){
			imglist = result;
			backLayer.removeChild(loadingLayer);
			loadingLayer = null;
			gameInit();
		}
	);
}

LGlobal.setDebug(true); is to turn on the debug mode, so that when creating a rigid body, all box2dweb will be The created debug rigid body is also displayed together. When releasing the finished product, the debug mode should be turned off.

The LLoadManage class has three parameters, $list, $onupdate, $oncomplete,

$list is the image array to be read, $onupdate is the function that needs to be called during reading, $oncomplete It is the function called when the reading is completed.

The LoadingSample3 class is the progress bar display function in the lufylegend.js library. In addition to the LoadingSample3 class, there are also the LoadingSample1 class and the LoadingSample2 class.

is created Before creating the rigid body, first create four walls, up, down, left and right, to control the movement range of the rigid body to be created later.

wallLayer = new LSprite();
	wallLayer.x = 400;
	wallLayer.y = 0;
	backLayer.addChild(wallLayer);
	wallLayer.addBodyPolygon(800,10,0);
	wallLayer = new LSprite();
	wallLayer.x = 0;
	wallLayer.y = 200;
	backLayer.addChild(wallLayer);
	wallLayer.addBodyPolygon(10,400,0);
	wallLayer = new LSprite();
	wallLayer.x = 400;
	wallLayer.y = 400;
	backLayer.addChild(wallLayer);
	wallLayer.addBodyPolygon(800,10,0);
	wallLayer = new LSprite();
	wallLayer.x = 800;
	wallLayer.y = 200;
	backLayer.addChild(wallLayer);
	wallLayer.addBodyPolygon(10,400,0);

For children who don’t know how to use LSprite, please read my previous articles. I won’t be too wordy here.

addBodyPolygon(w,h,type,density,friction,restitution) is to add a rectangular body to LSprite, the parameters are, (width, height, static or dynamic, density, friction, elasticity)

If the third parameter sets the body to be static, the following parameters can be omitted. Here, the four walls are set to static.

Then, add a mouse click event to backLayer, and prepare to add a rigid body when the mouse clicks.

##

backLayer.addEventListener(LMouseEvent.MOUSE_UP,add);

Add a rigid body in the add method, first The simplest one is to add a circular rigid body. The code for adding a circular rigid body is as follows

	cLayer = new LSprite();
	cLayer.x = 50 + Math.random()*700;
	cLayer.y = 50;
	backLayer.addChild(cLayer);
	bitmap = new LBitmap(new LBitmapData(imglist["bird1"]));
	cLayer.addChild(bitmap);
	cLayer.addBodyCircle(bitmap.getWidth()*0.5,bitmap.getHeight()*0.5,bitmap.getWidth()*0.5,1,.5,.4,.5);

addBodyCircle(radius,cx,cy,type,density,friction,restitution) is to add a circular body to LSprite , the parameters are, (radius, circle center coordinates x, y, static or dynamic, density, friction, elasticity)

Okay, after running the code, keep clicking the mouse to get the following results

Test URL

http://lufy.netne.net/lufylegend-js/lufylegend-1.4/box2d/sample01/index.html

Next, modify the add method. In addition to adding a circular rigid body, there is a certain probability of adding a rectangular rigid body. The following

	var rand = Math.random();
	if(rand < 0.5){
		cLayer = new LSprite();
		cLayer.x = 50 + Math.random()*700;
		cLayer.y = 50;
		backLayer.addChild(cLayer);
		bitmap = new LBitmap(new LBitmapData(imglist["bird1"]));
		cLayer.addChild(bitmap);
		cLayer.addBodyCircle(bitmap.getWidth()*0.5,bitmap.getHeight()*0.5,bitmap.getWidth()*0.5,1,.5,.4,.5);
	}else{
		cLayer = new LSprite();
		cLayer.x = 50 + Math.random()*700;
		cLayer.y = 50;
		backLayer.addChild(cLayer);
		bitmap = new LBitmap(new LBitmapData(imglist["stage01"]));
		cLayer.addChild(bitmap);
		cLayer.addBodyPolygon(bitmap.getWidth(),bitmap.getHeight(),1,5,.4,.2);
	}

addBodyPolygon method has been introduced above, adding a rectangular rigid body to LSprite.

After running the code, keep clicking the mouse to get the following results

Test URL

http://lufy.netne.net/lufylegend -js/lufylegend-1.4/box2d/sample01/index2.html

Finally, add a triangular rigid body. The starting point can be any polygonal rigid body. The addBodyVertices method of LSprite is used,

addBodyVertices(vertices,cx,cy,type,density,friction,restitution) is to add any polygonal rigid body based on the vertex array. The parameters are (vertex array, center coordinates, static or dynamic, density, friction, elasticity)

It should be mentioned that there is a small bug in this method, which changes the coordinates of LSprite to (0,0), so you need to use the SetPosition method to re-set the coordinates of LSprite. This bug will be fixed next time in lufylegend.js It will be solved when it is updated. The code for adding the triangular rigid body this time is as follows

cLayer = new LSprite();
backLayer.addChild(cLayer);
bitmap = new LBitmap(new LBitmapData(imglist["bird2"]));
cLayer.addChild(bitmap);
var shapeArray = [
[[0,54],[27,0],[54,54]]
];
cLayer.addBodyVertices(shapeArray,27,27,1,.5,.4,.5);
cLayer.box2dBody.SetPosition(new LGlobal.box2d.b2Vec2((50 + Math.random()*700)/LGlobal.box2d.drawScale,50/LGlobal.box2d.drawScale));

After running the code, keep clicking the mouse to get the following results

Test URL

http://lufy.netne.net/lufylegend-js/lufylegend-1.4/box2d/sample01/index3.html

This article is over, the final code is presented, please look forward to the next tutorial

 
 


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