import com.actionsnippet.qbox.*;

[SWF (backgroundColor=0xAA0000, width=700, height=600, frameRate=60)]

var sim:QuickBox2D = new QuickBox2D(this);

sim.createStageWalls();

/**
create a dancing pill
*/
// all x and y coords are relative to the center of the group
var partA:QuickObject = sim.addCircle({x:-1, y:0, radius:0.5, restitution:.9});
var partB:QuickObject = sim.addCircle({x:1, y:0, radius:0.5, restitution:.9});
var partC:QuickObject = sim.addBox({x:0, y:0, width:2, height:1});
// all the parts are passed into the objects array
// addGroup() groups the parts together into one rigid body
var pill:QuickObject = sim.addGroup({objects:[partA, partB, partC], x:3, y:3, angle:0.3});

/**
create another group
*/
partA = sim.addCircle({x:0, y:0, radius:1});
partB = sim.addBox({x:0, y:1, width:1, height:1, fillColor:0x666666});
partC = sim.addBox({x:0, y:-1, width:1, height:1, fillColor:0x666666});
sim.addGroup({objects:[partA, partB, partC], x:8, y:3, angle:0.3});

/**
create two circles linked together by a stretchy joint
*/
partA = sim.addCircle({x:15, y:3, fillColor:0x000000, anglularDamping:1});
partB = sim.addCircle({x:17, y:3, fillColor:0xFFFFFF, anglularDamping:1});
// if x1, y1, x2 and y2 properties are not set, the joint is automatically placed
// at the b2Body's center
sim.addJoint({a:partA.body, b:partB.body, frequencyHz:1});

sim.start();
sim.mouseDrag();

You’ll need QuickBox2D Alpha 106 to run this… This snippet demo’s the addGroup() method, which allows for easy grouping of shapes. I updated the docs today to feature a simple explanation of how this works.

Have a look at the swf here…

import com.actionsnippet.qbox.*;
import Box2D.Common.Math.*;

[SWF (backgroundColor=0xaa0000, width=700, height=600)]

const TWO_PI:Number = Math.PI * 2;

var sim:QuickBox2D = new QuickBox2D(this,{gravityY:20, debug:false});

var i:int = 0;

// add some circles
var circles:Array = [];
var circleNum:int = 20;
for (i = 0; i<circleNum; i++){
	circles[i] = sim.addCircle({x: 8, y:-2 - i, radius:0.1 + Math.random()*0.4, fillColor:0x000000});
}

// add some boxes
var boxes:Array = [];
var boxNum:int = 20;
for (i= 0; i<boxNum; i++){
	var rx:Number = 4 + (i % 5) * 4;
	var ry:Number =  4 + int(i / 5) * 4;
	var ra:Number = Math.random() * TWO_PI;
	boxes[i] = sim.addBox({x:rx, y:ry, width:3, height:0.4, angle:ra, density:0,fillColor:0xFF2200});
}

// vector(0,0) used to reset velocity
var resetVec:b2Vec2 = new b2Vec2();

sim.start();
sim.mouseDrag();

addEventListener(Event.ENTER_FRAME, onLoop);
function onLoop(evt:Event):void {
	 // rotate all boxes
     for (i= 0; i<boxNum; i++){
		boxes[i].angle += .05; 
	 }
	 // move circles to top of sceen after they fall off bottom
	  for (i= 0; i<circleNum; i++){
		if (circles[i].y > 20){
			circles[i].y = -1;
			circles[i].x = Math.random()*(stage.stageWidth / 30 - 9) + 4;
			// access to Box2D b2Body methods
			circles[i].body.SetLinearVelocity(resetVec);
		}
	 }
}

This is another QuickBox2D experiment. If you don’t know what QuickBox2D is … read about it here.

Take a look at the swf here