boid(精子風味)

by satoru.net 08 Sep 2010

Tags

ai bactomons enemy flock formation
Embed

/**
 * Copyright satoru.net ( http://wonderfl.net/user/satoru.net )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/o7MG
 */

package {
	
import com.bit101.components.*;
import flash.display.*;
import flash.events.*;
import flash.utils.*;
import flash.geom.*;
[SWF(width="500", height="500", frameRate="100")]

public class main extends Sprite{
	var NUM_BOIDS:int = 30;
	var DIST_THRESHOLD1:int = 10;
	var DIST_THRESHOLD2:int = 20;
	var DIST_THRESHOLD3:int = 30;
	var FACTOR_COHESION = 100;
	var FACTOR_SEPARATION = 10;
	var FACTOR_ALINGMENT = 10;
	var VELOCITY_LIMIT = 3;
	var TRAIL_SCALE = 2;
	var prePosLength = 10;
	var flock:Array;
	var sh = new Sprite();
	var bmp = new Bitmap(new BitmapData(500,500,true,0x000000));
	var black = new BitmapData(500, 500, false, 0x000000);
	var gr = sh.graphics;

	function main() {
		addChild(sh);
		addChild(bmp);
		init();
		addEventListener(Event.ENTER_FRAME, interval);
		stage.addEventListener(MouseEvent.MOUSE_DOWN, doReset);
	}

	function init(){
		flock = new Array();
		for(var n=0;n<NUM_BOIDS;n++){
			var b = Boid();
			flock.push(b);
		}	
	}

	function setValue(key,val){
		for(var i in flock){
			flock[i][key] = val;
		}
	}

	function doReset(e:*){
		for(var i in flock){
			flock[i].remove();
			flock[i] = null;
		}	
		init();
	}

	function interval(e:*) {
		bmp.bitmapData.draw(black);
		for(var i in flock){
			flock[i].update();
		}
	}

	function getRandom(low,high){
		return low+Math.floor(Math.random()*((high-low)));
	}

	function Boid(){
	    var r1 = 1.0 //cohesion.value; // Cohesion:   pull to center of flock
	    var r2 = 0.8 //separation.value; // Separation: avoid bunching up
	    var r3 = 0.1 //alingment.value; // Alingment:  match average flock speed
		
		var o = {
			"shape":new Shape(),
			"v1":Vector(),
			"v2":Vector(),
			"v3":Vector(),
			"r1":r1,
			"r2":r2,
			"r3":r3,
			"vx":getRandom(-5, 5),
			"vy":getRandom(-5, 5),
			"xpos":getRandom(0,stage.stageWidth),
			"ypos":getRandom(0,stage.stageHeight),
			"prePos":new Array()
		};
		
		init();
		
		function init(){
			//o.gr = sh.graphics;
			o.gr = o.shape.graphics;
			return o;
		}
		
		o.remove = function(){
			o = null;
			return;
		}
		
		o.update = function(){
			updatePosition(); 
			savePosition();
			drawPoint();
		 }  
			
		function savePosition(){
			o.prePos.unshift({x:o.xpos,y:o.ypos});

			if(o.prePos.length >prePosLength){
				o.prePos.length = prePosLength;
			}
		}
		
	  function drawPoint(){
		o.gr.clear();
		o.gr.lineStyle(4,0xFFFFFF);	  

		o.gr.moveTo(o.xpos, o.ypos);
		o.gr.lineTo(o.xpos-TRAIL_SCALE*o.vx, o.ypos-TRAIL_SCALE*o.vy);

		for(var i in o.prePos){	
			var X = o.prePos[i].x;
			var Y = o.prePos[i].y;
			
			o.gr.lineStyle(1,0xFF00000);	
			o.gr.moveTo(X, Y);
			o.gr.lineTo(X-TRAIL_SCALE*o.vx, Y-TRAIL_SCALE*o.vy);
		}	
		
		bmp.bitmapData.draw(o.shape);
	  }	

	  function limitVelocity(){
	   var velocity = Math.sqrt(Math.pow(o.vx,2) + Math.pow(o.vy,2));
		if(velocity > VELOCITY_LIMIT){
		  o.vx = (o.vx/velocity)*VELOCITY_LIMIT;
		  o.vy = (o.vy/velocity)*VELOCITY_LIMIT;
		}
	  }
	  
	  function updatePosition(){
		if(o.isStop){
			return;
		}
		  
		o.v1.x = o.v1.y = o.v2.x = o.v2.y = o.v3.x = o.v3.y = 0;
		rule1();
		rule2();	
		rule3();
		
		// add vectors to velocities
		o.vx += o.r1*o.v1.x + o.r2*o.v2.x + o.r3*o.v3.x;
		o.vy += o.r1*o.v1.y + o.r2*o.v2.y + o.r3*o.v3.y;
		
		limitVelocity();
		
		o.xpos += o.vx;
		o.ypos += o.vy;
		
		if(o.xpos < 0){
		  o.xpos = stage.stageWidth;
		} else if(o.xpos > stage.stageWidth){
		  o.xpos = 0;
		}
		if(o.ypos < 0){
		  o.ypos = stage.stageHeight;
		} else if(o.ypos > stage.stageHeight){
		  o.ypos = 0;
		}
	  }  

	  // Cohesion
	  function rule1(){
		var count = 0;
		
		for(var i in flock){
		  if(o !== flock[i]){
			var len = Point.distance(new Point(o.xpos, o.ypos), new Point(flock[i].xpos, flock[i].ypos));
			if(len > DIST_THRESHOLD2 && len < DIST_THRESHOLD3){
			  o.v1.x += flock[i].xpos;
			  o.v1.y += flock[i].ypos;
			  count++;
			}
		  }
		}
		
		if(count > 0){
		  o.v1.x /= count;
		  o.v1.y /= count;
		  o.v1.x = (o.v1.x - o.xpos) / FACTOR_COHESION;
		  o.v1.y = (o.v1.y - o.ypos) / FACTOR_COHESION;
		}
	  }

	   function rule2(){
		for(var i in flock){
		  if(o !== flock[i]){
			var len = Point.distance(new Point(o.xpos, o.ypos), new Point(flock[i].xpos, flock[i].ypos));
			if(len < DIST_THRESHOLD1){
			  o.v2.x -= (flock[i].xpos - o.xpos)/FACTOR_SEPARATION;
			  o.v2.y -= (flock[i].ypos - o.ypos)/FACTOR_SEPARATION;
			}
		  }
		}
	  } 

	  // Alingment()
	  function rule3(){
		var count = 0;
		for(var i in flock){
		  if(o !== flock[i]){
			var len = Point.distance(new Point(o.xpos, o.ypos), new Point(flock[i].xpos, flock[i].ypos));
			if(len > DIST_THRESHOLD1 && len < DIST_THRESHOLD2){
			  o.v3.x += flock[i].vx;
			  o.v3.y += flock[i].vy;
			  count++;
			}
		  }
		}
		if(count > 0){
		  o.v3.x /= count;
		  o.v3.y /= count;
		  o.v3.x = (o.v3.x - o.vx)/FACTOR_ALINGMENT;
		  o.v3.y = (o.v3.y - o.vy)/FACTOR_ALINGMENT;
		}
	  }  
	  return o;  
	}

	function Vector(){
		return {x:0,y:0};
	}

}
}