Flash AS3 realizes simple sphere physical simulation

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Package { Import Flash.display.Sprite; Import flash.events.Event; Import Flash.geom.Point; Import Net.hires.debug.Stats; /** * ... * @author Lizhi */ [SWF (width = 465, height = 465, BackgroundColor = 0xffffff, framerate = 100)] public class Main extends Sprite { private var g:point = new Point (0,0.01); private var b:number = 0.5; private var cf:number = 0.02; private Var W:number; private Var H:number; private Var Sb:ball; private var max:number = 40; private Var Numcols:int; private Var Grid:array; Public Function Main (): void { W = stage.stagewidth; h = stage.stageheight; Numcols = Math.ceil (H/max); var c:int = 150; var B:ball; while (c-->0) { var ball:ball = new ball (); if (SB) { B.next = ball; b = ball; }else { SB = b = Ball; } ball.x = w * math.random (); BALL.Y = h * math.random (); BALL.R = 1 + * Math.random (); } SB.R = 20; AddEventListener (event.enter_frame, update); AddChild (New Stats ()); } Private Function Update (e:event): void { Grid = []; var b1:ball = sb; sb.x = MouseX; SB.Y = Mousey; while (B1) { var x:int = (b1.x + 0.5)/MAX; var y:int = (b1.y + 0.5)/MAX; var v:int = y * numcols + x; if (grid[v]==null) { GRID[V] = []; } Grid[v].push (B1); b1.c = 0; B1 = B1.next; } for (var k:int = grid.length-1 k >= 0;k--) { var balls:array = grid[k]; if (balls) { var arr2:array = grid[k-1]; if (ARR2) { Balls = Balls.concat (ARR2); } ARR2 = Grid[k-numcols]; if (ARR2) { Balls = Balls.concat (ARR2); } ARR2 = grid[k-numcols-1]; if (ARR2) { Balls = Balls.concat (ARR2); } ARR2 = Grid[k-numcols + 1]; if (ARR2) { Balls = Balls.concat (ARR2); } for (var i:int = 0; i < balls.length; i++) { B1 = Balls[i]; B1.fy + = G.y; if (B1.X-B1.R < 0) b1.fx + b; if (b1.x + B1.R > W) b1.fx-= b; if (B1.Y-B1.R < 0) B1.fy + b; if (B1.y + b1.r > H) b1.fy-= b; for (var j:int = i + 1; j < Balls.length; + +) { var b2:ball = balls[j]; var dx:number = b1.x-b2.x; var dy:number = b1.y-b2.y; var d:number = b1.r + b2.r; if (DX * dx + dy * Dy < d * d) { B1.FX + + dx *CF; B1.fy + dy *cf; B2.FX-= DX *CF; B2.fy-= dy * CF; b1.c = 0xff0000; b2.c = 0xff0000; } } } } } Graphics.clear (); B1 = sb; while (B1) { B1.VX + = b1.fx; B1.vy + = B1.fy; B1.VX *= 0.95; B1.vy *= 0.95; b1.x + = B1.VX; B1.y + = B1.vy; b1.fx = 0; B1.fy = 0; Graphics.linestyle (0,b1.c); Graphics.drawcircle (b1.x, B1.y, B1.R); B1 = B1.next; } } } } Class Ball { public Var Next:ball; public var c:uint = 0; public var x:number = 0; public var y:number = 0; public var r:number = 10; public var vx:number = 0; public var vy:number = 0; public var fx:number = 0; public var fy:number = 0; }