Force Field with Bresenham's line
/**
* Copyright Saqoosha ( http://wonderfl.net/user/Saqoosha )
* MIT License ( http://www.opensource.org/licenses/mit-license.php )
* Downloaded from: http://wonderfl.net/c/2gff
*/
// forked from Saqoosha's Force Field
package {
import __AS3__.vec.Vector;
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.display.BlendMode;
import flash.display.PixelSnapping;
import flash.display.Sprite;
import flash.display.StageQuality;
import flash.events.Event;
import flash.events.TimerEvent;
import flash.filters.BlurFilter;
import flash.filters.ColorMatrixFilter;
import flash.geom.ColorTransform;
import flash.geom.Matrix;
import flash.geom.Point;
import flash.utils.Timer;
import flash.utils.getTimer;
import frocessing.color.ColorHSV;
import net.hires.debug.Stats;
[SWF(backgroundColor=0x0, frameRate=60)]
public class ForceField2 extends Sprite {
private static const ZERO_POINT:Point = new Point();
private static const MAP_SCALE:Number = 0.25;
private static const TRAIL_SCALE:Number = 2;
private static const DRAW_SCALE:Number = 0.5;
private var _timer:Timer;
private var _seed:Number = new Date().getTime();
private var _offsets:Array = [new Point(), new Point()];
private var _forcemap:BitmapData;
private var _count:int = 0;
private var _particles:Vector.<Particle>;
// private var _canvas:Shape;
private var _canvas:BitmapData;
private var _fade:BitmapData;
private var _darken:ColorMatrixFilter = new ColorMatrixFilter([
1, 0, 0, 0, -2,
0, 1, 0, 0, -2,
0, 0, 1, 0, -2,
0, 0, 0, 1, 0
]);
private var _blur:BlurFilter = new BlurFilter(2, 2, 1);
private var _drawMatrix:Matrix = new Matrix(DRAW_SCALE, 0, 0, DRAW_SCALE, 0, 0);
private var _drawColor:ColorTransform = new ColorTransform(0.1, 0.1, 0.1);
public function ForceField2() {
this.stage.quality = StageQuality.LOW
this._timer = new Timer(500, 0);
this._timer.addEventListener(TimerEvent.TIMER, this._onTimer);
this._timer.start();
this._forcemap = new BitmapData(475 * MAP_SCALE, 475 * MAP_SCALE, false, 0x0);
this._particles = new Vector.<Particle>();
this._fade = new BitmapData(475 * DRAW_SCALE, 475 * DRAW_SCALE, false, 0x0);
var bm:Bitmap = this.addChild(new Bitmap(this._fade, PixelSnapping.AUTO, true)) as Bitmap;
bm.scaleX = bm.scaleY = 1 / DRAW_SCALE;
this._canvas = new BitmapData(475, 475, true, 0x0);
var b:Bitmap = this.addChild(new Bitmap(this._canvas)) as Bitmap;
b.blendMode = BlendMode.ADD;
this.addEventListener(Event.ENTER_FRAME, this._onEnterFrame);
this.stage.addChild(new Stats());
}
private function _onTimer(e:TimerEvent = null):void {
var t:int = getTimer();
this._offsets[0].x = t / 20;
this._offsets[1].y = t / 35;
this._forcemap.perlinNoise(150, 150, 2, this._seed, true, true, 3, false, this._offsets);
}
private var color:ColorHSV = new ColorHSV(0, 0.5);
private function _onEnterFrame(e:Event):void {
var n:int = 10;
while (n--) {
var a:Number = getTimer() / 1000 + Math.random() * Math.PI;
color.h = (getTimer() / 20000) * 360;
var p:Particle = new Particle(237, 237, Math.cos(a), Math.sin(a), color.value);
this._particles.push(p);
}
// var g:Graphics = this._canvas.graphics;
// g.clear();
this._canvas.lock();
this._canvas.fillRect(this._canvas.rect, 0x0);
n = this._particles.length;
while (n--) {
p = this._particles[n];
var c:uint = this._forcemap.getPixel(p.x * MAP_SCALE, p.y * MAP_SCALE);
p.vx += (((c >> 16) & 0xff) - 0x80) / 0x80 * 0.3;
p.vy += (((c >> 8) & 0xff) - 0x80) / 0x80 * 0.3;
p.x += p.vx;
p.y += p.vy;
p.life -= 0.005;
if (p.life < 0 || p.x < -10 || p.x > 485 || p.y < -10 || p.y > 485) {
this._particles.splice(n, 1);
} else {
this._drawLine(p.x, p.y, p.x - (p.x - p.px) * TRAIL_SCALE, p.y - (p.y - p.py) * TRAIL_SCALE, p.color, 0.5 * p.life);
p.px = p.x;
p.py = p.y;
}
}
this._canvas.unlock();
if (this._count & 1) {
this._fade.lock();
this._fade.draw(this._canvas, this._drawMatrix, this._drawColor, BlendMode.ADD);
this._fade.applyFilter(this._fade, this._fade.rect, ZERO_POINT, this._blur);
this._fade.unlock();
}
if (this._count & 0x4) {
this._onTimer();
}
this._count++;
}
private function _drawLine(x0:int, y0:int, x1:int, y1:int, color:int, alpha:Number):void {
var steep:Boolean = Math.abs(y1 - y0) > Math.abs(x1 - x0);
var tmp:int;
if (steep) {
tmp = x0;
x0 = y0;
y0 = tmp;
tmp = x1;
x1 = y1;
y1 = tmp;
}
if (x0 > x1) {
tmp = x0;
x0 = x1;
x1 = tmp;
tmp = y0;
y0 = y1;
y1 = tmp;
}
var deltax:int = x1 - x0;
var deltay:int = Math.abs(y1 - y0);
var error:int = deltax / 2;
var ystep:int;
var y:int = y0;
if (y0 < y1) {
ystep = 1;
} else {
ystep = -1;
}
for (var x:int = x0; x <= x1; x++) {
if (steep) {
this._canvas.setPixel32(y, x, color | ((alpha * 0xff) << 24));
} else {
this._canvas.setPixel32(x, y, color | ((alpha * 0xff) << 24));
}
error = error - deltay;
if (error < 0) {
y = y + ystep;
error = error + deltax;
}
}
}
}
}
class Particle {
public var x:Number = 0;
public var y:Number = 0;
public var px:Number = 0;
public var py:Number = 0;
public var vx:Number = 0;
public var vy:Number = 0;
public var life:Number = 1;
public var color:uint = 0xffffff;
public function Particle(x:Number = 0, y:Number = 0, vx:Number = 0, vy:Number = 0, color:uint = 0xffffff) {
this.x = this.px = x;
this.y = this.py = y;
this.vx = vx;
this.vy = vy;
this.color = color;
}
}