topical media & game development
#graphic-flex-image-effects-08-Flex-BurningMan.ax
#graphic-flex-image-effects-08-Flex-BurningMan.ax
[swf]
[flash]
flex
package {
import aether.utils.ImageUtil;
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.display.BitmapDataChannel;
import flash.display.Sprite;
import flash.events.Event;
import flash.filters.BlurFilter;
import flash.filters.DisplacementMapFilter;
import flash.filters.DisplacementMapFilterMode;
import flash.filters.GradientGlowFilter;
import flash.geom.ColorTransform;
import flash.geom.Point;
[SWF(width=250, height=450, backgroundColor=0x000000)]
Demonstrates how flames may be dynamically generated from any object. This uses a loaded image
that is then recolored and distorted, constantly over time, creating the flame illusion.
public class @ax-graphic-flex-image-effects-08-Flex-BurningMan extends graphic_flex_image_effects_08_Flex_AbstractImageLoader {
// the rate at which the flames should move
private static const FLICKER_RATE:Number = 10;
private var _flame:BitmapData;
private var _perlinNoise:BitmapData;
private var _perlinOffsets:Array;
private var _perlinSeed:int;
Constructor. Sends path of image to load to super class.
public function @ax-graphic-flex-image-effects-08-Flex-BurningMan() {
super("graphic-flex-image-effects-08-assets-man.png");
}
Called after image loads in super class. This places loaded image, recolors it using
a GradientGlowFilter, then sets up the flame and noise properties that will be used in
the flame animation. Finally, the handler for the animation is set up.
override protected function runPostImageLoad():void {
_loadedBitmap.x = (stage.stageWidth - _loadedBitmap.width)/2;
_loadedBitmap.y = stage.stageHeight - _loadedBitmap.height - 5;
// creates flame colors on image using a filter
_loadedBitmap.filters = [
new GradientGlowFilter(
0,
45,
[0xFF0000, 0xFFFF00],
[1, 1],
[50, 255],
15,
15
)
];
// initializes properties that will be used in the animating
makeFlame();
makeNoise();
addChild(_loadedBitmap);
addEventListener(Event.ENTER_FRAME, onSpriteEnterFrame);
}
Creates the bitmap data that will be used to draw the flames.
private function makeFlame():void {
// flame image is same size as stage, fully transparent
_flame = new BitmapData(
stage.stageWidth,
stage.stageHeight,
true,
0x00000000
);
addChild(new Bitmap(_flame));
}
Initializes Perlin noise properties that will be used in flame animation.
private function makeNoise():void {
// noise bitmap data is same size as flame bitmap data
_perlinNoise = _flame.clone();
_perlinSeed = int(new Date());
// only one octave requires only one point
_perlinOffsets = [new Point()];
}
Applies the Perlin noise to the bitmap data, offsetting the octave displacement
by the FLICKER_RATE each time this method is called.
private function applyNoise():void {
_perlinNoise.perlinNoise(
20,
20,
1,
_perlinSeed,
false,
true,
BitmapDataChannel.RED,
true,
_perlinOffsets
);
// altering offset contributes to upward animation of flames
(_perlinOffsets[0] as Point).y += FLICKER_RATE;
}
Updates the flame bitmap data each frame, creating the animation.
private function drawFlame():void {
// draw the current stage image into flame at a reduced brightness and alpha
_flame.draw(
stage,
null,
new ColorTransform(.9, .9, .9, .7)
);
// blur drawn image slightly, more on y axis
ImageUtil.applyFilter(
_flame,
new BlurFilter(2, 4)
);
// move the flame image up slightly, creating upward movement of flames
_flame.scroll(0, -4);
// apply new Perlin noise with altered offset
applyNoise();
// displacement flame image with updates Perlin noise
ImageUtil.applyFilter(
_flame,
new DisplacementMapFilter(
_perlinNoise,
new Point(),
BitmapDataChannel.RED,
BitmapDataChannel.RED,
2,
8,
DisplacementMapFilterMode.CLAMP
)
);
}
Handler for ENTER_FRAME event. Redraws flame.
parameter: event Event dispatched by this sprite.
private function onSpriteEnterFrame(event:Event):void {
drawFlame();
}
}
}
(C) Æliens
04/09/2009
You may not copy or print any of this material without explicit permission of the author or the publisher.
In case of other copyright issues, contact the author.
