forked from: Hello Snow!!!
Hellow Snow!!!
// forked from nitoyon's Hello Snow!!!
// Hellow Snow!!!
// forked from Saqoosha's Snow
package {
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.display.BlendMode;
import flash.display.PixelSnapping;
import flash.display.Sprite;
import flash.events.Event;
import flash.filters.BlurFilter;
import flash.geom.Matrix;
import flash.geom.Point;
import flash.geom.Rectangle;
import flash.text.TextField;
import flash.text.TextFieldAutoSize;
import flash.text.TextFormat;
[SWF(width=465, height=465, backgroundColor=0x0, frameRate=120)]
public class Snow extends Sprite {
private static const WIND_X:Number = 40;
private static const WIND_Y:Number = -15;
private static const GRAVITY:Number = 10;
private static const START_Y:Number = 200;
private var _canvas:BitmapData;
private var _textBmp:BitmapData;
private var _glow:BitmapData;
private var _glowMtx:Matrix;
private var _snow:Array;
private var _snow_prepare:Array;
private var _text:TextField;
private var _log:TextField;
public function Snow() {
stage.scaleMode = "noScale";
_text = new TextField();
_text.defaultTextFormat = new TextFormat('Verdana', 48, 0xffffff, true);
_text.text = "心语难诉,但求一醉!";
_text.autoSize = "left";
_textBmp = new BitmapData(465, 465, false, 0x000000);
this._canvas = new BitmapData(465, 465, false, 0x000000);
//this.addChild(new Bitmap(_textBmp));
this.addChild(new Bitmap(this._canvas));
this._snow = [];
this._snow_prepare = [];
this._glow = new BitmapData(465 / 4, 465 / 4, false, 0x0); // キラキラを描く用のん。カンバスの 4 分の 1 のサイズ
var bm:Bitmap = this.addChild(new Bitmap(this._glow, PixelSnapping.NEVER, true)) as Bitmap; // smoothing を true にして配置
bm.scaleX = bm.scaleY = 4; // 4 倍にする。
bm.blendMode = BlendMode.ADD; // 加算モードで合成
this._glowMtx = new Matrix(0.25, 0, 0, 0.25);
// init _snow_prepare
this.addEventListener(Event.ENTER_FRAME, function(event:Event):void{
for(var i:int = 0; i < 3; i++){
if(_snow_prepare.length){
var index:int = Math.random() * Math.min(30, _snow_prepare.length);
var particle:SnowParticle = _snow_prepare[index];
_snow_prepare.splice(index, 1);
_textBmp.setPixel(particle.x, particle.y, 0x000000);
_snow.push(particle);
}
}
if(_snow_prepare.length || _snow.length){
update(null);
}else{
init();
}
});
init();
}
public function init():void{
var mtx:Matrix = new Matrix();
mtx.ty = START_Y;
_textBmp.draw(_text, mtx);
var rect:Rectangle = _textBmp.getColorBoundsRect(0, 0, false);
for(var x:int = rect.left; x <= rect.right; x++){
for(var y:int = rect.top; y <= rect.bottom; y++){
var col:uint = _textBmp.getPixel(x, y);
if(col != 0x000000){
_snow_prepare.push(new SnowParticle(x, y, col, Math.random(), -Math.random()));
}
}
}
_snow_prepare.sort(function(a:SnowParticle, b:SnowParticle):int{
var _a:int = a.x + a.y * 3;
var _b:int = b.x + b.y * 3;
return _a > _b ? 1 : _a == _b ? 0 : -1;
});
}
// 雪を動かすよーー
public function update(e:Event):void {
this._canvas.lock(); // いっぱい setPixel するときは必ず lock しよう
this._canvas.fillRect(this._canvas.rect, 0x0); // カンバスをクリア
this._canvas.copyPixels(_textBmp, _textBmp.rect, new Point(0, 0));
var n:int = this._snow.length;
var d:Number = 1.0;
var wind_x:Number = (Math.random() > .4 ? WIND_X : 0) / 1000;
var wind_y:Number = (GRAVITY + (Math.random() > .6 ? WIND_Y : WIND_Y / 2)) / 1000;
while (n--) {
var p:SnowParticle = this._snow[n];
p.vx += wind_x * p.s;
p.vy += wind_y * p.s;
p.vx *= 0.99; // 空気抵抗
p.vy *= 0.99; // y 方向にも
p.x += p.vx; // 動かす
p.y += p.vy;
this._canvas.setPixel(p.x, p.y, p.c); // 雪 1 粒描く
if (p.y < 0 || p.y > this.stage.stageHeight || p.x > this.stage.stageWidth) { // もし画面外にでちゃったら
this._snow.splice(n, 1); // とりのぞく
}
}
this._canvas.unlock(); // lock したやつは必ず unlock
this._glow.draw(this._canvas, this._glowMtx); // キラキラを描く
}
}
}
class SnowParticle {
public var x:Number;
public var y:Number;
public var vx:Number;
public var vy:Number;
public var s:Number;
public var c:int;
public function SnowParticle(x:Number, y:Number, color:uint, vx:Number, vy:Number) {
this.x = x;
this.y = y;
this.vx = vx;
this.vy = vy;
this.s = 1;
this.c = color;
}
}