煙火背景

語法說明：

在 var fireNo = 5; 中修改煙火的樣式
在 var fireSize = 80; 中修改煙火的大小
在 var speed = 5; 中修改煙火的展開速度
在 var wa = 6; 中修改特效總使用時間
在 var fireColor = new Array('#ffffff','#ff0000','#00ff00','#ffff00','#00ffff','#ff00ff','#ff8000','#ff80ff','#ff0080'); 中修改煙火的顏色
在 setTimeout("hanabi()",2000); 中修改煙火之間間隔的時間(每1秒=1000)

<script language="JavaScript">

var fireNo = 5;

var fireSize = 80;

var speed = 5;

var wa = 6;
var space = 15
var fireColor = new Array('#ffffff','#ff0000','#00ff00','#ffff00','#00ffff','#ff00ff','#ff8000','#ff80ff','#ff0080');
var _dom=(document.all?3:(document.getElementById?1:(document.layers?2:0)));
var fireLay="";
for (i=0; i<fireNo*wa; i++) {
    if (_dom == 1 || _dom == 3) {
        fireLay += '<DIV id="fire' + i + '" style="position:absolute; width:1px; height:1px left:0px; top=0px; font-size:1px; background:#FFFFFF;"></DIV>';
    }
    if (_dom == 2) {
        fireLay += '<LAYER name="fire'+ i +'" left="0" top="0" clip="0,0,1,1" bgcolor="#FFFFFF"></LAYER>\n';
    }
}
document.writeln(fireLay);
function getWindowSize() {
    if(_dom == 1 || _dom == 2) {
        win_width = self.innerWidth;
        win_height = self.innerHeight;
    }
    if (_dom == 3) {
        win_width = document.body.clientWidth;
        win_height = document.body.clientHeight;
    }
}
function getScrollPosY() {
    if (_dom == 1) return scrollY;
    if (_dom == 2) return pageYOffset;
    if (_dom == 3) return document.body.scrollTop;
}
function showLayer(layerName){
    if (_dom == 1) document.getElementById(layerName).style.visibility = "visible";
    if (_dom == 2) document.layers[layerName].visibility = "show";
    if (_dom == 3) document.all(layerName).style.visibility = "visible";
}
function hideLayer(layerName){
    if (_dom == 1) document.getElementById(layerName).style.visibility = "hidden";
    if (_dom == 2) document.layers[layerName].visibility = "hide";
    if (_dom == 3) document.all(layerName).style.visibility = "hidden";
}
function hanabi() {
	for (i=0; i<fireNo*wa; i++) {
		if (_dom == 1) var div = document.getElementById("fire" + i).style;
		if (_dom == 2) var div = document.layers["fire" + i];
		if (_dom == 3) var div = document.all("fire" + i).style;
		zure1 = Math.floor(i/fireNo)%2 == 0 ? 0:(Math.PI / fireNo);
		zure2 = Math.floor(i/fireNo) * space;
		ran = (radius1>(fireSize*0.8)) ? Math.floor(Math.random()*20-10) : 0;
		radius2 = (radius1 - zure2) > 0 ? radius1 - zure2 : 0;
		if ((radius1 - zure2) > fireSize) { hideLayer("fire" + i); }
		else { showLayer("fire" + i); }
		div.left = centerX + Math.cos(i * (Math.PI * 2 / fireNo) + zure1) * (radius2) + ran;
		div.top = centerY + Math.sin(i * (Math.PI * 2 / fireNo) + zure1) * (radius2) + ran;
		if (radius2 < fireSize * 0.4) {
			if (_dom == 1 || _dom == 3) {
				div.background = startColor;
				div.width = 1;
				div.height = 1;
			}
			if (_dom == 2){
				div.bgColor = startColor;
				div.clip.width = 1;
				div.clip.height = 1;
			}
		} else if (radius2 < fireSize * 0.8) {
			if (_dom == 1 || _dom == 3) {
				div.width = 2;
				div.height = 2;
			}
			if (_dom == 2){
				div.clip.width = 2;
				div.clip.height = 2;
			}
		} else {
			if (_dom == 1 || _dom == 3) {
				div.background = fireColor[Math.floor(Math.random() * fireColor.length)];
				div.width = Math.floor(Math.random()*2+1);
				div.height = Math.floor(Math.random()*2+1);
			}
			if (_dom == 2){
				div.bgColor = fireColor[Math.floor(Math.random() * fireColor.length)];
				div.clip.width = Math.floor(Math.random()*2+1);
				div.clip.height = Math.floor(Math.random()*2+1);
			}
		}
	}
	radius1 += speed;
	if (radius1 > (fireSize + space * wa)) { setHanabiPos(); }
	else { setTimeout("hanabi()",10);}
}
function setHanabiPos() {
	rev = 0; radius1 = 0;
	getWindowSize(); sclY = getScrollPosY();
	startColor = fireColor[Math.floor(Math.random() * fireColor.length)];
    centerX =  Math.floor(Math.random() * (win_width - (fireSize + space * wa) * 2) + (fireSize + space * wa));
    centerY =  Math.floor(Math.random() * (win_height - (fireSize + space * wa) * 2) + (fireSize + space * wa)) + sclY;

    setTimeout("hanabi()",2000);
}
setHanabiPos();
-->
</script>