AS3中常用的一些公式收集整理

作者: 嘎嘎 2009-04-02,07:52 下午周四

收集了一些AS3动画常用的算法,比如缓动,弹性,旋转等等.

缓动公式:

1 2	sprite.x += (targetX - sprite.x) * easing;//easing为缓动系数变量 sprite.y += (targetY - sprite.y) * easing;

弹性公式:

1
2
3
4

vx += (targetX - sprite.x) * spring;//spring为弹性系数
vy += (targetY - sprite.y) * spring;
sprite.x += (vx *= friction);//friction为摩擦力
sprite.y += (vy *= friction);

偏移弹性公式:

1
2
3
4
5

var dx:Number = sprite.x - fixedX;
var dy:Number = sprite.y - fixedY;
var angle:Number = Math.atan2(dy, dx);
var targetX:Number = fixedX + Math.cos(angle) * springLength;
var targetY:Number = fixedX + Math.sin(angle) * springLength;

向鼠标旋转(或向某点旋转)

1
2
3

dx = mouseX - sprite.x;
dy = mouseY - sprite.y;
sprite.rotation = Math.atan2(dy, dx) * 180 / Math.PI;

波形运动:

1
2
3
4

public function onEnterFrame1(event:Event):void {
ball.y=centerScale+Math.sin(angle)*range;
angle+=speed;
}

心跳:

1
2
3
4
5

public function onEnterFrame1(event:Event):void {
ball.scaleX=centerScale+Math.sin(angle)*range;
ball.scaleY=centerScale+Math.sin(angle)*range;
angle+=speed;
}

圆心旋转:

1
2
3
4
5

public function onEnterFrame(event:Event):void {
ball.x=centerX+Math.cos(angle)*radius;
ball.y=centerY+Math.sin(angle)*radius;
angle+=speed;
}

椭圆旋转:

1
2
3
4
5

public function onEnterFrame(event:Event):void {
ball.x=centerX+Math.cos(angle)*radiusX;
ball.y=centerY+Math.sin(angle)*radiusY;
angle+=speed;
}

颜色运算得到透明值:

1
2
3
4
5

var t:uint=0x77ff8877
var s:uint=0xff000000
var h:uint=t&s
var m:uint=h>>>24
trace(m)

转换为十进制:

1	trace(hexValue);

十进制转换为十六进制:

1	decimalValue.toString(16)

颜色提取:

1
2
3
4
5
6
7

red = color24 >> 16;
green = color24 >> 8 & 0xFF;
blue = color24 & 0xFF;
alpha = color32 >> 24;
red = color32 >> 16 & 0xFF;
green = color32 >> 8 & 0xFF;
blue = color232 & 0xFF;

按位计算得到颜色值:

1 2	color24 = red << 16 \| green << 8 \| blue; color32 = alpha << 24 \| red << 16 \| green << 8 \| blue;

过控制点的曲线:

1
2
3
4
5
6

// xt, yt is the point you want to draw through
// x0, y0 and x2, y2 are the end points of the curve
x1 = xt * 2 – (x0 + x2) / 2;
y1 = yt * 2 – (y0 + y2) / 2;
moveTo(x0, y0);
curveTo(x1, y1, x2, y2);