ActionScript3 常用公式

角的正弦值 = 對邊 / 斜邊

角的余弦值 = 鄰邊 / 斜邊

角的正切值 = 對邊 / 鄰邊 

角度制與弧度制的相互轉換：

弧度 = 角度 * math.pi / 180

角度 = 弧度 * 180 / math.pi

計算兩點間距離：

dx = x2 – x1;

dy = y2 – y1;

dist = math.sqrt(dx*dx + dy*dy);

緩動公式:

sprite.x += (targetx - sprite.x) * easing;//easing為緩動係數變數

sprite.y += (targety - sprite.y) * easing;

彈性公式:

vx += (targetx - sprite.x) * spring;//spring為彈性係數

vy += (targety - sprite.y) * spring;

sprite.x += (vx *= friction);//friction為摩擦力

sprite.y += (vy *= friction);

偏移彈性公式:

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;

向滑鼠旋轉(或向某點旋轉)

dx = mou*** - sprite.x;

dy = mousey - sprite.y;

sprite.rotation = math.atan2(dy, dx) * 180 / math.pi;

波形運動:

public function onenterframe1(event:event):void

心跳:public function onenterframe1(event:event):void

圓心旋**

public function onenterframe(event:event):void

橢圓旋**

public function onenterframe(event:event):void

顏色運算得到透明值:

var t:uint=0×77ff8877

var s:uint=0xff000000

var h:uint=t&s

var m:uint=h>>>24

trace(m)

轉換為十進位制:

trace(hexvalue);

十進位制轉換為十六進製制:

decimalvalue.tostring(16)

顏色提取:

red = color24 >> 16;

green = color24 >> 8 & 0xff;

blue = color24 & 0xff;

alpha = color32 >> 24;

red = color32 >> 16 & 0xff;

green = color32 >> 8 & 0xff;

blue = color232 & 0xff;

按位計算得到顏色值:

color24 = red << 16 | green << 8 | blue;

color32 = alpha << 24 | red << 16 | green << 8 | blue;

過控制點的曲線:

// xt, yt是你想要讓曲線通過的那一點

// x0, y0 和x2, y2 是曲線的終點

xt * 2 – (x0 + x2) / 2;

y1 = yt * 2 – (y0 + y2) / 2;

moveto(x0, y0);