as3 一些常用物理公式（AS3 some commonly used physical formulas）.docVIP

as3 一些常用物理公式（AS3 some commonly used physical formulas） Follow the mouse: To rotate into / / x, y coordinates to replace mouseX, mouseY DX = mouseX - sprite.x; Dy = mouseY - sprite.y; Sprite.rotation = Math.atan2 (Dy, DX) * 180 / Math.PI; Create waveform: / / x, y or other attributes assigned to the Sprite film or movie clip, As the drawing / coordinate, etc.. Public, function, onEnterFrame (event:Event) { Value = center + Math.sin (angle) * range; Angle = speed; } Create circles: / / x, y or other attributes assigned to the Sprite film or movie clip, As the drawing / coordinate, etc.. Public, function, onEnterFrame (event:Event) { Xposition = centerX + Math.cos (angle) * radius; Yposition = centerY + Math.sin (angle) * radius; Angle = speed; } Create ellipse: / / x, y or other attributes assigned to the Sprite film or movie clip, As the drawing / coordinate, etc.. Public, function, onEnterFrame (event:Event) { Xposition = centerX + Math.cos (angle) * radiusX; Yposition = centerY + Math.sin (angle) * radiusY; Angle = speed; } Get the distance between two points: / / x1, Y1 and X2, Y2 is two points / / can also be Sprite / MovieClip coordinates, the coordinates of the mouse, etc.. DX = X2 - x1; Dy = Y2 - y1; Dist = Math.sqrt (dx*dx + dy*dy); Color combination: Color24 = red green 8 16 | | blue; Color32 = Alpha 24 red 16 | | green 8 | blue; Color extraction: Red = color24 16; Green = color24 8 0xFF; Blue = color24 0xFF; Alpha = color32 24; Red = color32 16 0xFF; Green = color32 8 0xFF; Blue = color232 0xFF; Draw a curve through a point: XT / YT is a point, we want to pass through Y0 / / x0, and X2, Y2 is a curve X1 = XT * 2 - (x0 + x2) / 2; Y1 = YT * 2 - (Y0 + Y2) / 2; MoveTo (x0, Y0); CurveTo (x1, Y1, X2, Y2); Angular speed is converted to x, y speed: VX = speed * Math.cos (angle); Vy = speed * Math.sin (angle); Angular acceleration (the force acting on the object) is converted to x, y acceleration: Ax = force * Math.cos (angle); Ay = force * Math.sin (