常用公式 距离、波形、力
http://www.cnblogs.com/rob0121/articles/2117625.html
基本三角函数的计算: 角的正弦值 = 对边 / 斜边 角的余弦值 = 邻边 / 斜边 角的正切值 = 对边 / 邻边 角度制与弧度制的相互转换: 弧度 = 角度 * Math.PI / 180 角度 = 弧度 * 180 / Math.PI //计算两点间距离: dx = x2 – x1; dy = y2 – y1; dist = Math.sqrt(dx*dx + dy*dy); //缓动公式: sprite.x += (targetX - sprite.x) * easing;//easing为缓动系数变量 sprite.y += (targetY - sprite.y) * easing; //弹性公式: 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: 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) dx = mouseX - sprite.x; dy = mouseY - sprite.y; sprite.rotation = Math.atan2(dy, dx) * 180 / Math.PI; //波形运动: public function onEnterFrame1(event:Event):void { ball.y=centerScale+Math.sin(angle)*range; angle+=speed; } //心跳: 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: 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: 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: var t:uint=0×77ff8877 var s:uint=0xff000000 var h:uint=t&s var m:uint=h>>>24 trace(m) //转换为十进制: trace(hexValue); //十进制转换为十六进制: decimalValue.toString(16) //颜色提取: red = color24 >> 16; green = color24 >> 8 & 0xFF; blue = color24 & 0xFF; alpha = color32 >> 24; red = color32 >> 16 & 0xFF; green = color32 >> 8 & 0xFF; blue = color232 & 0xFF; //按位计算得到颜色值: color24 = red << 16 | green << 8 | blue; color32 = alpha << 24 | red << 16 | green << 8 | blue; //过控制点的曲线: // xt, yt是你想要让曲线通过的那一点 // x0, y0 和x2, y2 是曲线的终点 xt * 2 – (x0 + x2) / 2; y1 = yt * 2 – (y0 + y2) / 2; moveTo(x0, y0); curveTo(x1, y1, x2, y2); //向鼠标(或者任何一个点)旋转: // 用要旋转到的 x, y 坐标替换 mouseX, mouseY dx = mouseX - sprite.x; dy = mouseY - sprite.y; sprite.rotation = Math.atan2(dy, dx) * 180 / Math.PI; //创建波形: // 将 x, y 或其它属性赋值给 Sprite 影片或影片剪辑, // 作为绘图坐标,等等。 public function onEnterFrame(event:Event){ value = center + Math.sin(angle) * range; angle += speed; } //创建圆形: // 将 x, y 或其它属性赋值给 Sprite 影片或影片剪辑, // 作为绘图坐标,等等。 public function onEnterFrame(event:Event){ xposition = centerX + Math.cos(angle) * radius; yposition = centerY + Math.sin(angle) * radius; angle += speed; } //创建椭圆: // 将 x, y 或其它属性赋值给 Sprite 影片或影片剪辑, // 作为绘图坐标,等等。 public function onEnterFrame(event:Event){ xposition = centerX + Math.cos(angle) * radiusX; yposition = centerY + Math.sin(angle) * radiusY; angle += speed; } //获得两点间的距离: // x1, y1 和 x2, y2 是两个点 // 也可以是 Sprite / MovieClip 坐标,鼠标坐标,等等。 dx = x2 – x1; dy = y2 – y1; dist = Math.sqrt(dx*dx + dy*dy); //颜色组合: color24 = red < < 16 | green << 8 | blue; color32 = alpha << 24 | red << 16 | green << 8 | blue; //颜色提取: red = color24 >> 16; green = color24 >> 8 & 0xFF; blue = color24 & 0xFF; alpha = color32 >> 24; red = color32 >> 16 & 0xFF; green = color32 >> 8 & 0xFF; blue = color232 & 0xFF; //穿过某点绘制曲线: // xt, yt 是我们想要穿过的一点 // x0, y0 以及 x2, y2 是曲线的两端 x1 = xt * 2 – (x0 + x2) / 2; y1 = yt * 2 – (y0 + y2) / 2; moveTo(x0, y0); curveTo(x1, y1, x2, y2); //角速度转换为 x, y 速度: vx = speed * Math.cos(angle); vy = speed * Math.sin(angle); //角加速度(作用于物体上的 force)转换为 x, y 加速度: ax = force * Math.cos(angle); ay = force * Math.sin(angle); //将加速度加入速度: vx += ax; vy += ay; //移除出界对象: if(sprite.x - sprite.width / 2 > right || sprite.x + sprite.width / 2 < left || sprite.y – sprite.height / 2 > bottom || sprite.y + sprite.height / 2 < top){ // 删除影片的代码 } //重置出界对象: if(sprite.x - sprite.width / 2 > right || sprite.x + sprite.width / 2 < left || sprite.y – sprite.height / 2 > bottom || sprite.y + sprite.height / 2 < top){ // 重置影片的位置和速度 } //屏幕环绕出界对象: if(sprite.x - sprite.width / 2 > right){ sprite.x = left - sprite.width / 2; }else if(sprite.x + sprite.width / 2 < left){ sprite.x = right + sprite.width / 2; }if(sprite.y – sprite.height / 2 > bottom){ sprite.y = top – sprite.height / 2; }else if(sprite.y + sprite.height / 2 < top){ sprite.y = bottom + sprite.height / 2; } //摩擦力应用(正确方法): speed = Math.sqrt(vx * vx + vy * vy); angle = Math.atan2(vy, vx); if(speed > friction){ speed -= friction; }else{ speed = 0; } vx = Math.cos(angle) * speed; vy = Math.sin(angle) * speed; //摩擦力应用(简便方法): vx *= friction; vy *= friction; //简单缓动运动: //长形 var dx:Number = targetX - sprite.x; var dy:Number = targetY - sprite.y; vx = dx * easing; vy = dy * easing; sprite.x += vx; sprite.y += vy; //中形: vx = (targetX - sprite.x) * easing; vy = (targetY - sprite.y) * easing; sprite.x += vx; sprite.y += vy; //短形: sprite.x += (targetX - sprite.x) * easing; sprite.y += (targetY - sprite.y) * easing; //简单弹性运动: //长形 var ax:Number = (targetX - sprite.x) * spring; var ay:Number = (targetY - sprite.y) * spring; vx += ax; vy += ay; vx *= friction; vy *= friction; sprite.x += vx; sprite.y += vy; //中形: vx += (targetX - sprite.x) * spring; vy += (targetY - sprite.y) * spring; vx *= friction; vy *= friction; sprite.x += vx; sprite.y += vy; //短形: vx += (targetX - sprite.x) * spring; vy += (targetY - sprite.y) * spring; sprite.x += (vx *= friction); sprite.y += (vy *= friction); //偏移弹性运动: 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; // 如前例弹性运动到 targetX, targetY //距离碰撞检测: // 从影片 spriteA 和 spriteB 开始 // 如果使用一个空白影片,或影片没有半径(radius)属性 // 可以用宽度或高度除以 2。 var dx:Number = spriteB.x - spriteA.x; var dy:Number = spriteB.y - spriteA.y; var dist:Number = Math.sqrt(dx * dx + dy * dy); if(dist < spriteA.radius + spriteB.radius){ // 处理碰撞 } //多物体碰撞检测: var numObjects:uint = 10; for(var i:uint = 0; i < numObjects - 1; i++){ // 使用变量 i 提取引用 var objectA = objects[i]; for(var j:uint = i+1; j{ // // 使用变量 j 提取引用 var objectB = objects[j]; // perform collision detection // between objectA and objectB } } //坐标旋转: x1 = Math.cos(angle) * x - Math.sin(angle) * y; y1 = Math.cos(angle) * y + Math.sin(angle) * x; //反坐标旋转: x1 = Math.cos(angle) * x + Math.sin(angle) * y; y1 = Math.cos(angle) * y - Math.sin(angle) * x; //动量守恒的 ActionScript 表达式,短形: var vxTotal:Number = vx0 - vx1; vx0 = ((ball0.mass - ball1.mass) * vx0 + 2 * ball1.mass * vx1) / (ball0.mass + ball1.mass); vx1 = vxTotal + vx0; //万有引力: function gravitate(partA:Ball, partB:Ball):void{ var dx:Number = partB.x - partA.x; var dy:Number = partB.y - partA.y; var distSQ:Number = dx * dx + dy * dy; var dist:Number = Math.sqrt(distSQ); var force:Number = partA.mass * partB.mass / distSQ; var ax:Number = force * dx / dist; var ay:Number = force * dy / dist; partA.vx += ax / partA.mass; partA.vy += ay / partA.mass; partB.vx -= ax / partB.mass; partB.vy -= ay / partB.mass; } //余弦定理: A = Math.acos((b * b + c * c - a * a) / (2 * b * c)); B = Math.acos((a * a + c * c - b * b) / (2 * a * c)); C = Math.acos((a * a + b * b - c * c) / (2 * a * b));
//基本透视法: scale = fl / (fl + zpos); sprite.scaleX = sprite.scaleY = scale; sprite.alpha = scale; // 可选 sprite.x = vanishingPointX + xpos * scale; sprite.y = vanishingPointY + ypos * scale; //Z 排序: 假设有一个带有 zpos 属性的 3D 物体的数组 objectArray.sortOn("zpos", Array.DESCENDING | Array.NUMERIC); for(var i:uint = 0; i < numObjects; i++){ setChildIndex(objectArray[i], i); } //坐标旋转: x1 = cos(angleZ) * xpos - sin(angleZ) * ypos; y1 = cos(angleZ) * ypos + sin(angleZ) * xpos; x1 = cos(angleY) * xpos - sin(angleY) * zpos; z1 = cos(angleY) * zpos + sin(angleY) * xpos; y1 = cos(angleX) * ypos - sin(angleX) * zpos; z1 = cos(angleX) * zpos + sin(angleX) * ypos; //3D 距离: dist = Math.sqrt(dx * dx + dy * dy + dz * dz);