魚移到左上角，不會跟著鼠標動，求解答，代碼如下：
momObj.prototype.init = function()
{
this.x = canWidth * 0.5;
this.y = canHeight * 0.5;
this.angle = 0;
this.bigEye.src = "./src/bigEye0.png" ;
this.bigBody.src = "./src/bigSwim0.png" ;
this.bigTail.src = ?"./src/bigTail0.png" ;
}
momObj.prototype.draw = function()
{
//lerp x,y
this.x = lerpDistance(mx, this.x, 0.98); ? ?//讓大魚的坐標一直趨向于鼠標的坐標
this.y = lerpDistance(my, this.y, 0.98);
//delta angle（角度差）
//Math.atan2(x,y)
var deltaY = my - this.y;
var deltaX = mx - this.x;
var beta = Math.atan2(deltaY ，deltaX);//返回值是[-PI，PI]
this.angle = lerpAngle(beta, this.angle, 0.6);?
ctx1.save();
ctx1.translate(this.x,this.y); ?//大魚的相對原點
ctx1.rotate(this.angle); ? ?//旋轉畫布
ctx1.drawImage(this.bigEye, -this.bigEye.width * 0.5, -this.bigEye.height * 0.5);
ctx1.drawImage(this.bigBody, -this.bigBody.width * 0.5, -this.bigBody.height * 0.5);
ctx1.drawImage(this.bigTail, -this.bigTail.width * 0.5 + 30, -this.bigTail.height * 0.5);
ctx1.restore();
}
2018-08-08
什么問題？
2016-09-21
main.js
//初始化部分
mom = new momObj();
mom.init();
mx = canWidth * 0.5;
my = canHeight * 0.5;
//循環部分
ctx1.clearRect(0,0,canWidth,canHeight); //ctx1每一幀的都要清除掉，不然會被覆蓋，使畫的圖形變粗
mom.draw();
function onMouseMove(e) ??
{
if (e.offSetX || e.layerX) ??
{
mx = e.offSetX == undefined ? e.offSetX : e.layerX;
my = e.offSetY == undefined ? e.offSetY : e.layerY;
//console.log(mx);
}
}