我算的角度有点不对，那个拉杆可以控制弧形的弯曲程度，但是坐标和角度都有点偏差，求助大佬

这是相关的代码

var r = 100;

let txt = this.selectedLayer.text;

var arcStrength = this.selectedLayer.arcStrength / 2;

this.selectedLayer.style.width = r * 2 + this.selectedLayer.style.fontSize / 2 + 15;

this.selectedLayer.style.height = r;

// 计算字符间距

if (this.selectedLayer.style.letterSpacing == 0) {

    this.selectedLayer.style.letterSpacing = 0.2;

}

for (var i = 0; i < txt.length; i++) {

var du = (i * this.selectedLayer.style.letterSpacing - ((txt.length - 1) * this.selectedLayer.style.letterSpacing) / 2);

if (texStelection == 1) {

//180度上弧文字

var x1 = (r + arcStrength * 0.5) + (r + arcStrength * 0.5) * Math.sin(du);

var y1 = (r - arcStrength * 0.5) + -(r - arcStrength * 0.5) * Math.cos(du);

// var x1 = r +r * Math.sin(du);

// var y1 = r + -r  * Math.cos(du);

//旋转角度

var x = 360 / txt.length * du;

this.selectedLayer.text[i].left = x1;

this.selectedLayer.text[i].top = y1;

arcXMax = Math.max(arcXMax, this.selectedLayer.text[i].left);

arcXMin = Math.min(arcXMin, this.selectedLayer.text[i].left);

arcYMax = Math.max(arcYMax, this.selectedLayer.text[i].top);

arcYMin = Math.min(arcYMin, this.selectedLayer.text[i].top);

this.selectedLayer.text[i].rotate = (du) * (360 / 6.28) / 100 * (-arcStrength + 100)

this.selectedLayer.style.height = arcYMax - arcYMin + this.selectedLayer.style.fontSize * 1.25;