FabricJs -如何在对象旋转后重新计算对象内的点

// 创建一个矩形对象
var rect = new fabric.Rect({
  left: 100,
  top: 100,
  width: 200,
  height: 100,
  fill: 'red',
  angle: 45 // 设置旋转角度为45度
});

// 获取对象的旋转角度
var angle = rect.angle;

// 获取对象的中心点坐标
var centerX = rect.left + rect.width / 2;
var centerY = rect.top + rect.height / 2;

// 计算对象内点的坐标
var pointX = rect.left + rect.width / 4; // 假设要计算的点位于矩形的左上角
var pointY = rect.top + rect.height / 4;
var cos = Math.cos(angle * Math.PI / 180);
var sin = Math.sin(angle * Math.PI / 180);
var rotatedX = centerX + (pointX - centerX) * cos - (pointY - centerY) * sin;
var rotatedY = centerY + (pointX - centerX) * sin + (pointY - centerY) * cos;

console.log("旋转后的点坐标：", rotatedX, rotatedY);