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SYS_Math.rotate() method

Rotate the polygon

Signature

function rotate(
	polygon: TSYS_MathPolygonInput,
	angle: number,
	centerX?: number,
	centerY?: number,
): Array<ISYS_MathPoint>;

Parameters

Parameter	Type	Description
polygon	TSYS_MathPolygonInput	Polygon
angle	number	Rotation angle (in degrees, positive values are counterclockwise)
centerX	number	(Optional) X coordinate of the rotation center, defaulting to the centroid
centerY	number	(Optional) Y coordinate of the rotation center, defaulting to the centroid

Returns

Array<ISYS_MathPoint>

Array of discrete points after rotation

Example

// 1. 定义一个矩形安装座
const mount = [{ x: 0, y: 0 }, { x: 100, y: 0 }, { x: 100, y: 80 }, { x: 0, y: 80 }];

// 2. 不传中心：绕质心 (50, 40) 逆时针旋转 90 度，占位原地转身
const selfRotated = eda.sys_Math.rotate(mount, 90);
console.log('绕质心旋转后的顶点：', JSON.stringify(selfRotated));

// 3. 传中心参数：绕坐标原点 (0, 0) 旋转 90 度，图形整体公转
// 逆时针 90 度把 (x, y) 映射为 (-y, x)
const originRotated = eda.sys_Math.rotate(mount, 90, 0, 0);
console.log('绕原点旋转后的顶点：', JSON.stringify(originRotated));

// 4. 负角度顺时针旋转，与正角度互为逆变换
const back = eda.sys_Math.rotate(originRotated, -90, 0, 0);
console.log('再顺时针转回后的第一个点：', JSON.stringify(back[0]));