js屏幕坐标转换

/**
 * 原点坐标
 * @property {number} x
 * @property {number} y
 */
export interface OriginPoint{
    x: number;
    y: number;
}

/**
 *  已知某一点坐标，旋转角度，长度，求另一点坐标
 *  @param originPoint 原点坐标
 *  @param {number} degree 旋转角度
 *  @param {number} len 长度
 *  @return {OriginPoint} 另一点坐标
 */
export const calculateCoordinatePoint = (originPoint: OriginPoint, degree: number, len: number): OriginPoint => {
    let rotate: number = (degree - 90 + 360) % 360; //这里是因为一开始以y轴下方为0度的
    let point: OriginPoint = {
        x: len,
        y: 0
    };
    //计算某一点旋转后的坐标点，这里假设传入的点为原点
    let relativeOriginPoint: OriginPoint = calculateRotate(point, rotate);
    //计算相对坐标系的坐标
    return calculateCoordinateRelativePoint(originPoint, relativeOriginPoint);
};


/**
 * 计算某一点旋转后的坐标点
 * @param {OriginPoint} point 原点坐标
 * @param {number} degree 旋转角度
 * @return {OriginPoint}
 */
export const calculateRotate = (point: OriginPoint, degree: number): OriginPoint => {
    let x: number = point.x * Math.cos(degree * Math.PI / 180) + point.y * Math.sin(degree * Math.PI / 180);
    let y: number = -point.x * Math.sin(degree * Math.PI / 180) + point.y * Math.cos(degree * Math.PI / 180);
    return {
        x: Math.round(x * 100) / 100,
        y: Math.round(y * 100) / 100
    };
};


/**
 * 计算相对坐标系的坐标
 * @param {OriginPoint} origin 原点坐标
 * @param {OriginPoint} relativeOriginPoint 相对原点坐标
 */
export const calculateCoordinateRelativePoint = (origin, relativeOriginPoint): OriginPoint => {
    let x = relativeOriginPoint.x + origin.x;
    let y = relativeOriginPoint.y + origin.y;
    return {
        x: Math.round(x * 100) / 100,
        y: Math.round(y * 100) / 100
    };
};