118 lines
2.5 KiB
TypeScript
118 lines
2.5 KiB
TypeScript
|
||
|
||
|
||
export const Vector = {
|
||
|
||
/**
|
||
* 向量相加
|
||
* @param v1
|
||
* @param v2
|
||
*/
|
||
add(v1: [number, number], v2: [number, number]): [number, number] {
|
||
return [v1[0] + v2[0], v1[1] + v2[1]];
|
||
},
|
||
|
||
/**
|
||
* 向量相减
|
||
* @param v1
|
||
* @param v2
|
||
*/
|
||
subtract(v1: [number, number], v2: [number, number]): [number, number] {
|
||
return [v1[0] - v2[0], v1[1] - v2[1]];
|
||
},
|
||
|
||
/**
|
||
* 向量点积
|
||
* @param v1
|
||
* @param v2
|
||
*/
|
||
dot(v1: [number, number], v2: [number, number]): number {
|
||
return v1[0] * v2[0] + v1[1] * v2[1];
|
||
},
|
||
|
||
/**
|
||
* 向量缩放
|
||
* @param v
|
||
* @param n
|
||
*/
|
||
scale(v: [number, number], n: number): [number, number] {
|
||
return [v[0] * n, v[1] * n];
|
||
},
|
||
|
||
/**
|
||
* 向量求模长
|
||
* @param v
|
||
*/
|
||
length(v: [number, number]): number {
|
||
return Math.sqrt(v[0]**2 + v[1]**2);
|
||
},
|
||
|
||
/**
|
||
* 绕某点旋转向量
|
||
* @param radian 角度（弧度制）
|
||
* @param point 旋转的点
|
||
* @param center 绕的点
|
||
*/
|
||
rotation(radian: number, point: [number, number], center: [number, number] = [0, 0]): [number, number] {
|
||
if(radian === 0) return point;
|
||
|
||
radian = -radian;
|
||
|
||
let cos = Math.cos(radian),
|
||
sin = Math.sin(radian),
|
||
dv = [point[0] - center[0], point[1] - center[1]],
|
||
v = [0, 0];
|
||
|
||
v[0] = center[0] + (dv[0] * cos - dv[1] * sin);
|
||
v[1] = center[1] + (dv[0] * sin + dv[1] * cos);
|
||
|
||
return v as [number, number];
|
||
},
|
||
|
||
/**
|
||
* 求向量法向
|
||
*/
|
||
tangent(v: [number, number]): [number, number] {
|
||
return [-v[1], v[0]];
|
||
},
|
||
|
||
/**
|
||
* 向量单位化
|
||
*/
|
||
normalize(v: [number, number]): [number, number] {
|
||
let len = Vector.length(v);
|
||
|
||
if(len === 0) {
|
||
return [0, 0];
|
||
}
|
||
else if(len === 1) {
|
||
return v;
|
||
}
|
||
else {
|
||
return [v[0] / len, v[1] / len];
|
||
}
|
||
},
|
||
|
||
/**
|
||
* 求一个向量（点）按照direction方向，延长len长度后的坐标
|
||
* @param v
|
||
* @param direction
|
||
* @param len
|
||
*/
|
||
location(v: [number, number], direction: [number, number], len: number): [number, number] {
|
||
return Vector.add(v, Vector.scale(Vector.normalize(direction), len));
|
||
},
|
||
|
||
/**
|
||
* 向量取反
|
||
*/
|
||
negative(v: [number, number]): [number, number] {
|
||
return Vector.scale(v, -1);
|
||
}
|
||
};
|
||
|
||
|
||
|
||
|
||
|