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@jtopo/core / GeomUtils
Class: GeomUtils
几何顶点（坐标）生成与操作工具类
此类生成的所有顶点坐标均经过归一化（[-1, 1]）处理。
归一化后的顶点坐标极大地简化了图形变换操作，如缩放、旋转、斜切等。
Since
2.6.0
Table of contents
Constructors
Methods
- getBoundingBox
- getFirstIntersectPoint
- getLineIntersectPoint
- getLineIntersectPoints
- isPointInPolygon
- normalizePoints
- pointsToNormalVecs
- rotatePoints
Constructors
constructor
new GeomUtils()
Methods
getBoundingBox
Static getBoundingBox(points): Rectangle
计算一组点的最小外接矩形（Bounding Box）
Parameters
| Name | Type | Description |
|---|---|---|
points | PointLike[] | 点集合 |
Returns
包含所有点的最小矩形
getFirstIntersectPoint
Static getFirstIntersectPoint(p1, p2, segPoints, isClosed): Object
Parameters
| Name | Type |
|---|---|
p1 | PointLike |
p2 | PointLike |
segPoints | PointLike[] |
isClosed | boolean |
Returns
Object
| Name | Type |
|---|---|
x | number |
y | number |
getLineIntersectPoint
Static getLineIntersectPoint(p1, p2, p3, p4): Object
Parameters
| Name | Type |
|---|---|
p1 | PointLike |
p2 | PointLike |
p3 | PointLike |
p4 | PointLike |
Returns
Object
| Name | Type |
|---|---|
x | number |
y | number |
getLineIntersectPoints
Static getLineIntersectPoints(p1, p2, segPoints, isClosed): PointLike[]
Parameters
| Name | Type |
|---|---|
p1 | PointLike |
p2 | PointLike |
segPoints | PointLike[] |
isClosed | boolean |
Returns
isPointInPolygon
Static isPointInPolygon(point, polygon): boolean
Parameters
| Name | Type |
|---|---|
point | PointLike |
polygon | PointLike[] |
Returns
boolean
normalizePoints
Static normalizePoints(points): { x: number ; y: number }[]
归一化（[-1, 1]）到一个尺寸为2x2的正方形内
Parameters
| Name | Type | Description |
|---|---|---|
points | PointLike[] | 顶点坐标数组 |
Returns
{ x: number ; y: number }[]
坐标归一化后的坐标数组
pointsToNormalVecs
Static pointsToNormalVecs(out, points, isClosed?): void
点坐标转换为法向向量
Parameters
| Name | Type | Description |
|---|---|---|
out | vec2[] | - |
points | PointLike[] | 点坐标数组 |
isClosed? | boolean | 是否闭合 |
Returns
void
向量数组
rotatePoints
Static rotatePoints(normalPoints, angle, cx?, cy?): PointLike[]
旋转点坐标
Parameters
| Name | Type | Description |
|---|---|---|
normalPoints | PointLike[] | 归一化坐标数组 |
angle | number | |
cx? | number | 旋转中心x坐标，默认为几何原点 |
cy? | number | 旋转中心y坐标, 默认为几何原点 |