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

• constructor

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

Rectangle

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

PointLike[]

---

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	Default value	Description
out	vec2[]	undefined	-
points	PointLike[]	undefined	点坐标数组
isClosed	boolean	false	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	Default value	Description
normalPoints	PointLike[]	undefined	归一化坐标数组
angle	number	undefined
cx	number	0	旋转中心x坐标，默认为几何原点
cy	number	0	旋转中心y坐标, 默认为几何原点

Returns

PointLike[]