Liubing\LB
3d8d4d18f3
先修复一下，错误的场景 删除不必要的钓场资产 修复into场景 update:更新meta文件，修复报错 update:修复资源 修复第一章节建造 修复建造第三章 update:删除多余内容 update:更新README.md update:还原图标 update:更新README update:更新配置
120 lines
3.3 KiB
C#
120 lines
3.3 KiB
C#
using UnityEngine;
|
||
using System.Collections.Generic;
|
||
|
||
public class Triangulator
|
||
{
|
||
private List<Vector2> m_points = new List<Vector2>();
|
||
|
||
public Triangulator(Vector2[] points)
|
||
{
|
||
m_points = new List<Vector2>(points);
|
||
}
|
||
|
||
public int[] Triangulate()
|
||
{
|
||
List<int> indices = new List<int>();
|
||
|
||
int n = m_points.Count;
|
||
if (n < 3)
|
||
return indices.ToArray();
|
||
|
||
int[] V = new int[n];
|
||
if (Area() > 0)//如果逆时针选点，点的index正向记录
|
||
{
|
||
for (int v = 0; v < n; v++)
|
||
V[v] = v;
|
||
}
|
||
else
|
||
{//如果顺时针选点，点的index反向记录
|
||
for (int v = 0; v < n; v++)
|
||
V[v] = (n - 1) - v;
|
||
}
|
||
|
||
int nv = n;
|
||
int count = 2 * nv;
|
||
for (int v = nv - 1; nv > 2;)
|
||
{
|
||
if ((count--) <= 0)
|
||
return indices.ToArray();
|
||
|
||
int u = v;
|
||
if (nv <= u)
|
||
u = 0;
|
||
v = u + 1;
|
||
if (nv <= v)
|
||
v = 0;
|
||
int w = v + 1;
|
||
if (nv <= w)
|
||
w = 0;
|
||
|
||
if (Snip(u, v, w, nv, V))//u,v,w三点是否能构成三角面
|
||
{
|
||
int a, b, c, s, t;
|
||
a = V[u];
|
||
b = V[v];
|
||
c = V[w];
|
||
indices.Add(a);
|
||
indices.Add(b);
|
||
indices.Add(c);
|
||
for (s = v, t = v + 1; t < nv; s++, t++)//增加一个三角数据，把这个三角剪去
|
||
V[s] = V[t];
|
||
nv--;
|
||
count = 2 * nv;
|
||
}
|
||
}
|
||
|
||
indices.Reverse();//翻转法线
|
||
return indices.ToArray();
|
||
}
|
||
|
||
private float Area()
|
||
{
|
||
int n = m_points.Count;
|
||
float A = 0.0f;
|
||
for (int p = n - 1, q = 0; q < n; p = q++)
|
||
{
|
||
Vector2 pval = m_points[p];
|
||
Vector2 qval = m_points[q];
|
||
A += pval.x * qval.y - qval.x * pval.y;//两向量叉乘只取z值，如果为负则顺时针
|
||
}
|
||
return (A * 0.5f);
|
||
}
|
||
|
||
private bool Snip(int u, int v, int w, int n, int[] V)
|
||
{
|
||
int p;
|
||
Vector2 A = m_points[V[u]];
|
||
Vector2 B = m_points[V[v]];
|
||
Vector2 C = m_points[V[w]];
|
||
if (Mathf.Epsilon > (((B.x - A.x) * (C.y - A.y)) - ((B.y - A.y) * (C.x - A.x))))//判断三点是否为顺时针排列，如果是的话是凹陷，不计算三角
|
||
return false;
|
||
for (p = 0; p < n; p++)
|
||
{
|
||
if ((p == u) || (p == v) || (p == w))
|
||
continue;
|
||
Vector2 P = m_points[V[p]];
|
||
if (InsideTriangle(A, B, C, P))//是否有其他的点在三角形内部，是，不计算三角
|
||
return false;
|
||
}
|
||
return true;
|
||
}
|
||
|
||
private bool InsideTriangle(Vector2 A, Vector2 B, Vector2 C, Vector2 P)
|
||
{
|
||
float ax, ay, bx, by, cx, cy, apx, apy, bpx, bpy, cpx, cpy;
|
||
float cCROSSap, bCROSScp, aCROSSbp;
|
||
|
||
ax = C.x - B.x; ay = C.y - B.y;
|
||
bx = A.x - C.x; by = A.y - C.y;
|
||
cx = B.x - A.x; cy = B.y - A.y;
|
||
apx = P.x - A.x; apy = P.y - A.y;
|
||
bpx = P.x - B.x; bpy = P.y - B.y;
|
||
cpx = P.x - C.x; cpy = P.y - C.y;
|
||
|
||
aCROSSbp = ax * bpy - ay * bpx;
|
||
cCROSSap = cx * apy - cy * apx;
|
||
bCROSScp = bx * cpy - by * cpx;
|
||
|
||
return ((aCROSSbp >= 0.0f) && (bCROSScp >= 0.0f) && (cCROSSap >= 0.0f));//都是逆时针，P在ABC内
|
||
}
|
||
} |