Add lineIntersection test

Author: simonlindholm

content/geometry/lineIntersection.h

@@ -13,7 +13,7 @@ Products of three coordinates are used in intermediate steps so watch out for ov
 \begin{minipage}{15mm}
 \includegraphics[width=\textwidth]{content/geometry/lineIntersection}
 \end{minipage}
- * Status: tested through half-plane tests
+ * Status: fuzz-tested, and tested through half-plane tests
  * Usage:
  * 	auto res = lineInter(s1,e1,s2,e2);
  * 	if (res.first == 1)

fuzz-tests/geometry/LineIntersection.cpp

@@ -0,0 +1,31 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+#define rep(i, a, b) for(int i = a; i < int(b); ++i)
+#define trav(a, v) for(auto& a : v)
+#define all(x) x.begin(), x.end()
+#define sz(x) (int)(x).size()
+
+typedef long long ll;
+typedef pair<int, int> pii;
+typedef vector<int> vi;
+
+#include "../../content/geometry/lineIntersection.h"
+#include "../../content/geometry/lineDistance.h"
+
+int main() {
+	rep(t,0,1000000) {
+		const int GRID=10;
+		Point<double>
+			a(rand()%GRID, rand()%GRID),
+			b(rand()%GRID, rand()%GRID),
+			c(rand()%GRID, rand()%GRID),
+			d(rand()%GRID, rand()%GRID);
+		auto pa = lineInter(a,b,c,d);
+		if (pa.first == 1) {
+			assert(lineDist(a, b, pa.second) < 1e-8);
+			assert(lineDist(c, d, pa.second) < 1e-8);
+		}
+	}
+	cout<<"Tests passed!"<<endl;
+}