1 files changed, 24 insertions, 10 deletions

diff --git a/core/math/geometry.h b/core/math/geometry.h
index ca4363e129..83b9467a30 100644
--- a/core/math/geometry.h
+++ b/core/math/geometry.h
@@ -33,9 +33,9 @@
 
 #include "dvector.h"
 #include "face3.h"
-#include "math_2d.h"
 #include "object.h"
 #include "print_string.h"
+#include "rect2.h"
 #include "triangulate.h"
 #include "vector.h"
 #include "vector3.h"
@@ -502,16 +502,15 @@ public:
 	}
 
 	static bool is_point_in_triangle(const Vector2 &s, const Vector2 &a, const Vector2 &b, const Vector2 &c) {
-		int as_x = s.x - a.x;
-		int as_y = s.y - a.y;
+		Vector2 an = a - s;
+		Vector2 bn = b - s;
+		Vector2 cn = c - s;
 
-		bool s_ab = (b.x - a.x) * as_y - (b.y - a.y) * as_x > 0;
+		bool orientation = an.cross(bn) > 0;
 
-		if (((c.x - a.x) * as_y - (c.y - a.y) * as_x > 0) == s_ab) return false;
+		if ((bn.cross(cn) > 0) != orientation) return false;
 
-		if (((c.x - b.x) * (s.y - b.y) - (c.y - b.y) * (s.x - b.x) > 0) != s_ab) return false;
-
-		return true;
+		return (cn.cross(an) > 0) == orientation;
 	}
 
 	static bool is_point_in_polygon(const Vector2 &p_point, const Vector<Vector2> &p_polygon);
@@ -530,6 +529,21 @@ public:
 		return p_segment[0] + n * d; // inside
 	}
 
+	static bool line_intersects_line_2d(const Vector2 &p_from_a, const Vector2 &p_dir_a, const Vector2 &p_from_b, const Vector2 &p_dir_b, Vector2 &r_result) {
+
+		// see http://paulbourke.net/geometry/pointlineplane/
+
+		const real_t denom = p_dir_b.y * p_dir_a.x - p_dir_b.x * p_dir_a.y;
+		if (Math::abs(denom) < CMP_EPSILON) { // parallel?
+			return false;
+		}
+
+		const Vector2 v = p_from_a - p_from_b;
+		const real_t t = (p_dir_b.x * v.y - p_dir_b.y * v.x) / denom;
+		r_result = p_from_a + t * p_dir_a;
+		return true;
+	}
+
 	static bool segment_intersects_segment_2d(const Vector2 &p_from_a, const Vector2 &p_to_a, const Vector2 &p_from_b, const Vector2 &p_to_b, Vector2 *r_result) {
 
 		Vector2 B = p_to_a - p_from_a;
@@ -876,14 +890,14 @@ public:
 		for (int i = 0; i < n; ++i) {
 			while (k >= 2 && vec2_cross(H[k - 2], H[k - 1], P[i]) <= 0)
 				k--;
-			H[k++] = P[i];
+			H.write[k++] = P[i];
 		}
 
 		// Build upper hull
 		for (int i = n - 2, t = k + 1; i >= 0; i--) {
 			while (k >= t && vec2_cross(H[k - 2], H[k - 1], P[i]) <= 0)
 				k--;
-			H[k++] = P[i];
+			H.write[k++] = P[i];
 		}
 
 		H.resize(k);