4 files changed, 36 insertions, 6 deletions

diff --git a/core/math/convex_hull.cpp b/core/math/convex_hull.cpp
index 21cb0efe20..f67035c803 100644
--- a/core/math/convex_hull.cpp
+++ b/core/math/convex_hull.cpp
@@ -2260,10 +2260,21 @@ Error ConvexHullComputer::convex_hull(const Vector<Vector3> &p_points, Geometry3
 
 	r_mesh.vertices = ch.vertices;
 
-	r_mesh.edges.resize(ch.edges.size());
+	// Copy the edges over. There's two "half-edges" for every edge, so we pick only one of them.
+	r_mesh.edges.resize(ch.edges.size() / 2);
+	uint32_t edges_copied = 0;
 	for (uint32_t i = 0; i < ch.edges.size(); i++) {
-		r_mesh.edges.write[i].a = (&ch.edges[i])->get_source_vertex();
-		r_mesh.edges.write[i].b = (&ch.edges[i])->get_target_vertex();
+		uint32_t a = (&ch.edges[i])->get_source_vertex();
+		uint32_t b = (&ch.edges[i])->get_target_vertex();
+		if (a < b) { // Copy only the "canonical" edge. For the reverse edge, this will be false.
+			ERR_BREAK(edges_copied >= (uint32_t)r_mesh.edges.size());
+			r_mesh.edges.write[edges_copied].a = a;
+			r_mesh.edges.write[edges_copied].b = b;
+			edges_copied++;
+		}
+	}
+	if (edges_copied != (uint32_t)r_mesh.edges.size()) {
+		ERR_PRINT("Invalid edge count.");
 	}
 
 	r_mesh.faces.resize(ch.faces.size());
diff --git a/core/math/geometry_2d.h b/core/math/geometry_2d.h
index e1a5bfe6f2..8e5830f9b3 100644
--- a/core/math/geometry_2d.h
+++ b/core/math/geometry_2d.h
@@ -182,7 +182,15 @@ public:
 		C = Vector2(C.x * Bn.x + C.y * Bn.y, C.y * Bn.x - C.x * Bn.y);
 		D = Vector2(D.x * Bn.x + D.y * Bn.y, D.y * Bn.x - D.x * Bn.y);
 
-		if ((C.y < 0 && D.y < 0) || (C.y >= 0 && D.y >= 0)) {
+		// Fail if C x B and D x B have the same sign (segments don't intersect).
+		// (equivalent to condition (C.y < 0 && D.y < CMP_EPSILON) || (C.y > 0 && D.y > CMP_EPSILON))
+		if (C.y * D.y > CMP_EPSILON) {
+			return false;
+		}
+
+		// Fail if segments are parallel or colinear.
+		// (when A x B == zero, i.e (C - D) x B == zero, i.e C x B == D x B)
+		if (Math::is_equal_approx(C.y, D.y)) {
 			return false;
 		}
 
@@ -193,7 +201,7 @@ public:
 			return false;
 		}
 
-		// (4) Apply the discovered position to line A-B in the original coordinate system.
+		// Apply the discovered position to line A-B in the original coordinate system.
 		if (r_result) {
 			*r_result = p_from_a + B * ABpos;
 		}
@@ -353,8 +361,14 @@ public:
 		for (int i = 0; i < c; i++) {
 			const Vector2 &v1 = p[i];
 			const Vector2 &v2 = p[(i + 1) % c];
-			if (segment_intersects_segment(v1, v2, p_point, further_away, nullptr)) {
+
+			Vector2 res;
+			if (segment_intersects_segment(v1, v2, p_point, further_away, &res)) {
 				intersections++;
+				if (res.is_equal_approx(p_point)) {
+					// Point is in one of the polygon edges.
+					return true;
+				}
 			}
 		}
 
diff --git a/core/math/vector2.cpp b/core/math/vector2.cpp
index 54abc1b7f2..b53dc05a00 100644
--- a/core/math/vector2.cpp
+++ b/core/math/vector2.cpp
@@ -34,6 +34,10 @@ real_t Vector2::angle() const {
 	return Math::atan2(y, x);
 }
 
+Vector2 Vector2::from_angle(const real_t p_angle) {
+	return Vector2(Math::cos(p_angle), Math::sin(p_angle));
+}
+
 real_t Vector2::length() const {
 	return Math::sqrt(x * x + y * y);
 }
diff --git a/core/math/vector2.h b/core/math/vector2.h
index 330b4741b1..332c0475fa 100644
--- a/core/math/vector2.h
+++ b/core/math/vector2.h
@@ -147,6 +147,7 @@ struct Vector2 {
 	bool operator>=(const Vector2 &p_vec2) const { return x == p_vec2.x ? (y >= p_vec2.y) : (x > p_vec2.x); }
 
 	real_t angle() const;
+	static Vector2 from_angle(const real_t p_angle);
 
 	_FORCE_INLINE_ Vector2 abs() const {
 		return Vector2(Math::abs(x), Math::abs(y));