Add helpers for testing for triangle overlap/containedness

2 files changed, 18 insertions, 0 deletions

diff --git a/game/geoData.cpp b/game/geoData.cpp
index 49cf892..ae43f3f 100644
--- a/game/geoData.cpp
+++ b/game/geoData.cpp
@@ -359,3 +359,19 @@ GeoData::update_vertex_normals_only()
 		this->set_normal(vh, glm::normalize(n));
 	}
 }
+
+bool
+GeoData::triangleOverlapsTriangle(const Triangle<2> & a, const Triangle<2> & b)
+{
+	return triangleContainsPoint(a.x, b) || triangleContainsPoint(a.y, b) || triangleContainsPoint(a.z, b)
+			|| triangleContainsPoint(b.x, a) || triangleContainsPoint(b.y, a) || triangleContainsPoint(b.z, a)
+			|| linesCross(a.x, a.y, b.x, b.y) || linesCross(a.x, a.y, b.y, b.z) || linesCross(a.x, a.y, b.z, b.x)
+			|| linesCross(a.y, a.z, b.x, b.y) || linesCross(a.y, a.z, b.y, b.z) || linesCross(a.y, a.z, b.z, b.x)
+			|| linesCross(a.z, a.x, b.x, b.y) || linesCross(a.z, a.x, b.y, b.z) || linesCross(a.z, a.x, b.z, b.x);
+}
+
+bool
+GeoData::triangleContainsTriangle(const Triangle<2> & a, const Triangle<2> & b)
+{
+	return triangleContainsPoint(a.x, b) && triangleContainsPoint(a.y, b) && triangleContainsPoint(a.z, b);
+}
diff --git a/game/geoData.h b/game/geoData.h
index e234bfe..2fd3aa5 100644
--- a/game/geoData.h
+++ b/game/geoData.h
@@ -103,6 +103,8 @@ protected:
 
 	[[nodiscard]] static bool triangleContainsPoint(const GlobalPosition2D, const Triangle<2> &);
 	[[nodiscard]] bool triangleContainsPoint(const GlobalPosition2D, FaceHandle) const;
+	[[nodiscard]] static bool triangleOverlapsTriangle(const Triangle<2> &, const Triangle<2> &);
+	[[nodiscard]] static bool triangleContainsTriangle(const Triangle<2> &, const Triangle<2> &);
 	[[nodiscard]] HalfedgeHandle findBoundaryStart() const;
 
 	void update_vertex_normals_only();