diff -r 9444de9762c3 -r 57de8fab2237 src/geometry.h
--- a/src/geometry.h	Sun Apr 09 17:05:40 2023 +0300
+++ b/src/geometry.h	Mon Apr 10 12:40:49 2023 +0300
@@ -138,8 +138,9 @@
 LineSegment2D bottom(const QRectF& rectangle);
 LineSegment2D left(const QRectF& rectangle);
 LineSegment2D right(const QRectF& rectangle);
-bool isConvex(const Quadrilateral& quad);
-bool isConvex(const std::vector<glm::vec3>& polygon);
+enum class convexity_e { concave, convex };
+convexity_e quadrilateral_convexity(const Quadrilateral& quad);
+convexity_e polygon_convexity(const std::vector<glm::vec3>& polygon);
 Winding winding(const QPolygonF& polygon);
 struct ScalingExtract
 {