Colors. Lines.

src/include/geom.h

@@ -32,6 +32,9 @@ void tri_destroy(Tri* tri);
 // Check if a point is within the triangle. Uses barycentric coordinate system.
 bool tri_within(Pt pt, Tri* tri);
 
+// Get the center point of a Tri.
+Pt tri_center(Tri* tri);
+
 typedef struct {
     Color col;
     size_t ntris;