geometry: make the attributes of points optional

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>

diff --git a/lib/geometry/points_and_lines.nit b/lib/geometry/points_and_lines.nit
index 3dc158a..eef5606 100644 (file)
--- a/lib/geometry/points_and_lines.nit
+++ b/lib/geometry/points_and_lines.nit
@@ -88,8 +88,8 @@ end
 class Point[N: Numeric]
        super IPoint[N]
 
-       redef var x: N is writable
-       redef var y: N is writable
+       redef var x: N = 0.0 is writable, optional
+       redef var y: N = 0.0 is writable, optional
 end
 
 # Abstract 3d point, strongly linked to its implementation `Point3d`
@@ -107,7 +107,7 @@ class Point3d[N: Numeric]
        super IPoint3d[N]
        super Point[N]
 
-       redef var z: N is writable
+       redef var z: N = 0.0 is writable, optional
 end
 
 # Abstract 2D line segment between two ordered points