Geometry: Adds padded on boxes

Signed-off-by: Romain Chanoir <chanoir.romain@courrier.uqam.ca>

diff --git a/lib/geometry/boxes.nit b/lib/geometry/boxes.nit
index 61af367..6478c45 100644 (file)
--- a/lib/geometry/boxes.nit
+++ b/lib/geometry/boxes.nit
@@ -74,6 +74,15 @@ interface Boxed[N: Numeric]
                return self.left <= other.right and other.left <= self.right and
                        self.top >= other.bottom and other.top >= self.bottom
        end
+
+       # Create a bounding box that englobes the actual bounding box.
+       # `dist` is the distance between the inner boundaries and the outer boundaries.
+       # ~~~
+       # var p = new Point[Int](5,10)
+       # var b = p.padded(3)
+       # assert b.top == 2 and b.bot = 8 and b.left == 7 and b.right == 13
+       # ~~~
+       fun padded(dist: N): Box[N] do return new Box[N].lrtb(left - dist, right + dist, top + dist, bottom - dist)
 end
 
 # A 2d bounded object and an implementation of `Boxed`
@@ -201,6 +210,8 @@ interface Boxed3d[N: Numeric]
                return super and (not other isa Boxed3d[N] or
                        (self.back <= other.front and other.back <= self.front))
        end
+
+       redef fun padded(dist: N): Box3d[N] do return new Box3d[N].lrtbfb(left - dist, right + dist, top + dist, bottom - dist, front + dist, back - dist)
 end
 
 # A 3d bounded object and an implementation of Boxed