[longomatch] Fix Area conversion in scalled canvas

[Andoni Morales Alastruey <amorales src gnome org>]

commit e3fe995c603adf6a8b824c46a3efea43feb92aae
Author: Andoni Morales Alastruey <ylatuya gmail com>
Date:   Sun Oct 26 19:52:03 2014 +0100

    Fix Area conversion in scalled canvas

 LongoMatch.Drawing.Cairo/CairoBackend.cs |   18 +++++++++---------
 1 files changed, 9 insertions(+), 9 deletions(-)
---
diff --git a/LongoMatch.Drawing.Cairo/CairoBackend.cs b/LongoMatch.Drawing.Cairo/CairoBackend.cs
index 9c0b961..5c6921c 100644
--- a/LongoMatch.Drawing.Cairo/CairoBackend.cs
+++ b/LongoMatch.Drawing.Cairo/CairoBackend.cs
@@ -190,20 +190,20 @@ namespace LongoMatch.Drawing.Cairo
 
                public Area UserToDevice (Area a)
                {
-                       double x, y, d1, d2;
+                       double x, y, x2, y2, x3, y3;
                        
                        x = a.Start.X;
                        y = a.Start.Y;
                        CContext.UserToDevice (ref x, ref y);
                        Area ua = new Area (new Point (x, y), 0, 0);
-                       d1 = 0;
-                       d2 = a.Width;
-                       CContext.UserToDeviceDistance (ref d1, ref d2);
-                       ua.Width = d2 - d1;
-                       d1 = 0;
-                       d2 = a.Height;
-                       CContext.UserToDeviceDistance (ref d1, ref d2);
-                       ua.Height = d2 - d1;
+                       x2 = a.TopRight.X;
+                       y2 = a.TopRight.Y;
+                       CContext.UserToDevice (ref x2, ref y2);
+                       ua.Width = x2 - x;
+                       x3 = a.BottomLeft.X;
+                       y3 = a.BottomLeft.Y;
+                       CContext.UserToDevice (ref x3, ref y3);
+                       ua.Height = y3 - y;
                        return ua;
                }