From 35c31a3fb51130e50857487ab8cea8ee7c5cb954 Mon Sep 17 00:00:00 2001
From: Maciej Suminski <maciej.suminski@cern.ch>
Date: Wed, 9 Jul 2014 15:02:56 +0200
Subject: [PATCH] Fixed grid drawing when the grid origin has negative
 coordinates.

---
 common/gal/graphics_abstraction_layer.cpp | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/common/gal/graphics_abstraction_layer.cpp b/common/gal/graphics_abstraction_layer.cpp
index 00e976b19a..d21b12b783 100644
--- a/common/gal/graphics_abstraction_layer.cpp
+++ b/common/gal/graphics_abstraction_layer.cpp
@@ -157,10 +157,10 @@ void GAL::DrawGrid()
         assert( gridEndY >= gridStartY );
 
         // Correct the index, else some lines are not correctly painted
-        gridStartX  -= ( gridOrigin.x / gridSize.x ) + 1;
-        gridStartY  -= ( gridOrigin.y / gridSize.y ) + 1;
-        gridEndX    += ( gridOrigin.x / gridSize.x ) + 1;
-        gridEndY    += ( gridOrigin.y / gridSize.y ) + 1;
+        gridStartX -= abs( gridOrigin.x / gridSize.x ) + 1;
+        gridStartY -= abs( gridOrigin.y / gridSize.y ) + 1;
+        gridEndX += abs( gridOrigin.x / gridSize.x ) + 1;
+        gridEndY += abs( gridOrigin.y / gridSize.y ) + 1;
 
         // Draw the grid behind all other layers
         SetLayerDepth( depthRange.y * 0.75 );