Viewport es mou a l'abad

data/viewport.lua

@@ -12,9 +12,15 @@ function viewport.new()
 			 print=viewport.print,
 			 room=viewport.coord2room,
              roomXY= viewport.room2coord,
-             tile= viewport.coord2tile } 
+             tile= viewport.coord2tile,
+             screen_coords = viewport.screen_coords } 
 end
 
+function viewport:screen_coords ( x, y )
+    local scr_x = x-self.x
+    local scr_y = y-self.y
+    return scr_x, scr_y
+end
 
 function viewport:coord2tile ()
 	local tw = arcade_config.tiles_width