--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/orpg/mapper/isometric.py	Tue Jul 14 16:41:58 2009 -0500
@@ -0,0 +1,102 @@
+# Copyright (C) 2000-2001 The OpenRPG Project
+#
+#    openrpg-dev@lists.sourceforge.net
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+# --
+#
+# File: mapper/isometric.py
+# Author: Todd Faris (Snowdog)
+# Maintainer:
+# Version:
+#
+# Description:
+#   helper class definition for drawing and line collision within an isometric grid
+#   based on a interger based coordinate system where X increase to the right
+#   and Y increases in the downward direction
+
+
+class IsoGrid:
+    def __init__(self,width):
+        self.ratio = 2.0
+        self.width = width
+        self.height = 0
+        self.CalcRatio()
+        self.center_x = 0
+        self.center_y = 0
+
+    def Ratio(self, r ):
+        "changes the height/width ratio of the isometric rectangle with respect to the horizontal (x) axis"
+        self.ratio = float(r)
+        self.CalcRatio()
+
+    def CalcRatio(self):
+        if (self.ratio <= 0): self.ratio = 1
+        self.height = int( float(self.width)/float(self.ratio) )
+
+    def BoundPlace(self, left,top):
+        "Places the isometric rectangle using its upper left bounding corner for positioning"
+        dx,dy = self.CornerOffset()
+        self.Recenter( left+dx, top+dy)
+
+    def Recenter(self,x,y):
+        "Places the isomentric rectangle using the centerpoint"
+        self.center_x = x
+        self.center_y = y
+
+    def Top(self):
+        "Returns the topmost point of the isometric rectangle as a tuple (x,y)"
+        x = int(self.center_x)
+        y = int(self.center_y) - int(self.height/2)
+        return(x,y)
+
+    def Left(self):
+        "Returns the leftmost point of the isometric rectangle as a tuple (x,y)"
+        x = int(self.center_x) - int(self.width/2)
+        y = int(self.center_y)
+        return(x,y)
+
+    def Right(self):
+        "Returns the rightmost point of the isometric rectangle as a tuple (x,y)"
+        x,y = self.Left()
+        x = x + self.width
+        return(x,y)
+
+    def Bottom(self):
+        "Returns the bottommost point of the isometric rectangle as a tuple (x,y)"
+        x,y = self.Top()
+        y = y + self.height
+        return(x,y)
+
+    def Center(self):
+        "Returns the center point of the isometric rectangle as a tuple (x,y)"
+        x = int(self.center_x)
+        y = int(self.center_y)
+        return(x,y)
+
+    def CornerOffset(self):
+        """Returns a tuple (delta_x,delta_y) representing the offset from the centerpoint
+        of the isometric rectangle to the upper left corner of its rectangular bounding box"""
+        dx = float(self.width/2)
+        dy = float(self.height/2)
+        return (dx,dy)
+
+    def Height(self):
+        "Returns the height of the isometric rectangle based on current ratio"
+        return int(self.height)
+
+    def Width(self):
+        "returns the width of the isomentric rectangle"
+        return int(self.width)