--- /dev/null
+// $Id$
+//
+// SuperTux
+// Copyright (C) 2009 Matt McCutchen
+//
+// 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+#include "aatriangle.hpp"
+
+int AATriangle::vertical_flip(int dir) {
+ int direction = dir & AATriangle::DIRECTION_MASK;
+ direction = 3 - direction;
+ int deform = dir & AATriangle::DEFORM_MASK;
+ switch (deform) {
+ case AATriangle::DEFORM1:
+ deform = AATriangle::DEFORM2;
+ break;
+ case AATriangle::DEFORM2:
+ deform = AATriangle::DEFORM1;
+ break;
+ default:
+ // unchanged
+ break;
+ }
+ return (direction | deform);
+}