WIP for SAGA engine.

 o text formatting is not consistent with rules, just indent utility is too
   dumb for that
 o it does not use OSystem, i.e. it runs on direct SDL calls
 o it may not even compile on your box
 o if you enable it, expect zillions of warnings
 o no sound

Now it runs ITE intro as reinherit did

svn-id: r13564

1 files changed, 72 insertions, 0 deletions

diff --git a/saga/math.cpp b/saga/math.cpp
new file mode 100644
index 0000000000..1c3b12fc93
--- /dev/null
+++ b/saga/math.cpp
@@ -0,0 +1,72 @@
+/* ScummVM - Scumm Interpreter
+ * Copyright (C) 2004 The ScummVM project
+ *
+ * The ReInherit Engine is (C)2000-2003 by Daniel Balsom.
+ *
+ * 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.
+ *
+ * $Header$
+ *
+ */
+/*
+
+ Description:   
+ 
+    Math routines
+
+ Notes: 
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "reinherit.h"
+
+namespace Saga {
+
+int
+MATH_HitTestPoly(R_POINT * points, unsigned int npoints, R_POINT test_point)
+{
+	int yflag0;
+	int yflag1;
+	int inside_flag = 0;
+	unsigned int pt;
+
+	R_POINT *vtx0 = &points[npoints - 1];
+	R_POINT *vtx1 = &points[0];
+
+	yflag0 = (vtx0->y >= test_point.y);
+
+	for (pt = 0; pt < npoints; pt++, vtx1++) {
+
+		yflag1 = (vtx1->y >= test_point.y);
+
+		if (yflag0 != yflag1) {
+
+			if (((vtx1->y - test_point.y) * (vtx0->x - vtx1->x) >=
+				(vtx1->x - test_point.x) * (vtx0->y -
+				    vtx1->y)) == yflag1) {
+
+				inside_flag = !inside_flag;
+			}
+		}
+		yflag0 = yflag1;
+		vtx0 = vtx1;
+	}
+
+	return inside_flag;
+}
+
+} // End of namespace Saga