circles intersection and tourel beacon

[aversive.git] / modules / base / math / geometry / circles.h

diff --git a/modules/base/math/geometry/circles.h b/modules/base/math/geometry/circles.h
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+++ b/modules/base/math/geometry/circles.h
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+/*
+ *  Copyright Droids Corporation (2009)
+ *
+ *  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
+ *
+ *  Revision : $Id: f16.h,v 1.6.4.3 2008-05-10 15:06:26 zer0 Exp $
+ *
+ */
+
+#ifndef _CIRCLES_H_
+#define _CIRCLES_H_
+
+typedef struct _circle {
+       double x;
+       double y;
+       double r;
+} circle_t;
+
+/* return true if a point is in the disc */
+uint8_t pt_is_inside_circle(const point_t *p, circle_t *c);
+
+/*
+ * return values:
+ *  0 dont cross
+ *  1 one intersection point
+ *  2 two intersection points
+ *
+ *  p1, p2 arguments are the crossing points coordinates. Both p1 and
+ *  p2 are dummy for 0 result. When result is 1, p1 and p2 are set to
+ *  the same value.
+ */
+uint8_t circle_intersect(const circle_t *c1, const circle_t *c2,
+                        point_t *p1, point_t *p2);
+
+#endif /* _CIRCLES_H_ */