maptool/refine/rmath.h

/*
 * This file is a part of Poly2Tri-C
 * (c) Barak Itkin <lightningismyname@gmail.com>
 * http://code.google.com/p/poly2tri-c/
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * * Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 * * Neither the name of Poly2Tri nor the names of its contributors may be
 *   used to endorse or promote products derived from this software without specific
 *   prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef __P2TC_REFINE_MATH_H__
#define __P2TC_REFINE_MATH_H__

#include <glib.h>
#include "vector2.h"
#include "circle.h"

gdouble   p2tr_math_length_sq  (gdouble x1,
                                gdouble y1,
                                gdouble x2,
                                gdouble y2);

gdouble   p2tr_math_length_sq2 (const P2trVector2 *pt1,
                                const P2trVector2 *pt2);


/**
 * Find the circumscribing circle of a triangle defined by the given
 * points.
 * @param[in] A The first vertex of the triangle
 * @param[in] B The second vertex of the triangle
 * @param[in] C The third vertex of the triangle
 * @param[out] circle The circumscribing circle of the triangle
 */
void      p2tr_math_triangle_circumcircle (const P2trVector2 *A,
                                           const P2trVector2 *B,
                                           const P2trVector2 *C,
                                           P2trCircle    *circle);

typedef enum
{
  P2TR_INTRIANGLE_OUT = -1,
  P2TR_INTRIANGLE_ON = 0,
  P2TR_INTRIANGLE_IN = 1
} P2trInTriangle;

/**
 * Return the barycentric coordinates of a point inside a triangle. This
 * means that the computation returns @ref u and @ref v so that the
 * following equation is satisfied:
 * {{{ AP = u * AB + v * AC }}}
 *
 * @param[in] A The first point of the triangle
 * @param[in] B The second point of the triangle
 * @param[in] C The third point of the triangle
 * @param[in] P The point whose barycentric coordinates should be
 *              computed
 * @param[out] u The first barycentric coordinate
 * @param[out] v The second barycentric coordinate
 */
void p2tr_math_triangle_barcycentric (const P2trVector2 *A,
                                      const P2trVector2 *B,
                                      const P2trVector2 *C,
                                      const P2trVector2 *P,
                                      gdouble           *u,
                                      gdouble           *v);

P2trInTriangle p2tr_math_intriangle (const P2trVector2 *A,
                                     const P2trVector2 *B,
                                     const P2trVector2 *C,
                                     const P2trVector2 *P);

P2trInTriangle p2tr_math_intriangle2 (const P2trVector2 *A,
                                      const P2trVector2 *B,
                                      const P2trVector2 *C,
                                      const P2trVector2 *P,
                                      gdouble           *u,
                                      gdouble           *v);

typedef enum
{
  P2TR_ORIENTATION_CW = -1,
  P2TR_ORIENTATION_LINEAR = 0,
  P2TR_ORIENTATION_CCW = 1
} P2trOrientation;

P2trOrientation p2tr_math_orient2d (const P2trVector2 *A,
                                    const P2trVector2 *B,
                                    const P2trVector2 *C);

typedef enum
{
  P2TR_INCIRCLE_IN,
  P2TR_INCIRCLE_ON,
  P2TR_INCIRCLE_OUT
} P2trInCircle;

P2trInCircle p2tr_math_incircle (const P2trVector2 *A,
                                 const P2trVector2 *B,
                                 const P2trVector2 *C,
                                 const P2trVector2 *D);

gboolean  p2tr_math_diametral_circle_contains (const P2trVector2 *X,
                                               const P2trVector2 *Y,
                                               const P2trVector2 *W);

gboolean  p2tr_math_diametral_lens_contains   (const P2trVector2 *X,
                                               const P2trVector2 *Y,
                                               const P2trVector2 *W);
#endif
1	/*
2	* This file is a part of Poly2Tri-C
3	* (c) Barak Itkin <lightningismyname@gmail.com>
4	* http://code.google.com/p/poly2tri-c/
5	*
6	* All rights reserved.
7	*
8	* Redistribution and use in source and binary forms, with or without modification,
9	* are permitted provided that the following conditions are met:
10	*
11	* * Redistributions of source code must retain the above copyright notice,
12	* this list of conditions and the following disclaimer.
13	* * Redistributions in binary form must reproduce the above copyright notice,
14	* this list of conditions and the following disclaimer in the documentation
15	* and/or other materials provided with the distribution.
16	* * Neither the name of Poly2Tri nor the names of its contributors may be
17	* used to endorse or promote products derived from this software without specific
18	* prior written permission.
19	*
20	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
23	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
24	* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
25	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
26	* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
27	* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
28	* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
29	* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
30	* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31	*/
32
33	#ifndef __P2TC_REFINE_MATH_H__
34	#define __P2TC_REFINE_MATH_H__
35
36	#include <glib.h>
37	#include "vector2.h"
38	#include "circle.h"
39
40	gdouble p2tr_math_length_sq (gdouble x1,
41	gdouble y1,
42	gdouble x2,
43	gdouble y2);
44
45	gdouble p2tr_math_length_sq2 (const P2trVector2 *pt1,
46	const P2trVector2 *pt2);
47
48
49	/**
50	* Find the circumscribing circle of a triangle defined by the given
51	* points.
52	* @param[in] A The first vertex of the triangle
53	* @param[in] B The second vertex of the triangle
54	* @param[in] C The third vertex of the triangle
55	* @param[out] circle The circumscribing circle of the triangle
56	*/
57	void p2tr_math_triangle_circumcircle (const P2trVector2 *A,
58	const P2trVector2 *B,
59	const P2trVector2 *C,
60	P2trCircle *circle);
61
62	typedef enum
63	{
64	P2TR_INTRIANGLE_OUT = -1,
65	P2TR_INTRIANGLE_ON = 0,
66	P2TR_INTRIANGLE_IN = 1
67	} P2trInTriangle;
68
69	/**
70	* Return the barycentric coordinates of a point inside a triangle. This
71	* means that the computation returns @ref u and @ref v so that the
72	* following equation is satisfied:
73	* {{{ AP = u * AB + v * AC }}}
74	*
75	* @param[in] A The first point of the triangle
76	* @param[in] B The second point of the triangle
77	* @param[in] C The third point of the triangle
78	* @param[in] P The point whose barycentric coordinates should be
79	* computed
80	* @param[out] u The first barycentric coordinate
81	* @param[out] v The second barycentric coordinate
82	*/
83	void p2tr_math_triangle_barcycentric (const P2trVector2 *A,
84	const P2trVector2 *B,
85	const P2trVector2 *C,
86	const P2trVector2 *P,
87	gdouble *u,
88	gdouble *v);
89
90	P2trInTriangle p2tr_math_intriangle (const P2trVector2 *A,
91	const P2trVector2 *B,
92	const P2trVector2 *C,
93	const P2trVector2 *P);
94
95	P2trInTriangle p2tr_math_intriangle2 (const P2trVector2 *A,
96	const P2trVector2 *B,
97	const P2trVector2 *C,
98	const P2trVector2 *P,
99	gdouble *u,
100	gdouble *v);
101
102	typedef enum
103	{
104	P2TR_ORIENTATION_CW = -1,
105	P2TR_ORIENTATION_LINEAR = 0,
106	P2TR_ORIENTATION_CCW = 1
107	} P2trOrientation;
108
109	P2trOrientation p2tr_math_orient2d (const P2trVector2 *A,
110	const P2trVector2 *B,
111	const P2trVector2 *C);
112
113	typedef enum
114	{
115	P2TR_INCIRCLE_IN,
116	P2TR_INCIRCLE_ON,
117	P2TR_INCIRCLE_OUT
118	} P2trInCircle;
119
120	P2trInCircle p2tr_math_incircle (const P2trVector2 *A,
121	const P2trVector2 *B,
122	const P2trVector2 *C,
123	const P2trVector2 *D);
124
125	gboolean p2tr_math_diametral_circle_contains (const P2trVector2 *X,
126	const P2trVector2 *Y,
127	const P2trVector2 *W);
128
129	gboolean p2tr_math_diametral_lens_contains (const P2trVector2 *X,
130	const P2trVector2 *Y,
131	const P2trVector2 *W);
132	#endif