Stellarium  0.90.0
geom.h
1 /*
2  * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
3  * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining a
6  * copy of this software and associated documentation files (the "Software"),
7  * to deal in the Software without restriction, including without limitation
8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9  * and/or sell copies of the Software, and to permit persons to whom the
10  * Software is furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice including the dates of first publication and
13  * either this permission notice or a reference to
14  * http://oss.sgi.com/projects/FreeB/
15  * shall be included in all copies or substantial portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20  * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
21  * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
22  * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23  * SOFTWARE.
24  *
25  * Except as contained in this notice, the name of Silicon Graphics, Inc.
26  * shall not be used in advertising or otherwise to promote the sale, use or
27  * other dealings in this Software without prior written authorization from
28  * Silicon Graphics, Inc.
29  */
30 /*
31 ** Author: Eric Veach, July 1994.
32 **
33 */
34 
35 #ifndef __geom_h_
36 #define __geom_h_
37 
38 #include "mesh.h"
39 
40 #ifdef NO_BRANCH_CONDITIONS
41 /* MIPS architecture has special instructions to evaluate boolean
42  * conditions -- more efficient than branching, IF you can get the
43  * compiler to generate the right instructions (SGI compiler doesn't)
44  */
45 #define VertEq(u, v) (((u)->s == (v)->s) & ((u)->t == (v)->t))
46 #define VertLeq(u, v) (((u)->s < (v)->s) | \
47  ((u)->s == (v)->s & (u)->t <= (v)->t))
48 #else
49 
50 #define VertEq(u, v) ((u)->s == (v)->s && (u)->t == (v)->t)
51 #define VertLeq(u, v) (((u)->s < (v)->s) || \
52  ((u)->s == (v)->s && (u)->t <= (v)->t))
53 #endif
54 
55 #define EdgeEval(u, v, w) __gl_edgeEval(u, v, w)
56 #define EdgeSign(u, v, w) __gl_edgeSign(u, v, w)
57 
58 /* Versions of VertLeq, EdgeSign, EdgeEval with s and t transposed. */
59 
60 #define TransLeq(u,v) (((u)->t < (v)->t) || \
61  ((u)->t == (v)->t && (u)->s <= (v)->s))
62 #define TransEval(u,v,w) __gl_transEval(u,v,w)
63 #define TransSign(u,v,w) __gl_transSign(u,v,w)
64 
65 #define EdgeGoesLeft(e) VertLeq((e)->Dst, (e)->Org)
66 #define EdgeGoesRight(e) VertLeq((e)->Org, (e)->Dst)
67 
68 #undef ABS
69 #define ABS(x) ((x)<0 ? -(x) : (x))
70 #define VertL1dist(u, v) (ABS(u->s-v->s)+ABS(u->t-v->t))
71 
72 #define VertCCW(u, v, w) __gl_vertCCW(u, v, w)
73 
74 int __gl_vertLeq(GLUESvertex* u, GLUESvertex* v);
75 GLfloat __gl_edgeEval(GLUESvertex* u, GLUESvertex* v, GLUESvertex* w);
76 GLfloat __gl_edgeSign(GLUESvertex* u, GLUESvertex* v, GLUESvertex* w);
77 GLfloat __gl_transEval(GLUESvertex* u, GLUESvertex* v, GLUESvertex* w);
78 GLfloat __gl_transSign(GLUESvertex* u, GLUESvertex* v, GLUESvertex* w);
79 int __gl_vertCCW(GLUESvertex* u, GLUESvertex* v, GLUESvertex* w);
80 void __gl_edgeIntersect(GLUESvertex* o1, GLUESvertex* d1,
81  GLUESvertex* o2, GLUESvertex* d2,
82  GLUESvertex* v);
83 
84 #endif /* __geom_h_ */