2 * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
3 * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
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:
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.
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
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.
31 ** Author: Eric Veach, July 1994.
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)
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))
49 #define VertEq(u,v) ((u)->s == (v)->s && (u)->t == (v)->t)
50 #define VertLeq(u,v) (((u)->s < (v)->s) || \
51 ((u)->s == (v)->s && (u)->t <= (v)->t))
54 #define EdgeEval(u,v,w) __gl_edgeEval(u,v,w)
55 #define EdgeSign(u,v,w) __gl_edgeSign(u,v,w)
57 /* Versions of VertLeq, EdgeSign, EdgeEval with s and t transposed. */
59 #define TransLeq(u,v) (((u)->t < (v)->t) || \
60 ((u)->t == (v)->t && (u)->s <= (v)->s))
61 #define TransEval(u,v,w) __gl_transEval(u,v,w)
62 #define TransSign(u,v,w) __gl_transSign(u,v,w)
65 #define EdgeGoesLeft(e) VertLeq( (e)->Dst, (e)->Org )
66 #define EdgeGoesRight(e) VertLeq( (e)->Org, (e)->Dst )
69 #define ABS(x) ((x) < 0 ? -(x) : (x))
70 #define VertL1dist(u,v) (ABS(u->s - v->s) + ABS(u->t - v->t))
72 #define VertCCW(u,v,w) __gl_vertCCW(u,v,w)
74 int __gl_vertLeq( GLUvertex *u, GLUvertex *v );
75 GLdouble __gl_edgeEval( GLUvertex *u, GLUvertex *v, GLUvertex *w );
76 GLdouble __gl_edgeSign( GLUvertex *u, GLUvertex *v, GLUvertex *w );
77 GLdouble __gl_transEval( GLUvertex *u, GLUvertex *v, GLUvertex *w );
78 GLdouble __gl_transSign( GLUvertex *u, GLUvertex *v, GLUvertex *w );
79 int __gl_vertCCW( GLUvertex *u, GLUvertex *v, GLUvertex *w );
80 void __gl_edgeIntersect( GLUvertex *o1, GLUvertex *d1,
81 GLUvertex *o2, GLUvertex *d2,