geom.h

/*
 * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
 * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice including the dates of first publication and
 * either this permission notice or a reference to
 * http://oss.sgi.com/projects/FreeB/
 * shall be included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
 * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * Except as contained in this notice, the name of Silicon Graphics, Inc.
 * shall not be used in advertising or otherwise to promote the sale, use or
 * other dealings in this Software without prior written authorization from
 * Silicon Graphics, Inc.
 */
/*
** Author: Eric Veach, July 1994.
**
*/

#ifndef __geom_h_
#define __geom_h_

#include "mesh.h"

#ifdef NO_BRANCH_CONDITIONS
/* MIPS architecture has special instructions to evaluate boolean
 * conditions -- more efficient than branching, IF you can get the
 * compiler to generate the right instructions (SGI compiler doesn't)
 */
#define VertEq(u, v)    (((u)->s == (v)->s) & ((u)->t == (v)->t))
#define VertLeq(u, v)   (((u)->s < (v)->s) | \
                         ((u)->s == (v)->s & (u)->t <= (v)->t))
#else

#define VertEq(u, v)    ((u)->s == (v)->s && (u)->t == (v)->t)
#define VertLeq(u, v)   (((u)->s < (v)->s) || \
                         ((u)->s == (v)->s && (u)->t <= (v)->t))
#endif

#define EdgeEval(u, v, w) __gl_edgeEval(u, v, w)
#define EdgeSign(u, v, w) __gl_edgeSign(u, v, w)

/* Versions of VertLeq, EdgeSign, EdgeEval with s and t transposed. */

#define TransLeq(u,v)   (((u)->t < (v)->t) || \
                         ((u)->t == (v)->t && (u)->s <= (v)->s))
#define TransEval(u,v,w)        __gl_transEval(u,v,w)
#define TransSign(u,v,w)        __gl_transSign(u,v,w)

#define EdgeGoesLeft(e)         VertLeq((e)->Dst, (e)->Org)
#define EdgeGoesRight(e)        VertLeq((e)->Org, (e)->Dst)

#undef ABS
#define ABS(x) ((x)<0 ? -(x) : (x))
#define VertL1dist(u, v) (ABS(u->s-v->s)+ABS(u->t-v->t))

#define VertCCW(u, v, w) __gl_vertCCW(u, v, w)

int     __gl_vertLeq(GLUESvertex* u, GLUESvertex* v);
GLfloat __gl_edgeEval(GLUESvertex* u, GLUESvertex* v, GLUESvertex* w);
GLfloat __gl_edgeSign(GLUESvertex* u, GLUESvertex* v, GLUESvertex* w);
GLfloat __gl_transEval(GLUESvertex* u, GLUESvertex* v, GLUESvertex* w);
GLfloat __gl_transSign(GLUESvertex* u, GLUESvertex* v, GLUESvertex* w);
int     __gl_vertCCW(GLUESvertex* u, GLUESvertex* v, GLUESvertex* w);
void    __gl_edgeIntersect(GLUESvertex* o1, GLUESvertex* d1,
                           GLUESvertex* o2, GLUESvertex* d2,
                           GLUESvertex* v);

#endif /* __geom_h_ */