1/*
2** License Applicability. Except to the extent portions of this file are
3** made subject to an alternative license as permitted in the SGI Free
4** Software License B, Version 1.1 (the "License"), the contents of this
5** file are subject only to the provisions of the License. You may not use
6** this file except in compliance with the License. You may obtain a copy
7** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
8** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
9**
10** http://oss.sgi.com/projects/FreeB
11**
12** Note that, as provided in the License, the Software is distributed on an
13** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
14** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
15** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
16** PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
17**
18** Original Code. The Original Code is: OpenGL Sample Implementation,
19** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
20** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
21** Copyright in any portions created by third parties is as indicated
22** elsewhere herein. All Rights Reserved.
23**
24** Additional Notice Provisions: The application programming interfaces
25** established by SGI in conjunction with the Original Code are The
26** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
27** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
28** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
29** Window System(R) (Version 1.3), released October 19, 1998. This software
30** was created using the OpenGL(R) version 1.2.1 Sample Implementation
31** published by SGI, but has not been independently verified as being
32** compliant with the OpenGL(R) version 1.2.1 Specification.
33*/
34
35/*
36 * arc.c++
37 *
38 */
39
40#include <stdio.h>
41#include "glimports.h"
42#include "mystdio.h"
43#include "myassert.h"
44#include "arc.h"
45#include "bin.h"
46#include "pwlarc.h"
47#include "simplemath.h"
48
49/* local preprocessor definitions */
50#define ZERO		0.00001/*0.000001*/
51
52const int	Arc::bezier_tag = (1<<13);
53const int	Arc::arc_tag = (1<<3);
54const int	Arc::tail_tag = (1<<6);
55
56/*--------------------------------------------------------------------------
57 * makeSide - attach a pwl arc to an arc and mark it as a border arc
58 *--------------------------------------------------------------------------
59 */
60
61void
62Arc::makeSide( PwlArc *pwl, arc_side side )
63{
64    assert( pwl != 0);
65    assert( pwlArc == 0 );
66    assert( pwl->npts > 0 );
67    assert( pwl->pts != 0);
68    pwlArc = pwl;
69    clearbezier();
70    setside( side );
71}
72
73
74/*--------------------------------------------------------------------------
75 * numpts - count number of points on arc loop
76 *--------------------------------------------------------------------------
77 */
78
79int
80Arc::numpts( void )
81{
82    Arc_ptr jarc = this;
83    int npts = 0;
84    do {
85	npts += jarc->pwlArc->npts;
86	jarc = jarc->next;
87    } while( jarc != this );
88    return npts;
89}
90
91/*--------------------------------------------------------------------------
92 * markverts - mark each point with id of arc
93 *--------------------------------------------------------------------------
94 */
95
96void
97Arc::markverts( void )
98{
99    Arc_ptr jarc = this;
100
101    do {
102	TrimVertex *p = jarc->pwlArc->pts;
103	for( int i=0; i<jarc->pwlArc->npts; i++ )
104	    p[i].nuid = jarc->nuid;
105	jarc = jarc->next;
106    } while( jarc != this );
107}
108
109/*--------------------------------------------------------------------------
110 * getextrema - find axis extrema on arc loop
111 *--------------------------------------------------------------------------
112 */
113
114void
115Arc::getextrema( Arc_ptr extrema[4] )
116{
117    REAL leftpt, botpt, rightpt, toppt;
118
119    extrema[0] = extrema[1] = extrema[2] = extrema[3] = this;
120
121    leftpt = rightpt = this->tail()[0];
122    botpt  = toppt   = this->tail()[1];
123
124    for( Arc_ptr jarc = this->next; jarc != this; jarc = jarc->next ) {
125	if ( jarc->tail()[0] <	leftpt ||
126	    (jarc->tail()[0] <= leftpt && jarc->rhead()[0]<=leftpt))  {
127	    leftpt = jarc->pwlArc->pts->param[0];
128	    extrema[1] = jarc;
129	}
130	if ( jarc->tail()[0] >	rightpt ||
131	    (jarc->tail()[0] >= rightpt && jarc->rhead()[0] >= rightpt)) {
132	    rightpt = jarc->pwlArc->pts->param[0];
133	    extrema[3] = jarc;
134	}
135	if ( jarc->tail()[1] <	botpt ||
136	    (jarc->tail()[1] <= botpt && jarc->rhead()[1] <= botpt ))  {
137	    botpt = jarc->pwlArc->pts->param[1];
138	    extrema[2] = jarc;
139	}
140	if ( jarc->tail()[1] >	toppt ||
141	    (jarc->tail()[1] >= toppt && jarc->rhead()[1] >= toppt))  {
142	    toppt = jarc->pwlArc->pts->param[1];
143	    extrema[0] = jarc;
144	}
145    }
146}
147
148
149/*-------------------------------------------------------------------------
150 * show - print to the stdout the vertices of a pwl arc
151 *-------------------------------------------------------------------------
152 */
153
154void
155Arc::show()
156{
157#ifndef NDEBUG
158    _glu_dprintf( "\tPWLARC NP: %d FL: 1\n", pwlArc->npts );
159    for( int i = 0; i < pwlArc->npts; i++ ) {
160	 _glu_dprintf( "\t\tVERTEX %f %f\n", pwlArc->pts[i].param[0],
161			pwlArc->pts[i].param[1] );
162    }
163#endif
164}
165
166/*-------------------------------------------------------------------------
167 * print - print out the vertices of all pwl arcs on a loop
168 *-------------------------------------------------------------------------
169 */
170
171void
172Arc::print( void )
173{
174    Arc_ptr jarc = this;
175
176#ifndef NDEBUG
177    _glu_dprintf( "BGNTRIM\n" );
178#endif
179    do {
180	jarc->show( );
181	jarc = jarc->next;
182    } while (jarc != this);
183#ifndef NDEBUG
184    _glu_dprintf("ENDTRIM\n" );
185#endif
186}
187
188/*-------------------------------------------------------------------------
189 * isDisconnected - check if tail of arc and head of prev meet
190 *-------------------------------------------------------------------------
191 */
192
193int
194Arc::isDisconnected( void )
195{
196    if( pwlArc == 0 ) return 0;
197    if( prev->pwlArc == 0 ) return 0;
198
199    REAL *p0 = tail();
200    REAL *p1 = prev->rhead();
201
202    if( ((p0[0] - p1[0]) > ZERO) || ((p1[0] - p0[0]) > ZERO) ||
203	((p0[1] - p1[1]) > ZERO) || ((p1[1] - p0[1]) > ZERO)  ) {
204#ifndef NDEBUG
205	_glu_dprintf( "x coord = %f %f %f\n", p0[0], p1[0], p0[0] - p1[0] );
206	_glu_dprintf( "y coord = %f %f %f\n", p0[1], p1[1], p0[1] - p1[1] );
207#endif
208	return 1;
209    } else {
210	/* average two points together */
211	p0[0] = p1[0] = (p1[0] + p0[0]) * 0.5;
212	p0[1] = p1[1] = (p1[1] + p0[1]) * 0.5;
213	return 0;
214    }
215}
216
217/*-------------------------------------------------------------------------
218 * neq_vert - assert that two 2D vertices are not equal
219 *-------------------------------------------------------------------------
220 */
221
222inline static int
223neq_vert( REAL	*v1, REAL *v2 )
224{
225     return ((v1[0] != v2[0]) || (v1[1] != v2[1] )) ? 1 : 0;
226}
227
228/*-------------------------------------------------------------------------
229 * check - verify consistency of a loop, including
230 *		1) if pwl, no two consecutive vertices are identical
231 *		2) the circular link pointers are valid
232 *		3) the geometric info at the head and tail are consistent
233 *-------------------------------------------------------------------------
234 */
235
236int
237Arc::check( void )
238{
239    if( this == 0 ) return 1;
240    Arc_ptr jarc = this;
241    do {
242	assert( (jarc->pwlArc != 0) || (jarc->bezierArc != 0) );
243
244	if (jarc->prev == 0 || jarc->next == 0) {
245#ifndef NDEBUG
246	    _glu_dprintf( "checkjarc:null next/prev pointer\n");
247	    jarc->print( );
248#endif
249	    return 0;
250	}
251
252	if (jarc->next->prev != jarc) {
253#ifndef NDEBUG
254	    _glu_dprintf( "checkjarc: pointer linkage screwed up\n");
255	    jarc->print( );
256#endif
257	    return 0;
258	}
259
260	if( jarc->pwlArc ) {
261#ifndef NDEBUG
262	    assert( jarc->pwlArc->npts >= 1 );
263	    assert( jarc->pwlArc->npts < 100000 );
264/*
265	    for( int i=0; i < jarc->pwlArc->npts-1; i++ )
266		assert( neq_vert( jarc->pwlArc->pts[i].param,
267			     jarc->pwlArc->pts[i+1].param) );
268*/
269#endif
270	    if( jarc->prev->pwlArc ) {
271		if( jarc->tail()[1] != jarc->prev->rhead()[1] ) {
272#ifndef NDEBUG
273		    _glu_dprintf( "checkjarc: geometric linkage screwed up 1\n");
274		    jarc->prev->show();
275		    jarc->show();
276#endif
277		    return 0;
278		}
279		if( jarc->tail()[0] != jarc->prev->rhead()[0] ) {
280
281#ifndef NDEBUG
282		    _glu_dprintf( "checkjarc: geometric linkage screwed up 2\n");
283		    jarc->prev->show();
284		    jarc->show();
285#endif
286		    return 0;
287		}
288	    }
289	    if( jarc->next->pwlArc ) {
290		if( jarc->next->tail()[0] != jarc->rhead()[0] ) {
291#ifndef NDEBUG
292			_glu_dprintf( "checkjarc: geometric linkage screwed up 3\n");
293			jarc->show();
294			jarc->next->show();
295#endif
296			return 0;
297		}
298		if( jarc->next->tail()[1] != jarc->rhead()[1] ) {
299#ifndef NDEBUG
300			_glu_dprintf( "checkjarc: geometric linkage screwed up 4\n");
301			jarc->show();
302			jarc->next->show();
303#endif
304			return 0;
305		}
306	    }
307	    if( jarc->isbezier() ) {
308		assert( jarc->pwlArc->npts == 2 );
309		assert( (jarc->pwlArc->pts[0].param[0] == \
310                        jarc->pwlArc->pts[1].param[0]) ||\
311                        (jarc->pwlArc->pts[0].param[1] == \
312                        jarc->pwlArc->pts[1].param[1]) );
313	    }
314	}
315	jarc = jarc->next;
316    } while (jarc != this);
317    return 1;
318}
319
320
321#define TOL 0.00001
322
323inline long tooclose( REAL x, REAL y )
324{
325    return (glu_abs(x-y) < TOL) ?  1 : 0;
326}
327
328
329/*--------------------------------------------------------------------------
330 * append - append a jordan arc to a circularly linked list
331 *--------------------------------------------------------------------------
332 */
333
334Arc_ptr
335Arc::append( Arc_ptr jarc )
336{
337    if( jarc != 0 ) {
338	next = jarc->next;
339	prev = jarc;
340	next->prev = prev->next = this;
341    } else {
342	next = prev = this;
343    }
344    return this;
345}
346
347