source: trunk/src/opengl/glu/nurbs/internals/arc.cpp

Last change on this file was 2689, checked in by jeroen, 26 years ago

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1/* $Id: arc.cpp,v 1.1 2000-02-09 08:50:20 jeroen Exp $ */
2/*
3** License Applicability. Except to the extent portions of this file are
4** made subject to an alternative license as permitted in the SGI Free
5** Software License B, Version 1.0 (the "License"), the contents of this
6** file are subject only to the provisions of the License. You may not use
7** this file except in compliance with the License. You may obtain a copy
8** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
9** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
10**
11** http://oss.sgi.com/projects/FreeB
12**
13** Note that, as provided in the License, the Software is distributed on an
14** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
15** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
16** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
17** PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
18**
19** Original Code. The Original Code is: OpenGL Sample Implementation,
20** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
21** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
22** Copyright in any portions created by third parties is as indicated
23** elsewhere herein. All Rights Reserved.
24**
25** Additional Notice Provisions: The application programming interfaces
26** established by SGI in conjunction with the Original Code are The
27** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
28** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
29** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
30** Window System(R) (Version 1.3), released October 19, 1998. This software
31** was created using the OpenGL(R) version 1.2.1 Sample Implementation
32** published by SGI, but has not been independently verified as being
33** compliant with the OpenGL(R) version 1.2.1 Specification.
34*/
35
36/*
37 * arc.c++
38 *
39 * $Date: 2000-02-09 08:50:20 $ $Revision: 1.1 $
40 * $Header: /home/ktk/tmp/odin/2007/netlabs.cvs/odin32/src/opengl/glu/nurbs/internals/arc.cpp,v 1.1 2000-02-09 08:50:20 jeroen Exp $
41 */
42
43#include <stdio.h>
44#include "glimports.h"
45#include "mystdio.h"
46#include "myassert.h"
47#include "arc.h"
48#include "bin.h"
49#include "bezierarc.h"
50#include "pwlarc.h"
51#include "simplemath.h"
52
53/* local preprocessor definitions */
54#define ZERO 0.00001/*0.000001*/
55
56const int Arc::bezier_tag = (1<<13);
57const int Arc::arc_tag = (1<<3);
58const int Arc::tail_tag = (1<<6);
59
60/*--------------------------------------------------------------------------
61 * makeSide - attach a pwl arc to an arc and mark it as a border arc
62 *--------------------------------------------------------------------------
63 */
64
65void
66Arc::makeSide( PwlArc *pwl, arc_side side )
67{
68 assert( pwl != 0);
69 assert( pwlArc == 0 );
70 assert( pwl->npts > 0 );
71 assert( pwl->pts != 0);
72 pwlArc = pwl;
73 clearbezier();
74 setside( side );
75}
76
77
78/*--------------------------------------------------------------------------
79 * numpts - count number of points on arc loop
80 *--------------------------------------------------------------------------
81 */
82
83int
84Arc::numpts( void )
85{
86 Arc_ptr jarc = this;
87 int npts = 0;
88 do {
89 npts += jarc->pwlArc->npts;
90 jarc = jarc->next;
91 } while( jarc != this );
92 return npts;
93}
94
95/*--------------------------------------------------------------------------
96 * markverts - mark each point with id of arc
97 *--------------------------------------------------------------------------
98 */
99
100void
101Arc::markverts( void )
102{
103 Arc_ptr jarc = this;
104
105 do {
106 TrimVertex *p = jarc->pwlArc->pts;
107 for( int i=0; i<jarc->pwlArc->npts; i++ )
108 p[i].nuid = jarc->nuid;
109 jarc = jarc->next;
110 } while( jarc != this );
111}
112
113/*--------------------------------------------------------------------------
114 * getextrema - find axis extrema on arc loop
115 *--------------------------------------------------------------------------
116 */
117
118void
119Arc::getextrema( Arc_ptr extrema[4] )
120{
121 REAL leftpt, botpt, rightpt, toppt;
122
123 extrema[0] = extrema[1] = extrema[2] = extrema[3] = this;
124
125 leftpt = rightpt = this->tail()[0];
126 botpt = toppt = this->tail()[1];
127
128 for( Arc_ptr jarc = this->next; jarc != this; jarc = jarc->next ) {
129 if ( jarc->tail()[0] < leftpt ||
130 (jarc->tail()[0] <= leftpt && jarc->rhead()[0]<=leftpt)) {
131 leftpt = jarc->pwlArc->pts->param[0];
132 extrema[1] = jarc;
133 }
134 if ( jarc->tail()[0] > rightpt ||
135 (jarc->tail()[0] >= rightpt && jarc->rhead()[0] >= rightpt)) {
136 rightpt = jarc->pwlArc->pts->param[0];
137 extrema[3] = jarc;
138 }
139 if ( jarc->tail()[1] < botpt ||
140 (jarc->tail()[1] <= botpt && jarc->rhead()[1] <= botpt )) {
141 botpt = jarc->pwlArc->pts->param[1];
142 extrema[2] = jarc;
143 }
144 if ( jarc->tail()[1] > toppt ||
145 (jarc->tail()[1] >= toppt && jarc->rhead()[1] >= toppt)) {
146 toppt = jarc->pwlArc->pts->param[1];
147 extrema[0] = jarc;
148 }
149 }
150}
151
152
153/*-------------------------------------------------------------------------
154 * show - print to the stdout the vertices of a pwl arc
155 *-------------------------------------------------------------------------
156 */
157
158void
159Arc::show()
160{
161#ifndef NDEBUG
162 dprintf( "\tPWLARC NP: %d FL: 1\n", pwlArc->npts );
163 for( int i = 0; i < pwlArc->npts; i++ ) {
164 dprintf( "\t\tVERTEX %f %f\n", pwlArc->pts[i].param[0],
165 pwlArc->pts[i].param[1] );
166 }
167#endif
168}
169
170/*-------------------------------------------------------------------------
171 * print - print out the vertices of all pwl arcs on a loop
172 *-------------------------------------------------------------------------
173 */
174
175void
176Arc::print( void )
177{
178 Arc_ptr jarc = this;
179
180 if( ! this ) {
181#ifndef NDEBUG
182 dprintf( "\n\nEMPTY TRIM\n\n" );
183#endif
184 return;
185 }
186
187#ifndef NDEBUG
188 dprintf( "BGNTRIM\n" );
189#endif
190 do {
191 jarc->show( );
192 jarc = jarc->next;
193 } while (jarc != this);
194#ifndef NDEBUG
195 dprintf("ENDTRIM\n" );
196#endif
197}
198
199/*-------------------------------------------------------------------------
200 * isDisconnected - check if tail of arc and head of prev meet
201 *-------------------------------------------------------------------------
202 */
203
204int
205Arc::isDisconnected( void )
206{
207 if( pwlArc == 0 ) return 0;
208 if( prev->pwlArc == 0 ) return 0;
209
210 REAL *p0 = tail();
211 REAL *p1 = prev->rhead();
212
213 if( ((p0[0] - p1[0]) > ZERO) || ((p1[0] - p0[0]) > ZERO) ||
214 ((p0[1] - p1[1]) > ZERO) || ((p1[1] - p0[1]) > ZERO) ) {
215#ifndef NDEBUG
216 dprintf( "x coord = %f %f %f\n", p0[0], p1[0], p0[0] - p1[0] );
217 dprintf( "y coord = %f %f %f\n", p0[1], p1[1], p0[1] - p1[1] );
218#endif
219 return 1;
220 } else {
221 /* average two points together */
222 p0[0] = p1[0] = (p1[0] + p0[0]) * 0.5;
223 p0[1] = p1[1] = (p1[1] + p0[1]) * 0.5;
224 return 0;
225 }
226}
227
228/*-------------------------------------------------------------------------
229 * neq_vert - assert that two 2D vertices are not equal
230 *-------------------------------------------------------------------------
231 */
232
233inline static int
234neq_vert( REAL *v1, REAL *v2 )
235{
236 return ((v1[0] != v2[0]) || (v1[1] != v2[1] )) ? 1 : 0;
237}
238
239/*-------------------------------------------------------------------------
240 * check - verify consistency of a loop, including
241 * 1) if pwl, no two consecutive vertices are identical
242 * 2) the circular link pointers are valid
243 * 3) the geometric info at the head and tail are consistent
244 *-------------------------------------------------------------------------
245 */
246
247int
248Arc::check( void )
249{
250 if( this == 0 ) return 1;
251 Arc_ptr jarc = this;
252 do {
253 assert( (jarc->pwlArc != 0) || (jarc->bezierArc != 0) );
254
255 if (jarc->prev == 0 || jarc->next == 0) {
256#ifndef NDEBUG
257 dprintf( "checkjarc:null next/prev pointer\n");
258 jarc->print( );
259#endif
260 return 0;
261 }
262
263 if (jarc->next->prev != jarc) {
264#ifndef NDEBUG
265 dprintf( "checkjarc: pointer linkage screwed up\n");
266 jarc->print( );
267#endif
268 return 0;
269 }
270
271 if( jarc->pwlArc ) {
272#ifndef NDEBUG
273 assert( jarc->pwlArc->npts >= 1 );
274 assert( jarc->pwlArc->npts < 100000 );
275/*
276 for( int i=0; i < jarc->pwlArc->npts-1; i++ )
277 assert( neq_vert( jarc->pwlArc->pts[i].param,
278 jarc->pwlArc->pts[i+1].param) );
279*/
280#endif
281 if( jarc->prev->pwlArc ) {
282 if( jarc->tail()[1] != jarc->prev->rhead()[1] ) {
283#ifndef NDEBUG
284 dprintf( "checkjarc: geometric linkage screwed up 1\n");
285 jarc->prev->show();
286 jarc->show();
287#endif
288 return 0;
289 }
290 if( jarc->tail()[0] != jarc->prev->rhead()[0] ) {
291
292#ifndef NDEBUG
293 dprintf( "checkjarc: geometric linkage screwed up 2\n");
294 jarc->prev->show();
295 jarc->show();
296#endif
297 return 0;
298 }
299 }
300 if( jarc->next->pwlArc ) {
301 if( jarc->next->tail()[0] != jarc->rhead()[0] ) {
302#ifndef NDEBUG
303 dprintf( "checkjarc: geometric linkage screwed up 3\n");
304 jarc->show();
305 jarc->next->show();
306#endif
307 return 0;
308 }
309 if( jarc->next->tail()[1] != jarc->rhead()[1] ) {
310#ifndef NDEBUG
311 dprintf( "checkjarc: geometric linkage screwed up 4\n");
312 jarc->show();
313 jarc->next->show();
314#endif
315 return 0;
316 }
317 }
318 if( jarc->isbezier() ) {
319 assert( jarc->pwlArc->npts == 2 );
320 assert( (jarc->pwlArc->pts[0].param[0] == \
321 jarc->pwlArc->pts[1].param[0]) ||\
322 (jarc->pwlArc->pts[0].param[1] == \
323 jarc->pwlArc->pts[1].param[1]) );
324 }
325 }
326 jarc = jarc->next;
327 } while (jarc != this);
328 return 1;
329}
330
331
332#define TOL 0.00001
333
334inline long tooclose( REAL x, REAL y )
335{
336 return (abs(x-y) < TOL) ? 1 : 0;
337}
338
339
340/*--------------------------------------------------------------------------
341 * append - append a jordan arc to a circularly linked list
342 *--------------------------------------------------------------------------
343 */
344
345Arc_ptr
346Arc::append( Arc_ptr jarc )
347{
348 if( jarc != 0 ) {
349 next = jarc->next;
350 prev = jarc;
351 next->prev = prev->next = this;
352 } else {
353 next = prev = this;
354 }
355 return this;
356}
357
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