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:
10 ** http://oss.sgi.com/projects/FreeB
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.
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.
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.
41 #include "glimports.h"
47 #include "simplemath.h"
49 /* local preprocessor definitions */
50 #define ZERO 0.00001/*0.000001*/
52 const int Arc::bezier_tag = (1<<13);
53 const int Arc::arc_tag = (1<<3);
54 const int Arc::tail_tag = (1<<6);
56 /*--------------------------------------------------------------------------
57 * makeSide - attach a pwl arc to an arc and mark it as a border arc
58 *--------------------------------------------------------------------------
62 Arc::makeSide( PwlArc *pwl, arc_side side )
65 assert( pwlArc == 0 );
66 assert( pwl->npts > 0 );
67 assert( pwl->pts != 0);
74 /*--------------------------------------------------------------------------
75 * numpts - count number of points on arc loop
76 *--------------------------------------------------------------------------
85 npts += jarc->pwlArc->npts;
87 } while( jarc != this );
91 /*--------------------------------------------------------------------------
92 * markverts - mark each point with id of arc
93 *--------------------------------------------------------------------------
97 Arc::markverts( void )
102 TrimVertex *p = jarc->pwlArc->pts;
103 for( int i=0; i<jarc->pwlArc->npts; i++ )
104 p[i].nuid = jarc->nuid;
106 } while( jarc != this );
109 /*--------------------------------------------------------------------------
110 * getextrema - find axis extrema on arc loop
111 *--------------------------------------------------------------------------
115 Arc::getextrema( Arc_ptr extrema[4] )
117 REAL leftpt, botpt, rightpt, toppt;
119 extrema[0] = extrema[1] = extrema[2] = extrema[3] = this;
121 leftpt = rightpt = this->tail()[0];
122 botpt = toppt = this->tail()[1];
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];
130 if ( jarc->tail()[0] > rightpt ||
131 (jarc->tail()[0] >= rightpt && jarc->rhead()[0] >= rightpt)) {
132 rightpt = jarc->pwlArc->pts->param[0];
135 if ( jarc->tail()[1] < botpt ||
136 (jarc->tail()[1] <= botpt && jarc->rhead()[1] <= botpt )) {
137 botpt = jarc->pwlArc->pts->param[1];
140 if ( jarc->tail()[1] > toppt ||
141 (jarc->tail()[1] >= toppt && jarc->rhead()[1] >= toppt)) {
142 toppt = jarc->pwlArc->pts->param[1];
149 /*-------------------------------------------------------------------------
150 * show - print to the stdout the vertices of a pwl arc
151 *-------------------------------------------------------------------------
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] );
166 /*-------------------------------------------------------------------------
167 * print - print out the vertices of all pwl arcs on a loop
168 *-------------------------------------------------------------------------
177 _glu_dprintf( "BGNTRIM\n" );
182 } while (jarc != this);
184 _glu_dprintf("ENDTRIM\n" );
188 /*-------------------------------------------------------------------------
189 * isDisconnected - check if tail of arc and head of prev meet
190 *-------------------------------------------------------------------------
194 Arc::isDisconnected( void )
196 if( pwlArc == 0 ) return 0;
197 if( prev->pwlArc == 0 ) return 0;
200 REAL *p1 = prev->rhead();
202 if( ((p0[0] - p1[0]) > ZERO) || ((p1[0] - p0[0]) > ZERO) ||
203 ((p0[1] - p1[1]) > ZERO) || ((p1[1] - p0[1]) > ZERO) ) {
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] );
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;
217 /*-------------------------------------------------------------------------
218 * neq_vert - assert that two 2D vertices are not equal
219 *-------------------------------------------------------------------------
223 neq_vert( REAL *v1, REAL *v2 )
225 return ((v1[0] != v2[0]) || (v1[1] != v2[1] )) ? 1 : 0;
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 *-------------------------------------------------------------------------
239 if( this == 0 ) return 1;
242 assert( (jarc->pwlArc != 0) || (jarc->bezierArc != 0) );
244 if (jarc->prev == 0 || jarc->next == 0) {
246 _glu_dprintf( "checkjarc:null next/prev pointer\n");
252 if (jarc->next->prev != jarc) {
254 _glu_dprintf( "checkjarc: pointer linkage screwed up\n");
262 assert( jarc->pwlArc->npts >= 1 );
263 assert( jarc->pwlArc->npts < 100000 );
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) );
270 if( jarc->prev->pwlArc ) {
271 if( jarc->tail()[1] != jarc->prev->rhead()[1] ) {
273 _glu_dprintf( "checkjarc: geometric linkage screwed up 1\n");
279 if( jarc->tail()[0] != jarc->prev->rhead()[0] ) {
282 _glu_dprintf( "checkjarc: geometric linkage screwed up 2\n");
289 if( jarc->next->pwlArc ) {
290 if( jarc->next->tail()[0] != jarc->rhead()[0] ) {
292 _glu_dprintf( "checkjarc: geometric linkage screwed up 3\n");
298 if( jarc->next->tail()[1] != jarc->rhead()[1] ) {
300 _glu_dprintf( "checkjarc: geometric linkage screwed up 4\n");
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]) );
316 } while (jarc != this);
323 inline long tooclose( REAL x, REAL y )
325 return (glu_abs(x-y) < TOL) ? 1 : 0;
329 /*--------------------------------------------------------------------------
330 * append - append a jordan arc to a circularly linked list
331 *--------------------------------------------------------------------------
335 Arc::append( Arc_ptr jarc )
340 next->prev = prev->next = this;