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.
40 #include "glimports.h"
43 #include "gridvertex.h"
44 #include "gridtrimvertex.h"
53 const float Mesher::ZERO = 0.0;
55 Mesher::Mesher( Backend& b )
57 p( sizeof( GridTrimVertex ), 100, "GridTrimVertexPool" )
64 lastedge = 0; //needed to prevent purify UMR
67 Mesher::~Mesher( void )
69 if( vdata ) delete[] vdata;
73 Mesher::init( unsigned int npts )
76 if( stacksize < npts ) {
78 if( vdata ) delete[] vdata;
79 vdata = new GridTrimVertex_p[stacksize];
84 Mesher::push( GridTrimVertex *gt )
86 assert( itop+1 != (int)stacksize );
98 backend.bgntmesh( "addedge" );
121 Mesher::finishLower( GridTrimVertex *gtlower )
124 nextlower( gtlower=new(p) GridTrimVertex );
131 Mesher::finishUpper( GridTrimVertex *gtupper )
134 nextupper( gtupper=new(p) GridTrimVertex );
143 GridTrimVertex *gtlower, *gtupper;
146 nextupper( gtupper = new(p) GridTrimVertex );
147 nextlower( gtlower = new(p) GridTrimVertex );
153 nextupper( gtupper = new(p) GridTrimVertex );
154 nextlower( gtlower );
156 assert( gtupper->t && gtlower->t );
158 if( gtupper->t->param[0] < gtlower->t->param[0] ) {
161 if( nextupper( gtupper=new(p) GridTrimVertex ) == 0 ) {
162 finishLower(gtlower);
165 } else if( gtupper->t->param[0] > gtlower->t->param[0] ) {
168 if( nextlower( gtlower=new(p) GridTrimVertex ) == 0 ) {
169 finishUpper(gtupper);
173 if( lastedge == 0 ) {
176 if( nextupper(gtupper=new(p) GridTrimVertex) == 0 ) {
177 finishLower(gtlower);
183 if( nextlower( gtlower=new(p) GridTrimVertex ) == 0 ) {
184 finishUpper(gtupper);
191 if( gtupper->t->param[0] < gtlower->t->param[0] ) {
194 if( nextupper( gtupper=new(p) GridTrimVertex ) == 0 ) {
195 finishLower(gtlower);
198 } else if( gtupper->t->param[0] > gtlower->t->param[0] ) {
201 if( nextlower( gtlower=new(p) GridTrimVertex ) == 0 ) {
202 finishUpper(gtupper);
206 if( lastedge == 0 ) {
209 if( nextupper( gtupper=new(p) GridTrimVertex ) == 0 ) {
210 finishLower(gtlower);
216 if( nextlower( gtlower=new(p) GridTrimVertex ) == 0 ) {
217 finishUpper(gtupper);
226 Mesher::isCcw( int ilast )
228 REAL area = det3( vdata[ilast]->t, vdata[itop-1]->t, vdata[itop-2]->t );
229 return (area < ZERO) ? 0 : 1;
233 Mesher::isCw( int ilast )
235 REAL area = det3( vdata[ilast]->t, vdata[itop-1]->t, vdata[itop-2]->t );
236 return (area > -ZERO) ? 0 : 1;
240 Mesher::equal( int x, int y )
242 return( last[0] == vdata[x] && last[1] == vdata[y] );
246 Mesher::copy( int x, int y )
248 last[0] = vdata[x]; last[1] = vdata[y];
252 Mesher::move( int x, int y )
258 Mesher::output( int x )
260 backend.tmeshvert( vdata[x] );
263 /*---------------------------------------------------------------------------
264 * addedge - addedge an edge to the triangulation
266 * This code has been re-written to generate large triangle meshes
267 * from a monotone polygon. Although smaller triangle meshes
268 * could be generated faster and with less code, larger meshes
269 * actually give better SYSTEM performance. This is because
270 * vertices are processed in the backend slower than they are
271 * generated by this code and any decrease in the number of vertices
272 * results in a decrease in the time spent in the backend.
273 *---------------------------------------------------------------------------
279 register int ilast = itop;
281 if( lastedge == 0 ) {
282 if( equal( 0, 1 ) ) {
285 for( register int i = 2; i < ilast; i++ ) {
289 copy( ilast, ilast-1 );
290 } else if( equal( ilast-2, ilast-1) ) {
293 for( register int i = ilast-3; i >= 0; i-- ) {
299 closeMesh(); openMesh();
302 for( register int i = 1; i < ilast; i++ ) {
306 copy( ilast, ilast-1 );
312 for( register int i = 2; i < ilast; i++ ) {
316 copy( ilast-1, ilast );
317 } else if( equal( ilast-1, ilast-2) ) {
320 for( register int i = ilast-3; i >= 0; i-- ) {
326 closeMesh(); openMesh();
329 for( register int i = 1; i < ilast; i++ ) {
333 copy( ilast-1, ilast );
337 //for( register long k=0; k<=ilast; k++ ) pop( k );
343 register int ilast = itop;
345 if( lastedge == 0 ) {
346 if( equal( 0, 1 ) ) {
349 for( register int i = 2; i < ilast; i++ ) {
353 copy( ilast, ilast-1 );
354 } else if( equal( ilast-2, ilast-1) ) {
357 for( register int i = ilast-3; i >= 0; i-- ) {
363 closeMesh(); openMesh();
366 for( register int i = 1; i < ilast; i++ ) {
370 copy( ilast, ilast-1 );
373 //for( register long k=0; k<ilast-1; k++ ) pop( k );
378 if( ! isCcw( ilast ) ) return;
381 } while( (itop > 1) && isCcw( ilast ) );
383 if( equal( ilast-1, ilast-2 ) ) {
386 for( register int i=ilast-3; i>=itop-1; i-- ) {
390 copy( ilast, itop-1 );
391 } else if( equal( itop, itop-1 ) ) {
394 for( register int i = itop+1; i < ilast; i++ ) {
398 copy( ilast-1, ilast );
400 closeMesh(); openMesh();
403 for( register int i=ilast-2; i>=itop-1; i-- ) {
407 copy( ilast, itop-1 );
409 //for( register int k=itop; k<ilast; k++ ) pop( k );
417 register int ilast = itop;
419 if( lastedge == 1 ) {
423 for( register int i = 2; i < ilast; i++ ) {
427 copy( ilast-1, ilast );
428 } else if( equal( ilast-1, ilast-2) ) {
431 for( register int i = ilast-3; i >= 0; i-- ) {
437 closeMesh(); openMesh();
440 for( register int i = 1; i < ilast; i++ ) {
444 copy( ilast-1, ilast );
448 //for( register long k=0; k<ilast-1; k++ ) pop( k );
453 if( ! isCw( ilast ) ) return;
456 } while( (itop > 1) && isCw( ilast ) );
458 if( equal( ilast-2, ilast-1) ) {
461 for( register int i=ilast-3; i>=itop-1; i--) {
465 copy( itop-1, ilast );
466 } else if( equal( itop-1, itop) ) {
469 for( register int i=itop+1; i<ilast; i++ ) {
473 copy( ilast, ilast-1 );
475 closeMesh(); openMesh();
478 for( register int i=ilast-2; i>=itop-1; i-- ) {
482 copy( itop-1, ilast );
484 //for( register int k=itop; k<ilast; k++ ) pop( k );