/* ** License Applicability. Except to the extent portions of this file are ** made subject to an alternative license as permitted in the SGI Free ** Software License B, Version 1.1 (the "License"), the contents of this ** file are subject only to the provisions of the License. You may not use ** this file except in compliance with the License. You may obtain a copy ** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600 ** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at: ** ** http://oss.sgi.com/projects/FreeB ** ** Note that, as provided in the License, the Software is distributed on an ** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS ** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND ** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A ** PARTICULAR PURPOSE, AND NON-INFRINGEMENT. ** ** Original Code. The Original Code is: OpenGL Sample Implementation, ** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics, ** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc. ** Copyright in any portions created by third parties is as indicated ** elsewhere herein. All Rights Reserved. ** ** Additional Notice Provisions: The application programming interfaces ** established by SGI in conjunction with the Original Code are The ** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released ** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version ** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X ** Window System(R) (Version 1.3), released October 19, 1998. This software ** was created using the OpenGL(R) version 1.2.1 Sample Implementation ** published by SGI, but has not been independently verified as being ** compliant with the OpenGL(R) version 1.2.1 Specification. */ /* * varray.c++ * */ #include "glimports.h" #include "myassert.h" #include "mystdio.h" #include "varray.h" #include "arc.h" #include "simplemath.h" // glu_abs() #define TINY 0.0001 inline long sgn( REAL x ) { return (x < -TINY) ? -1 : ((x > TINY) ? 1 : 0 ); } Varray::Varray( void ) { int i; varray = 0; size = 0; numquads = 0; for (i = 0; i < 1000; i++) { vval[i] = 0; voffset[i] = 0; } } Varray::~Varray( void ) { if( varray ) delete[] varray; } inline void Varray::update( Arc_ptr arc, long dir[2], REAL val ) { register long ds = sgn(arc->tail()[0] - arc->prev->tail()[0]); register long dt = sgn(arc->tail()[1] - arc->prev->tail()[1]); if( dir[0] != ds || dir[1] != dt ) { dir[0] = ds; dir[1] = dt; append( val ); } } void Varray::grow( long guess ) { if( size < guess ) { size = guess * 2; if( varray ) delete[] varray; varray = new REAL[size]; assert( varray != 0 ); } } long Varray::init( REAL delta, Arc_ptr toparc, Arc_ptr botarc ) { Arc_ptr left = toparc->next; Arc_ptr right = toparc; long ldir[2], rdir[2]; ldir[0] = sgn( left->tail()[0] - left->prev->tail()[0] ); ldir[1] = sgn( left->tail()[1] - left->prev->tail()[1] ); rdir[0] = sgn( right->tail()[0] - right->prev->tail()[0] ); rdir[1] = sgn( right->tail()[1] - right->prev->tail()[1] ); vval[0] = toparc->tail()[1]; numquads = 0; while( 1 ) { switch( sgn( left->tail()[1] - right->prev->tail()[1] ) ) { case 1: left = left->next; update( left, ldir, left->prev->tail()[1] ); break; case -1: right = right->prev; update( right, rdir, right->tail()[1] ); break; case 0: if( glu_abs(left->tail()[1] - botarc->tail()[1]) < TINY) goto end; if( glu_abs(left->tail()[0]-right->prev->tail()[0]) < TINY && glu_abs(left->tail()[1]-right->prev->tail()[1]) < TINY) goto end; left = left->next; break; } } end: append( botarc->tail()[1] ); grow( ((long) ((vval[0] - vval[numquads])/delta)) + numquads + 2 ); long i, index = 0; for( i=0; i<numquads; i++ ) { voffset[i] = index; varray[index++] = vval[i]; REAL dist = vval[i] - vval[i+1]; if( dist > delta ) { long steps = ((long) (dist/delta)) +1; float deltav = - dist / (REAL) steps; for( long j=1; j<steps; j++ ) varray[index++] = vval[i] + j * deltav; } } voffset[i] = index; varray[index] = vval[i]; return index; }