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Diffstat (limited to 'mesalib/src/glu/sgi/libnurbs/internals/curve.cc')
| -rw-r--r-- | mesalib/src/glu/sgi/libnurbs/internals/curve.cc | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/mesalib/src/glu/sgi/libnurbs/internals/curve.cc b/mesalib/src/glu/sgi/libnurbs/internals/curve.cc new file mode 100644 index 000000000..33e275264 --- /dev/null +++ b/mesalib/src/glu/sgi/libnurbs/internals/curve.cc @@ -0,0 +1,198 @@ +/* +** 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. +*/ + +/* + * curve.c++ + * + */ + +#include "glimports.h" +#include "myassert.h" +#include "mystdio.h" +#include "mymath.h" +#include "curve.h" +#include "mapdesc.h" +#include "types.h" +#include "quilt.h" +#include "nurbsconsts.h" + +/*-------------------------------------------------------------------------- + * Curve::Curve - copy curve from quilt and transform control points + *-------------------------------------------------------------------------- + */ + +Curve::Curve( Quilt_ptr geo, REAL pta, REAL ptb, Curve *c ) +{ + mapdesc = geo->mapdesc; + next = c; + needsSampling = mapdesc->isRangeSampling() ? 1 : 0; + cullval = mapdesc->isCulling() ? CULL_ACCEPT : CULL_TRIVIAL_ACCEPT; + order = geo->qspec[0].order; + stride = MAXCOORDS; + + REAL *ps = geo->cpts; + Quiltspec_ptr qs = geo->qspec; + ps += qs->offset; + ps += qs->index * qs->order * qs->stride; + + if( needsSampling ) + mapdesc->xformSampling( ps, qs->order, qs->stride, spts, stride ); + + if( cullval == CULL_ACCEPT ) + mapdesc->xformCulling( ps, qs->order, qs->stride, cpts, stride ); + + /* set untrimmed curve range */ + range[0] = qs->breakpoints[qs->index]; + range[1] = qs->breakpoints[qs->index+1]; + range[2] = range[1] - range[0]; + + if( range[0] != pta ) { + Curve lower( *this, pta, 0 ); + lower.next = next; + *this = lower; + } + if( range[1] != ptb ) { + Curve lower( *this, ptb, 0 ); + } +} + +/*-------------------------------------------------------------------------- + * Curve::Curve - subdivide a curve along an isoparametric line + *-------------------------------------------------------------------------- + */ + +Curve::Curve( Curve& upper, REAL value, Curve *c ) +{ + Curve &lower = *this; + + lower.next = c; + lower.mapdesc = upper.mapdesc; + lower.needsSampling = upper.needsSampling; + lower.order = upper.order; + lower.stride = upper.stride; + lower.cullval = upper.cullval; + + REAL d = (value - upper.range[0]) / upper.range[2]; + + if( needsSampling ) + mapdesc->subdivide( upper.spts, lower.spts, d, upper.stride, upper.order ); + + if( cullval == CULL_ACCEPT ) + mapdesc->subdivide( upper.cpts, lower.cpts, d, upper.stride, upper.order ); + + lower.range[0] = upper.range[0]; + lower.range[1] = value; + lower.range[2] = value - upper.range[0]; + upper.range[0] = value; + upper.range[2] = upper.range[1] - value; +} + + +/*-------------------------------------------------------------------------- + * Curve::clamp - clamp the sampling rate to a given maximum + *-------------------------------------------------------------------------- + */ + +void +Curve::clamp( void ) +{ + if( stepsize < minstepsize ) + stepsize = mapdesc->clampfactor * minstepsize; +} + +void +Curve::setstepsize( REAL max ) +{ + stepsize = ( max >= 1.0 ) ? (range[2] / max) : range[2]; + minstepsize = stepsize; +} + +void +Curve::getstepsize( void ) +{ + minstepsize= 0; + + if( mapdesc->isConstantSampling() ) { + // fixed number of samples per patch in each direction + // maxrate is number of s samples per patch + setstepsize( mapdesc->maxrate ); + } else if( mapdesc->isDomainSampling() ) { + // maxrate is number of s samples per unit s length of domain + setstepsize( mapdesc->maxrate * range[2] ); + } else { + // upper bound on path length between sample points + + assert( order <= MAXORDER ); + + /* points have been transformed, therefore they are homogeneous */ + REAL tmp[MAXORDER][MAXCOORDS]; + const int tstride = sizeof(tmp[0]) / sizeof(REAL); + int val = mapdesc->project( spts, stride, &tmp[0][0], tstride, order ); + + if( val == 0 ) { + // control points cross infinity, therefore derivatives are undefined + setstepsize( mapdesc->maxrate ); + } else { + REAL t = mapdesc->getProperty( N_PIXEL_TOLERANCE ); + if( mapdesc->isParametricDistanceSampling() ) { + REAL d = mapdesc->calcPartialVelocity( &tmp[0][0], tstride, order, 2, range[2] ); + stepsize = (d > 0.0) ? sqrtf( 8.0 * t / d ) : range[2]; + minstepsize = ( mapdesc->maxrate > 0.0 ) ? (range[2] / mapdesc->maxrate) : 0.0; + } else if( mapdesc->isPathLengthSampling() ) { + // t is upper bound on path (arc) length + REAL d = mapdesc->calcPartialVelocity( &tmp[0][0], tstride, order, 1, range[2] ); + stepsize = ( d > 0.0 ) ? (t / d) : range[2]; + minstepsize = ( mapdesc->maxrate > 0.0 ) ? (range[2] / mapdesc->maxrate) : 0.0; + } else { + // control points cross infinity, therefore partials are undefined + setstepsize( mapdesc->maxrate ); + } + } + } +} + +int +Curve::needsSamplingSubdivision( void ) +{ + return ( stepsize < minstepsize ) ? 1 : 0; +} + +int +Curve::cullCheck( void ) +{ + if( cullval == CULL_ACCEPT ) + cullval = mapdesc->cullCheck( cpts, order, stride ); + return cullval; +} + |