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IABSD.fr/xenocara/lib/libGLU/src/libnurbs/internals/arctess.cc

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  • Author : jsg
    Date : 2019-11-27 10:26:12
    Hash : f42e66cb
    Message : update to GLU 9.0.1 Among other minor changes this adds a stddef.h include for NULL required to build with Mesa 19.2 headers.

  • lib/libGLU/src/libnurbs/internals/arctess.cc
  • /*
    ** 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.
    */
    
    /*
     * arctessellator.c++
     *
     */
    
    #include "glimports.h"
    #include "mystdio.h"
    #include "myassert.h"
    #include "arctess.h"
    #include "bufpool.h"
    #include "simplemath.h"
    #include "bezierarc.h"
    #include "trimvertex.h"
    #include "trimvertpool.h"
    
    #define NOELIMINATION
    
    #define steps_function(large, small, rate) (max(1, 1+ (int) ((large-small)/rate)));
    
    /*-----------------------------------------------------------------------------
     * ArcTessellator - construct an ArcTessellator
     *-----------------------------------------------------------------------------
     */
    
    ArcTessellator::ArcTessellator( TrimVertexPool& t, Pool& p ) 
    	: pwlarcpool(p), trimvertexpool(t)
    {
    }
    
    /*-----------------------------------------------------------------------------
     * ~ArcTessellator - destroy an ArcTessellator
     *-----------------------------------------------------------------------------
     */
    
    ArcTessellator::~ArcTessellator( void )
    {
    }
    
    /*-----------------------------------------------------------------------------
     * bezier - construct a bezier arc and attach it to an Arc
     *-----------------------------------------------------------------------------
     */
    
    void
    ArcTessellator::bezier( Arc *arc, REAL s1, REAL s2, REAL t1, REAL t2 )
    {
        assert( arc != 0 );
        assert( ! arc->isTessellated() );
    
    #ifndef NDEBUG
        switch( arc->getside() ) {
    	case arc_left:
    	    assert( s1 == s2 );
    	    assert( t2 < t1 );
    	    break;
    	case arc_right:
    	    assert( s1 == s2 );
    	    assert( t1 < t2 );
    	    break;
    	case arc_top:
    	    assert( t1 == t2 );
    	    assert( s2 < s1 );
    	    break;
    	case arc_bottom:
    	    assert( t1 == t2 );
    	    assert( s1 < s2 );
    	    break;
    	case arc_none:
    	    (void) abort();
    	    break;
        }
    #endif
        
        TrimVertex *p = trimvertexpool.get(2);
        arc->pwlArc = new(pwlarcpool) PwlArc( 2, p );
        p[0].param[0] = s1;
        p[0].param[1] = t1;
        p[1].param[0] = s2;
        p[1].param[1] = t2;
        assert( (s1 == s2) || (t1 == t2) );
        arc->setbezier();
    }
    
    
    /*-----------------------------------------------------------------------------
     * pwl_left - construct a left boundary pwl arc and attach it to an arc
     *-----------------------------------------------------------------------------
     */
    
    void
    ArcTessellator::pwl_left( Arc *arc, REAL s, REAL t1, REAL t2, REAL rate )
    {
        assert( t2 < t1 );
    
    /*    if(rate <= 0.06) rate = 0.06;*/
    /*    int nsteps = 1 + (int) ((t1 - t2) / rate ); */
        int nsteps = steps_function(t1, t2, rate);
    
    
        REAL stepsize = (t1 - t2) / (REAL) nsteps;
    
        TrimVertex *newvert = trimvertexpool.get( nsteps+1 );
        int i;
        for( i = nsteps; i > 0; i-- ) {
    	newvert[i].param[0] = s;
    	newvert[i].param[1] = t2;
    	t2 += stepsize;
        }
        newvert[i].param[0] = s;
        newvert[i].param[1] = t1;
    
        arc->makeSide( new(pwlarcpool) PwlArc( nsteps+1, newvert ), arc_left );
    }
    
    /*-----------------------------------------------------------------------------
     * pwl_right - construct a right boundary pwl arc and attach it to an arc
     *-----------------------------------------------------------------------------
     */
    
    void
    ArcTessellator::pwl_right( Arc *arc, REAL s, REAL t1, REAL t2, REAL rate )
    {
        assert( t1 < t2 );
    
    /*    if(rate <= 0.06) rate = 0.06;*/
    
    /*    int nsteps = 1 + (int) ((t2 - t1) / rate ); */
        int nsteps = steps_function(t2,t1,rate);
        REAL stepsize = (t2 - t1) / (REAL) nsteps;
    
        TrimVertex *newvert = trimvertexpool.get( nsteps+1 );
        int i;
        for( i = 0; i < nsteps; i++ ) {
    	newvert[i].param[0] = s;
    	newvert[i].param[1] = t1;
    	t1 += stepsize;
        }
        newvert[i].param[0] = s;
        newvert[i].param[1] = t2;
    
        arc->makeSide( new(pwlarcpool) PwlArc( nsteps+1, newvert ), arc_right );
    }
    
    
    /*-----------------------------------------------------------------------------
     * pwl_top - construct a top boundary pwl arc and attach it to an arc
     *-----------------------------------------------------------------------------
     */
    
    void
    ArcTessellator::pwl_top( Arc *arc, REAL t, REAL s1, REAL s2, REAL rate )
    {
        assert( s2 < s1 );
    
    /*    if(rate <= 0.06) rate = 0.06;*/
    
    /*    int nsteps = 1 + (int) ((s1 - s2) / rate ); */
        int nsteps = steps_function(s1,s2,rate);
        REAL stepsize = (s1 - s2) / (REAL) nsteps;
    
        TrimVertex *newvert = trimvertexpool.get( nsteps+1 );
        int i;
        for( i = nsteps; i > 0; i-- ) {
    	newvert[i].param[0] = s2;
    	newvert[i].param[1] = t;
    	s2 += stepsize;
        }
        newvert[i].param[0] = s1;
        newvert[i].param[1] = t;
    
        arc->makeSide( new(pwlarcpool) PwlArc( nsteps+1, newvert ), arc_top );
    }
    
    /*-----------------------------------------------------------------------------
     * pwl_bottom - construct a bottom boundary pwl arc and attach it to an arc
     *-----------------------------------------------------------------------------
     */
    
    void
    ArcTessellator::pwl_bottom( Arc *arc, REAL t, REAL s1, REAL s2, REAL rate )
    {
        assert( s1 < s2 );
    
    /*    if(rate <= 0.06) rate = 0.06;*/
    
    /*    int nsteps = 1 + (int) ((s2 - s1) / rate ); */
        int nsteps = steps_function(s2,s1,rate);
        REAL stepsize = (s2 - s1) / (REAL) nsteps;
    
        TrimVertex *newvert = trimvertexpool.get( nsteps+1 );
        int i;
        for( i = 0; i < nsteps; i++ ) {
    	newvert[i].param[0] = s1;
    	newvert[i].param[1] = t;
    	s1 += stepsize;
        }
        newvert[i].param[0] = s2;
        newvert[i].param[1] = t;
    
        arc->makeSide( new(pwlarcpool) PwlArc( nsteps+1, newvert ), arc_bottom );
    }
    
    /*-----------------------------------------------------------------------------
     * pwl - construct a pwl arc and attach it to an arc
     *-----------------------------------------------------------------------------
     */
    
    void
    ArcTessellator::pwl( Arc *arc, REAL s1, REAL s2, REAL t1, REAL t2, REAL rate )
    {
    
    /*    if(rate <= 0.06) rate = 0.06;*/
    
        int snsteps = 1 + (int) (glu_abs(s2 - s1) / rate );
        int tnsteps = 1 + (int) (glu_abs(t2 - t1) / rate );
        int nsteps = max(1,max( snsteps, tnsteps ));
    
        REAL sstepsize = (s2 - s1) / (REAL) nsteps;
        REAL tstepsize = (t2 - t1) / (REAL) nsteps;
        TrimVertex *newvert = trimvertexpool.get( nsteps+1 );
        long i;
        for( i = 0; i < nsteps; i++ ) {
    	newvert[i].param[0] = s1;
    	newvert[i].param[1] = t1;
    	s1 += sstepsize;
    	t1 += tstepsize;
        }
        newvert[i].param[0] = s2;
        newvert[i].param[1] = t2;
    
        /* arc->makeSide( new(pwlarcpool) PwlArc( nsteps+1, newvert ), arc_bottom ); */
        arc->pwlArc = new(pwlarcpool) PwlArc( nsteps+1, newvert );
    
        arc->clearbezier();
        arc->clearside( );
    }
    
    
    /*-----------------------------------------------------------------------------
     * tessellateLinear - constuct a linear pwl arc and attach it to an Arc
     *-----------------------------------------------------------------------------
     */
    
    void
    ArcTessellator::tessellateLinear( Arc *arc, REAL geo_stepsize, REAL arc_stepsize, int isrational )
    {
        assert( arc->pwlArc == NULL );
        REAL s1, s2, t1, t2;
    
        //we don't need to scale by arc_stepsize if the trim curve
        //is piecewise linear. Reason: In pwl_right, pwl_left, pwl_top, pwl_left,
        //and pwl, the nsteps is computed by deltaU (or V) /stepsize. 
        //The quantity deltaU/arc_stepsize doesn't have any meaning. And
        //it causes problems: see bug 517641
        REAL stepsize = geo_stepsize; /* * arc_stepsize*/;
    
        BezierArc *b = arc->bezierArc;
    
        if( isrational ) {
    	s1 = b->cpts[0] / b->cpts[2];
    	t1 = b->cpts[1] / b->cpts[2];
    	s2 = b->cpts[b->stride+0] / b->cpts[b->stride+2];
    	t2 = b->cpts[b->stride+1] / b->cpts[b->stride+2];
        } else {
    	s1 = b->cpts[0];
    	t1 = b->cpts[1];
    	s2 = b->cpts[b->stride+0];
    	t2 = b->cpts[b->stride+1];
        }
        if( s1 == s2 )
    	if( t1 < t2 )
    	    pwl_right( arc, s1, t1, t2, stepsize );
    	else
    	    pwl_left( arc, s1, t1, t2, stepsize );
        else if( t1 == t2 )
    	if( s1 < s2 ) 
    	    pwl_bottom( arc, t1, s1, s2, stepsize );
    	else
    	    pwl_top( arc, t1, s1, s2, stepsize );
        else
    	pwl( arc, s1, s2, t1, t2, stepsize );
    }
    
    /*-----------------------------------------------------------------------------
     * tessellateNonlinear - constuct a nonlinear pwl arc and attach it to an Arc
     *-----------------------------------------------------------------------------
     */
    
    void
    ArcTessellator::tessellateNonlinear( Arc *arc, REAL geo_stepsize, REAL arc_stepsize, int isrational )
    {
        assert( arc->pwlArc == NULL );
    
        REAL stepsize	= geo_stepsize * arc_stepsize;
    
        BezierArc *bezierArc = arc->bezierArc;
    
        REAL size; //bounding box size of the curve in UV 
        {
          int i,j;
          REAL min_u, min_v, max_u,max_v;
          min_u = max_u = bezierArc->cpts[0];
          min_v = max_v = bezierArc->cpts[1];
          for(i=1, j=bezierArc->stride; i<bezierArc->order; i++, j+= bezierArc->stride)
    	{
    	  if(bezierArc->cpts[j] < min_u)
    	    min_u = bezierArc->cpts[j];
    	  if(bezierArc->cpts[j] > max_u)
    	    max_u = bezierArc->cpts[j];
    	  if(bezierArc->cpts[j+1] < min_v)
    	    min_v = bezierArc->cpts[j+1];	  
    	  if(bezierArc->cpts[j+1] > max_v)
    	    max_v = bezierArc->cpts[j+1]; 
    	}
    
          size = max_u - min_u;
          if(size < max_v - min_v)
    	size = max_v - min_v;
        }
          
        /*int	nsteps 		= 1 + (int) (1.0/stepsize);*/
    
        int nsteps = (int) (size/stepsize);
        if(nsteps <=0)
          nsteps=1;
    
        TrimVertex *vert	= trimvertexpool.get( nsteps+1 );
        REAL dp 		= 1.0/nsteps;
    
    
        arc->pwlArc 	= new(pwlarcpool) PwlArc();
        arc->pwlArc->pts 	= vert;
    
        if( isrational ) {
            REAL pow_u[MAXORDER], pow_v[MAXORDER], pow_w[MAXORDER];
        	trim_power_coeffs( bezierArc, pow_u, 0 );
        	trim_power_coeffs( bezierArc, pow_v, 1 );
            trim_power_coeffs( bezierArc, pow_w, 2 );
    
    	/* compute first point exactly */
            REAL *b = bezierArc->cpts;
    	vert->param[0] = b[0]/b[2];
    	vert->param[1] = b[1]/b[2];
    
    	/* strength reduction on p = dp * step would introduce error */
    	int step;
    #ifndef NOELIMINATION
    	int ocanremove = 0;
    #endif
        	long order =  bezierArc->order;
    	for( step=1, ++vert; step<nsteps; step++, vert++ ) {
    	    REAL p = dp * step;
        	    REAL u = pow_u[0];
                REAL v = pow_v[0];
    	    REAL w = pow_w[0];
    	    for( int i = 1; i < order; i++ ) {
    	        u = u * p + pow_u[i];
    	        v = v * p + pow_v[i];
    	        w = w * p + pow_w[i];
                }
                vert->param[0] = u/w;
        	    vert->param[1] = v/w;
    #ifndef NOELIMINATION
    	    REAL ds = glu_abs(vert[0].param[0] - vert[-1].param[0]);
    	    REAL dt = glu_abs(vert[0].param[1] - vert[-1].param[1]);
    	    int canremove = (ds<geo_stepsize && dt<geo_stepsize) ? 1 : 0;
    	    REAL ods=0.0, odt=0.0;
    
    	    if( ocanremove && canremove ) {
    		REAL nds = ds + ods;
    		REAL ndt = dt + odt;
    		if( nds<geo_stepsize && ndt<geo_stepsize ) {
    		    // remove previous point
    		    --vert;
    		    vert[0].param[0] = vert[1].param[0];
    		    vert[0].param[1] = vert[1].param[1];
    		    ods = nds;
    		    odt = ndt;
    		    ocanremove = 1;
    		} else {
    		    ocanremove = canremove;
    		    ods = ds;
    		    odt = dt;
    		}
    	    } else {
    		ocanremove = canremove;
    		ods = ds;
    		odt = dt;
    	    }
    #endif	
    	}
    
    	/* compute last point exactly */
    	b += (order - 1) * bezierArc->stride;
    	vert->param[0] = b[0]/b[2];
    	vert->param[1] = b[1]/b[2];
    
        } else {
            REAL pow_u[MAXORDER], pow_v[MAXORDER];
    	trim_power_coeffs( bezierArc, pow_u, 0 );
    	trim_power_coeffs( bezierArc, pow_v, 1 );
    
    	/* compute first point exactly */
            REAL *b = bezierArc->cpts;
    	vert->param[0] = b[0];
    	vert->param[1] = b[1];
    
    	/* strength reduction on p = dp * step would introduce error */
    	int step;
    #ifndef NOELIMINATION
    	int ocanremove = 0;
    #endif
        	long order =  bezierArc->order;
    	for( step=1, ++vert; step<nsteps; step++, vert++ ) {
    	    REAL p = dp * step;
    	    REAL u = pow_u[0];
                REAL v = pow_v[0];
                for( int i = 1; i < bezierArc->order; i++ ) {
    	        u = u * p + pow_u[i];
    	        v = v * p + pow_v[i];
                }
                vert->param[0] = u;
    	    vert->param[1] = v;
    #ifndef NOELIMINATION
    	    REAL ds = glu_abs(vert[0].param[0] - vert[-1].param[0]);
    	    REAL dt = glu_abs(vert[0].param[1] - vert[-1].param[1]);
    	    int canremove = (ds<geo_stepsize && dt<geo_stepsize) ? 1 : 0;
    	    REAL ods=0.0, odt=0.0;
    
    	    if( ocanremove && canremove ) {
    		REAL nds = ds + ods;
    		REAL ndt = dt + odt;
    		if( nds<geo_stepsize && ndt<geo_stepsize ) {
    		    // remove previous point
    		    --vert;
    		    vert[0].param[0] = vert[1].param[0];
    		    vert[0].param[1] = vert[1].param[1];
    		    ods = nds;
    		    odt = ndt;
    		    ocanremove = 1;
    		} else {
    		    ocanremove = canremove;
    		    ods = ds;
    		    odt = dt;
    		}
    	    } else {
    		ocanremove = canremove;
    		ods = ds;
    		odt = dt;
    	    }
    #endif	
    	}
    
    	/* compute last point exactly */
    	b += (order - 1) * bezierArc->stride;
    	vert->param[0] = b[0];
    	vert->param[1] = b[1];
        }
        arc->pwlArc->npts = vert - arc->pwlArc->pts + 1;
    /*
        for( TrimVertex *vt=pwlArc->pts; vt != vert-1; vt++ ) {
    	if( tooclose( vt[0].param[0], vt[1].param[0] ) )
    	    vt[1].param[0] = vt[0].param[0];
    	if( tooclose( vt[0].param[1], vt[1].param[1] ) )
    	    vt[1].param[1] = vt[0].param[1];
        }
    */
    }
    
    const REAL ArcTessellator::gl_Bernstein[][MAXORDER][MAXORDER] = {
     {
      {1, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 }
     },
     {
      {-1, 1, 0, 0, 0, 0, 0, 0 },
      {1, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 }
     },
     {
      {1, -2, 1, 0, 0, 0, 0, 0 },
      {-2, 2, 0, 0, 0, 0, 0, 0 },
      {1, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 }
     },
     {
      {-1, 3, -3, 1, 0, 0, 0, 0 },
      {3, -6, 3, 0, 0, 0, 0, 0 },
      {-3, 3, 0, 0, 0, 0, 0, 0 },
      {1, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 }
     },
     {
      {1, -4, 6, -4, 1, 0, 0, 0 },
      {-4, 12, -12, 4, 0, 0, 0, 0 },
      {6, -12, 6, 0, 0, 0, 0, 0 },
      {-4, 4, 0, 0, 0, 0, 0, 0 },
      {1, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 }
     },
     {
      {-1, 5, -10, 10, -5, 1, 0, 0 },
      {5, -20, 30, -20, 5, 0, 0, 0 },
      {-10, 30, -30, 10, 0, 0, 0, 0 },
      {10, -20, 10, 0, 0, 0, 0, 0 },
      {-5, 5, 0, 0, 0, 0, 0, 0 },
      {1, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 }
     },
     {
      {1, -6, 15, -20, 15, -6, 1, 0 },
      {-6, 30, -60, 60, -30, 6, 0, 0 },
      {15, -60, 90, -60, 15, 0, 0, 0 },
      {-20, 60, -60, 20, 0, 0, 0, 0 },
      {15, -30, 15, 0, 0, 0, 0, 0 },
      {-6, 6, 0, 0, 0, 0, 0, 0 },
      {1, 0, 0, 0, 0, 0, 0, 0 },
      {0, 0, 0, 0, 0, 0, 0, 0 }
     },
     {
      {-1, 7, -21, 35, -35, 21, -7, 1 },
      {7, -42, 105, -140, 105, -42, 7, 0 },
      {-21, 105, -210, 210, -105, 21, 0, 0 },
      {35, -140, 210, -140, 35, 0, 0, 0 },
      {-35, 105, -105, 35, 0, 0, 0, 0 },
      {21, -42, 21, 0, 0, 0, 0, 0 },
      {-7, 7, 0, 0, 0, 0, 0, 0 },
      {1, 0, 0, 0, 0, 0, 0, 0 }
     }};
    
    
    /*-----------------------------------------------------------------------------
     * trim_power_coeffs - compute power basis coefficients from bezier coeffients
     *-----------------------------------------------------------------------------
     */
    void
    ArcTessellator::trim_power_coeffs( BezierArc *bez_arc, REAL *p, int coord )
    {
        int stride = bez_arc->stride;
        int order = bez_arc->order;
        REAL *base = bez_arc->cpts + coord;
    
        REAL const (*mat)[MAXORDER][MAXORDER] = &gl_Bernstein[order-1];
        REAL const (*lrow)[MAXORDER] = &(*mat)[order];
    
        /* WIN32 didn't like the following line within the for-loop */
        REAL const (*row)[MAXORDER] =  &(*mat)[0];
        for( ; row != lrow; row++ ) {
    	REAL s = 0.0;
    	REAL *point = base;
    	REAL const *mlast = *row + order;
    	for( REAL const *m = *row; m != mlast; m++, point += stride ) 
    	    s += *(m) * (*point);
    	*(p++) = s;
        }
    }