/*
** 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.
*/

/*
 * backend.h
 *
 * $Date$ $Revision$
 * $Header: //depot/main/gfx/lib/glu/libnurbs/internals/backend.h#4 $
 */

#ifndef __glubackend_h_
#define __glubackend_h_

#include "trimvertex.h"
#include "gridvertex.h"
#include "gridtrimvertex.h"

class BasicCurveEvaluator;
class BasicSurfaceEvaluator;

class Backend {
private:
    BasicCurveEvaluator&	curveEvaluator;
    BasicSurfaceEvaluator&	surfaceEvaluator;
public:
  			Backend( BasicCurveEvaluator &c, BasicSurfaceEvaluator& e )
			: curveEvaluator(c), surfaceEvaluator(e) {}

    /* surface backend routines */
    void		bgnsurf( int, int, long  );
    void		patch( REAL, REAL, REAL, REAL );
    void		surfpts( long, REAL *, long, long, int, int,
          			 REAL, REAL, REAL, REAL );
    void		surfbbox( long, REAL *, REAL * );
    void		surfgrid( REAL, REAL, long, REAL, REAL, long ); 
    void		surfmesh( long, long, long, long ); 
    void		bgntmesh( char * );
    void		endtmesh( void );
    void		swaptmesh( void );
    void		tmeshvert( GridTrimVertex * );
    void		tmeshvert( TrimVertex * );
    void		tmeshvert( GridVertex * );
    void		tmeshvert( REAL u,  REAL v );
    void		linevert( TrimVertex * );
    void		linevert( GridVertex * );
    void		bgnoutline( void );
    void		endoutline( void );
    void		endsurf( void );
    void		triangle( TrimVertex*, TrimVertex*, TrimVertex* );

    void                bgntfan();
    void                endtfan();
    void                bgnqstrip();
    void                endqstrip();
    void                evalUStrip(int n_upper, REAL v_upper, REAL* upper_val, 
				   int n_lower, REAL v_lower, REAL* lower_val
				   );
    void                evalVStrip(int n_left, REAL u_left, REAL* left_val, 
				   int n_right, REAL v_right, REAL* right_val
				   );
    void                tmeshvertNOGE(TrimVertex *t);
    void                tmeshvertNOGE_BU(TrimVertex *t);
    void                tmeshvertNOGE_BV(TrimVertex *t);
    void                preEvaluateBU(REAL u);
    void                preEvaluateBV(REAL v);
	

    /* curve backend routines */
    void		bgncurv( void );
    void		segment( REAL, REAL );
    void		curvpts( long, REAL *, long, int, REAL, REAL );
    void		curvgrid( REAL, REAL, long );
    void		curvmesh( long, long );
    void		curvpt( REAL  );  
    void		bgnline( void );
    void		endline( void );
    void		endcurv( void );
private:
#ifndef NOWIREFRAME
    int			wireframetris;
    int			wireframequads;
    int			npts;
    REAL		mesh[3][4];
    int			meshindex;
#endif
};

#endif /* __glubackend_h_ */
