backend.cc

Mesa is an open-source implementation of the OpenGL specification - a system for rendering interacti

/*
** 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.c++
 *
 * $Date: 2004/05/12 15:29:36 $ $Revision: 1.2 $
 * $Header: /home/krh/git/sync/mesa-cvs-repo/Mesa/src/glu/sgi/libnurbs/internals/backend.cc,v 1.2 2004/05/12 15:29:36 brianp Exp $
 */

/* Bezier surface backend
	- interprets display mode (wireframe,shaded,...)
*/
#include <stdio.h>
#include "glimports.h"
#include "mystdio.h"
#include "backend.h"
#include "basiccrveval.h"
#include "basicsurfeval.h"
#include "nurbsconsts.h"

#define NOWIREFRAME


/*-------------------------------------------------------------------------
 * bgnsurf - preamble to surface definition and evaluations
 *-------------------------------------------------------------------------
 */
void
Backend::bgnsurf( int wiretris, int wirequads, long nuid )
{
/*#ifndef NOWIREFRAME*/ //need this for old version
    wireframetris = wiretris;
    wireframequads = wirequads;
/*#endif*/

    /*in the spec, GLU_DISPLAY_MODE is either
     * GLU_FILL
     * GLU_OUTLINE_POLY
     * GLU_OUTLINE_PATCH.
     *In fact, GLU_FLL is has the same effect as
     * set GL_FRONT_AND_BACK to be GL_FILL
     * and GLU_OUTLINE_POLY is the same as set 
     *     GL_FRONT_AND_BACK to be GL_LINE
     *It is more efficient to do this once at the beginning of
     *each surface than to do it for each primitive.
     *   The internal has more options: outline_triangle and outline_quad
     *can be seperated. But since this is not in spec, and more importantly,
     *this is not so useful, so we don't need to keep this option.
     */

    surfaceEvaluator.bgnmap2f( nuid );

    if(wiretris)
      surfaceEvaluator.polymode(N_MESHLINE);
    else
      surfaceEvaluator.polymode(N_MESHFILL);
}

void
Backend::patch( REAL ulo, REAL uhi, REAL vlo, REAL vhi )
{
    surfaceEvaluator.domain2f( ulo, uhi, vlo, vhi );
}

void
Backend::surfbbox( long type, REAL *from, REAL *to )
{
    surfaceEvaluator.range2f( type, from, to );
}

/*-------------------------------------------------------------------------
 * surfpts - pass a desription of a surface map
 *-------------------------------------------------------------------------
 */
void 
Backend::surfpts(
    long type, 		/* geometry, color, texture, normal	*/
    REAL *pts, 		/* control points			*/
    long ustride,	/* distance to next point in u direction */
    long vstride,	/* distance to next point in v direction */
    int uorder,	/* u parametric order			*/
    int vorder,	/* v parametric order			*/
    REAL ulo,		/* u lower bound			*/
    REAL uhi,		/* u upper bound			*/
    REAL vlo,		/* v lower bound			*/
    REAL vhi )		/* v upper bound			*/
{
    surfaceEvaluator.map2f( type,ulo,uhi,ustride,uorder,vlo,vhi,vstride,vorder,pts );
    surfaceEvaluator.enable( type );
}

/*-------------------------------------------------------------------------
 * surfgrid - define a lattice of points with origin and offset
 *-------------------------------------------------------------------------
 */
void
Backend::surfgrid( REAL u0, REAL u1, long nu, REAL v0, REAL v1, long nv )
{
    surfaceEvaluator.mapgrid2f( nu, u0, u1, nv, v0, v1 );
}

/*-------------------------------------------------------------------------
 * surfmesh - evaluate a mesh of points on lattice
 *-------------------------------------------------------------------------
 */
void
Backend::surfmesh( long u, long v, long n, long m )
{
#ifndef NOWIREFRAME
    if( wireframequads ) {
	long v0,  v1;
	long u0f = u, u1f = u+n;
	long v0f = v, v1f = v+m;
	long parity = (u & 1);

        for( v0 = v0f, v1 = v0f++ ; v0<v1f; v0 = v1, v1++ ) {
	    surfaceEvaluator.bgnline();
	    for( long u = u0f; u<=u1f; u++ ) {
		if( parity ) {
		    surfaceEvaluator.evalpoint2i( u, v0 );
		    surfaceEvaluator.evalpoint2i( u, v1 );
		} else {
		    surfaceEvaluator.evalpoint2i( u, v1 );
		    surfaceEvaluator.evalpoint2i( u, v0 );
		}
		parity = 1 - parity;
	    }
	    surfaceEvaluator.endline();
	}
    } else {
	surfaceEvaluator.mapmesh2f( N_MESHFILL, u, u+n, v, v+m );
    }
#else
    if( wireframequads ) {

	surfaceEvaluator.mapmesh2f( N_MESHLINE, u, u+n, v, v+m );
    } else {

	surfaceEvaluator.mapmesh2f( N_MESHFILL, u, u+n, v, v+m );
    }
#endif
}

/*-------------------------------------------------------------------------
 * endsurf - postamble to surface
 *-------------------------------------------------------------------------
 */
void
Backend::endsurf( void )
{
    surfaceEvaluator.endmap2f();
}

/***************************************/
void
Backend::bgntfan( void )
{
  surfaceEvaluator.bgntfan();
/*
  if(wireframetris)	
    surfaceEvaluator.polymode( N_MESHLINE );
  else
    surfaceEvaluator.polymode( N_MESHFILL );
*/
}

void
Backend::endtfan( void )
{
   surfaceEvaluator.endtfan();
}

void
Backend::bgnqstrip( void )
{
   surfaceEvaluator.bgnqstrip();
/*
  if(wireframequads)
    surfaceEvaluator.polymode( N_MESHLINE );
  else
    surfaceEvaluator.polymode( N_MESHFILL );    
*/
}

void
Backend::endqstrip( void )
{
   surfaceEvaluator.endqstrip();
}

void
Backend::evalUStrip(int n_upper, REAL v_upper, REAL* upper_val,
                       int n_lower, REAL v_lower, REAL* lower_val
                       )
{
	surfaceEvaluator.evalUStrip(n_upper, v_upper, upper_val, 
				      n_lower, v_lower, lower_val);
}

void 
Backend::evalVStrip(int n_left, REAL u_left, REAL* left_val, 
		    int n_right, REAL u_right, REAL* right_val
		    )
{
  surfaceEvaluator.evalVStrip(n_left, u_left, left_val,
				n_right, u_right, right_val);
}

/***************************************/
   

/*-------------------------------------------------------------------------
 * bgntmesh - preamble to a triangle mesh
 *-------------------------------------------------------------------------
 */
void
Backend::bgntmesh( const char * )		
{
#ifndef NOWIREFRAME

    meshindex = 0;	/* I think these need to be initialized to zero */
    npts = 0;

    if( !wireframetris ) {
        surfaceEvaluator.bgntmesh();
    }
#else

    if( wireframetris ) {
        surfaceEvaluator.bgntmesh();
	surfaceEvaluator.polymode( N_MESHLINE );
    } else {
        surfaceEvaluator.bgntmesh();
	surfaceEvaluator.polymode( N_MESHFILL );
    }
#endif
}

void
Backend::tmeshvert( GridTrimVertex *v )
{
    if( v->isGridVert() ) {
	tmeshvert( v->g );
    } else {
	tmeshvert( v->t );
    }
}

void
Backend::tmeshvertNOGE(TrimVertex *t)
{
//	surfaceEvaluator.inDoEvalCoord2NOGE( t->param[0], t->param[1], temp, ttt);
#ifdef USE_OPTTT
	surfaceEvaluator.inDoEvalCoord2NOGE( t->param[0], t->param[1], t->cache_point, t->cache_normal);    
#endif
}

//opt for a line with the same u.
void
Backend::tmeshvertNOGE_BU(TrimVertex *t)
{
#ifdef USE_OPTTT
	surfaceEvaluator.inDoEvalCoord2NOGE_BU( t->param[0], t->param[1], t->cache_point, t->cache_normal);    
#endif