vfont.c

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/*                         V F O N T . C
 * BRL-CAD
 *
 * Copyright (c) 2004-2006 United States Government as represented by
 * the U.S. Army Research Laboratory.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this file; see the file named COPYING for more
 * information.
 */

/** \addtogroup vfont */
/*@{*/
/** @file vfont.c
 *
 * @brief Berkely Vector Fonts
 *
 *      Provide a machine-independent interface to files containing
 *      Berkeley VFONT format fonts, stored with VAX byte ordering
 *      and word alignment.
 *
 *  @author
 *      Michael John Muuss
 *
 *  @par Source -
 *      SECAD/VLD Computing Consortium, Bldg 394
 *@n    The U. S. Army Ballistic Research Laboratory
 *@n    Aberdeen Proving Ground, Maryland  21005-5066
 */


#ifndef lint
static const char libbu_vfont_RCSid[] = "@(#)$Header: /cvsroot/brlcad/brlcad/src/libbu/vfont.c,v 14.15 2006/09/03 15:14:07 lbutler Exp $ (BRL)";
#endif

#include "common.h"

#include <stdio.h>
#include "machine.h"
#include "vfont-if.h"
#include "bu.h"

#define FONTDIR2        "/usr/lib/vfont"
#define DEFAULT_FONT    "nonie.r.12"
#define FONTNAMESZ      128

/*
 * Forward Definitions
 */
static int vax_gshort(unsigned char *);

/**
 *                      V F O N T _ G E T
 *
 *  Fetch the named font, and return a struct vfont pointer.
 *
 *  First the filename provided is used, then the BRL-CAD font
 *  directory is searched (for places where "system" directories
 *  are considered sacred), and then finally the ordinary
 *  font directory is searched.
 *
 *  The font files are treated as pure byte streams, and are expected
 *  to be in VAX order.
 *
 *  VFONT_NULL is returned on error.  On ordinary errors, the function
 *  is silent.  On extraordinary errors, a remark is placed on stderr.
 */
struct vfont *
vfont_get(char *font)
{
        register struct vfont   *vfp = VFONT_NULL;
        register FILE           *fp = NULL;
        register int    i;
        char            fname[FONTNAMESZ];
        unsigned char   header[2*5];            /* 5 16-bit vax shorts */
        unsigned char   dispatch[10*256];       /* 256 10-byte structs */
        int             magic;
        int             size;

        if( font == NULL )
                font = DEFAULT_FONT;

        /* Open the file and read in the header information. */
        if( (fp = fopen( font, "r" )) == NULL )  {
                sprintf( fname, "%s/%s", (char *)bu_brlcad_data("vfont", 0), font );
                if( (fp = fopen( fname, "r" )) == NULL )  {
                        sprintf( fname, "%s/%s", FONTDIR2, font );
                        if( (fp = fopen( fname, "r" )) == NULL )  {
                                return(VFONT_NULL);
                        }
                }
        }
        if( fread( (char *)header, sizeof(header), 1, fp ) != 1 ||
            fread( (char *)dispatch, sizeof(dispatch), 1, fp ) != 1 )  {
                fprintf(stderr, "vfont_get(%s):  header read error\n", fname );
                fclose(fp);
                return(VFONT_NULL);
        }
        magic = vax_gshort( &header[0*2] ) & 0xFFFF;
        size = vax_gshort( &header[1*2] ) & 0xFFFF;     /* unsigned short */

        if( magic != 0436 )  {
                fprintf(stderr, "vfont_get(%s):  bad magic number 0%o\n",
                        fname, magic );
                fclose(fp);
                return(VFONT_NULL);
        }

        if( (vfp = (struct vfont *)bu_malloc(sizeof(struct vfont), "vfont")) == VFONT_NULL )  {
                fprintf(stderr,"vfont_get(%s):  malloc failure 1\n", fname );
                fclose(fp);
                return(VFONT_NULL);
        }

        /* Read in the bit maps */
        if( (vfp->vf_bits = (char *)bu_malloc(size, "vfont bits")) == (char *)0 )  {
                fprintf(stderr,"vfont_get(%s):  malloc failure 2 (%d)\n",
                        fname, size);
                fclose(fp);
                bu_free( (char *)vfp, "vfont");
                return(VFONT_NULL);
        }
        if( fread( vfp->vf_bits, size, 1, fp ) != 1 )  {
                fprintf(stderr,"vfont_get(%s):  bitmap read error\n", fname );
                fclose(fp);
                bu_free( vfp->vf_bits, "vfont bits" );
                bu_free( (char *)vfp, "vfont" );
                return(VFONT_NULL);
        }

        /*
         *  Convert VAX data in header[] and dispatch[] arrays to
         *  native machine form.
         */
        vfp->vf_maxx = vax_gshort( &header[2*2] );
        vfp->vf_maxy = vax_gshort( &header[3*2] );
        vfp->vf_xtend = vax_gshort( &header[4*2] );

        for( i=0; i<255; i++ )  {
                register struct vfont_dispatch  *vdp = &(vfp->vf_dispatch[i]);
                register unsigned char          *cp = &dispatch[i*10];

                vdp->vd_addr = vax_gshort( &cp[0] );
                vdp->vd_nbytes = vax_gshort( &cp[2] );
                vdp->vd_up = SXT( cp[4] );
                vdp->vd_down = SXT( cp[5] );
                vdp->vd_left = SXT( cp[6] );
                vdp->vd_right = SXT( cp[7] );
                vdp->vd_width = vax_gshort( &cp[8] );
        }
        fclose(fp);
        return(vfp);
}

/**
 *                      V A X _ G S H O R T
 *
 *  Obtain a 16-bit signed integer from two adjacent characters,
 *  stored in VAX order, regardless of word alignment.
 */
static int
vax_gshort(unsigned char *msgp)
{
        register unsigned char *p = (unsigned char *) msgp;
        register int    i;

        if( (i = (p[1] << 8) | p[0]) & 0x8000 )
                return(i | ~0xFFFF);    /* Sign extend */
        return(i);
}

/**
 *                      V F O N T _ F R E E
 *
 *  Return the storage associated with a struct vfont
 */
void
vfont_free(register struct vfont *vfp)
{
        bu_free( vfp->vf_bits, "vfont bits" );
        bu_free( (char *)vfp, "vfont" );
}
/*@}*/
/*
 * Local Variables:
 * mode: C
 * tab-width: 8
 * c-basic-offset: 4
 * indent-tabs-mode: t
 * End:
 * ex: shiftwidth=4 tabstop=8
 */

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