/*
  open_font -- open font file and extract needed information
  Copyright (C) 1998, 1999 Dieter Baron

  This file is part of ttftot42, to use TrueType fonts in PostScript.
  The author can be contacted at <dillo@giga.or.at>

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  This program 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 General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/



#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <ctype.h>

#include <ftxpost.h>
#include <ftxerr18.h>

#include "t42.h"

static char *weight_name[] = {
    "Thin", "Extra Light", "Light", "Regular", "Medium",
    "Semibold", "Bold", "Extra Bold", "Black"
};
int nweight = sizeof(weight_name)/sizeof(weight_name[0]);

static char *fixed2str(TT_Fixed f, int prec);
static int read_dir(font *f, char *fname);



font *
open_font(char *fname, int what)
{
    font *f;
    int err, i, j, weight;
    char *version;

    TT_Face face;
    TT_Face_Properties prop;
    TT_Postscript *ps;
    TT_Header *hdr;
    TT_OS2 *os2;
    TT_Post post;

    if ((f=(font *)malloc(sizeof(font))) == NULL)
	return NULL;

    if ((err=TT_Open_Face(fte, fname, &face)) != TT_Err_Ok) {
	fprintf(stderr, "%s: can't open font %s: %s\n",
		prg, fname, TT_ErrToString18(err));
	return NULL;
    }
    TT_Get_Face_Properties(face, &prop);
    TT_Load_PS_Names(face, &post);

    hdr = prop.header;
    os2 = prop.os2;
    ps = prop.postscript;
    
    /* fill out info */

    f->face = face;
    f->nglyph = prop.num_Glyphs;
    f->nnames = prop.num_Names;
    f->long_loc = hdr->Index_To_Loc_Format;
    f->units_per_em = hdr->Units_Per_EM;
    
    f->font_bbox.llx = SCALE(hdr->xMin);
    f->font_bbox.lly = SCALE(hdr->yMin);
    f->font_bbox.urx = SCALE(hdr->xMax);
    f->font_bbox.ury = SCALE(hdr->yMax);

    f->vm_min = ps->minMemType42;
    f->vm_max = ps->maxMemType42;
    f->italic_angle = fixed2str(ps->italicAngle, 3);
    f->underline_position = ps->underlinePosition;
    f->underline_thickness = ps->underlineThickness;
    f->is_fixed_pitch = ps->isFixedPitch;

    weight = (os2->usWeightClass-50)/100;
    if (weight >= nweight)
	weight = nweight-1;
    f->weight = strdup(weight_name[weight]);
    f->ascender = SCALE(os2->sTypoAscender);
    f->descender = SCALE(os2->sTypoDescender);

    f->tt_version = strdup("001.000"); /* FreeType only supports version 1.0 */
    f->version = (char *)malloc(8);
    version = get_name(f->face, f->nnames, TT_NAME_ID_VERSION_STRING);
    if ((version && strncasecmp(version, "Version ", 8) == 0
	 && isdigit(version[8]) && version[9] == '.'
	 && isdigit(version[10]) && isdigit(version[10]))) {
	sprintf(f->version, "00%c.%c%c0",
		version[8], version[10], version[11]);
    }
    else
	sprintf(f->version, "%03ld.%03ld",
		hdr->Font_Revision >> 16,
		((hdr->Font_Revision & 0xffff)*1000)/0x10000);
    
    f->font_name = get_name(f->face, f->nnames, TT_NAME_ID_PS_NAME);
    for (j=i=0; i<strlen(f->font_name); i++) {
	if (!strchr(" \t\n\r()<>[]/%", f->font_name[i]))
	    f->font_name[j++] = f->font_name[i];
    }
    f->font_name[j] = '\0';
    f->full_name = get_name(f->face, f->nnames, TT_NAME_ID_FULL_NAME);
    f->family_name = get_name(f->face, f->nnames, TT_NAME_ID_FONT_FAMILY);
    /* XXX: the following is wrong */
    f->notice = get_name(f->face, f->nnames, TT_NAME_ID_COPYRIGHT);

    if (what & WHAT_FONT) {
	if (read_dir(f, fname) != 0) {
	    close_font(f);
	    return NULL;
	}
    }
    if (what & WHAT_AFM) {
	if ((err=TT_New_Instance(f->face, &f->fi)) != TT_Err_Ok) {
	    fprintf(stderr, "%s: %s: can't create font instance: %s\n",
		    prg, fname, TT_ErrToString18(err));
	    close_font(f);
	    return NULL;
	}

	if (TT_New_Glyph(f->face, &f->fg) != TT_Err_Ok) {
	    fprintf(stderr, "%s: %s: can't create glyph container: %s\n",
		    prg, fname, TT_ErrToString18(err));
	    close_font(f);
	    return NULL;
	}
    }

    return f;
}



static char *
fixed2str(TT_Fixed f, int prec)
{
    char b[23], *p;
    int r, fr;
    
    p = b;
    if (prec == 0)
	prec = INT_MAX;

    sprintf(p, "%d", (int)f>>16);
    if ((f & 0xffff) != 0) {
	f &= 0xffff;
	p = p+strlen(p);
	*(p++) = '.';

	fr = 0;
	while (f != 0) {
	    f *= 10;
	    r = f/0x10000;
	    if (prec > 0)
		fr = fr*10 + r;
	    else {
		fr += r>=5;
		break;
	    }
	    f -= r*0x10000;
	    --prec;
	}
	sprintf(p, "%d", fr);
    }
    
    return strdup(b);
}



static int
read_dir(font *f, char *fname)
{
    static char *table_name[] = {
	"cvt ", "fpgm", "glyf", "head", "hhea", "hmtx", "loca", "maxp", "prep"
    };

    int ntables, i, j;
    TT_Long len;
    struct table *dir;
    unsigned char bh[12], *b;

    len = 12;
    TT_Get_Font_Data(f->face, 0, 0, bh, &len);

    ntables = (bh[4]<<8)+bh[5];

    dir = (struct table *)xmalloc(sizeof(struct table)*ntables);
    b = (unsigned char *)xmalloc(ntables*16);

    len = ntables*16;
    TT_Get_Font_Data(f->face, 0, 12, b, &len);

    for (i=0; i<16*ntables; i+=16) {
	memcpy(dir[i/16].tag, b+i, 4);
	dir[i/16].tag[4] = '\0';
	dir[i/16].checksum = (((((b[i+4]<<8)+b[i+5])<<8)+b[i+6])<<8)+b[i+7];
	dir[i/16].offset = (((((b[i+8]<<8)+b[i+9])<<8)+b[i+10])<<8)+b[i+11];
	dir[i/16].length = (((((b[i+12]<<8)+b[i+13])<<8)+b[i+14])<<8)+b[i+15];
    }
    free(b);

    for (i=j=0; i<ntables && j<9; i++) {
	if (strcmp(dir[i].tag, table_name[j]) == 0) {
	    f->dir[j] = dir[i];

	    if (j != TABLE_GLYF && f->dir[j].length > MAX_STRLEN) {
		fprintf(stderr, "%s: %s: table `%s' too long\n",
		    prg, fname, f->dir[j].tag);
		free(dir);
		return -1;
	    }
	    
	    j++;
	}
    }
    free(dir);

    /* XXX: check for missing table */

    return 0;
}