/* t1.c */

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

  Part of the dvipng distribution

  This program 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 3 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
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with this program. If not, see
  <http://www.gnu.org/licenses/>.

  Copyright (C) 2002-2008 Jan-Åke Larsson

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

#include "dvipng.h"
#ifdef HAVE_ALLOCA_H
# include <alloca.h>
#endif

void LoadT1(int32_t c, struct char_entry * ptr)
{
  GLYPH *glyph;
  int original_width,original_height;
  int i,j,k,width,height;
  unsigned short   shrunk_width,shrunk_height;
  short   xoffset,yoffset;
  unsigned short   i_offset,j_offset;

  DEBUG_PRINT(DEBUG_T1,("\n  LOAD T1 CHAR\t%d",c));
  if ((glyph=
       T1_SetChar(currentfont->T1id, c,
		  (float)currentfont->dpi*currentfont->d/65536/72.27,
		  currentfont->psfontmap==NULL ? NULL : currentfont->psfontmap->t1_transformp))
      ==NULL)
      Fatal("cannot load T1 char %d",c);

  DEBUG_PRINT(DEBUG_T1,(" (%d)",ptr->tfmw));
  
  original_width = glyph->metrics.rightSideBearing 
    - glyph->metrics.leftSideBearing;
  original_height  = glyph->metrics.ascent - glyph->metrics.descent;
  DEBUG_PRINT(DEBUG_T1,(" %dx%d",original_width,original_height));

  if (original_width > 0x7fff || original_height > 0x7fff)
    Fatal("character %d too large in file %s", c, currentfont->name);

  /* 
   * Hotspot issues: Shrinking to the topleft corner rather than the
     hotspot will displace glyphs a fraction of a pixel. We deal with
     this in as follows: The glyph is shrunk to its hotspot by
     offsetting the bitmap somewhat to put the hotspot in the lower
     left corner of a "shrink square". Shrinking to the topleft corner
     will then act as shrinking to the hotspot. This may enlarge the
     bitmap somewhat, of course.  (Also remember that the below
     calculation of i/j_offset is in integer arithmetics.)
     
     There will still be a displacement from rounding the dvi
     position, but vertically it will be equal for all glyphs on a
     line, so we displace a whole line vertically by fractions of a
     pixel. This is acceptible, IMHO. Sometime there will be support
     for subpixel positioning, horizontally. Will do for now, I
     suppose.
   */
  xoffset = -glyph->metrics.leftSideBearing;
  /* printf("xoffset: %d\n",xoffset); */
  i_offset = ( shrinkfactor - xoffset % shrinkfactor ) % shrinkfactor;
  width = original_width+i_offset;
  ptr->xOffset = xoffset+i_offset;

  yoffset = glyph->metrics.ascent-1;
  /* printf("yoffset: %d\n",yoffset); */
  j_offset = ( shrinkfactor - (yoffset-(shrinkfactor-1)) % shrinkfactor )
    % shrinkfactor;
  height = original_height+j_offset;
  ptr->yOffset = yoffset+j_offset;

  DEBUG_PRINT(DEBUG_T1,(" (%dx%d)",width,height));
  /* 
     Extra marginal so that we do not crop the image when shrinking.
  */
  shrunk_width = (width + shrinkfactor - 1) / shrinkfactor;
  shrunk_height = (height + shrinkfactor - 1) / shrinkfactor;
  ptr->w = shrunk_width;
  ptr->h = shrunk_height;

  /* printf("(%d,%d) ",ptr->w,ptr->h); */
  DEBUG_PRINT(DEBUG_GLYPH,("\nDRAW GLYPH %d\n", (int)c));

  /*
    Shrink raster while doing antialiasing. 
  */
  if ((ptr->data = calloc(shrunk_width*shrunk_height,sizeof(char))) == NULL)
    Fatal("unable to allocate image space for char %c", (char)c);
  for (j = 0; j < original_height; j++) {	
    for (i = 0; i < (original_width+7)/8 ; i++) {    
      for (k = 0; k < 8 ; k++) {
	DEBUG_PRINT(DEBUG_GLYPH,
		    ("%c",
		     (glyph->bits[i+j*((original_width+7)/8)] & (1<<k)) ?
		      'x' : ' '));
	ptr->data[(i*8+k+i_offset)/shrinkfactor
		  +(j+j_offset)/shrinkfactor*shrunk_width] += 
	  (glyph->bits[i+j*((original_width+7)/8)] & (1<<k) ? 1 : 0);
      }
    }    
    DEBUG_PRINT(DEBUG_GLYPH,("|\n"));
  }	
  for (j = 0; j < shrunk_height; j++) {	
    for (i = 0; i < shrunk_width; i++) {    
      ptr->data[i+j*shrunk_width] = ptr->data[i+j*shrunk_width]
	*255/shrinkfactor/shrinkfactor;
      DEBUG_PRINT(DEBUG_GLYPH,("%3u ",ptr->data[i+j*shrunk_width]));
    }
    DEBUG_PRINT(DEBUG_GLYPH,("|\n"));
  }	 
}

bool InitT1(struct font_entry * tfontp)
{
  if (libt1==NULL) {
    if ((libt1=T1_InitLib( NO_LOGFILE | IGNORE_CONFIGFILE
			   | IGNORE_FONTDATABASE | T1_NO_AFM)) == NULL) {
      Warning("an error occured during t1lib initialisation, disabling it"); 
      option_flags &= ~USE_LIBT1;
      return(false);
    }
# ifdef DEBUG
    else 
      DEBUG_PRINT(DEBUG_T1,("\n  T1LIB VERSION: %s", T1_GetLibIdent()));
# endif
  }

  DEBUG_PRINT((DEBUG_DVI|DEBUG_T1),("\n  OPEN T1 FONT:\t'%s'", tfontp->name));
  tfontp->T1id = T1_AddFont( tfontp->name );
  if (tfontp->T1id < 0) {
    Warning("t1lib could not open font file %s", tfontp->name);
    return(false);
  } 
  if (T1_LoadFont(tfontp->T1id)) {
    Warning("t1lib could not load font file %s", tfontp->name);
    return(false);
  } 
  Message(BE_VERBOSE,"<%s>", tfontp->name);
  if (tfontp->psfontmap!=NULL && tfontp->psfontmap->encoding != NULL) {
    DEBUG_PRINT(DEBUG_T1,("\n  USE ENCODING:\t'%s'", tfontp->psfontmap->encoding->name));
    if (T1_ReencodeFont(tfontp->T1id,tfontp->psfontmap->encoding->charname)) {
      Warning("unable to use font encoding '%s' for %s", 
	      tfontp->psfontmap->encoding->name,tfontp->name);
      return(false);
    }
  }
  tfontp->type = FONT_TYPE_T1;
  return(true);
}


void UnLoadT1(struct char_entry *ptr)
{
  if (ptr->data!=NULL)
    free(ptr->data);
  ptr->data=NULL;
}


void DoneT1(struct font_entry *tfontp)
{
  int c=0;

  int error = T1_DeleteFont( tfontp->T1id );
  if (error)
    Warning("font file %s could not be closed", tfontp->name);
  while(c<NFNTCHARS) {
    if (tfontp->chr[c]!=NULL) {
      UnLoadT1((struct char_entry*)tfontp->chr[c]);
      free(tfontp->chr[c]);
      tfontp->chr[c]=NULL;
    }
    c++;
  }
  tfontp->name[0]='\0';
}