output-cgm.c

/* output-cgm.c: CGM output

   Copyright (C) 1999, 2000, 2001 Martin Weber.

   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 2.1 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with this library; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
   USA. */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif /* Def: HAVE_CONFIG_H */

#include "types.h"
#include "spline.h"
#include "color.h"
#include "output-cgm.h"
#include "xstd.h"
#include "autotrace.h"
#include <string.h>

#define CGM_BEGINMETAFILE        0x0020
#define CGM_BEGINPICTURE         0x0060
#define CGM_METAFILEVERSION      0x1022
#define CGM_METAFILEDESCRIPTION  0x1040

typedef unsigned short int UI16;
typedef unsigned char      UI8;

/* endianess independent IO functions */

static at_bool write16(FILE *fdes, UI16 data)
{
  size_t count = 0;
  UI8 outch;
  
  outch = (UI8) ((data >> 8) & 0x0FF);
  count += fwrite(&outch, 1, 1, fdes);
  
  outch = (UI8) (data & 0x0FF);
  count += fwrite(&outch, 1, 1, fdes);

  return (count == sizeof(UI16)) ? true : false;
}

static at_bool write8(FILE *fdes, UI8 data)
{
  size_t count = 0;

  count = fwrite(&data, 1, 1, fdes);
  
  return (count == sizeof(UI8)) ? true : false;
}


static at_bool output_beginmetafilename(FILE *fdes, const char *string)
{
  int len = strlen (string);
 
  if (len + 1 < 0x001F)
    write16(fdes, CGM_BEGINMETAFILE + len + 1);
  else
    {
      write16(fdes, CGM_BEGINMETAFILE + 0x001F);
      write16(fdes, len + 1);
	}

  write8(fdes, len);

  while (*string != '\0')
    {
	  write8(fdes, *string);
	  string++;
    }

  if (len % 2 == 0)
	  write8(fdes, 0);


  return true;
}

static at_bool output_beginpicture(FILE *fdes, const char *string)
{
  int len = strlen (string);
 
  if (len + 1 < 0x001F)
    write16(fdes, CGM_BEGINPICTURE + len + 1);
  else
    {
      write16(fdes, CGM_BEGINPICTURE + 0x001F);
      write16(fdes, len + 1);
	}

  write8(fdes, len);

  while (*string != '\0')
    {
	  write8(fdes, *string);
	  string++;
    }

  if (len % 2 == 0)
	  write8(fdes, 0);


  return true;
}

static at_bool output_metafiledescription(FILE *fdes, const char *string)
{
  int len = strlen (string);
 
  if (len + 1 < 0x001F)
    write16(fdes, CGM_METAFILEDESCRIPTION + len + 1);
  else
    {
      write16(fdes, CGM_METAFILEDESCRIPTION + 0x001F);
      write16(fdes, len + 1);
	}

  write8(fdes, len);

  while (*string != '\0')
    {
	  write8(fdes, *string);
	  string++;
    }

  if (len % 2 == 0)
	  write8(fdes, 0);


  return true;
}

int output_cgm_writer(FILE* cgm_file, at_string name,
		      int llx, int lly, int urx, int ury, 
		      at_output_opts_type * opts,
		      spline_list_array_type shape,
		      at_msg_func msg_func, 
		      at_address msg_data)
{
  unsigned this_list;
  char *des;
  const char * version_string = at_version(true);

  output_beginmetafilename (cgm_file, name);

  write16 (cgm_file, CGM_METAFILEVERSION);
  write16 (cgm_file, 0x0002);

  des = (char *) malloc (strlen ("created by ") + strlen (version_string) + 1);
  strcpy (des, "created by ");
  strcat (des, version_string);
  output_metafiledescription (cgm_file, des);
  free (des);

  write16 (cgm_file, 0x1166); /* metafile element list */
  write16 (cgm_file, 0x0001);
  write16 (cgm_file, 0xFFFF);
  write16 (cgm_file, 0x0001);

  output_beginpicture(cgm_file, "pic1");

  write16 (cgm_file, 0x2042);/* color selection modes (1 = direct) */
  write16 (cgm_file, 0x0001);

  write16 (cgm_file, 0x20C8);/* vdc extend */
  write16 (cgm_file, llx/*0x0000*/);
  write16 (cgm_file, urx/*0x7FFF*/);
  write16 (cgm_file, ury/*0x7FFF*/);
  write16 (cgm_file, lly/*0x0000*/);

  write16 (cgm_file, 0x0080);/* begin picture body */


  for (this_list = 0; this_list < SPLINE_LIST_ARRAY_LENGTH (shape);
       this_list++)
    {
      unsigned this_spline;

      spline_list_type list = SPLINE_LIST_ARRAY_ELT (shape, this_list);

	  if (this_list > 0)
	    {
	      if (shape.centerline)
		write16 (cgm_file, 0x0200); /* end a compound line */
	      else
		write16 (cgm_file, 0x0120); /* end a figure */
	    }

      if (shape.centerline)
        write16 (cgm_file, 0x5083);/* line */
      else
	    write16 (cgm_file, 0x52E3);/* fill */;

	  /* color output */
	  if (list.clockwise && shape.background_color != NULL)
	    {
          write8 (cgm_file, shape.background_color->r);
          write8 (cgm_file, shape.background_color->g);
          write8 (cgm_file, shape.background_color->b);
	    }
	  else
	    {
          write8 (cgm_file, list.color.r);
          write8 (cgm_file, list.color.g);
          write8 (cgm_file, list.color.b);
	    }
      write8 (cgm_file, 0);

      if (shape.centerline)
        {
          write16 (cgm_file, 0x53C2);/* edge visibility on */
          write16 (cgm_file, 0x0001);
        }
      else
        {
          write16 (cgm_file, 0x52C2);/* interior style solid */
          write16 (cgm_file, 0x0001);
        }

	  if (shape.centerline)
	    write16 (cgm_file, 0x01E0); /* begin a compound line */
	  else
		write16 (cgm_file, 0x0100); /* begin a figure */   

      for (this_spline = 0; this_spline < SPLINE_LIST_LENGTH (list);
           this_spline++)
        {
          spline_type s = SPLINE_LIST_ELT (list, this_spline);

          if (SPLINE_DEGREE (s) == LINEARTYPE)
		  {
            write16 (cgm_file, 0x4028); /* polyline */
            write16 (cgm_file, (UI16) START_POINT (s).x);
            write16 (cgm_file, ury - (UI16) START_POINT (s).y);
            write16 (cgm_file, (UI16) END_POINT (s).x);
            write16 (cgm_file, ury - (UI16) END_POINT (s).y);
		  }
          else
		  {
            write16 (cgm_file, 0x4352); /* polybezier */
            write16 (cgm_file, 0x0002); /* continuous */
            write16 (cgm_file, (UI16) START_POINT (s).x);
            write16 (cgm_file, ury - (UI16) START_POINT (s).y);
            write16 (cgm_file, (UI16) CONTROL1 (s).x);
            write16 (cgm_file, ury - (UI16) CONTROL1 (s).y);
            write16 (cgm_file, (UI16) CONTROL2 (s).x); 
            write16 (cgm_file, ury - (UI16) CONTROL2 (s).y);
            write16 (cgm_file, (UI16) END_POINT (s).x);
            write16 (cgm_file, ury - (UI16) END_POINT (s).y);
		  }
        }
  }

  if (SPLINE_LIST_ARRAY_LENGTH(shape) > 0)
    {
      if (shape.centerline)
	write16 (cgm_file, 0x0200); /* end a compound line */
      else
	write16 (cgm_file, 0x0120); /* end a figure */
    }

  write16 (cgm_file, 0x00A0); /* end picture */

  write16 (cgm_file, 0x0040); /* end metafile */

  return(0);

}