src/freetype/type1/t1afm.c

/***************************************************************************/
/*                                                                         */
/*  t1afm.c                                                                */
/*                                                                         */
/*    AFM support for Type 1 fonts (body).                                 */
/*                                                                         */
/*  Copyright 1996-2000 by                                                 */
/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
/*                                                                         */
/*  This file is part of the FreeType project, and may only be used,       */
/*  modified, and distributed under the terms of the FreeType project      */
/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
/*  this file you indicate that you have read the license and              */
/*  understand and accept it fully.                                        */
/*                                                                         */
/***************************************************************************/


#ifdef FT_FLAT_COMPILE

#include "t1afm.h"

#else

#include <type1/t1afm.h>

#endif


#include <freetype/internal/ftstream.h>
#include <freetype/internal/t1types.h>

#include <stdlib.h>  /* for qsort()   */
#include <string.h>  /* for strcmp()  */
#include <ctype.h>   /* for isalnum() */


  /*************************************************************************/
  /*                                                                       */
  /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
  /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
  /* messages during execution.                                            */
  /*                                                                       */
#undef  FT_COMPONENT
#define FT_COMPONENT  trace_t1afm


  LOCAL_FUNC
  void  T1_Done_AFM( FT_Memory  memory,
                     T1_AFM*    afm )
  {
    FREE( afm->kern_pairs );
    afm->num_pairs = 0;
  }


#undef  IS_KERN_PAIR
#define IS_KERN_PAIR( p )  ( p[0] == 'K' && p[1] == 'P' )

#define IS_ALPHANUM( c )  ( isalnum( c ) || \
                            c == '_'     || \
                            c == '.'     )


  /* read a glyph name and return the equivalent glyph index */
  static
  FT_UInt  afm_atoindex( FT_Byte**  start,
                         FT_Byte*   limit,
                         T1_Font*   type1 )
  {
    FT_Byte*  p = *start;
    FT_Int    len;
    FT_UInt   result = 0;
    char      temp[64];


    /* skip whitespace */
    while ( ( *p == ' ' || *p == '\t' || *p == ':' || *p == ';' ) &&
            p < limit                                             )
      p++;
    *start = p;

    /* now, read glyph name */
    while ( IS_ALPHANUM( *p ) && p < limit )
      p++;

    len = p - *start;

    if ( len > 0 && len < 64 )
    {
      FT_Int  n;


      /* copy glyph name to intermediate array */
      MEM_Copy( temp, *start, len );
      temp[len] = 0;

      /* lookup glyph name in face array */
      for ( n = 0; n < type1->num_glyphs; n++ )
      {
        char*  gname = (char*)type1->glyph_names[n];


        if ( gname && gname[0] == temp[0] && strcmp( gname, temp ) == 0 )
        {
          result = n;
          break;
        }
      }
    }
    *start = p;
    return result;
  }


  /* read an integer */
  static
  int  afm_atoi( FT_Byte**  start,
                 FT_Byte*   limit )
  {
    FT_Byte*  p    = *start;
    int       sum  = 0;
    int       sign = 1;


    /* skip everything that is not a number */
    while ( p < limit && !isdigit( *p ) )
    {
      sign = 1;
      if ( *p == '-' )
        sign = -1;

      p++;
    }

    while ( p < limit && isdigit( *p ) )
    {
      sum = sum * 10 + ( *p - '0' );
      p++;
    }
    *start = p;

    return sum * sign;
  }


#undef  KERN_INDEX
#define KERN_INDEX( g1, g2 )  ( ( (FT_ULong)g1 << 16 ) | g2 )


  /* compare two kerning pairs */
  static
  int  compare_kern_pairs( const void*  a,
                           const void*  b )
  {
    T1_Kern_Pair*  pair1 = (T1_Kern_Pair*)a;
    T1_Kern_Pair*  pair2 = (T1_Kern_Pair*)b;

    FT_ULong  index1 = KERN_INDEX( pair1->glyph1, pair1->glyph2 );
    FT_ULong  index2 = KERN_INDEX( pair2->glyph1, pair2->glyph2 );


    return ( index1 - index2 );
  }


  /* parse an AFM file -- for now, only read the kerning pairs */
  LOCAL_FUNC
  FT_Error  T1_Read_AFM( FT_Face    t1_face,
                         FT_Stream  stream )
  {
    FT_Error       error;
    FT_Memory      memory = stream->memory;
    FT_Byte*       start;
    FT_Byte*       limit;
    FT_Byte*       p;
    FT_Int         count = 0;
    T1_Kern_Pair*  pair;
    T1_Font*       type1 = &((T1_Face)t1_face)->type1;
    T1_AFM*        afm   = 0;


    if ( ACCESS_Frame( stream->size ) )
      return error;

    start = (FT_Byte*)stream->cursor;
    limit = (FT_Byte*)stream->limit;
    p     = start;

    /* we are now going to count the occurences of `KP' or `KPX' in */
    /* the AFM file                                                 */
    count = 0;
    for ( p = start; p < limit - 3; p++ )
    {
      if ( IS_KERN_PAIR( p ) )
        count++;
    }

    /* Actually, kerning pairs are simply optional! */
    if ( count == 0 )
      goto Exit;

    /* allocate the pairs */
    if ( ALLOC( afm, sizeof ( *afm ) )                       ||
         ALLOC_ARRAY( afm->kern_pairs, count, T1_Kern_Pair ) )
      goto Exit;

    /* now, read each kern pair */
    pair           = afm->kern_pairs;
    afm->num_pairs = count;

    /* save in face object */
    ((T1_Face)t1_face)->afm_data = afm;

    for ( p = start; p < limit - 3; p++ )
    {
      if ( IS_KERN_PAIR( p ) )
      {
        FT_Byte*  q;


        /* skip keyword (KP or KPX) */
        q = p + 2;
        if ( *q == 'X' )
          q++;

        pair->glyph1    = afm_atoindex( &q, limit, type1 );
        pair->glyph2    = afm_atoindex( &q, limit, type1 );
        pair->kerning.x = afm_atoi( &q, limit );

        pair->kerning.y = 0;
        if ( p[2] != 'X' )
          pair->kerning.y = afm_atoi( &q, limit );

        pair++;
      }
    }

    /* now, sort the kern pairs according to their glyph indices */
    qsort( afm->kern_pairs, count, sizeof ( T1_Kern_Pair ),
           compare_kern_pairs );

  Exit:
    if ( error )
      FREE( afm );

    FORGET_Frame();

    return error;
  }


  /* find the kerning for a given glyph pair */
  LOCAL_FUNC
  void  T1_Get_Kerning( T1_AFM*     afm,
                        FT_UInt     glyph1,
                        FT_UInt     glyph2,
                        FT_Vector*  kerning )
  {
    T1_Kern_Pair  *min, *mid, *max;
    FT_ULong      index = KERN_INDEX( glyph1, glyph2 );


    /* simple binary search */
    min = afm->kern_pairs;
    max = min + afm->num_pairs - 1;

    while ( min <= max )
    {
      FT_ULong  midi;


      mid  = min + ( max - min ) / 2;
      midi = KERN_INDEX( mid->glyph1, mid->glyph2 );

      if ( midi == index )
      {
        *kerning = mid->kerning;
        return;
      }

      if ( midi < index )
        min = mid + 1;
      else
        max = mid - 1;
    }

    kerning->x = 0;
    kerning->y = 0;
  }


/* END */
Commit	Line	Data
	1	/***************************************************************************/
	2	/* */
	3	/* t1afm.c */
	4	/* */
	5	/* AFM support for Type 1 fonts (body). */
	6	/* */
	7	/* Copyright 1996-2000 by */
	8	/* David Turner, Robert Wilhelm, and Werner Lemberg. */
	9	/* */
	10	/* This file is part of the FreeType project, and may only be used, */
	11	/* modified, and distributed under the terms of the FreeType project */
	12	/* license, LICENSE.TXT. By continuing to use, modify, or distribute */
	13	/* this file you indicate that you have read the license and */
	14	/* understand and accept it fully. */
	15	/* */
	16	/***************************************************************************/
	17
	18
	19	#ifdef FT_FLAT_COMPILE
	20
	21	#include "t1afm.h"
	22
	23	#else
	24
	25	#include <type1/t1afm.h>
	26
	27	#endif
	28
	29
	30	#include <freetype/internal/ftstream.h>
	31	#include <freetype/internal/t1types.h>
	32
	33	#include <stdlib.h> /* for qsort() */
	34	#include <string.h> /* for strcmp() */
	35	#include <ctype.h> /* for isalnum() */
	36
	37
	38	/*************************************************************************/
	39	/* */
	40	/* The macro FT_COMPONENT is used in trace mode. It is an implicit */
	41	/* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */
	42	/* messages during execution. */
	43	/* */
	44	#undef FT_COMPONENT
	45	#define FT_COMPONENT trace_t1afm
	46
	47
	48	LOCAL_FUNC
	49	void T1_Done_AFM( FT_Memory memory,
	50	T1_AFM* afm )
	51	{
	52	FREE( afm->kern_pairs );
	53	afm->num_pairs = 0;
	54	}
	55
	56
	57	#undef IS_KERN_PAIR
	58	#define IS_KERN_PAIR( p ) ( p[0] == 'K' && p[1] == 'P' )
	59
	60	#define IS_ALPHANUM( c ) ( isalnum( c ) \|\| \
	61	c == '_' \|\| \
	62	c == '.' )
	63
	64
	65	/* read a glyph name and return the equivalent glyph index */
	66	static
	67	FT_UInt afm_atoindex( FT_Byte** start,
	68	FT_Byte* limit,
	69	T1_Font* type1 )
	70	{
	71	FT_Byte* p = *start;
	72	FT_Int len;
	73	FT_UInt result = 0;
	74	char temp[64];
	75
	76
	77	/* skip whitespace */
	78	while ( ( p == ' ' \|\| p == '\t' \|\| p == ':' \|\| p == ';' ) &&
	79	p < limit )
	80	p++;
	81	*start = p;
	82
	83	/* now, read glyph name */
	84	while ( IS_ALPHANUM( *p ) && p < limit )
	85	p++;
	86
	87	len = p - *start;
	88
	89	if ( len > 0 && len < 64 )
	90	{
	91	FT_Int n;
	92
	93
	94	/* copy glyph name to intermediate array */
	95	MEM_Copy( temp, *start, len );
	96	temp[len] = 0;
	97
	98	/* lookup glyph name in face array */
	99	for ( n = 0; n < type1->num_glyphs; n++ )
	100	{
	101	char* gname = (char*)type1->glyph_names[n];
	102
	103
	104	if ( gname && gname[0] == temp[0] && strcmp( gname, temp ) == 0 )
	105	{
	106	result = n;
	107	break;
	108	}
	109	}
	110	}
	111	*start = p;
	112	return result;
	113	}
	114
	115
	116	/* read an integer */
	117	static
	118	int afm_atoi( FT_Byte** start,
	119	FT_Byte* limit )
	120	{
	121	FT_Byte* p = *start;
	122	int sum = 0;
	123	int sign = 1;
	124
	125
	126	/* skip everything that is not a number */
	127	while ( p < limit && !isdigit( *p ) )
	128	{
	129	sign = 1;
	130	if ( *p == '-' )
	131	sign = -1;
	132
	133	p++;
	134	}
	135
	136	while ( p < limit && isdigit( *p ) )
	137	{
	138	sum = sum * 10 + ( *p - '0' );
	139	p++;
	140	}
	141	*start = p;
	142
	143	return sum * sign;
	144	}
	145
	146
	147	#undef KERN_INDEX
	148	#define KERN_INDEX( g1, g2 ) ( ( (FT_ULong)g1 << 16 ) \| g2 )
	149
	150
	151	/* compare two kerning pairs */
	152	static
	153	int compare_kern_pairs( const void* a,
	154	const void* b )
	155	{
	156	T1_Kern_Pair* pair1 = (T1_Kern_Pair*)a;
	157	T1_Kern_Pair* pair2 = (T1_Kern_Pair*)b;
	158
	159	FT_ULong index1 = KERN_INDEX( pair1->glyph1, pair1->glyph2 );
	160	FT_ULong index2 = KERN_INDEX( pair2->glyph1, pair2->glyph2 );
	161
	162
	163	return ( index1 - index2 );
	164	}
	165
	166
	167	/* parse an AFM file -- for now, only read the kerning pairs */
	168	LOCAL_FUNC
	169	FT_Error T1_Read_AFM( FT_Face t1_face,
	170	FT_Stream stream )
	171	{
	172	FT_Error error;
	173	FT_Memory memory = stream->memory;
	174	FT_Byte* start;
	175	FT_Byte* limit;
	176	FT_Byte* p;
	177	FT_Int count = 0;
	178	T1_Kern_Pair* pair;
	179	T1_Font* type1 = &((T1_Face)t1_face)->type1;
	180	T1_AFM* afm = 0;
	181
	182
	183	if ( ACCESS_Frame( stream->size ) )
	184	return error;
	185
	186	start = (FT_Byte*)stream->cursor;
	187	limit = (FT_Byte*)stream->limit;
	188	p = start;
	189
	190	/* we are now going to count the occurences of `KP' or `KPX' in */
	191	/* the AFM file */
	192	count = 0;
	193	for ( p = start; p < limit - 3; p++ )
	194	{
	195	if ( IS_KERN_PAIR( p ) )
	196	count++;
	197	}
	198
	199	/* Actually, kerning pairs are simply optional! */
	200	if ( count == 0 )
	201	goto Exit;
	202
	203	/* allocate the pairs */
	204	if ( ALLOC( afm, sizeof ( *afm ) ) \|\|
	205	ALLOC_ARRAY( afm->kern_pairs, count, T1_Kern_Pair ) )
	206	goto Exit;
	207
	208	/* now, read each kern pair */
	209	pair = afm->kern_pairs;
	210	afm->num_pairs = count;
	211
	212	/* save in face object */
	213	((T1_Face)t1_face)->afm_data = afm;
	214
	215	for ( p = start; p < limit - 3; p++ )
	216	{
	217	if ( IS_KERN_PAIR( p ) )
	218	{
	219	FT_Byte* q;
	220
	221
	222	/* skip keyword (KP or KPX) */
	223	q = p + 2;
	224	if ( *q == 'X' )
	225	q++;
	226
	227	pair->glyph1 = afm_atoindex( &q, limit, type1 );
	228	pair->glyph2 = afm_atoindex( &q, limit, type1 );
	229	pair->kerning.x = afm_atoi( &q, limit );
	230
	231	pair->kerning.y = 0;
	232	if ( p[2] != 'X' )
	233	pair->kerning.y = afm_atoi( &q, limit );
	234
	235	pair++;
	236	}
	237	}
	238
	239	/* now, sort the kern pairs according to their glyph indices */
	240	qsort( afm->kern_pairs, count, sizeof ( T1_Kern_Pair ),
	241	compare_kern_pairs );
	242
	243	Exit:
	244	if ( error )
	245	FREE( afm );
	246
	247	FORGET_Frame();
	248
	249	return error;
	250	}
	251
	252
	253	/* find the kerning for a given glyph pair */
	254	LOCAL_FUNC
	255	void T1_Get_Kerning( T1_AFM* afm,
	256	FT_UInt glyph1,
	257	FT_UInt glyph2,
	258	FT_Vector* kerning )
	259	{
	260	T1_Kern_Pair min, mid, *max;
	261	FT_ULong index = KERN_INDEX( glyph1, glyph2 );
	262
	263
	264	/* simple binary search */
	265	min = afm->kern_pairs;
	266	max = min + afm->num_pairs - 1;
	267
	268	while ( min <= max )
	269	{
	270	FT_ULong midi;
	271
	272
	273	mid = min + ( max - min ) / 2;
	274	midi = KERN_INDEX( mid->glyph1, mid->glyph2 );
	275
	276	if ( midi == index )
	277	{
	278	*kerning = mid->kerning;
	279	return;
	280	}
	281
	282	if ( midi < index )
	283	min = mid + 1;
	284	else
	285	max = mid - 1;
	286	}
	287
	288	kerning->x = 0;
	289	kerning->y = 0;
	290	}
	291
	292
	293	/* END */