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cabec872 RR |
1 | /***************************************************************************/ |
2 | /* */ | |
3 | /* cidafm.c */ | |
4 | /* */ | |
5 | /* AFM support for CID-keyed 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 "cidafm.h" | |
22 | ||
23 | #else | |
24 | ||
25 | #include <cid/cidafm.h> | |
26 | ||
27 | #endif | |
28 | ||
29 | ||
30 | #include <freetype/internal/ftstream.h> | |
31 | #include <freetype/internal/t1types.h> | |
32 | #include <freetype/internal/t1errors.h> | |
33 | ||
34 | #include <stdlib.h> /* for qsort() */ | |
35 | #include <string.h> /* for strcmp() */ | |
36 | #include <ctype.h> /* for isalnum() */ | |
37 | ||
38 | ||
39 | /*************************************************************************/ | |
40 | /* */ | |
41 | /* The macro FT_COMPONENT is used in trace mode. It is an implicit */ | |
42 | /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */ | |
43 | /* messages during execution. */ | |
44 | /* */ | |
45 | #undef FT_COMPONENT | |
46 | #define FT_COMPONENT trace_cidafm | |
47 | ||
48 | ||
49 | LOCAL_FUNC | |
50 | void CID_Done_AFM( FT_Memory memory, | |
51 | CID_AFM* afm ) | |
52 | { | |
53 | FREE( afm->kern_pairs ); | |
54 | afm->num_pairs = 0; | |
55 | } | |
56 | ||
57 | ||
58 | #undef IS_KERN_PAIR | |
59 | #define IS_KERN_PAIR( p ) ( p[0] == 'K' && p[1] == 'P' ) | |
60 | ||
61 | #define IS_ALPHANUM( c ) ( isalnum( c ) || \ | |
62 | c == '_' || \ | |
63 | c == '.' ) | |
64 | ||
65 | ||
66 | /* read a glyph name and return the equivalent glyph index */ | |
67 | static | |
68 | FT_UInt afm_atoindex( FT_Byte** start, | |
69 | FT_Byte* limit, | |
70 | T1_Font* type1 ) | |
71 | { | |
72 | FT_Byte* p = *start; | |
73 | FT_Int len; | |
74 | FT_UInt result = 0; | |
75 | char temp[64]; | |
76 | ||
77 | ||
78 | /* skip whitespace */ | |
79 | while ( ( *p == ' ' || *p == '\t' || *p == ':' || *p == ';' ) && | |
80 | p < limit ) | |
81 | p++; | |
82 | *start = p; | |
83 | ||
84 | /* now, read glyph name */ | |
85 | while ( IS_ALPHANUM( *p ) && p < limit ) | |
86 | p++; | |
87 | ||
88 | len = p - *start; | |
89 | ||
90 | if ( len > 0 && len < 64 ) | |
91 | { | |
92 | FT_Int n; | |
93 | ||
94 | ||
95 | /* copy glyph name to intermediate array */ | |
96 | MEM_Copy( temp, *start, len ); | |
97 | temp[len] = 0; | |
98 | ||
99 | /* lookup glyph name in face array */ | |
100 | for ( n = 0; n < type1->num_glyphs; n++ ) | |
101 | { | |
102 | char* gname = (char*)type1->glyph_names[n]; | |
103 | ||
104 | ||
105 | if ( gname && gname[0] == temp[0] && strcmp( gname, temp ) == 0 ) | |
106 | { | |
107 | result = n; | |
108 | break; | |
109 | } | |
110 | } | |
111 | } | |
112 | *start = p; | |
113 | return result; | |
114 | } | |
115 | ||
116 | ||
117 | /* read an integer */ | |
118 | static | |
119 | int afm_atoi( FT_Byte** start, | |
120 | FT_Byte* limit ) | |
121 | { | |
122 | FT_Byte* p = *start; | |
123 | int sum = 0; | |
124 | int sign = 1; | |
125 | ||
126 | ||
127 | /* skip everything that is not a number */ | |
128 | while ( p < limit && !isdigit( *p ) ) | |
129 | { | |
130 | sign = 1; | |
131 | if ( *p == '-' ) | |
132 | sign = -1; | |
133 | ||
134 | p++; | |
135 | } | |
136 | ||
137 | while ( p < limit && isdigit( *p ) ) | |
138 | { | |
139 | sum = sum * 10 + ( *p - '0' ); | |
140 | p++; | |
141 | } | |
142 | *start = p; | |
143 | ||
144 | return sum * sign; | |
145 | } | |
146 | ||
147 | ||
148 | #undef KERN_INDEX | |
149 | #define KERN_INDEX( g1, g2 ) ( ( (FT_ULong)g1 << 16 ) | g2 ) | |
150 | ||
151 | ||
152 | /* compare two kerning pairs */ | |
153 | static | |
154 | int compare_kern_pairs( const void* a, | |
155 | const void* b ) | |
156 | { | |
157 | CID_Kern_Pair* pair1 = (CID_Kern_Pair*)a; | |
158 | CID_Kern_Pair* pair2 = (CID_Kern_Pair*)b; | |
159 | ||
160 | FT_ULong index1 = KERN_INDEX( pair1->glyph1, pair1->glyph2 ); | |
161 | FT_ULong index2 = KERN_INDEX( pair2->glyph1, pair2->glyph2 ); | |
162 | ||
163 | ||
164 | return ( index1 - index2 ); | |
165 | } | |
166 | ||
167 | ||
168 | /* parse an AFM file -- for now, only read the kerning pairs */ | |
169 | LOCAL_FUNC | |
170 | FT_Error CID_Read_AFM( FT_Face cid_face, | |
171 | FT_Stream stream ) | |
172 | { | |
173 | FT_Error error; | |
174 | FT_Memory memory = stream->memory; | |
175 | FT_Byte* start; | |
176 | FT_Byte* limit; | |
177 | FT_Byte* p; | |
178 | FT_Int count = 0; | |
179 | CID_Kern_Pair* pair; | |
180 | T1_Font* type1 = &((T1_Face)t1_face)->type1; | |
181 | CID_AFM* afm = 0; | |
182 | ||
183 | ||
184 | if ( ACCESS_Frame( stream->size ) ) | |
185 | return error; | |
186 | ||
187 | start = (FT_Byte*)stream->cursor; | |
188 | limit = (FT_Byte*)stream->limit; | |
189 | p = start; | |
190 | ||
191 | /* we are now going to count the occurrences of `KP' or `KPX' in */ | |
192 | /* the AFM file. */ | |
193 | count = 0; | |
194 | for ( p = start; p < limit - 3; p++ ) | |
195 | { | |
196 | if ( IS_KERN_PAIR( p ) ) | |
197 | count++; | |
198 | } | |
199 | ||
200 | /* Actually, kerning pairs are simply optional! */ | |
201 | if ( count == 0 ) | |
202 | goto Exit; | |
203 | ||
204 | /* allocate the pairs */ | |
205 | if ( ALLOC( afm, sizeof ( *afm ) ) || | |
206 | ALLOC_ARRAY( afm->kern_pairs, count, CID_Kern_Pair ) ) | |
207 | goto Exit; | |
208 | ||
209 | /* now, read each kern pair */ | |
210 | pair = afm->kern_pairs; | |
211 | afm->num_pairs = count; | |
212 | ||
213 | /* save in face object */ | |
214 | ((T1_Face)t1_face)->afm_data = afm; | |
215 | ||
216 | for ( p = start; p < limit - 3; p++ ) | |
217 | { | |
218 | if ( IS_KERN_PAIR( p ) ) | |
219 | { | |
220 | FT_Byte* q; | |
221 | ||
222 | ||
223 | /* skip keyword (`KP' or `KPX') */ | |
224 | q = p + 2; | |
225 | if ( *q == 'X' ) | |
226 | q++; | |
227 | ||
228 | pair->glyph1 = afm_atoindex( &q, limit, type1 ); | |
229 | pair->glyph2 = afm_atoindex( &q, limit, type1 ); | |
230 | pair->kerning.x = afm_atoi( &q, limit ); | |
231 | ||
232 | pair->kerning.y = 0; | |
233 | if ( p[2] != 'X' ) | |
234 | pair->kerning.y = afm_atoi( &q, limit ); | |
235 | ||
236 | pair++; | |
237 | } | |
238 | } | |
239 | ||
240 | /* now, sort the kern pairs according to their glyph indices */ | |
241 | qsort( afm->kern_pairs, count, sizeof ( CID_Kern_Pair ), | |
242 | compare_kern_pairs ); | |
243 | ||
244 | Exit: | |
245 | if ( error ) | |
246 | FREE( afm ); | |
247 | ||
248 | FORGET_Frame(); | |
249 | ||
250 | return error; | |
251 | } | |
252 | ||
253 | ||
254 | /* find the kerning for a given glyph pair */ | |
255 | LOCAL_FUNC | |
256 | void CID_Get_Kerning( CID_AFM* afm, | |
257 | FT_UInt glyph1, | |
258 | FT_UInt glyph2, | |
259 | FT_Vector* kerning ) | |
260 | { | |
261 | CID_Kern_Pair *min, *mid, *max; | |
262 | FT_ULong index = KERN_INDEX( glyph1, glyph2 ); | |
263 | ||
264 | ||
265 | /* simple binary search */ | |
266 | min = afm->kern_pairs; | |
267 | max = min + afm->num_pairs - 1; | |
268 | ||
269 | while ( min <= max ) | |
270 | { | |
271 | FT_ULong midi; | |
272 | ||
273 | ||
274 | mid = min + ( max - min ) / 2; | |
275 | midi = KERN_INDEX( mid->glyph1, mid->glyph2 ); | |
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 */ |