1 | /**************************************************************************** |
2 | * |
3 | * ttmtx.c |
4 | * |
5 | * Load the metrics tables common to TTF and OTF fonts (body). |
6 | * |
7 | * Copyright (C) 2006-2023 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 | #include <freetype/internal/ftdebug.h> |
20 | #include <freetype/internal/ftstream.h> |
21 | #include <freetype/tttags.h> |
22 | |
23 | #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT |
24 | #include <freetype/internal/services/svmetric.h> |
25 | #endif |
26 | |
27 | #include "ttmtx.h" |
28 | |
29 | #include "sferrors.h" |
30 | |
31 | |
32 | /* IMPORTANT: The TT_HoriHeader and TT_VertHeader structures should */ |
33 | /* be identical except for the names of their fields, */ |
34 | /* which are different. */ |
35 | /* */ |
36 | /* This ensures that `tt_face_load_hmtx' is able to read */ |
37 | /* both the horizontal and vertical headers. */ |
38 | |
39 | |
40 | /************************************************************************** |
41 | * |
42 | * The macro FT_COMPONENT is used in trace mode. It is an implicit |
43 | * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log |
44 | * messages during execution. |
45 | */ |
46 | #undef FT_COMPONENT |
47 | #define FT_COMPONENT ttmtx |
48 | |
49 | |
50 | /************************************************************************** |
51 | * |
52 | * @Function: |
53 | * tt_face_load_hmtx |
54 | * |
55 | * @Description: |
56 | * Load the `hmtx' or `vmtx' table into a face object. |
57 | * |
58 | * @Input: |
59 | * face :: |
60 | * A handle to the target face object. |
61 | * |
62 | * stream :: |
63 | * The input stream. |
64 | * |
65 | * vertical :: |
66 | * A boolean flag. If set, load `vmtx'. |
67 | * |
68 | * @Return: |
69 | * FreeType error code. 0 means success. |
70 | */ |
71 | FT_LOCAL_DEF( FT_Error ) |
72 | tt_face_load_hmtx( TT_Face face, |
73 | FT_Stream stream, |
74 | FT_Bool vertical ) |
75 | { |
76 | FT_Error error; |
77 | FT_ULong tag, table_size; |
78 | FT_ULong* ptable_offset; |
79 | FT_ULong* ptable_size; |
80 | |
81 | |
82 | if ( vertical ) |
83 | { |
84 | tag = TTAG_vmtx; |
85 | ptable_offset = &face->vert_metrics_offset; |
86 | ptable_size = &face->vert_metrics_size; |
87 | } |
88 | else |
89 | { |
90 | tag = TTAG_hmtx; |
91 | ptable_offset = &face->horz_metrics_offset; |
92 | ptable_size = &face->horz_metrics_size; |
93 | } |
94 | |
95 | error = face->goto_table( face, tag, stream, &table_size ); |
96 | if ( error ) |
97 | goto Fail; |
98 | |
99 | *ptable_size = table_size; |
100 | *ptable_offset = FT_STREAM_POS(); |
101 | |
102 | Fail: |
103 | return error; |
104 | } |
105 | |
106 | |
107 | /************************************************************************** |
108 | * |
109 | * @Function: |
110 | * tt_face_load_hhea |
111 | * |
112 | * @Description: |
113 | * Load the `hhea' or 'vhea' table into a face object. |
114 | * |
115 | * @Input: |
116 | * face :: |
117 | * A handle to the target face object. |
118 | * |
119 | * stream :: |
120 | * The input stream. |
121 | * |
122 | * vertical :: |
123 | * A boolean flag. If set, load `vhea'. |
124 | * |
125 | * @Return: |
126 | * FreeType error code. 0 means success. |
127 | */ |
128 | FT_LOCAL_DEF( FT_Error ) |
129 | tt_face_load_hhea( TT_Face face, |
130 | FT_Stream stream, |
131 | FT_Bool vertical ) |
132 | { |
133 | FT_Error error; |
134 | TT_HoriHeader* ; |
135 | |
136 | static const FT_Frame_Field [] = |
137 | { |
138 | #undef FT_STRUCTURE |
139 | #define FT_STRUCTURE TT_HoriHeader |
140 | |
141 | FT_FRAME_START( 36 ), |
142 | FT_FRAME_ULONG ( Version ), |
143 | FT_FRAME_SHORT ( Ascender ), |
144 | FT_FRAME_SHORT ( Descender ), |
145 | FT_FRAME_SHORT ( Line_Gap ), |
146 | FT_FRAME_USHORT( advance_Width_Max ), |
147 | FT_FRAME_SHORT ( min_Left_Side_Bearing ), |
148 | FT_FRAME_SHORT ( min_Right_Side_Bearing ), |
149 | FT_FRAME_SHORT ( xMax_Extent ), |
150 | FT_FRAME_SHORT ( caret_Slope_Rise ), |
151 | FT_FRAME_SHORT ( caret_Slope_Run ), |
152 | FT_FRAME_SHORT ( caret_Offset ), |
153 | FT_FRAME_SHORT ( Reserved[0] ), |
154 | FT_FRAME_SHORT ( Reserved[1] ), |
155 | FT_FRAME_SHORT ( Reserved[2] ), |
156 | FT_FRAME_SHORT ( Reserved[3] ), |
157 | FT_FRAME_SHORT ( metric_Data_Format ), |
158 | FT_FRAME_USHORT( number_Of_HMetrics ), |
159 | FT_FRAME_END |
160 | }; |
161 | |
162 | |
163 | if ( vertical ) |
164 | { |
165 | void *v = &face->vertical; |
166 | |
167 | |
168 | error = face->goto_table( face, TTAG_vhea, stream, 0 ); |
169 | if ( error ) |
170 | goto Fail; |
171 | |
172 | header = (TT_HoriHeader*)v; |
173 | } |
174 | else |
175 | { |
176 | error = face->goto_table( face, TTAG_hhea, stream, 0 ); |
177 | if ( error ) |
178 | goto Fail; |
179 | |
180 | header = &face->horizontal; |
181 | } |
182 | |
183 | if ( FT_STREAM_READ_FIELDS( metrics_header_fields, header ) ) |
184 | goto Fail; |
185 | |
186 | FT_TRACE3(( "Ascender: %5d\n" , header->Ascender )); |
187 | FT_TRACE3(( "Descender: %5d\n" , header->Descender )); |
188 | FT_TRACE3(( "number_Of_Metrics: %5u\n" , header->number_Of_HMetrics )); |
189 | |
190 | header->long_metrics = NULL; |
191 | header->short_metrics = NULL; |
192 | |
193 | Fail: |
194 | return error; |
195 | } |
196 | |
197 | |
198 | /************************************************************************** |
199 | * |
200 | * @Function: |
201 | * tt_face_get_metrics |
202 | * |
203 | * @Description: |
204 | * Return the horizontal or vertical metrics in font units for a |
205 | * given glyph. The values are the left side bearing (top side |
206 | * bearing for vertical metrics) and advance width (advance height |
207 | * for vertical metrics). |
208 | * |
209 | * @Input: |
210 | * face :: |
211 | * A pointer to the TrueType face structure. |
212 | * |
213 | * vertical :: |
214 | * If set to TRUE, get vertical metrics. |
215 | * |
216 | * gindex :: |
217 | * The glyph index. |
218 | * |
219 | * @Output: |
220 | * abearing :: |
221 | * The bearing, either left side or top side. |
222 | * |
223 | * aadvance :: |
224 | * The advance width or advance height, depending on |
225 | * the `vertical' flag. |
226 | */ |
227 | FT_LOCAL_DEF( void ) |
228 | tt_face_get_metrics( TT_Face face, |
229 | FT_Bool vertical, |
230 | FT_UInt gindex, |
231 | FT_Short *abearing, |
232 | FT_UShort *aadvance ) |
233 | { |
234 | FT_Error error; |
235 | FT_Stream stream = face->root.stream; |
236 | TT_HoriHeader* ; |
237 | FT_ULong table_pos, table_size, table_end; |
238 | FT_UShort k; |
239 | |
240 | #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT |
241 | FT_Service_MetricsVariations var = |
242 | (FT_Service_MetricsVariations)face->tt_var; |
243 | #endif |
244 | |
245 | |
246 | if ( vertical ) |
247 | { |
248 | void* v = &face->vertical; |
249 | |
250 | |
251 | header = (TT_HoriHeader*)v; |
252 | table_pos = face->vert_metrics_offset; |
253 | table_size = face->vert_metrics_size; |
254 | } |
255 | else |
256 | { |
257 | header = &face->horizontal; |
258 | table_pos = face->horz_metrics_offset; |
259 | table_size = face->horz_metrics_size; |
260 | } |
261 | |
262 | table_end = table_pos + table_size; |
263 | |
264 | k = header->number_Of_HMetrics; |
265 | |
266 | if ( k > 0 ) |
267 | { |
268 | if ( gindex < (FT_UInt)k ) |
269 | { |
270 | table_pos += 4 * gindex; |
271 | if ( table_pos + 4 > table_end ) |
272 | goto NoData; |
273 | |
274 | if ( FT_STREAM_SEEK( table_pos ) || |
275 | FT_READ_USHORT( *aadvance ) || |
276 | FT_READ_SHORT( *abearing ) ) |
277 | goto NoData; |
278 | } |
279 | else |
280 | { |
281 | table_pos += 4 * ( k - 1 ); |
282 | if ( table_pos + 2 > table_end ) |
283 | goto NoData; |
284 | |
285 | if ( FT_STREAM_SEEK( table_pos ) || |
286 | FT_READ_USHORT( *aadvance ) ) |
287 | goto NoData; |
288 | |
289 | table_pos += 4 + 2 * ( gindex - k ); |
290 | if ( table_pos + 2 > table_end ) |
291 | *abearing = 0; |
292 | else |
293 | { |
294 | if ( FT_STREAM_SEEK( table_pos ) ) |
295 | *abearing = 0; |
296 | else |
297 | (void)FT_READ_SHORT( *abearing ); |
298 | } |
299 | } |
300 | } |
301 | else |
302 | { |
303 | NoData: |
304 | *abearing = 0; |
305 | *aadvance = 0; |
306 | } |
307 | |
308 | #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT |
309 | if ( var && face->blend ) |
310 | { |
311 | FT_Face f = FT_FACE( face ); |
312 | FT_Int a = (FT_Int)*aadvance; |
313 | FT_Int b = (FT_Int)*abearing; |
314 | |
315 | |
316 | if ( vertical ) |
317 | { |
318 | if ( var->vadvance_adjust ) |
319 | var->vadvance_adjust( f, gindex, &a ); |
320 | if ( var->tsb_adjust ) |
321 | var->tsb_adjust( f, gindex, &b ); |
322 | } |
323 | else |
324 | { |
325 | if ( var->hadvance_adjust ) |
326 | var->hadvance_adjust( f, gindex, &a ); |
327 | if ( var->lsb_adjust ) |
328 | var->lsb_adjust( f, gindex, &b ); |
329 | } |
330 | |
331 | *aadvance = (FT_UShort)a; |
332 | *abearing = (FT_Short)b; |
333 | } |
334 | #endif |
335 | } |
336 | |
337 | |
338 | /* END */ |
339 | |