1 | /**************************************************************************** |
2 | * |
3 | * gxvmorx1.c |
4 | * |
5 | * TrueTypeGX/AAT morx table validation |
6 | * body for type1 (Contextual Substitution) subtable. |
7 | * |
8 | * Copyright (C) 2005-2023 by |
9 | * suzuki toshiya, Masatake YAMATO, Red Hat K.K., |
10 | * David Turner, Robert Wilhelm, and Werner Lemberg. |
11 | * |
12 | * This file is part of the FreeType project, and may only be used, |
13 | * modified, and distributed under the terms of the FreeType project |
14 | * license, LICENSE.TXT. By continuing to use, modify, or distribute |
15 | * this file you indicate that you have read the license and |
16 | * understand and accept it fully. |
17 | * |
18 | */ |
19 | |
20 | /**************************************************************************** |
21 | * |
22 | * gxvalid is derived from both gxlayout module and otvalid module. |
23 | * Development of gxlayout is supported by the Information-technology |
24 | * Promotion Agency(IPA), Japan. |
25 | * |
26 | */ |
27 | |
28 | |
29 | #include "gxvmorx.h" |
30 | |
31 | |
32 | /************************************************************************** |
33 | * |
34 | * The macro FT_COMPONENT is used in trace mode. It is an implicit |
35 | * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log |
36 | * messages during execution. |
37 | */ |
38 | #undef FT_COMPONENT |
39 | #define FT_COMPONENT gxvmorx |
40 | |
41 | |
42 | typedef struct GXV_morx_subtable_type1_StateOptRec_ |
43 | { |
44 | FT_ULong substitutionTable; |
45 | FT_ULong substitutionTable_length; |
46 | FT_UShort substitutionTable_num_lookupTables; |
47 | |
48 | } GXV_morx_subtable_type1_StateOptRec, |
49 | *GXV_morx_subtable_type1_StateOptRecData; |
50 | |
51 | |
52 | #define \ |
53 | ( GXV_STATETABLE_HEADER_SIZE + 2 ) |
54 | |
55 | |
56 | static void |
57 | gxv_morx_subtable_type1_substitutionTable_load( FT_Bytes table, |
58 | FT_Bytes limit, |
59 | GXV_Validator gxvalid ) |
60 | { |
61 | FT_Bytes p = table; |
62 | |
63 | GXV_morx_subtable_type1_StateOptRecData optdata = |
64 | (GXV_morx_subtable_type1_StateOptRecData)gxvalid->xstatetable.optdata; |
65 | |
66 | |
67 | GXV_LIMIT_CHECK( 2 ); |
68 | optdata->substitutionTable = FT_NEXT_USHORT( p ); |
69 | } |
70 | |
71 | |
72 | static void |
73 | gxv_morx_subtable_type1_subtable_setup( FT_ULong table_size, |
74 | FT_ULong classTable, |
75 | FT_ULong stateArray, |
76 | FT_ULong entryTable, |
77 | FT_ULong* classTable_length_p, |
78 | FT_ULong* stateArray_length_p, |
79 | FT_ULong* entryTable_length_p, |
80 | GXV_Validator gxvalid ) |
81 | { |
82 | FT_ULong o[4]; |
83 | FT_ULong *l[4]; |
84 | FT_ULong buff[5]; |
85 | |
86 | GXV_morx_subtable_type1_StateOptRecData optdata = |
87 | (GXV_morx_subtable_type1_StateOptRecData)gxvalid->xstatetable.optdata; |
88 | |
89 | |
90 | o[0] = classTable; |
91 | o[1] = stateArray; |
92 | o[2] = entryTable; |
93 | o[3] = optdata->substitutionTable; |
94 | l[0] = classTable_length_p; |
95 | l[1] = stateArray_length_p; |
96 | l[2] = entryTable_length_p; |
97 | l[3] = &(optdata->substitutionTable_length); |
98 | |
99 | gxv_set_length_by_ulong_offset( o, l, buff, 4, table_size, gxvalid ); |
100 | } |
101 | |
102 | |
103 | static void |
104 | gxv_morx_subtable_type1_entry_validate( |
105 | FT_UShort state, |
106 | FT_UShort flags, |
107 | GXV_StateTable_GlyphOffsetCPtr glyphOffset_p, |
108 | FT_Bytes table, |
109 | FT_Bytes limit, |
110 | GXV_Validator gxvalid ) |
111 | { |
112 | #ifdef GXV_LOAD_TRACE_VARS |
113 | FT_UShort setMark; |
114 | FT_UShort dontAdvance; |
115 | #endif |
116 | FT_UShort reserved; |
117 | FT_Short markIndex; |
118 | FT_Short currentIndex; |
119 | |
120 | GXV_morx_subtable_type1_StateOptRecData optdata = |
121 | (GXV_morx_subtable_type1_StateOptRecData)gxvalid->xstatetable.optdata; |
122 | |
123 | FT_UNUSED( state ); |
124 | FT_UNUSED( table ); |
125 | FT_UNUSED( limit ); |
126 | |
127 | |
128 | #ifdef GXV_LOAD_TRACE_VARS |
129 | setMark = (FT_UShort)( ( flags >> 15 ) & 1 ); |
130 | dontAdvance = (FT_UShort)( ( flags >> 14 ) & 1 ); |
131 | #endif |
132 | |
133 | reserved = (FT_UShort)( flags & 0x3FFF ); |
134 | |
135 | markIndex = (FT_Short)( glyphOffset_p->ul >> 16 ); |
136 | currentIndex = (FT_Short)( glyphOffset_p->ul ); |
137 | |
138 | GXV_TRACE(( " setMark=%01d dontAdvance=%01d\n" , |
139 | setMark, dontAdvance )); |
140 | |
141 | if ( 0 < reserved ) |
142 | { |
143 | GXV_TRACE(( " non-zero bits found in reserved range\n" )); |
144 | GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA ); |
145 | } |
146 | |
147 | GXV_TRACE(( "markIndex = %d, currentIndex = %d\n" , |
148 | markIndex, currentIndex )); |
149 | |
150 | if ( optdata->substitutionTable_num_lookupTables < markIndex + 1 ) |
151 | optdata->substitutionTable_num_lookupTables = |
152 | (FT_UShort)( markIndex + 1 ); |
153 | |
154 | if ( optdata->substitutionTable_num_lookupTables < currentIndex + 1 ) |
155 | optdata->substitutionTable_num_lookupTables = |
156 | (FT_UShort)( currentIndex + 1 ); |
157 | } |
158 | |
159 | |
160 | static void |
161 | gxv_morx_subtable_type1_LookupValue_validate( FT_UShort glyph, |
162 | GXV_LookupValueCPtr value_p, |
163 | GXV_Validator gxvalid ) |
164 | { |
165 | FT_UNUSED( glyph ); /* for the non-debugging case */ |
166 | |
167 | GXV_TRACE(( "morx subtable type1 subst.: %d -> %d\n" , glyph, value_p->u )); |
168 | |
169 | if ( value_p->u > gxvalid->face->num_glyphs ) |
170 | FT_INVALID_GLYPH_ID; |
171 | } |
172 | |
173 | |
174 | static GXV_LookupValueDesc |
175 | gxv_morx_subtable_type1_LookupFmt4_transit( |
176 | FT_UShort relative_gindex, |
177 | GXV_LookupValueCPtr base_value_p, |
178 | FT_Bytes lookuptbl_limit, |
179 | GXV_Validator gxvalid ) |
180 | { |
181 | FT_Bytes p; |
182 | FT_Bytes limit; |
183 | FT_UShort offset; |
184 | GXV_LookupValueDesc value; |
185 | |
186 | /* XXX: check range? */ |
187 | offset = (FT_UShort)( base_value_p->u + |
188 | relative_gindex * sizeof ( FT_UShort ) ); |
189 | |
190 | p = gxvalid->lookuptbl_head + offset; |
191 | limit = lookuptbl_limit; |
192 | |
193 | GXV_LIMIT_CHECK ( 2 ); |
194 | value.u = FT_NEXT_USHORT( p ); |
195 | |
196 | return value; |
197 | } |
198 | |
199 | |
200 | /* |
201 | * TODO: length should be limit? |
202 | **/ |
203 | static void |
204 | gxv_morx_subtable_type1_substitutionTable_validate( FT_Bytes table, |
205 | FT_Bytes limit, |
206 | GXV_Validator gxvalid ) |
207 | { |
208 | FT_Bytes p = table; |
209 | FT_UShort i; |
210 | |
211 | GXV_morx_subtable_type1_StateOptRecData optdata = |
212 | (GXV_morx_subtable_type1_StateOptRecData)gxvalid->xstatetable.optdata; |
213 | |
214 | |
215 | /* TODO: calculate offset/length for each lookupTables */ |
216 | gxvalid->lookupval_sign = GXV_LOOKUPVALUE_UNSIGNED; |
217 | gxvalid->lookupval_func = gxv_morx_subtable_type1_LookupValue_validate; |
218 | gxvalid->lookupfmt4_trans = gxv_morx_subtable_type1_LookupFmt4_transit; |
219 | |
220 | for ( i = 0; i < optdata->substitutionTable_num_lookupTables; i++ ) |
221 | { |
222 | FT_ULong offset; |
223 | |
224 | |
225 | GXV_LIMIT_CHECK( 4 ); |
226 | offset = FT_NEXT_ULONG( p ); |
227 | |
228 | gxv_LookupTable_validate( table + offset, limit, gxvalid ); |
229 | } |
230 | |
231 | /* TODO: overlapping of lookupTables in substitutionTable */ |
232 | } |
233 | |
234 | |
235 | /* |
236 | * subtable for Contextual glyph substitution is a modified StateTable. |
237 | * In addition to classTable, stateArray, entryTable, the field |
238 | * `substitutionTable' is added. |
239 | */ |
240 | FT_LOCAL_DEF( void ) |
241 | gxv_morx_subtable_type1_validate( FT_Bytes table, |
242 | FT_Bytes limit, |
243 | GXV_Validator gxvalid ) |
244 | { |
245 | FT_Bytes p = table; |
246 | |
247 | GXV_morx_subtable_type1_StateOptRec st_rec; |
248 | |
249 | |
250 | GXV_NAME_ENTER( "morx chain subtable type1 (Contextual Glyph Subst)" ); |
251 | |
252 | GXV_LIMIT_CHECK( GXV_MORX_SUBTABLE_TYPE1_HEADER_SIZE ); |
253 | |
254 | st_rec.substitutionTable_num_lookupTables = 0; |
255 | |
256 | gxvalid->xstatetable.optdata = |
257 | &st_rec; |
258 | gxvalid->xstatetable.optdata_load_func = |
259 | gxv_morx_subtable_type1_substitutionTable_load; |
260 | gxvalid->xstatetable.subtable_setup_func = |
261 | gxv_morx_subtable_type1_subtable_setup; |
262 | gxvalid->xstatetable.entry_glyphoffset_fmt = |
263 | GXV_GLYPHOFFSET_ULONG; |
264 | gxvalid->xstatetable.entry_validate_func = |
265 | gxv_morx_subtable_type1_entry_validate; |
266 | |
267 | gxv_XStateTable_validate( p, limit, gxvalid ); |
268 | |
269 | gxv_morx_subtable_type1_substitutionTable_validate( |
270 | table + st_rec.substitutionTable, |
271 | table + st_rec.substitutionTable + st_rec.substitutionTable_length, |
272 | gxvalid ); |
273 | |
274 | GXV_EXIT; |
275 | } |
276 | |
277 | |
278 | /* END */ |
279 | |