1 /*
2 * Copyright © 2018 Adobe Inc.
3 *
4 * This is part of HarfBuzz, a text shaping library.
5 *
6 * Permission is hereby granted, without written agreement and without
7 * license or royalty fees, to use, copy, modify, and distribute this
8 * software and its documentation for any purpose, provided that the
9 * above copyright notice and the following two paragraphs appear in
10 * all copies of this software.
11 *
12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16 * DAMAGE.
17 *
18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23 *
24 * Adobe Author(s): Michiharu Ariza
25 */
26 #ifndef HB_CFF_INTERP_DICT_COMMON_HH
27 #define HB_CFF_INTERP_DICT_COMMON_HH
28
29 #include "hb-cff-interp-common.hh"
30 #include <math.h>
31 #include <float.h>
32
33 namespace CFF {
34
35 using namespace OT;
36
37 /* an opstr and the parsed out dict value(s) */
38 struct dict_val_t : op_str_t
39 {
40 void init () { single_val.set_int (0); }
41 void fini () {}
42
43 number_t single_val;
44 };
45
46 typedef dict_val_t num_dict_val_t;
47
48 template <typename VAL> struct dict_values_t : parsed_values_t<VAL> {};
49
50 template <typename OPSTR=op_str_t>
51 struct top_dict_values_t : dict_values_t<OPSTR>
52 {
53 void init ()
54 {
55 dict_values_t<OPSTR>::init ();
56 charStringsOffset = 0;
57 FDArrayOffset = 0;
58 }
59 void fini () { dict_values_t<OPSTR>::fini (); }
60
61 unsigned int calculate_serialized_op_size (const OPSTR& opstr) const
62 {
63 switch (opstr.op)
64 {
65 case OpCode_CharStrings:
66 case OpCode_FDArray:
67 return OpCode_Size (OpCode_longintdict) + 4 + OpCode_Size (opstr.op);
68
69 default:
70 return opstr.str.length;
71 }
72 }
73
74 unsigned int charStringsOffset;
75 unsigned int FDArrayOffset;
76 };
77
78 struct dict_opset_t : opset_t<number_t>
79 {
80 static void process_op (op_code_t op, interp_env_t<number_t>& env)
81 {
82 switch (op) {
83 case OpCode_longintdict: /* 5-byte integer */
84 env.argStack.push_longint_from_substr (env.str_ref);
85 break;
86
87 case OpCode_BCD: /* real number */
88 env.argStack.push_real (parse_bcd (env.str_ref));
89 break;
90
91 default:
92 opset_t<number_t>::process_op (op, env);
93 break;
94 }
95 }
96
97 static double parse_bcd (byte_str_ref_t& str_ref)
98 {
99 bool neg = false;
100 double int_part = 0;
101 uint64_t frac_part = 0;
102 uint32_t frac_count = 0;
103 bool exp_neg = false;
104 uint32_t exp_part = 0;
105 bool exp_overflow = false;
106 enum Part { INT_PART=0, FRAC_PART, EXP_PART } part = INT_PART;
107 enum Nibble { DECIMAL=10, EXP_POS, EXP_NEG, RESERVED, NEG, END };
108 const uint64_t MAX_FRACT = 0xFFFFFFFFFFFFFull; /* 1^52-1 */
109 const uint32_t MAX_EXP = 0x7FFu; /* 1^11-1 */
110
111 double value = 0.0;
112 unsigned char byte = 0;
113 for (uint32_t i = 0;; i++)
114 {
115 char d;
116 if ((i & 1) == 0)
117 {
118 if (!str_ref.avail ())
119 {
120 str_ref.set_error ();
121 return 0.0;
122 }
123 byte = str_ref[0];
124 str_ref.inc ();
125 d = byte >> 4;
126 }
127 else
128 d = byte & 0x0F;
129
130 switch (d)
131 {
132 case RESERVED:
133 str_ref.set_error ();
134 return value;
135
136 case END:
137 value = (double)(neg? -int_part: int_part);
138 if (frac_count > 0)
139 {
140 double frac = (frac_part / pow (10.0, (double)frac_count));
141 if (neg) frac = -frac;
142 value += frac;
143 }
144 if (unlikely (exp_overflow))
145 {
146 if (value == 0.0)
147 return value;
148 if (exp_neg)
149 return neg? -DBL_MIN: DBL_MIN;
150 else
151 return neg? -DBL_MAX: DBL_MAX;
152 }
153 if (exp_part != 0)
154 {
155 if (exp_neg)
156 value /= pow (10.0, (double)exp_part);
157 else
158 value *= pow (10.0, (double)exp_part);
159 }
160 return value;
161
162 case NEG:
163 if (i != 0)
164 {
165 str_ref.set_error ();
166 return 0.0;
167 }
168 neg = true;
169 break;
170
171 case DECIMAL:
172 if (part != INT_PART)
173 {
174 str_ref.set_error ();
175 return value;
176 }
177 part = FRAC_PART;
178 break;
179
180 case EXP_NEG:
181 exp_neg = true;
182 HB_FALLTHROUGH;
183
184 case EXP_POS:
185 if (part == EXP_PART)
186 {
187 str_ref.set_error ();
188 return value;
189 }
190 part = EXP_PART;
191 break;
192
193 default:
194 switch (part) {
195 default:
196 case INT_PART:
197 int_part = (int_part * 10) + d;
198 break;
199
200 case FRAC_PART:
201 if (likely (frac_part <= MAX_FRACT / 10))
202 {
203 frac_part = (frac_part * 10) + (unsigned)d;
204 frac_count++;
205 }
206 break;
207
208 case EXP_PART:
209 if (likely (exp_part * 10 + d <= MAX_EXP))
210 {
211 exp_part = (exp_part * 10) + d;
212 }
213 else
214 exp_overflow = true;
215 break;
216 }
217 }
218 }
219
220 return value;
221 }
222
223 static bool is_hint_op (op_code_t op)
224 {
225 switch (op)
226 {
227 case OpCode_BlueValues:
228 case OpCode_OtherBlues:
229 case OpCode_FamilyBlues:
230 case OpCode_FamilyOtherBlues:
231 case OpCode_StemSnapH:
232 case OpCode_StemSnapV:
233 case OpCode_StdHW:
234 case OpCode_StdVW:
235 case OpCode_BlueScale:
236 case OpCode_BlueShift:
237 case OpCode_BlueFuzz:
238 case OpCode_ForceBold:
239 case OpCode_LanguageGroup:
240 case OpCode_ExpansionFactor:
241 return true;
242 default:
243 return false;
244 }
245 }
246 };
247
248 template <typename VAL=op_str_t>
249 struct top_dict_opset_t : dict_opset_t
250 {
251 static void process_op (op_code_t op, interp_env_t<number_t>& env, top_dict_values_t<VAL> & dictval)
252 {
253 switch (op) {
254 case OpCode_CharStrings:
255 dictval.charStringsOffset = env.argStack.pop_uint ();
256 env.clear_args ();
257 break;
258 case OpCode_FDArray:
259 dictval.FDArrayOffset = env.argStack.pop_uint ();
260 env.clear_args ();
261 break;
262 case OpCode_FontMatrix:
263 env.clear_args ();
264 break;
265 default:
266 dict_opset_t::process_op (op, env);
267 break;
268 }
269 }
270 };
271
272 template <typename OPSET, typename PARAM, typename ENV=num_interp_env_t>
273 struct dict_interpreter_t : interpreter_t<ENV>
274 {
275 bool interpret (PARAM& param)
276 {
277 param.init ();
278 while (SUPER::env.str_ref.avail ())
279 {
280 OPSET::process_op (SUPER::env.fetch_op (), SUPER::env, param);
281 if (unlikely (SUPER::env.in_error ()))
282 return false;
283 }
284
285 return true;
286 }
287
288 private:
289 typedef interpreter_t<ENV> SUPER;
290 };
291
292 } /* namespace CFF */
293
294 #endif /* HB_CFF_INTERP_DICT_COMMON_HH */