xref: /aosp_15_r20/external/harfbuzz_ng/src/hb-cff-interp-dict-common.hh (revision 2d1272b857b1f7575e6e246373e1cb218663db8a)
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 
31 namespace CFF {
32 
33 using namespace OT;
34 
35 /* an opstr and the parsed out dict value(s) */
36 struct dict_val_t : op_str_t
37 {
initCFF::dict_val_t38   void init () {}
finiCFF::dict_val_t39   void fini () {}
40 };
41 
42 typedef dict_val_t num_dict_val_t;
43 
44 template <typename VAL> struct dict_values_t : parsed_values_t<VAL> {};
45 
46 template <typename OPSTR=op_str_t>
47 struct top_dict_values_t : dict_values_t<OPSTR>
48 {
initCFF::top_dict_values_t49   void init ()
50   {
51     dict_values_t<OPSTR>::init ();
52     charStringsOffset = 0;
53     FDArrayOffset = 0;
54   }
finiCFF::top_dict_values_t55   void fini () { dict_values_t<OPSTR>::fini (); }
56 
57   int  charStringsOffset;
58   int  FDArrayOffset;
59 };
60 
61 struct dict_opset_t : opset_t<number_t>
62 {
process_opCFF::dict_opset_t63   static void process_op (op_code_t op, interp_env_t<number_t>& env)
64   {
65     switch (op) {
66       case OpCode_longintdict:  /* 5-byte integer */
67 	env.argStack.push_longint_from_substr (env.str_ref);
68 	break;
69 
70       case OpCode_BCD:  /* real number */
71 	env.argStack.push_real (parse_bcd (env.str_ref));
72 	break;
73 
74       default:
75 	opset_t<number_t>::process_op (op, env);
76 	break;
77     }
78   }
79 
80   /* Turns CFF's BCD format into strtod understandable string */
parse_bcdCFF::dict_opset_t81   static double parse_bcd (byte_str_ref_t& str_ref)
82   {
83     if (unlikely (str_ref.in_error ())) return .0;
84 
85     enum Nibble { DECIMAL=10, EXP_POS, EXP_NEG, RESERVED, NEG, END };
86 
87     char buf[32] = {0};
88     unsigned char byte = 0;
89     for (unsigned i = 0, count = 0; count < ARRAY_LENGTH (buf); ++i, ++count)
90     {
91       unsigned nibble;
92       if (!(i & 1))
93       {
94 	if (unlikely (!str_ref.avail ())) break;
95 
96 	byte = str_ref[0];
97 	str_ref.inc ();
98 	nibble = byte >> 4;
99       }
100       else
101 	nibble = byte & 0x0F;
102 
103       if (unlikely (nibble == RESERVED)) break;
104       else if (nibble == END)
105       {
106 	const char *p = buf;
107 	double pv;
108 	if (unlikely (!hb_parse_double (&p, p + count, &pv, true/* whole buffer */)))
109 	  break;
110 	return pv;
111       }
112       else
113       {
114 	buf[count] = "0123456789.EE?-?"[nibble];
115 	if (nibble == EXP_NEG)
116 	{
117 	  ++count;
118 	  if (unlikely (count == ARRAY_LENGTH (buf))) break;
119 	  buf[count] = '-';
120 	}
121       }
122     }
123 
124     str_ref.set_error ();
125     return .0;
126   }
127 
is_hint_opCFF::dict_opset_t128   static bool is_hint_op (op_code_t op)
129   {
130     switch (op)
131     {
132       case OpCode_BlueValues:
133       case OpCode_OtherBlues:
134       case OpCode_FamilyBlues:
135       case OpCode_FamilyOtherBlues:
136       case OpCode_StemSnapH:
137       case OpCode_StemSnapV:
138       case OpCode_StdHW:
139       case OpCode_StdVW:
140       case OpCode_BlueScale:
141       case OpCode_BlueShift:
142       case OpCode_BlueFuzz:
143       case OpCode_ForceBold:
144       case OpCode_LanguageGroup:
145       case OpCode_ExpansionFactor:
146 	return true;
147       default:
148 	return false;
149     }
150   }
151 };
152 
153 template <typename VAL=op_str_t>
154 struct top_dict_opset_t : dict_opset_t
155 {
process_opCFF::top_dict_opset_t156   static void process_op (op_code_t op, interp_env_t<number_t>& env, top_dict_values_t<VAL> & dictval)
157   {
158     switch (op) {
159       case OpCode_CharStrings:
160 	dictval.charStringsOffset = env.argStack.pop_int ();
161 	env.clear_args ();
162 	break;
163       case OpCode_FDArray:
164 	dictval.FDArrayOffset = env.argStack.pop_int ();
165 	env.clear_args ();
166 	break;
167       case OpCode_FontMatrix:
168 	env.clear_args ();
169 	break;
170       default:
171 	dict_opset_t::process_op (op, env);
172 	break;
173     }
174   }
175 };
176 
177 template <typename OPSET, typename PARAM, typename ENV=num_interp_env_t>
178 struct dict_interpreter_t : interpreter_t<ENV>
179 {
dict_interpreter_tCFF::dict_interpreter_t180   dict_interpreter_t (ENV& env_) : interpreter_t<ENV> (env_) {}
181 
interpretCFF::dict_interpreter_t182   bool interpret (PARAM& param)
183   {
184     param.init ();
185     while (SUPER::env.str_ref.avail ())
186     {
187       OPSET::process_op (SUPER::env.fetch_op (), SUPER::env, param);
188       if (unlikely (SUPER::env.in_error ()))
189 	return false;
190     }
191 
192     return true;
193   }
194 
195   private:
196   typedef interpreter_t<ENV> SUPER;
197 };
198 
199 } /* namespace CFF */
200 
201 #endif /* HB_CFF_INTERP_DICT_COMMON_HH */
202