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 {
initCFF::dict_val_t40   void init () { single_val.set_int (0); }
finiCFF::dict_val_t41   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 {
initCFF::top_dict_values_t53   void init ()
54   {
55     dict_values_t<OPSTR>::init ();
56     charStringsOffset = 0;
57     FDArrayOffset = 0;
58   }
finiCFF::top_dict_values_t59   void fini () { dict_values_t<OPSTR>::fini (); }
60 
calculate_serialized_op_sizeCFF::top_dict_values_t61   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 {
process_opCFF::dict_opset_t80   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   /* Turns CFF's BCD format into strtod understandable string */
parse_bcdCFF::dict_opset_t98   static double parse_bcd (byte_str_ref_t& str_ref)
99   {
100     if (unlikely (str_ref.in_error ())) return .0;
101 
102     enum Nibble { DECIMAL=10, EXP_POS, EXP_NEG, RESERVED, NEG, END };
103 
104     char buf[32];
105     unsigned char byte = 0;
106     for (unsigned i = 0, count = 0; count < ARRAY_LENGTH (buf); ++i, ++count)
107     {
108       unsigned nibble;
109       if (!(i & 1))
110       {
111 	if (unlikely (!str_ref.avail ())) break;
112 
113 	byte = str_ref[0];
114 	str_ref.inc ();
115 	nibble = byte >> 4;
116       }
117       else
118 	nibble = byte & 0x0F;
119 
120       if (unlikely (nibble == RESERVED)) break;
121       else if (nibble == END)
122       {
123 	const char *p = buf;
124 	double pv;
125 	if (unlikely (!hb_parse_double (&p, p + count, &pv, true/* whole buffer */)))
126 	  break;
127 	return pv;
128       }
129       else
130       {
131 	buf[count] = "0123456789.EE?-?"[nibble];
132 	if (nibble == EXP_NEG)
133 	{
134 	  ++count;
135 	  if (unlikely (count == ARRAY_LENGTH (buf))) break;
136 	  buf[count] = '-';
137 	}
138       }
139     }
140 
141     str_ref.set_error ();
142     return .0;
143   }
144 
is_hint_opCFF::dict_opset_t145   static bool is_hint_op (op_code_t op)
146   {
147     switch (op)
148     {
149       case OpCode_BlueValues:
150       case OpCode_OtherBlues:
151       case OpCode_FamilyBlues:
152       case OpCode_FamilyOtherBlues:
153       case OpCode_StemSnapH:
154       case OpCode_StemSnapV:
155       case OpCode_StdHW:
156       case OpCode_StdVW:
157       case OpCode_BlueScale:
158       case OpCode_BlueShift:
159       case OpCode_BlueFuzz:
160       case OpCode_ForceBold:
161       case OpCode_LanguageGroup:
162       case OpCode_ExpansionFactor:
163 	return true;
164       default:
165 	return false;
166     }
167   }
168 };
169 
170 template <typename VAL=op_str_t>
171 struct top_dict_opset_t : dict_opset_t
172 {
process_opCFF::top_dict_opset_t173   static void process_op (op_code_t op, interp_env_t<number_t>& env, top_dict_values_t<VAL> & dictval)
174   {
175     switch (op) {
176       case OpCode_CharStrings:
177 	dictval.charStringsOffset = env.argStack.pop_uint ();
178 	env.clear_args ();
179 	break;
180       case OpCode_FDArray:
181 	dictval.FDArrayOffset = env.argStack.pop_uint ();
182 	env.clear_args ();
183 	break;
184       case OpCode_FontMatrix:
185 	env.clear_args ();
186 	break;
187       default:
188 	dict_opset_t::process_op (op, env);
189 	break;
190     }
191   }
192 };
193 
194 template <typename OPSET, typename PARAM, typename ENV=num_interp_env_t>
195 struct dict_interpreter_t : interpreter_t<ENV>
196 {
interpretCFF::dict_interpreter_t197   bool interpret (PARAM& param)
198   {
199     param.init ();
200     while (SUPER::env.str_ref.avail ())
201     {
202       OPSET::process_op (SUPER::env.fetch_op (), SUPER::env, param);
203       if (unlikely (SUPER::env.in_error ()))
204 	return false;
205     }
206 
207     return true;
208   }
209 
210   private:
211   typedef interpreter_t<ENV> SUPER;
212 };
213 
214 } /* namespace CFF */
215 
216 #endif /* HB_CFF_INTERP_DICT_COMMON_HH */
217