1 /****************************************************************************
2  *
3  * gxvmort0.c
4  *
5  *   TrueTypeGX/AAT mort table validation
6  *   body for type0 (Indic Script Rearrangement) subtable.
7  *
8  * Copyright (C) 2005-2019 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 "gxvmort.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  gxvmort
40 
41 
42   static const char* GXV_Mort_IndicScript_Msg[] =
43   {
44     "no change",
45     "Ax => xA",
46     "xD => Dx",
47     "AxD => DxA",
48     "ABx => xAB",
49     "ABx => xBA",
50     "xCD => CDx",
51     "xCD => DCx",
52     "AxCD => CDxA",
53     "AxCD => DCxA",
54     "ABxD => DxAB",
55     "ABxD => DxBA",
56     "ABxCD => CDxAB",
57     "ABxCD => CDxBA",
58     "ABxCD => DCxAB",
59     "ABxCD => DCxBA",
60 
61   };
62 
63 
64   static void
gxv_mort_subtable_type0_entry_validate(FT_Byte state,FT_UShort flags,GXV_StateTable_GlyphOffsetCPtr glyphOffset_p,FT_Bytes table,FT_Bytes limit,GXV_Validator gxvalid)65   gxv_mort_subtable_type0_entry_validate(
66     FT_Byte                         state,
67     FT_UShort                       flags,
68     GXV_StateTable_GlyphOffsetCPtr  glyphOffset_p,
69     FT_Bytes                        table,
70     FT_Bytes                        limit,
71     GXV_Validator                   gxvalid )
72   {
73     FT_UShort  markFirst;
74     FT_UShort  dontAdvance;
75     FT_UShort  markLast;
76     FT_UShort  reserved;
77     FT_UShort  verb = 0;
78 
79     FT_UNUSED( state );
80     FT_UNUSED( table );
81     FT_UNUSED( limit );
82 
83     FT_UNUSED( GXV_Mort_IndicScript_Msg[verb] ); /* for the non-debugging */
84     FT_UNUSED( glyphOffset_p );                  /* case                  */
85 
86 
87     markFirst   = (FT_UShort)( ( flags >> 15 ) & 1 );
88     dontAdvance = (FT_UShort)( ( flags >> 14 ) & 1 );
89     markLast    = (FT_UShort)( ( flags >> 13 ) & 1 );
90 
91     reserved = (FT_UShort)( flags & 0x1FF0 );
92     verb     = (FT_UShort)( flags & 0x000F );
93 
94     GXV_TRACE(( "  IndicScript MorphRule for glyphOffset 0x%04x",
95                 glyphOffset_p->u ));
96     GXV_TRACE(( " markFirst=%01d", markFirst ));
97     GXV_TRACE(( " dontAdvance=%01d", dontAdvance ));
98     GXV_TRACE(( " markLast=%01d", markLast ));
99     GXV_TRACE(( " %02d", verb ));
100     GXV_TRACE(( " %s\n", GXV_Mort_IndicScript_Msg[verb] ));
101 
102     if ( markFirst > 0 && markLast > 0 )
103     {
104       GXV_TRACE(( "  [odd] a glyph is marked as the first and last"
105                   "  in Indic rearrangement\n" ));
106       GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA );
107     }
108 
109     if ( markFirst > 0 && dontAdvance > 0 )
110     {
111       GXV_TRACE(( "  [odd] the first glyph is marked as dontAdvance"
112                   " in Indic rearrangement\n" ));
113       GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA );
114     }
115 
116     if ( 0 < reserved )
117     {
118       GXV_TRACE(( " non-zero bits found in reserved range\n" ));
119       GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA );
120     }
121     else
122       GXV_TRACE(( "\n" ));
123   }
124 
125 
126   FT_LOCAL_DEF( void )
gxv_mort_subtable_type0_validate(FT_Bytes table,FT_Bytes limit,GXV_Validator gxvalid)127   gxv_mort_subtable_type0_validate( FT_Bytes       table,
128                                     FT_Bytes       limit,
129                                     GXV_Validator  gxvalid )
130   {
131     FT_Bytes  p = table;
132 
133 
134     GXV_NAME_ENTER(
135       "mort chain subtable type0 (Indic-Script Rearrangement)" );
136 
137     GXV_LIMIT_CHECK( GXV_STATETABLE_HEADER_SIZE );
138 
139     gxvalid->statetable.optdata               = NULL;
140     gxvalid->statetable.optdata_load_func     = NULL;
141     gxvalid->statetable.subtable_setup_func   = NULL;
142     gxvalid->statetable.entry_glyphoffset_fmt = GXV_GLYPHOFFSET_NONE;
143     gxvalid->statetable.entry_validate_func =
144       gxv_mort_subtable_type0_entry_validate;
145 
146     gxv_StateTable_validate( p, limit, gxvalid );
147 
148     GXV_EXIT;
149   }
150 
151 
152 /* END */
153