1 | #ifndef OT_GLYF_SUBSETGLYPH_HH |
2 | #define OT_GLYF_SUBSETGLYPH_HH |
3 | |
4 | |
5 | #include "../../hb-open-type.hh" |
6 | |
7 | |
8 | namespace OT { |
9 | |
10 | struct glyf_accelerator_t; |
11 | |
12 | namespace glyf_impl { |
13 | |
14 | |
15 | struct SubsetGlyph |
16 | { |
17 | hb_codepoint_t old_gid; |
18 | Glyph source_glyph; |
19 | hb_bytes_t dest_start; /* region of source_glyph to copy first */ |
20 | hb_bytes_t dest_end; /* region of source_glyph to copy second */ |
21 | bool allocated; |
22 | |
23 | bool serialize (hb_serialize_context_t *c, |
24 | bool use_short_loca, |
25 | const hb_subset_plan_t *plan) const |
26 | { |
27 | TRACE_SERIALIZE (this); |
28 | |
29 | hb_bytes_t dest_glyph = dest_start.copy (c); |
30 | hb_bytes_t end_copy = dest_end.copy (c); |
31 | if (!end_copy.arrayZ || !dest_glyph.arrayZ) { |
32 | return false; |
33 | } |
34 | |
35 | dest_glyph = hb_bytes_t (&dest_glyph, dest_glyph.length + end_copy.length); |
36 | unsigned int pad_length = use_short_loca ? padding () : 0; |
37 | DEBUG_MSG (SUBSET, nullptr, "serialize %u byte glyph, width %u pad %u" , dest_glyph.length, dest_glyph.length + pad_length, pad_length); |
38 | |
39 | HBUINT8 pad; |
40 | pad = 0; |
41 | while (pad_length > 0) |
42 | { |
43 | (void) c->embed (pad); |
44 | pad_length--; |
45 | } |
46 | |
47 | if (unlikely (!dest_glyph.length)) return_trace (true); |
48 | |
49 | /* update components gids. */ |
50 | for (auto &_ : Glyph (dest_glyph).get_composite_iterator ()) |
51 | { |
52 | hb_codepoint_t new_gid; |
53 | if (plan->new_gid_for_old_gid (_.get_gid(), &new_gid)) |
54 | const_cast<CompositeGlyphRecord &> (_).set_gid (new_gid); |
55 | } |
56 | #ifndef HB_NO_VAR_COMPOSITES |
57 | for (auto &_ : Glyph (dest_glyph).get_var_composite_iterator ()) |
58 | { |
59 | hb_codepoint_t new_gid; |
60 | if (plan->new_gid_for_old_gid (_.get_gid(), &new_gid)) |
61 | const_cast<VarCompositeGlyphRecord &> (_).set_gid (new_gid); |
62 | } |
63 | #endif |
64 | |
65 | #ifndef HB_NO_BEYOND_64K |
66 | auto it = Glyph (dest_glyph).get_composite_iterator (); |
67 | if (it) |
68 | { |
69 | /* lower GID24 to GID16 in components if possible. |
70 | * |
71 | * TODO: VarComposite. Not as critical, since VarComposite supports |
72 | * gid24 from the first version. */ |
73 | char *p = it ? (char *) &*it : nullptr; |
74 | char *q = p; |
75 | const char *end = dest_glyph.arrayZ + dest_glyph.length; |
76 | while (it) |
77 | { |
78 | auto &rec = const_cast<CompositeGlyphRecord &> (*it); |
79 | ++it; |
80 | |
81 | q += rec.get_size (); |
82 | |
83 | rec.lower_gid_24_to_16 (); |
84 | |
85 | unsigned size = rec.get_size (); |
86 | |
87 | memmove (p, &rec, size); |
88 | |
89 | p += size; |
90 | } |
91 | memmove (p, q, end - q); |
92 | p += end - q; |
93 | |
94 | /* We want to shorten the glyph, but we can't do that without |
95 | * updating the length in the loca table, which is already |
96 | * written out :-(. So we just fill the rest of the glyph with |
97 | * harmless instructions, since that's what they will be |
98 | * interpreted as. |
99 | * |
100 | * Should move the lowering to _populate_subset_glyphs() to |
101 | * fix this issue. */ |
102 | |
103 | hb_memset (p, 0x7A /* TrueType instruction ROFF; harmless */, end - p); |
104 | p += end - p; |
105 | dest_glyph = hb_bytes_t (dest_glyph.arrayZ, p - (char *) dest_glyph.arrayZ); |
106 | |
107 | // TODO: Padding; & trim serialized bytes. |
108 | // TODO: Update length in loca. Ugh. |
109 | } |
110 | #endif |
111 | |
112 | if (plan->flags & HB_SUBSET_FLAGS_NO_HINTING) |
113 | Glyph (dest_glyph).drop_hints (); |
114 | |
115 | if (plan->flags & HB_SUBSET_FLAGS_SET_OVERLAPS_FLAG) |
116 | Glyph (dest_glyph).set_overlaps_flag (); |
117 | |
118 | return_trace (true); |
119 | } |
120 | |
121 | bool compile_bytes_with_deltas (const hb_subset_plan_t *plan, |
122 | hb_font_t *font, |
123 | const glyf_accelerator_t &glyf) |
124 | { |
125 | allocated = source_glyph.compile_bytes_with_deltas (plan, font, glyf, dest_start, dest_end); |
126 | return allocated; |
127 | } |
128 | |
129 | void free_compiled_bytes () |
130 | { |
131 | if (likely (allocated)) { |
132 | allocated = false; |
133 | dest_start.fini (); |
134 | dest_end.fini (); |
135 | } |
136 | } |
137 | |
138 | void drop_hints_bytes () |
139 | { source_glyph.drop_hints_bytes (dest_start, dest_end); } |
140 | |
141 | unsigned int length () const { return dest_start.length + dest_end.length; } |
142 | /* pad to 2 to ensure 2-byte loca will be ok */ |
143 | unsigned int padding () const { return length () % 2; } |
144 | unsigned int padded_size () const { return length () + padding (); } |
145 | }; |
146 | |
147 | |
148 | } /* namespace glyf_impl */ |
149 | } /* namespace OT */ |
150 | |
151 | |
152 | #endif /* OT_GLYF_SUBSETGLYPH_HH */ |
153 | |