SubsetGlyph.hh (3815B)
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 57 #ifndef HB_NO_BEYOND_64K 58 auto it = Glyph (dest_glyph).get_composite_iterator (); 59 if (it) 60 { 61 /* lower GID24 to GID16 in components if possible. */ 62 char *p = it ? (char *) &*it : nullptr; 63 char *q = p; 64 const char *end = dest_glyph.arrayZ + dest_glyph.length; 65 while (it) 66 { 67 auto &rec = const_cast<CompositeGlyphRecord &> (*it); 68 ++it; 69 70 q += rec.get_size (); 71 72 rec.lower_gid_24_to_16 (); 73 74 unsigned size = rec.get_size (); 75 76 memmove (p, &rec, size); 77 78 p += size; 79 } 80 memmove (p, q, end - q); 81 p += end - q; 82 83 /* We want to shorten the glyph, but we can't do that without 84 * updating the length in the loca table, which is already 85 * written out :-(. So we just fill the rest of the glyph with 86 * harmless instructions, since that's what they will be 87 * interpreted as. 88 * 89 * Should move the lowering to _populate_subset_glyphs() to 90 * fix this issue. */ 91 92 hb_memset (p, 0x7A /* TrueType instruction ROFF; harmless */, end - p); 93 p += end - p; 94 dest_glyph = hb_bytes_t (dest_glyph.arrayZ, p - (char *) dest_glyph.arrayZ); 95 96 // TODO: Padding; & trim serialized bytes. 97 // TODO: Update length in loca. Ugh. 98 } 99 #endif 100 101 if (plan->flags & HB_SUBSET_FLAGS_NO_HINTING) 102 Glyph (dest_glyph).drop_hints (); 103 104 if (plan->flags & HB_SUBSET_FLAGS_SET_OVERLAPS_FLAG) 105 Glyph (dest_glyph).set_overlaps_flag (); 106 107 return_trace (true); 108 } 109 110 bool compile_bytes_with_deltas (const hb_subset_plan_t *plan, 111 hb_font_t *font, 112 const glyf_accelerator_t &glyf) 113 { 114 allocated = source_glyph.compile_bytes_with_deltas (plan, font, glyf, dest_start, dest_end); 115 return allocated; 116 } 117 118 void free_compiled_bytes () 119 { 120 if (likely (allocated)) { 121 allocated = false; 122 dest_start.fini (); 123 dest_end.fini (); 124 } 125 } 126 127 void drop_hints_bytes () 128 { source_glyph.drop_hints_bytes (dest_start, dest_end); } 129 130 unsigned int length () const { return dest_start.length + dest_end.length; } 131 /* pad to 2 to ensure 2-byte loca will be ok */ 132 unsigned int padding () const { return length () % 2; } 133 unsigned int padded_size () const { return length () + padding (); } 134 }; 135 136 137 } /* namespace glyf_impl */ 138 } /* namespace OT */ 139 140 141 #endif /* OT_GLYF_SUBSETGLYPH_HH */