diff options
Diffstat (limited to 'gfx/harfbuzz/src/graph/classdef-graph.hh')
| -rw-r--r-- | gfx/harfbuzz/src/graph/classdef-graph.hh | 78 |
1 files changed, 55 insertions, 23 deletions
diff --git a/gfx/harfbuzz/src/graph/classdef-graph.hh b/gfx/harfbuzz/src/graph/classdef-graph.hh index 9cf845a82d..da6378820b 100644 --- a/gfx/harfbuzz/src/graph/classdef-graph.hh +++ b/gfx/harfbuzz/src/graph/classdef-graph.hh @@ -134,20 +134,23 @@ struct ClassDef : public OT::ClassDef struct class_def_size_estimator_t { + // TODO(garretrieger): update to support beyond64k coverage/classdef tables. + constexpr static unsigned class_def_format1_base_size = 6; + constexpr static unsigned class_def_format2_base_size = 4; + constexpr static unsigned coverage_base_size = 4; + constexpr static unsigned bytes_per_range = 6; + constexpr static unsigned bytes_per_glyph = 2; + template<typename It> class_def_size_estimator_t (It glyph_and_class) - : gids_consecutive (true), num_ranges_per_class (), glyphs_per_class () + : num_ranges_per_class (), glyphs_per_class () { - unsigned last_gid = (unsigned) -1; + reset(); for (auto p : + glyph_and_class) { unsigned gid = p.first; unsigned klass = p.second; - if (last_gid != (unsigned) -1 && gid != last_gid + 1) - gids_consecutive = false; - last_gid = gid; - hb_set_t* glyphs; if (glyphs_per_class.has (klass, &glyphs) && glyphs) { glyphs->add (gid); @@ -177,28 +180,54 @@ struct class_def_size_estimator_t } } - // Incremental increase in the Coverage and ClassDef table size - // (worst case) if all glyphs associated with 'klass' were added. - unsigned incremental_coverage_size (unsigned klass) const + void reset() { + class_def_1_size = class_def_format1_base_size; + class_def_2_size = class_def_format2_base_size; + included_glyphs.clear(); + included_classes.clear(); + } + + // Compute the size of coverage for all glyphs added via 'add_class_def_size'. + unsigned coverage_size () const { - // Coverage takes 2 bytes per glyph worst case, - return 2 * glyphs_per_class.get (klass).get_population (); + unsigned format1_size = coverage_base_size + bytes_per_glyph * included_glyphs.get_population(); + unsigned format2_size = coverage_base_size + bytes_per_range * num_glyph_ranges(); + return hb_min(format1_size, format2_size); } - // Incremental increase in the Coverage and ClassDef table size - // (worst case) if all glyphs associated with 'klass' were added. - unsigned incremental_class_def_size (unsigned klass) const + // Compute the new size of the ClassDef table if all glyphs associated with 'klass' were added. + unsigned add_class_def_size (unsigned klass) { - // ClassDef takes 6 bytes per range - unsigned class_def_2_size = 6 * num_ranges_per_class.get (klass); - if (gids_consecutive) - { - // ClassDef1 takes 2 bytes per glyph, but only can be used - // when gids are consecutive. - return hb_min (2 * glyphs_per_class.get (klass).get_population (), class_def_2_size); + if (!included_classes.has(klass)) { + hb_set_t* glyphs = nullptr; + if (glyphs_per_class.has(klass, &glyphs)) { + included_glyphs.union_(*glyphs); + } + + class_def_1_size = class_def_format1_base_size; + if (!included_glyphs.is_empty()) { + unsigned min_glyph = included_glyphs.get_min(); + unsigned max_glyph = included_glyphs.get_max(); + class_def_1_size += bytes_per_glyph * (max_glyph - min_glyph + 1); + } + + class_def_2_size += bytes_per_range * num_ranges_per_class.get (klass); + + included_classes.add(klass); } - return class_def_2_size; + return hb_min (class_def_1_size, class_def_2_size); + } + + unsigned num_glyph_ranges() const { + hb_codepoint_t start = HB_SET_VALUE_INVALID; + hb_codepoint_t end = HB_SET_VALUE_INVALID; + + unsigned count = 0; + while (included_glyphs.next_range (&start, &end)) { + count++; + } + return count; } bool in_error () @@ -214,9 +243,12 @@ struct class_def_size_estimator_t } private: - bool gids_consecutive; hb_hashmap_t<unsigned, unsigned> num_ranges_per_class; hb_hashmap_t<unsigned, hb_set_t> glyphs_per_class; + hb_set_t included_classes; + hb_set_t included_glyphs; + unsigned class_def_1_size; + unsigned class_def_2_size; }; |