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# frozen_string_literal: true
require_relative '../table/cmap'
require_relative '../table/glyf'
require_relative '../table/head'
require_relative '../table/hhea'
require_relative '../table/hmtx'
require_relative '../table/kern'
require_relative '../table/loca'
require_relative '../table/maxp'
require_relative '../table/name'
require_relative '../table/post'
require_relative '../table/simple'
module TTFunk
module Subset
# Base subset.
#
# @api private
class Base
# Microsoft Platform ID
MICROSOFT_PLATFORM_ID = 3
# Symbol Encoding ID for Microsoft Platform
MS_SYMBOL_ENCODING_ID = 0
# Original font
#
# @return [TTFunk::File]
attr_reader :original
# @param original [TTFunk::File]
def initialize(original)
@original = original
end
# Is this Unicode-based subset?
#
# @return [Boolean]
def unicode?
false
end
# Does this subset use Microsoft Symbolic encoding?
#
# @return [Boolean]
def microsoft_symbol?
new_cmap_table[:platform_id] == MICROSOFT_PLATFORM_ID &&
new_cmap_table[:encoding_id] == MS_SYMBOL_ENCODING_ID
end
# Get a mapping from this subset to Unicode.
#
# @return [Hash{Integer => Integer}]
def to_unicode_map
{}
end
# Encode this subset into a binary font representation.
#
# @param options [Hash]
# @return [String]
def encode(options = {})
encoder_klass.new(original, self, options).encode
end
# Encoder class for this subset.
#
# @return [TTFunk::TTFEncoder, TTFunk::OTFEncoder]
def encoder_klass
original.cff.exists? ? OTFEncoder : TTFEncoder
end
# Get the first Unicode cmap from the original font.
#
# @return [TTFunk::Table::Cmap::Subtable]
def unicode_cmap
@unicode_cmap ||= @original.cmap.unicode.first
end
# Get glyphs in this subset.
#
# @return [Hash{Integer => TTFunk::Table::Glyf::Simple,
# TTFunk::Table::Glyf::Compound}] if original is a TrueType font
# @return [Hash{Integer => TTFunk::Table::Cff::Charstring] if original is
# a CFF-based OpenType font
def glyphs
@glyphs ||= collect_glyphs(original_glyph_ids)
end
# Get glyphs by their IDs in the original font.
#
# @param glyph_ids [Array<Integer>]
# @return [Hash{Integer => TTFunk::Table::Glyf::Simple,
# TTFunk::Table::Glyf::Compound>] if original is a TrueType font
# @return [Hash{Integer => TTFunk::Table::Cff::Charstring}] if original is
# a CFF-based OpenType font
def collect_glyphs(glyph_ids)
collected =
glyph_ids.each_with_object({}) do |id, h|
h[id] = glyph_for(id)
end
additional_ids = collected.values
.select { |g| g && g.compound? }
.map(&:glyph_ids)
.flatten
collected.update(collect_glyphs(additional_ids)) if additional_ids.any?
collected
end
# Glyph ID mapping from the original font to this subset.
#
# @return [Hash{Integer => Integer}]
def old_to_new_glyph
@old_to_new_glyph ||=
begin
charmap = new_cmap_table[:charmap]
old_to_new =
charmap.each_with_object(0 => 0) do |(_, ids), map|
map[ids[:old]] = ids[:new]
end
next_glyph_id = new_cmap_table[:max_glyph_id]
glyphs.each_key do |old_id|
unless old_to_new.key?(old_id)
old_to_new[old_id] = next_glyph_id
next_glyph_id += 1
end
end
old_to_new
end
end
# Glyph ID mapping from this subset to the original font.
#
# @return [Hash{Integer => Integer}]
def new_to_old_glyph
@new_to_old_glyph ||= old_to_new_glyph.invert
end
private
def glyph_for(glyph_id)
if original.cff.exists?
original
.cff
.top_index[0]
.charstrings_index[glyph_id]
.glyph
else
original.glyph_outlines.for(glyph_id)
end
end
end
end
end
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