Add bin and edit workflow

bin/gems/ttfunk-1.8.0/lib/ttfunk/subset/base.rb

@@ -0,0 +1,161 @@
+# 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