Add bin and edit workflow

bin/gems/ttfunk-1.8.0/lib/ttfunk/table/maxp.rb

@@ -0,0 +1,227 @@
+# frozen_string_literal: true
+
+require_relative '../table'
+
+module TTFunk
+  class Table
+    # Maximum Profile (`maxp`) table
+    class Maxp < Table
+      # Default maximum levels of recursion.
+      DEFAULT_MAX_COMPONENT_DEPTH = 1
+
+      # Size of full table version 1.
+      MAX_V1_TABLE_LENGTH = 32
+
+      # Table version.
+      # @return [Integer]
+      attr_reader :version
+
+      # The number of glyphs in the font.
+      # @return [Integer]
+      attr_reader :num_glyphs
+
+      # Maximum points in a non-composite glyph.
+      # @return [Integer]
+      attr_reader :max_points
+
+      # Maximum contours in a non-composite glyph.
+      # @return [Integer]
+      attr_reader :max_contours
+
+      # Maximum points in a composite glyph.
+      # @return [Integer]
+      attr_reader :max_component_points
+
+      # Maximum contours in a composite glyph.
+      # @return [Integer]
+      attr_reader :max_component_contours
+
+      # Maximum zones.
+      # * 1 if instructions do not use the twilight zone (Z0)
+      # * 2 if instructions do use Z0
+      # @return [Integer]
+      attr_reader :max_zones
+
+      # Maximum points used in Z0.
+      # @return [Integer]
+      attr_reader :max_twilight_points
+
+      # Number of Storage Area locations.
+      # @return [Integer]
+      attr_reader :max_storage
+
+      # Number of FDEFs.
+      # @return [Integer]
+      attr_reader :max_function_defs
+
+      # Number of IDEFs.
+      # @return [Integer]
+      attr_reader :max_instruction_defs
+
+      # Maximum stack depth across Font Program, CVT Program and all glyph
+      # instructions.
+      # @return [Integer]
+      attr_reader :max_stack_elements
+
+      # Maximum byte count for glyph instructions.
+      # @return [Integer]
+      attr_reader :max_size_of_instructions
+
+      # Maximum number of components referenced at "top level" for any composite
+      # glyph.
+      # @return [Integer]
+      attr_reader :max_component_elements
+
+      # Maximum levels of recursion.
+      # @return [Integer]
+      attr_reader :max_component_depth
+
+      class << self
+        # Encode table.
+        #
+        # @param maxp [TTFunk::Table::Maxp]
+        # @param new2old_glyph [Hash{Integer => Integer}] keys are new glyph IDs, values
+        #   are old glyph IDs.
+        # @return [String]
+        def encode(maxp, new2old_glyph)
+          ''.b.tap do |table|
+            num_glyphs = new2old_glyph.length
+            table << [maxp.version, num_glyphs].pack('Nn')
+
+            if maxp.version == 0x10000
+              stats = stats_for(maxp, glyphs_from_ids(maxp, new2old_glyph.values))
+
+              table << [
+                stats[:max_points],
+                stats[:max_contours],
+                stats[:max_component_points],
+                stats[:max_component_contours],
+                # these all come from the fpgm and cvt tables, which
+                # we don't support at the moment
+                maxp.max_zones,
+                maxp.max_twilight_points,
+                maxp.max_storage,
+                maxp.max_function_defs,
+                maxp.max_instruction_defs,
+                maxp.max_stack_elements,
+                stats[:max_size_of_instructions],
+                stats[:max_component_elements],
+                stats[:max_component_depth],
+              ].pack('n*')
+            end
+          end
+        end
+
+        private
+
+        def glyphs_from_ids(maxp, glyph_ids)
+          glyph_ids.each_with_object([]) do |glyph_id, ret|
+            if (glyph = maxp.file.glyph_outlines.for(glyph_id))
+              ret << glyph
+            end
+          end
+        end
+
+        def stats_for(maxp, glyphs)
+          stats_for_simple(maxp, glyphs)
+            .merge(stats_for_compound(maxp, glyphs))
+            .transform_values { |agg| agg.value_or(0) }
+        end
+
+        def stats_for_simple(_maxp, glyphs)
+          max_component_elements = Max.new
+          max_points = Max.new
+          max_contours = Max.new
+          max_size_of_instructions = Max.new
+
+          glyphs.each do |glyph|
+            if glyph.compound?
+              max_component_elements << glyph.glyph_ids.size
+            else
+              max_points << glyph.end_point_of_last_contour
+              max_contours << glyph.number_of_contours
+              max_size_of_instructions << glyph.instruction_length
+            end
+          end
+
+          {
+            max_component_elements: max_component_elements,
+            max_points: max_points,
+            max_contours: max_contours,
+            max_size_of_instructions: max_size_of_instructions,
+          }
+        end
+
+        def stats_for_compound(maxp, glyphs)
+          max_component_points = Max.new
+          max_component_depth = Max.new
+          max_component_contours = Max.new
+
+          glyphs.each do |glyph|
+            next unless glyph.compound?
+
+            stats = totals_for_compound(maxp, [glyph], 0)
+            max_component_points << stats[:total_points]
+            max_component_depth << stats[:max_depth]
+            max_component_contours << stats[:total_contours]
+          end
+
+          {
+            max_component_points: max_component_points,
+            max_component_depth: max_component_depth,
+            max_component_contours: max_component_contours,
+          }
+        end
+
+        def totals_for_compound(maxp, glyphs, depth)
+          total_points = Sum.new
+          total_contours = Sum.new
+          max_depth = Max.new(depth)
+
+          glyphs.each do |glyph|
+            if glyph.compound?
+              stats = totals_for_compound(maxp, glyphs_from_ids(maxp, glyph.glyph_ids), depth + 1)
+
+              total_points << stats[:total_points]
+              total_contours << stats[:total_contours]
+              max_depth << stats[:max_depth]
+            else
+              stats = stats_for_simple(maxp, [glyph])
+              total_points << stats[:max_points]
+              total_contours << stats[:max_contours]
+            end
+          end
+
+          {
+            total_points: total_points,
+            total_contours: total_contours,
+            max_depth: max_depth,
+          }
+        end
+      end
+
+      private
+
+      def parse!
+        @version, @num_glyphs = read(6, 'Nn')
+
+        if @version == 0x10000
+          @max_points, @max_contours, @max_component_points,
+            @max_component_contours, @max_zones, @max_twilight_points,
+            @max_storage, @max_function_defs, @max_instruction_defs,
+            @max_stack_elements, @max_size_of_instructions,
+            @max_component_elements = read(24, 'n*')
+
+          # a number of fonts omit these last two bytes for some reason,
+          # so we have to supply a default here to prevent nils
+          @max_component_depth =
+            if length == MAX_V1_TABLE_LENGTH
+              read(2, 'n').first
+            else
+              DEFAULT_MAX_COMPONENT_DEPTH
+            end
+        end
+      end
+    end
+  end
+end