bitplane only color mapping works, let's make some bitplanes/copperlists

image_converter.rb

@@ -28,10 +28,17 @@ class Color
     @blue = blue
   end
 
+  WHITE = new(red: 15, green: 15, blue: 15)
+  BLACK = new(red: 0, green: 0, blue: 0)
+
   def ==(other)
     red == other.red && green == other.green && blue == other.blue
   end
 
+  def -(other)
+    red - other.red + green - other.green + blue - other.blue
+  end
+
   alias eql? ==
 
   def hash
@@ -87,4 +94,63 @@ image.each_pixel do |px, x, y|
   rows[y].add(pixel:, x:)
 end
 
-pp rows[50].colors_with_usage
+prioritized_colors = rows[50].colors_with_usage.to_a.sort { |a, b| b.last <=> a.last }
+
+presets_by_pixel_color = [
+  nil, Color::BLACK, Color::WHITE
+]
+
+unavailable_bitplane_colors = {
+  0 => true,
+  1 => true,
+  2 => true
+}
+
+MAX_BITPLANE_COLORS = 8
+
+bitplane_colors = [
+  nil,
+  Color::BLACK,
+  Color::WHITE
+]
+
+color_to_pixel_map = {}
+
+# take 5 + BLACK + WHITE colors into bitplane_colors
+
+prioritized_colors.map(&:first).each do |color|
+  maybe_preset_index = presets_by_pixel_color.find_index { |c| c && color == c }
+
+  if !maybe_preset_index.nil?
+    bitplane_colors[maybe_preset_index] = color
+    color_to_pixel_map[color] = maybe_preset_index
+
+    unavailable_bitplane_colors[maybe_preset_index] = true
+  elsif bitplane_colors.count < MAX_BITPLANE_COLORS
+    next_available_bitplane_color = 8.times.find { |i| !unavailable_bitplane_colors[i] }
+
+    bitplane_colors[next_available_bitplane_color] = color
+    color_to_pixel_map[color] = next_available_bitplane_color
+
+    unavailable_bitplane_colors[next_available_bitplane_color] = true
+  else
+    closest_match = bitplane_colors.each_with_index.map do |bp_color, index|
+      next unless bp_color
+
+      [(bp_color - color).abs, index]
+    end.compact.min_by(&:first)
+
+    pp color
+    pp closest_match
+    pp bitplane_colors[closest_match.last]
+    puts '************************'
+
+    color_to_pixel_map[color] = closest_match.last
+  end
+end
+
+pp prioritized_colors
+pp bitplane_colors
+pp color_to_pixel_map
+
+# .to_a.sort(&:last).reverse