update lowpoly example

examples/low_poly_reconstruction/low_poly_reconstruction.rb

@@ -1,21 +1,27 @@
+RubyVM::InstructionSequence.compile_option = {
+  tailcall_optimization: true,
+  trace_instruction: false
+}
+
 require_relative "../../lib/petri_dish"
 require "bundler/inline"
 
-$stdout.sync = true
+# $stdout.sync = true
 
 gemfile do
   source "https://rubygems.org"
   gem "rmagick", require: "rmagick"
   gem "delaunator", require: true
+  gem "pry"
 end
 
 LOW_POLY_RECONSTUCTION_PATH = "examples/low_poly_reconstruction".freeze
 INPUT_IMAGE_PATH = "#{LOW_POLY_RECONSTUCTION_PATH}/ruby.svg".freeze
 CONVERTED_INPUT_IMAGE_PATH = "#{LOW_POLY_RECONSTUCTION_PATH}/input_convert.png".freeze
-OUT_DIR = "#{LOW_POLY_RECONSTUCTION_PATH}/out".freeze
-IMAGE_HEIGHT_PX = 100
-IMAGE_WIDTH_PX = 100
-GREYSCALE_VALUES = (0..255).to_a
+OUT_DIR = "#{LOW_POLY_RECONSTUCTION_PATH}/out3".freeze
+IMAGE_HEIGHT_PX = 250
+IMAGE_WIDTH_PX = 250
+GRAYSCALE_VALUES = (0..255).to_a
 
 class LowPolyImageReconstruction
   Point = Struct.new(:x, :y, :grayscale)
@@ -29,7 +35,7 @@ def run
       PetriDish::Member.new(
         genes: (0..IMAGE_WIDTH_PX).step(10).map do |x|
                  (0..IMAGE_HEIGHT_PX).step(10).map do |y|
-                   Point.new(x + point_jitter, y + point_jitter, GREYSCALE_VALUES.sample)
+                   Point.new(x + point_jitter, y + point_jitter, GRAYSCALE_VALUES.sample)
                  end
                end.flatten,
         fitness_function: calculate_fitness(target_image)
@@ -42,16 +48,15 @@ def run
   def configuration
     PetriDish::Configuration.configure do |config|
       config.population_size = 50
-      config.mutation_rate = 0.1
-      config.elitism_rate = 0.1
-      config.max_generations = 2500
+      config.mutation_rate = 0.05
+      config.elitism_rate = 0.05
+      config.max_generations = 10_000
       config.fitness_function = calculate_fitness(target_image)
       config.parents_selection_function = roulette_wheel_parent_selection_function
       config.crossover_function = random_midpoint_crossover_function(config)
       config.mutation_function = nudge_mutation_function(config)
-      config.highest_fitness_callback = ->(member) { save_image(member_to_image(member, IMAGE_WIDTH_PX, IMAGE_HEIGHT_PX)) }
+      config.highest_fitness_callback = ->(member) { save_image(member_to_image(member)) }
       config.generation_start_callback = ->(current_generation) { generation_start_callback(current_generation) }
-      config.end_condition_function = ->(_member) { false }
     end
   end
 
@@ -117,9 +122,9 @@ def nudge_mutation_function(configuration)
       mutated_genes = member.genes.dup.map do |gene|
         if rand < configuration.mutation_rate
           Point.new(
-            gene.x + rand(-5..5) + point_jitter,
-            gene.y + rand(-5..5) + point_jitter,
-            (gene.grayscale + rand(-5..5)).clamp(0, 255)
+            (gene.x + rand(-10..10) + point_jitter).clamp(0, IMAGE_WIDTH_PX),
+            (gene.y + rand(-10..10) + point_jitter).clamp(0, IMAGE_HEIGHT_PX),
+            (gene.grayscale + rand(-25..25)).clamp(GRAYSCALE_VALUES.min, GRAYSCALE_VALUES.max)
           )
         else
           gene
@@ -131,14 +136,15 @@ def nudge_mutation_function(configuration)
 
   def calculate_fitness(target_image)
     ->(member) do
-      member_image = member_to_image(member, IMAGE_WIDTH_PX, IMAGE_HEIGHT_PX)
+      member_image = member_to_image(member)
       # Difference is a tuple of [mean_error_per_pixel, normalized_mean_error, normalized_maximum_error]
-      1 / (target_image.difference(member_image)[0]**2) # Use the mean error per pixel as the fitness
+      # (target_image.difference(member_image)[0])**2 # Use the mean error per pixel as the fitness
+      1 / target_image.distortion_channel(member_image, Magick::MeanSquaredErrorMetric, Magick::GrayChannel)**2
     end
   end
 
-  def member_to_image(member, width, height)
-    image = Magick::Image.new(width, height) { |options| options.background_color = "white" }
+  def member_to_image(member)
+    image = Magick::Image.new(IMAGE_WIDTH_PX, IMAGE_HEIGHT_PX) { |options| options.background_color = "white" }
     draw = Magick::Draw.new
 
     # Perform Delaunay triangulation on the points
@@ -165,12 +171,14 @@ def member_to_image(member, width, height)
   end
 
   def save_image(image)
-    image.write("#{OUT_DIR}/gen-#{@current_generation}.png")
+    image.write("#{OUT_DIR}/gen-#{@current_generation.to_s.rjust(4, "0")}.png")
   end
 
   def generation_start_callback(current_generation)
     @current_generation = current_generation
   end
 end
 
+# Put this in the gem so users can just call a method to set the compiler options
+
 LowPolyImageReconstruction.new.run