2019: Day 13 Part 1

2019/day13/part1.rb

@@ -0,0 +1,133 @@
+# frozen_string_literal: true
+
+require_relative 'intcode'
+
+Cell = Struct.new(:x, :y)
+
+class Screen
+  attr_reader :tiles
+
+  def initialize
+    @tiles = {}
+  end
+
+  def draw(x, y, tile)
+    @tiles[Cell.new(x, y)] = tile
+  end
+
+  def to_s
+    tl, br = corners
+
+    s = String.new
+    (tl.y..br.y).each do |y|
+      (tl.x..br.x).each do |x|
+        s << char(Cell.new(x, y))
+      end
+      s << "\n"
+    end
+    s
+  end
+
+  private
+
+  def corners
+    min_x = +Float::INFINITY
+    min_y = +Float::INFINITY
+    max_x = -Float::INFINITY
+    max_y = -Float::INFINITY
+
+    @tiles.keys.each do |p|
+      min_x = [min_x, p.x].min
+      min_y = [min_y, p.y].min
+      max_x = [max_x, p.x].max
+      max_y = [max_y, p.y].max
+    end
+
+    upper_left = Cell.new(min_x, min_y)
+    lower_right = Cell.new(max_x, max_y)
+    [upper_left, lower_right]
+  end
+
+  def char(cell)
+    tile = @tiles[cell]
+    case tile
+    when :empty
+      ' '
+    when :wall
+      '#'
+    when :block
+      'x'
+    when :horizontal_paddle
+      '_'
+    when :ball
+      'o'
+    when nil
+      ' '
+    else
+      raise StandardError, "Unexpected tile #{tile}"
+    end
+  end
+end
+
+class DoneExecuting < StandardError; end
+
+class Game
+  def initialize(program, screen)
+    @computer = Intcode::Computer.new(program.as_memory) { on_input }
+    @screen = screen
+  end
+
+  def on_input
+    raise NotImplementedError
+  end
+
+  def run
+    loop do
+      step
+      system 'clear'
+      puts @screen
+      sleep 0.01
+      blocks = @screen.tiles.values.count { |val| val == :block }
+      puts blocks
+    rescue DoneExecuting
+      nil
+    end
+  end
+
+  def step
+    x = next_output
+    y = next_output
+    tile_id = next_output
+
+    case tile_id
+    when 0
+      @screen.draw(x, y, :empty)
+    when 1
+      @screen.draw(x, y, :wall)
+    when 2
+      @screen.draw(x, y, :block)
+    when 3
+      @screen.draw(x, y, :horizontal_paddle)
+    when 4
+      @screen.draw(x, y, :ball)
+    end
+  end
+
+  def next_output
+    out = nil
+    out = tick until out
+    out
+  end
+
+  def tick
+    ret = @computer.tick
+    raise DoneExecuting if ret == :done_executing
+
+    ret
+  end
+end
+
+program = Intcode.read(File.join(__dir__, 'input'))
+screen = Screen.new
+game = Game.new(program, screen)
+game.run