npc.rb

class LCG
  def initialize(seed)
    @seed = seed
  end

  def rand()
    @seed = (@seed * 0x41c64e6d +  0x6073) % 2**32
    @seed >> 16
  end
end

class Context
  def initialize(seed)
    @lcg = LCG.new(seed)
    @log = []
    @log2 = []
    @frame = 0
  end

  attr_reader :frame

  def rand()
    @lcg.rand()
  end
  
  def log(message)
    @log << [@frame, message]
  end

  def log2(frame, message)
    @log2 << [frame, message]
  end

  def get_log() @log end
  def get_log2() @log2 end

  def inc_frame(n)
    @frame += n
  end
end

NPC = Struct.new(:name, :type, :w, :h, :all_directions, :x, :y, :timer, :direction, :state)

UP, DOWN, LEFT, RIGHT = 0, 1, 2, 3
DIRECTION = ["上", "下", "左", "右"]
DX = [ 0, 0, -1, 1]
DY = [-1, 1,  0, 0]

def rand_time(ctx, npc)
  time = 16 * (ctx.rand() % 4 + 1)
  ctx.log "#{npc.name} time -> #{time}"
  time
end

def init(ctx, npcs)
  npcs.each do |npc|
    if npc.type == :nonmovable then
      npc.timer = rand_time(ctx, npc)
    end
  end
end

def rand_direction(ctx, npc)
  direction = npc.all_directions[ctx.rand() % npc.all_directions.size]
  ctx.log "#{npc.name} direction -> #{direction}"
  direction
end

def advance(ctx, npcs)
  npcs.each do |npc|
    advance_npc(ctx, npc)
  end
end

def advance_npc(ctx, npc)
  if npc.type == :nonmovable then
    #puts " %s %2d" % [npc.name, npc.timer]
    npc.timer -= 1
    if npc.timer == 0 then
      npc.timer = rand_time(ctx, npc)
      direction = rand_direction(ctx, npc)
      if npc.direction != direction then
        ctx.log2 ctx.frame + 6, "#{npc.name}が#{DIRECTION[direction]}を向く"
      end
      npc.direction = direction
    end
  else
    #puts " %s %d %2d" % [npc.name, npc.state, npc.timer]
    case npc.state
    when 0
      npc.state = 1
    when 1
      npc.timer = rand_time(ctx, npc) - 1
      npc.state = 2
    when 2
      npc.timer -= 1
      if npc.timer == 0 then
        prev_direction = npc.direction
        npc.direction = rand_direction(ctx, npc)
        if movable(npc)
          ctx.log2 ctx.frame + 6, "#{npc.name}が#{DIRECTION[npc.direction]}へ移動"
          move(npc)
          npc.state = 4
          npc.timer = 7
        else
          if npc.direction != prev_direction then
            ctx.log2 ctx.frame + 6, "#{npc.name}が#{DIRECTION[npc.direction]}を向く"
          end
          npc.state = 0
        end
      end
    when 4
      npc.timer -= 1
      if npc.timer == 0 then
        npc.state = 0
      end
    end
  end
end

def movable(npc)
  new_x = npc.x + DX[npc.direction]
  new_y = npc.y + DY[npc.direction]
  0 <= new_x and new_x < npc.w and 0 <= new_y and new_y < npc.h
end

def move(npc)
  npc.x += DX[npc.direction]
  npc.y += DY[npc.direction]
end

def nonmovable_npc(name, all_directions, direction)
  NPC.new(name, :nonmovable, 0, 0, all_directions, 0, 0, direction, 0)
end

def movable_npc(name, w, h, x, y, direction)
  NPC.new(name, :movable, w, h, [UP, DOWN, LEFT, RIGHT], x, y, 0, direction, 0)
end

npcs = [
  nonmovable_npc("短パン", [UP, RIGHT], RIGHT),
  movable_npc("茶髪", 3, 2, 1, 1, LEFT),
  movable_npc("警官", 2, 3, 1, 1, UP),
  movable_npc("紳士", 3, 3, 1, 1, LEFT),
  nonmovable_npc("婦人", [UP, RIGHT], LEFT),
]

context = Context.new(0xe97e7b6a)

init context, npcs
context.inc_frame 30
500.times do |i|
  #puts "NPC loop #{i}"
  advance context, npcs
  context.inc_frame 2
end

context.get_log2().each {|f,x| puts "%4d %s" % [f, x] }