mupen64plus_env.py

from BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer

import abc
import array
import inspect
import os
import subprocess
import threading
import time
from termcolor import cprint
import yaml

import gym
from gym import error, spaces, utils
from gym.utils import seeding

import numpy as np

import wx
wx.App()


###############################################
class ImageHelper:

    BLACK_PIXEL = (0, 0, 0)

    def GetPixelColor(self, image_array, x, y):
        base_pixel = (x + (y * config['SCR_W'])) * 3
        red = image_array[base_pixel + 0]
        green = image_array[base_pixel + 1]
        blue = image_array[base_pixel + 2]
        return (red, green, blue)


###############################################
### Variables & Constants                   ###
###############################################

config = yaml.safe_load(open(os.path.join(os.path.dirname(inspect.stack()[0][1]), "config.yml")))

MILLIS_50 = 50.0 / 1000.0

IMAGE_HELPER = ImageHelper()


###############################################
class Mupen64PlusEnv(gym.Env):
    __metaclass__ = abc.ABCMeta
    metadata = {'render.modes': ['human']}

    def __init__(self, rom_path):
        self.step_count = 0
        self.running = True
        self.episode_over = False
        self.numpy_array = None
        self.pixel_array = array.array('B', [0] * (config['SCR_W'] *
                                                   config['SCR_H'] *
                                                   config['SCR_D']))
        self.controller_server, self.controller_server_thread = self._start_controller_server()
        self.emulator_process = self._start_emulator(rom_path=rom_path)
        self._navigate_menu()

        self.observation_space = \
            spaces.Box(low=0, high=255, shape=(config['SCR_H'], config['SCR_W'], config['SCR_D']))

        self.action_space = spaces.MultiDiscrete([[-80, 80], # Joystick X-axis
                                                  [-80, 80], # Joystick Y-axis
                                                  [0, 1], # A Button
                                                  [0, 1], # B Button
                                                  [0, 1]]) # RB Button

    def _step(self, action):
        #cprint('Step %i: %s' % (self.step_count, action), 'green')
        self.controller_server.send_controls(action)
        obs = self._observe()
        self.episode_over = self._evaluate_end_state()
        reward = self._get_reward()

        self.step_count += 1
        return obs, reward, self.episode_over, {}

    def _observe(self):
        #cprint('Observe called!', 'red')
        bmp = wx.Bitmap(config['SCR_W'], config['SCR_H'])
        wx.MemoryDC(bmp).Blit(0, 0,
                              config['SCR_W'], config['SCR_H'],
                              wx.ScreenDC(),
                              config['OFFSET_X'], config['OFFSET_Y'])
        bmp.CopyToBuffer(self.pixel_array)

        self.numpy_array = np.frombuffer(self.pixel_array, dtype=np.uint8)
        self.numpy_array = \
            self.numpy_array.reshape(config['SCR_H'], config['SCR_W'], config['SCR_D'])

        return self.numpy_array

    @abc.abstractmethod
    def _navigate_menu(self):
        return

    @abc.abstractmethod
    def _get_reward(self):
        #cprint('Get Reward called!', 'red')
        return 0

    @abc.abstractmethod
    def _evaluate_end_state(self):
        #cprint('Evaluate End State called!', 'red')
        return False

    @abc.abstractmethod
    def _reset(self):
        cprint('Reset called!', 'red')

        return self._observe()

    def _render(self, mode='human', close=False):
        # TODO: Implement xvfb support for background execution,
        # and implement this render method to display the window
        pass

    def _close(self):
        cprint('Close called!', 'red')
        self.running = False
        self._kill_emulator()
        self._stop_controller_server()

    def _start_controller_server(self):
        server = ControllerHTTPServer(('', config['PORT_NUMBER']),
                                      config['ACTION_TIMEOUT'])
        server_thread = threading.Thread(target=server.serve_forever, args=())
        server_thread.daemon = True
        server_thread.start()
        print('ControllerHTTPServer started on port ', config['PORT_NUMBER'])
        return server, server_thread

    def _stop_controller_server(self):
        #cprint('Stop Controller Server called!', 'red')
        if self.controller_server is not None:
            self.controller_server.shutdown()

    def _start_emulator(self,
                        rom_path,
                        res_w=config['SCR_W'],
                        res_h=config['SCR_H'],
                        input_driver_path=config['INPUT_DRIVER_PATH']):

        cmd = config['MUPEN_CMD'] + \
              " --resolution %ix%i" \
              " --input %s" \
              " %s" \
              % (res_w, res_h,
                 input_driver_path,
                 rom_path)

        print('Starting emulator with comand: %s' % cmd)

        emulator_process = subprocess.Popen(cmd.split(' '),
                                            shell=False,
                                            stderr=subprocess.STDOUT)
        emu_mon = EmulatorMonitor()
        monitor_thread = threading.Thread(target=emu_mon.monitor_emulator,
                                          args=[emulator_process])
        monitor_thread.daemon = True
        monitor_thread.start()

        return emulator_process

    def _kill_emulator(self):
        #cprint('Kill Emulator called!', 'red')
        self.controller_server.send_controls(ControllerHTTPServer.NOOP)
        if self.emulator_process is not None:
            self.emulator_process.kill()


###############################################
class EmulatorMonitor:
    def monitor_emulator(self, emulator):
        emu_return = emulator.poll()
        while emu_return is None:
            time.sleep(2)
            emu_return = emulator.poll()

        # TODO: this means our environment died... need to die too
        print('Emulator closed with code: ' + str(emu_return))


###############################################
class ControllerHTTPServer(HTTPServer, object):

    # Buttons
    NOOP = [0, 0, 0, 0, 0]
    A_BUTTON = [0, 0, 1, 0, 0]
    B_BUTTON = [0, 0, 0, 1, 0]
    RB_BUTTON = [0, 0, 0, 0, 1]
    JOYSTICK_UP = [0, 80, 0, 0, 0]
    JOYSTICK_DOWN = [0, -80, 0, 0, 0]
    JOYSTICK_LEFT = [-80, 0, 0, 0, 0]
    JOYSTICK_RIGHT = [80, 0, 0, 0, 0]

    def __init__(self, server_address, control_timeout):
        self.control_timeout = control_timeout
        self.controls = ControllerHTTPServer.NOOP
        self.hold_response = True
        self.running = True
        super(ControllerHTTPServer, self).__init__(server_address, self.ControllerRequestHandler)

    def send_controls(self, controls):
        #print('Send controls called')
        self.controls = controls
        self.hold_response = False

        # Wait for controls to be sent:
        start = time.time()
        while not self.hold_response and time.time() < start + self.control_timeout:
            time.sleep(MILLIS_50)

    def shutdown(self):
        self.running = False
        super(ControllerHTTPServer, self).shutdown()


    class ControllerRequestHandler(BaseHTTPRequestHandler, object):

        def log_message(self, format, *args):
            pass

        def write_response(self, resp_code, resp_data):
            self.send_response(resp_code)
            self.send_header("Content-type", "text/plain")
            self.end_headers()
            self.wfile.write(resp_data)

        def do_GET(self):

            while self.server.running and self.server.hold_response:
                time.sleep(MILLIS_50)

            if not self.server.running:
                print('Sending SHUTDOWN response')
                # TODO: This sometimes fails with a broken pipe because
                # the emulator has already stopped. Should handle gracefully
                self.write_response(500, "SHUTDOWN")

            ### respond with controller output
            self.write_response(200, self.server.controls)

            self.server.hold_response = True
            return

###############################################