#!/usr/bin/env python # -*- coding: utf-8 -*- # By Lilian Besson (Naereen) # https://github.com/Naereen/gym-nes-mario-bros # MIT License https://lbesson.mit-license.org/ # from __future__ import division, print_function # Python 2 compatibility import cv2 import numpy as np from collections import deque import gym from gym import spaces class NoopResetEnv(gym.Wrapper): def __init__(self, env=None, noop_max=30): """Sample initial states by taking random number of no-ops on reset. No-op is assumed to be action 0. """ super(NoopResetEnv, self).__init__(env) self.noop_max = noop_max assert env.unwrapped.get_action_meanings()[0] == 'NOOP' def _reset(self): """ Do no-op action for a number of steps in [1, noop_max].""" self.env.reset() noops = np.random.randint(1, self.noop_max + 1) for _ in range(noops): obs, _, _, _ = self.env.step(0) return obs class FireResetEnv(gym.Wrapper): def __init__(self, env=None): """Take action on reset for environments that are fixed until firing.""" super(FireResetEnv, self).__init__(env) assert env.unwrapped.get_action_meanings()[1] == 'FIRE' assert len(env.unwrapped.get_action_meanings()) >= 3 def _reset(self): self.env.reset() obs, _, _, _ = self.env.step(1) obs, _, _, _ = self.env.step(2) return obs class EpisodicLifeEnv(gym.Wrapper): def __init__(self, env=None): """Make end-of-life == end-of-episode, but only reset on true game over. Done by DeepMind for the DQN and co. since it helps value estimation. """ super(EpisodicLifeEnv, self).__init__(env) self.lives = 0 self.was_real_done = True self.was_real_reset = False def _step(self, action): obs, reward, done, info = self.env.step(action) self.was_real_done = done # check current lives, make loss of life terminal, # then update lives to handle bonus lives lives = self.env.unwrapped.ale.lives() if lives < self.lives and lives > 0: # for Qbert somtimes we stay in lives == 0 condtion for a few frames # so its important to keep lives > 0, so that we only reset once # the environment advertises done. done = True self.lives = lives return obs, reward, done, info def _reset(self): """Reset only when lives are exhausted. This way all states are still reachable even though lives are episodic, and the learner need not know about any of this behind-the-scenes. """ if self.was_real_done: obs = self.env.reset() self.was_real_reset = True else: # no-op step to advance from terminal/lost life state obs, _, _, _ = self.env.step(0) self.was_real_reset = False self.lives = self.env.unwrapped.ale.lives() return obs class MaxAndSkipEnv(gym.Wrapper): def __init__(self, env=None, skip=4): """Return only every `skip`-th frame""" super(MaxAndSkipEnv, self).__init__(env) # most recent raw observations (for max pooling across time steps) self._obs_buffer = deque(maxlen=2) self._skip = skip def _step(self, action): total_reward = 0.0 done = None for _ in range(self._skip): obs, reward, done, info = self.env.step(action) self._obs_buffer.append(obs) total_reward += reward if done: break max_frame = np.max(np.stack(self._obs_buffer), axis=0) return max_frame, total_reward, done, info def _reset(self): """Clear past frame buffer and init. to first obs. from inner env.""" self._obs_buffer.clear() obs = self.env.reset() self._obs_buffer.append(obs) return obs def _process_frame84(frame): img = np.reshape(frame, [210, 160, 3]).astype(np.float32) img = img[:, :, 0] * 0.299 + img[:, :, 1] * 0.587 + img[:, :, 2] * 0.114 resized_screen = cv2.resize(img, (84, 84), interpolation=cv2.INTER_LINEAR) x_t = resized_screen[18:102, :] x_t = np.reshape(x_t, [84, 84, 1]) return x_t.astype(np.uint8) class ProcessFrame84(gym.Wrapper): def __init__(self, env=None): super(ProcessFrame84, self).__init__(env) self.observation_space = spaces.Box(low=0, high=255, shape=(84, 84, 1), dtype=np.uint8) def _step(self, action): obs, reward, done, info = self.env.step(action) return _process_frame84(obs), reward, done, info def _reset(self): return _process_frame84(self.env.reset()) class ClippedRewardsWrapper(gym.Wrapper): def _step(self, action): obs, reward, done, info = self.env.step(action) return obs, np.sign(reward), done, info def wrap_deepmind_ram(env): env = EpisodicLifeEnv(env) env = NoopResetEnv(env, noop_max=30) env = MaxAndSkipEnv(env, skip=4) if 'FIRE' in env.unwrapped.get_action_meanings(): env = FireResetEnv(env) env = ClippedRewardsWrapper(env) return env def wrap_deepmind(env): assert 'NoFrameskip' in env.spec.id env = EpisodicLifeEnv(env) env = NoopResetEnv(env, noop_max=30) env = MaxAndSkipEnv(env, skip=4) if 'FIRE' in env.unwrapped.get_action_meanings(): env = FireResetEnv(env) # env = ProcessFrame84(env) env = ClippedRewardsWrapper(env) return env