Lib.rs

A thin wrapper of atari-env for Border.

The code under [atari_env] is adapted from the atari-env crate (rev = 0ef0422f953d79e96b32ad14284c9600bd34f335), because the crate registered in crates.io does not implement atari_env::AtariEnv::lives() method, which is required for episodic life environments.

This environment applies some preprocessing to observation as in atari_wrapper.py.

You need to place Atari Rom directories under the directory specified by environment variable ATARI_ROM_DIR. An easy way to do this is to use AutoROM Python package.

pip install autorom
mkdir $HOME/atari_rom
AutoROM --install-dir $HOME/atari_rom
export ATARI_ROM_DIR=$HOME/atari_rom

Here is an example of running Pong environment with a random policy.

use anyhow::Result;
use border_atari_env::{
    BorderAtariAct, BorderAtariActRawFilter, BorderAtariEnv, BorderAtariEnvConfig,
    BorderAtariObs, BorderAtariObsRawFilter,
};
use border_core::{util, Env as _, Policy, DefaultEvaluator, Evaluator as _};

type Obs = BorderAtariObs;
type Act = BorderAtariAct;
type ObsFilter = BorderAtariObsRawFilter<Obs>;
type ActFilter = BorderAtariActRawFilter<Act>;
type EnvConfig = BorderAtariEnvConfig<Obs, Act, ObsFilter, ActFilter>;
type Env = BorderAtariEnv<Obs, Act, ObsFilter, ActFilter>;

#[derive(Clone)]
struct RandomPolicyConfig {
    pub n_acts: usize,
}

struct RandomPolicy {
    n_acts: usize,
}

impl Policy<Env> for RandomPolicy {
    type Config = RandomPolicyConfig;

    fn build(config: Self::Config) -> Self {
        Self {
            n_acts: config.n_acts,
        }
    }

    fn sample(&mut self, _: &Obs) -> Act {
        fastrand::u8(..self.n_acts as u8).into()
    }
}

fn env_config(name: String) -> EnvConfig {
    EnvConfig::default().name(name)
}

fn main() -> Result<()> {
    env_logger::Builder::from_env(env_logger::Env::default().default_filter_or("info")).init();
    fastrand::seed(42);

    // Creates Pong environment
    let env_config = env_config("pong".to_string());

    // Creates a random policy
    let n_acts = 4; // number of actions;
    let policy_config = RandomPolicyConfig {
        n_acts: n_acts as _,
    };
    let mut policy = RandomPolicy::build(policy_config);

    // Runs evaluation
    let env_config = env_config.render(true);
    let _ = DefaultEvaluator::new(&env_config, 0, 5)?.evaluate(&mut policy);

    Ok(())
}