Added "Four Rooms" environment from Minigrid

pufferlib/config/ocean/four_rooms.ini

@@ -0,0 +1,14 @@
+[base]
+package = ocean
+env_name = puffer_four_rooms
+policy_name = Policy
+rnn_name = Recurrent
+
+[env]
+num_envs = 256
+
+[train]
+total_timesteps = 10_000_000
+gamma = 0.99
+learning_rate = 0.015
+minibatch_size = 32768

pufferlib/ocean/environment.py

@@ -155,6 +155,7 @@ def make_multiagent(buf=None, **kwargs):
     'pacman': 'Pacman',
     'checkers': 'Checkers',
     'asteroids': 'Asteroids',
+    'four_rooms': 'FourRooms',
     'whisker_racer': 'WhiskerRacer',
     'spaces': make_spaces,
     'multiagent': make_multiagent,

pufferlib/ocean/four_rooms/binding.c

@@ -0,0 +1,20 @@
+#include "four_rooms.h"
+
+#define Env FourRooms
+#include "../env_binding.h"
+
+static int my_init(Env* env, PyObject* args, PyObject* kwargs) {
+    env->size = unpack(kwargs, "size");
+    env->see_through_walls = 0;
+    // Allocate grid memory for full state (stores OBJECT_IDX values)
+    env->grid = (unsigned char*)calloc(env->size * env->size, sizeof(unsigned char));
+    return 0;
+}
+
+static int my_log(PyObject* dict, Log* log) {
+    assign_to_dict(dict, "perf", log->perf);
+    assign_to_dict(dict, "score", log->score);
+    assign_to_dict(dict, "episode_return", log->episode_return);
+    assign_to_dict(dict, "episode_length", log->episode_length);
+    return 0;
+}

pufferlib/ocean/four_rooms/four_rooms.c

@@ -0,0 +1,34 @@
+#include "four_rooms.h"
+
+int main() {
+    FourRooms env = {};
+    env.size = 19;
+    env.observations = (unsigned char*)calloc(7*7*3, sizeof(unsigned char)); // 7x7x3 for MinGrid encoding
+    env.actions = (int*)calloc(1, sizeof(int));
+    env.rewards = (float*)calloc(1, sizeof(float));
+    env.terminals = (unsigned char*)calloc(1, sizeof(unsigned char));
+    env.grid = (unsigned char*)calloc(env.size * env.size, sizeof(unsigned char));
+
+    c_reset(&env);
+    c_render(&env);
+    while (!WindowShouldClose()) {
+        if (IsKeyDown(KEY_LEFT_SHIFT)) {
+            env.actions[0] = 7; // Invalid action = no-op
+            if (IsKeyDown(KEY_UP) || IsKeyDown(KEY_W)) env.actions[0] = FORWARD;
+            if (IsKeyDown(KEY_LEFT) || IsKeyDown(KEY_A)) env.actions[0] = LEFT;
+            if (IsKeyDown(KEY_RIGHT) || IsKeyDown(KEY_D)) env.actions[0] = RIGHT;
+        } else {
+            env.actions[0] = rand() % 3; // Only use left, right, forward
+        }
+        c_step(&env);
+        c_render(&env);
+    }
+    free(env.observations);
+    free(env.actions);
+    free(env.rewards);
+    free(env.terminals);
+    free(env.grid);
+    c_close(&env);
+    return 0;
+}
+