Grid & Layouts¶

A CoGrid environment is built on a 2D grid. The grid state is stored as three parallel integer arrays:

Array	Contents
`wall_map`	Binary mask. `1` = impassable wall cell.
`object_type_map`	Integer type ID per cell (e.g. counter, pot, onion stack).
`object_state_map`	Per-cell state value (e.g. what a counter holds, pot cook progress).

All three share the same (H, W) shape and are updated each step by the engine.

ASCII Layouts¶

Layouts are defined as lists of equal-length strings. Each character maps to a registered object type via its char attribute.

layout = [
    "CCUCC",
    "O   O",
    "C   C",
    "C=C@C",
]

Built-in Characters¶

Char	Object	Meaning
`#`	Wall	Impassable, blocks visibility
`+`	Spawn	Agent start position (replaced with floor at runtime)
	Empty	Walkable floor tile

Environment-scoped objects add their own characters. For example, the Overcooked scope maps O to OnionStack, U to Pot, = to PlateStack, @ to DeliveryZone, and C to Counter.

Registering Layouts¶

Use register_layout() to store a named layout in the global registry:

from cogrid.core.grid.layouts import register_layout

register_layout(
    "my_layout_v0",
    [
        "######",
        "#O  @#",
        "# ++ #",
        "#C  C#",
        "######",
    ],
)

Parameters:

Parameter	Type	Description
`layout_id`	`str`	Unique name for the layout. Raises `ValueError` if already taken.
`layout`	`list[str]`	Grid rows as strings. All rows must be the same length.
`state_encoding`	`list[list[int]]` or `ndarray` or `None`	Optional initial `object_state_map` values. Defaults to all zeros.

The layout ID is referenced in the environment config:

config = {
    "grid": {"layout": "my_layout_v0"},
    ...
}

Retrieving Layouts¶

from cogrid.core.grid.layouts import get_layout

layout, state_encoding = get_layout("my_layout_v0")

Returns a (layout, state_encoding) tuple.

Layout Examples¶

Overcooked Cramped Room¶

CCUCC
O   O
C   C
C=C@C

A compact 4x5 kitchen with one pot (U), two onion stacks (O), a plate stack (=), and a delivery zone (@). Counters (C) line the perimeter.

Overcooked Coordination Ring¶

CCCUC
C   U
= C C
O   C
CO@CC

A ring-shaped layout that forces agents to navigate around a central counter. Two pots on the top and right edges.

Overcooked Mixed Kitchen¶

CUCCCUC
O+ C +T
=  C  =
C  C  C
CCCCC@C

A dual-recipe kitchen with both onion (O) and tomato (T) stacks, two pots, and two plate stacks.