Struct MetatileDef 

pub struct MetatileDef {
    pub size: (u8, u8),
    pub tiles: Vec<MetatileCell>,
    pub collision: Vec<CollisionCell>,
    pub trigger: Option<TriggerDef>,
    pub animation_group: Option<u8>,
    pub z_offset: i8,
}

A metatile — a logical unit comprised of N×N tiles.

This is the JRPG engine generalization of Game Boy’s “block” concept (4×4 tiles = 16 bytes). Variable-size support enables use with other tile-based games (2×2, 3×3, …).

Fields

size: (u8, u8)

Width and height in tiles, e.g. (4, 4) for GB blocks.

tiles: Vec<MetatileCell>

The tiles that make up this metatile, stored in row-major order. Must contain exactly size.0 * size.1 entries.

collision: Vec<CollisionCell>

Per-cell collision, same dimensions as size. If collision.len() differs from tile_count(), the engine should treat the whole metatile uniformly (e.g. all cells inherit the first collision entry).

trigger: Option<TriggerDef>

Optional trigger script that fires when the player interacts with or steps on this metatile.

animation_group: Option<u8>

Optional animation group index — tiles inside the metatile animate in lockstep if they share the same group.

z_offset: i8

Vertical render offset (pixels). Positive values render the metatile lower on screen, useful for layered maps or floating platforms. Default is 0.

Implementations

impl MetatileDef

pub fn new(size: (u8, u8)) -> Self

Creates an empty metatile of the given size.

All tiles default to tile ID 0 with no flips; all collision cells are Passable. trigger, animation_group and z_offset are initialised to their defaults.

Panics

Panics if either dimension is 0.

pub fn tile_count(&self) -> usize

Returns the total number of tiles in this metatile (size.0 * size.1).

pub fn from_gb_block(block_data: &[u8]) -> Self

Converts a 16-byte Game Boy .bst block into a 4×4 MetatileDef.

Each byte in block_data is a raw tile ID. Entries are placed in row-major order (top-left to bottom-right). All collision cells default to Passable.

Panics

Panics if block_data does not contain exactly 16 bytes.

Trait Implementations

impl Clone for MetatileDef

fn clone(&self) -> MetatileDef

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for MetatileDef

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.