Region

One 64 by 64 tile square of the world, expanded from the cache into the per-plane arrays the map renderer walks: heights, settings, ground overlays and underlays, and the objects standing on it.

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Region._InitArrays

procedure TRegion._InitArrays();

Allocates the region’s per-plane tile arrays - 4 planes of 64 by 64, indexed [z, x, y].

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Region.Create

function TRegion.Create(id: Integer): TRegion; static;
function TRegion.Create(x, y: Integer): TRegion; static; overload;

An empty region at the given position, addressed either by its packed id or by its region coordinates.

A region id packs its x into the high byte and its y into the low one, and each region covers 64 by 64 world tiles starting at BaseX, BaseY. The tile arrays are allocated but hold nothing until TRegion.LoadTerrain fills them.

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Region.LoadTerrain

procedure TRegion.LoadTerrain(constref map: TMapDefinition);

Expands a decoded TMapDefinition into the region’s per-plane tile arrays.

A ground tile with no stored height falls back to the procedural terrain height, which depends only on the tile’s world x and y, so the whole region’s worth is built in one pass the first time any tile asks for it. A tile on a higher plane with no stored height sits 240 above the one below it, the way the client does it.

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Region.LoadLocations

procedure TRegion.LoadLocations(constref locs: TLocationsDefinition);

Takes the region’s object placements from a decoded TLocationsDefinition, converting each one from a position within the region to a world coordinate.

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Region.GetOverlayID

function TRegion.GetOverlayID(z, x, y: Integer): Integer;

The ground overlay of one tile, or 0 if it has none.

The stored value keeps a flag in its top bit, which is masked off here.

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Region.GetUnderlayID

function TRegion.GetUnderlayID(z, x, y: Integer): Integer;

The ground underlay of one tile, or 0 if it has none, with the same flag bit masked off that TRegion.GetOverlayID masks.