JGR's Patchpack - NewGRF New Landscape Addition to NewGRF Specifications

NewGRF New Landscape Addition to NewGRF Specifications in JGR's Patchpack

This document describes the non-standard addition of the NewGRF new landscape feature to the Official OpenTTD NewGRF Specifications, as implemented in this patchpack.

This feature allows NewGRF custom graphics using Action 1/2/3 for landscape tiles. Currently this includes: rock tiles.

This feature may not necessarily match implementations of additional landscape graphics features in other patches, branches, etc.
This feature as implemented here MAY also be present in other patchpacks.

See the NewGRF additions document for background information on additions to the NewGRF specifications.

The functionality listed below is also supported in a fork of NML, see the associated NML new landscape and NML additions documents for more details.

NewGRFs which use this feature SHOULD use the feature testing mechanism to check whether the new landscape feature and/or feature ID mapping is supported.

NewGRFs which use this feature MUST use the feature ID mapping mechanism to map the non-standard NewGRF road stop feature to a local feature ID.

This feature is indicated by the feature name: new_landscape, version 1.
The feature name to use for feature ID mapping is new_landscape.
Features/properties/variables which require a higher version will indicate the required version. Unless indicated otherwise these will fall back to doing nothing on versions which do not support them.

IDs:

The ID field for Actions 0 and 3 must be set to one of the IDs in the table below (further IDs may be allocated for other purposes in future).

ID	Landscape type
0	Rocky tiles

Action 0 - New Landscape

See the Action 0 Specification for background information.

Properties:

Mappable name	Size in bytes	Description
newlandscape_enable_recolour	1	Enable recolour

Enable recolouring for new landscape graphics (mappable property: newlandscape_enable_recolour)

When enabled, in addition to returning a sprite, register 0x100 may be set to the following:

Bits	Meaning
0 - 23	Recolour sprite to use. Set to 0 for no recolouring.
24 - 31	Reserved, set to zero.

The property length is 1 byte. 0 is disabled (default). 1 is enabled.

Action 2 - New Landscape

See the Action 2 Specification for background information.

New landscape does not use the special sprite layout format.

Variational Action 2 - New Landscape

See the Variational Action 2 Specification for background information.

Variables:

Number	Mappable name	Description
40	newlandscape_terrain_type	Terrain type
41	newlandscape_tile_slope	Tile Slope
42	newlandscape_tile_height	Tile Height
43	newlandscape_tile_hash	Tile Hash
44	newlandscape_landscape_type	Landscape Type
60	newlandscape_land_info_nearby_tiles	Land info of nearby tiles

Tile terrain type (40, or mappable variable: newlandscape_terrain_type)

This has the same value as bits 0 - 7 of object (feature F) variable 41.

Value	Meaning
0	Normal
1	Desert
2	Rainforest
4	On or above snowline

Tile slope (41, or mappable variable: newlandscape_tile_slope)

This has the same value as bits 0 - 7 of industry tile (feature 9) variable 60 for this tile.

Tile height (42, or mappable variable: newlandscape_tile_height)

The height of the lowest corner of the tile (in units of 1).

Tile hash (43, or mappable variable: newlandscape_tile_hash)

Hash value derived from the coordinates of the tile, suitable for pseudo-randomising graphics.

Land info of nearby tile (60, or mappable variable: newlandscape_land_info_nearby_tiles)

This has the same value as industry tile (feature 9) variable 60.

Action 3 - New Landscape

See the Action 3 Specification for background information.

Note that this is not a generic callback, the sprite group must be assigned to an ID in the IDs table.

Action 3 ID	Expected number of sprites	Landscape type
0	19	Rocky tiles

Cargo type definitions are not used. Only the default set ID is used.

This is indicated by the feature name: new_landscape, version 1