NML:Alternative sprites
Vehicles, Stations, Canals, Bridges, Towns, Houses, Industries (Tiles), Cargos, Airports+Tiles, Objects, Railtypes, Roadtypes, Tramtypes, Terrain
A alternative_sprites block allows you to specify alternative 32bpp sprites that are drop-in replacements for some real sprites in your grf. The syntax is as follows:
alternative_sprites(block_name, zoom_level[, filename]) {
list of realsprites
}
block_name is the name of the replace/replace_new/fontglyph/spriteset-block for which you want to provide 32bpp sprites. zoom_level can be one of ZOOM_LEVEL_NORMAL, ZOOM_LEVEL_Z0, ZOOM_LEVEL_Z1 or ZOOM_LEVEL_Z2. Please note that ZOOM_LEVEL_NORMAL and ZOOM_LEVEL_Z2 are exactly the same, and that ZOOM_LEVEL_Z0 and ZOOM_LEVEL_Z1 are for the extra zoom project only (3rd party project, not officially supported). Specifying a filename is optional, it's only useful if you have multiple sprites in the same file. If every sprite is in a separate file you'll have to specify the filename for each realsprite anyway, so you can leave it out of the alternative_sprites-block.
The compiler nmlc will then create a sprite folder that must be copied in the TTD data/sprite/<name_of_the_newgrf> folder.
