NotRoadType Spec

 

Essential

• split RoadType to StreetType and TramType

• per tile, one StreetType and one TramType may be present

• they can coexist on the same tile in some cases, but do not influence each other

• construction tools for StreetType and TramType are independent

• adding/removing/converting StreetType on a tile does not affect TramType for tile and vice-versa

• subtypes

    ◦ up to 15 StreetType subtypes and 15 TramType subtypes (implementation detail: uses 4 bits each, uses 8 bits free in m8)

• drawing

    ◦ (lowest) Ground -> StreetType -> TramType -> Sidewalks + Decoration -> StreetTypeCatenary -> TramTypeCatenary (highest)

    ◦ drawing of rail crossings may or may not be fixed (road tile is enforced for tram crossings currently, this looked non-trivial to fix when I tried)

    ◦ methods _may_ be provided to enable more control over appearance, e.g. snow above snowline etc

• catenary

    ◦ both StreetType and TramType can provide catenary on a tile (implementation detail: flag or cb returning sprites)

    ◦ vehicle power on a tile is determined by vehicle against subtype label, unrelated to drawing of catenary sprites

    ◦ there is sophisticated handling of rail catenary to preserve continuity where railtypes cross, something similar needs to be provided for NotRoadTypes

• converting between subtypes

    ◦ a convert tool is needed, similar to rail conversion

    ◦ this will need to consider ownership carefully

        ▪ too restrictive = can’t overbuild current subtype in towns

        ▪ too permissive = deliberate or accidental breaking of existing routes by overbuilding current subtype

• drive-in stops:

    ◦ behaviour of articulated vehicles and trams unchanged, can’t use drive-in stops

    ◦ catenary needs to be provided for StreetType drive-in stops

• vehicles

    ◦ vehicles are StreetType XOR TramType (bool flag)

    ◦ each subtype has a label

    ◦ vehicle compatibility with a subtype is determined by label

    ◦ vehicle may determine some properties by subtype (power, possibly others)

• overtaking: out of scope

• newgrf author considerations

    ◦ user should be able to see whether catenary exists for road, tram, or both

    ◦ authors will need to draw catenary carefully to avoid it looking bad when StreetType and RoadType catenary are combined on a tile

 

Optional (proposed by frosch)

• split global toolbar to ‘road’ (StreetType) and ‘light rail’ (TramType)

• this makes the distinction between the transport types obvious

• in this way it’s clear that a tile can have

    ◦ 1 type of rail

    ◦ 1 type of road

    ◦ 1 type of light rail

• unknown: would the various vehicle menus, station menus etc also be split for ‘road’ and ‘light rail’?