Station tile height proposal

[peter1138]

To permit bridges over station tiles, we need to know the height of the station tile to avoid graphic collisions. We can include this for the default station graphics but for custom stations this needs to be provided by the author. Therefore I propose this:

Code: Select all

Define station heights (1B)

Size | Name | Meaning
B*   | num  | Number of different tiles supported
V    | data | Height in tile levels for this station tile

A height of 0 is a special-case meaning that no bridge can be above this station tile. If this property is not defined then no bridge can be above any of this station's tiles.

Because the station doesn't exist when testing the area for bridges, callback 14 is not tested, so only tiles 0-7 are valid. For consistency, callback 14 is not tested when building bridges over stations either.

In addition it may be useful for a station tile to test if it has a bridge above in a VarAction2. This will be a byte value specifying the height of the bridge above the tile, or 0 if there is no bridge. Could be a standalone variable or incorporated into an existing one with free bits.

Anything else?

[maquinista]

Thanks, nice idea.

I was planning to create a small GRF file with some buffers as tiles, because I like to add buffers at the end of my stations, but sometimes I'm limited between two bridges.

[michael blunck]

[...]

Code: Select all

Define station heights (1B)

Size | Name | Meaning
B*   | num  | Number of different tiles supported
V    | data | Height in tile levels for this station tile

A height of 0 is a special-case meaning that no bridge can be above this station tile. 
If this property is not defined then no bridge can be above any of this station's tiles.

Because the station doesn't exist when testing the area for bridges, callback 14 is not tested, so only tiles 0-7 are valid. For consistency, callback 14 is not tested when building bridges over stations either.

What exactly means "Number of different tiles supported"? And in "so only tiles 0-7 are valid", are you refering to TTD "tile *types*"? In what system of units is "height " being measured?

regards
Michael

[peter1138]

What exactly means "Number of different tiles supported"? And in "so only tiles 0-7 are valid", are you refering to TTD "tile *types*"? In what system of units is "height " being measured?

Yes, tile types, which is limited to 0-7. Therefore the passing the number tiles isn't strictly necessary but I added it as it would mean the spec doesn't need to change if that number ever changes, or if part of the station spec ever gets used for non-rail stations.

Units are basic height levels, not pixels or any imaginary scale. Building a normal bridge (with its own ramps) on flat land above a station would be 1 height level.

[michael blunck]

Yes, tile types, which is limited to 0-7. [...]

OK. So, in "V | data | Height in tile levels for this station tile" the height levels for those tile types are being specified, ordered from type = 0 to type = 7 (assuming this range for the time being)?

regards
Michael

[peter1138]

OK. So, in "V | data | Height in tile levels for this station tile" the height levels for those tile types are being specified, ordered from type = 0 to type = 7 (assuming this range for the time being)?

Yup, exactly that. I wrote it badly

[peter1138]

And a good example of why this feature would default to deny:

Plartburg Transport, 11th Oct 5028.png (46.44 KiB) Viewed 2672 times

[michael blunck]

Interesting work on "bridges over stations". BTW, what´s the current status with work on trigger re-randomisation for stations?

regards
Michael

[peter1138]

Hmm, custom tile layouts (callback 24) throw a spanner in the works, as it can't be tested until the station is partially built, which is obviously too late.

[peter1138]

Hmm, possible solution is to disallow CB24 if the heights specified are not all the same. If they're all the same then the custom layout doesn't make a difference.

[michael blunck]

Hmm, possible solution is to disallow CB24 if the heights specified are not all the same. If they're all the same then the custom layout doesn't make a difference.

I´d be interested in how much CB24 is in use at all. I don´t think it´s of much use for larger sets.

regards
Michael

[Zephyris]

Just wanted to say this looks like a great feature in progress... I look forward to anything that might come out of it

[peter1138]

I´d be interested in how much CB24 is in use at all. I don´t think it´s of much use for larger sets.

Indeed, most sets use CB14 instead. Notably it is used by some of the stations in ISR, and some amusingly also use RandomAction2s, which is why it can't be tested in the pre-build stage.