Changing pull request name to pass checks.

Firstly, I would not want this restriction unless it was a voluntary (opt-in) setting as that breaks many optimization-based playstyles that make use of vertical height differences. Also, it would not make sense to be unable to build a massive tunnel very deep (100+ tiles) below a mine where it would most likely not reach that far down.

Secondly, The commit message needs to be changed as well. Replace FR: with Feature:.

Hi James, I can work on make it an opt-in in settings (please can you provide code pointers on how to add a flag in settings?) and make it configurable so we can pick how deep we can build a tunnel under a mine. Seems to be a pretty easy thing to do. Thank you for the suggestions!

Just a note, some industry sets (including my Improved Town Industries) have mines which produce passengers as workers. I assume this won't be recognized as mines.

I don't know about the check for liquid cargos is needed — wouldn't a tunnel under an oil well be just as problematic as a coal mine?

Changing pull request name to pass checks.

you can call the pull request whatever you like. it's the commit message that the CI check cares about.

I don't know about the check for liquid cargos is needed — wouldn't a tunnel under an oil well be just as problematic as a coal mine?

problem is, you can't change this check, as it would influence the original use of this function

Alternate Suggestion:
instead of relying on this heuristic about cargo types/classes, add a flag to https://newgrf-specs.tt-wiki.net/wiki/Action0/Industries#Special_industry_flags_to_define_special_behavior_.281A.29 for "cannot have a tunnel underneath" (and possibly also for "is considered a 'mine' for station names", replacing the original use of this function)

if we add this to default industries, and the NewGRF authors used property 8 in a sane way (which they maybe didn't) it should propagate to new industries properly

Firstly, I would not want this restriction unless it was a voluntary (opt-in) setting as that breaks many optimization-based playstyles that make use of vertical height differences. Also, it would not make sense to be unable to build a massive tunnel very deep (100+ tiles) below a mine where it would most likely not reach that far down.

Secondly, The commit message needs to be changed as well. Replace FR: with Feature:.

James, I have addressed both comments and updated the code change. Please kindly review.

I don't know about the check for liquid cargos is needed — wouldn't a tunnel under an oil well be just as problematic as a coal mine?

problem is, you can't change this check, as it would influence the original use of this function

Updated, thank you!

Alternate Suggestion:
instead of relying on this heuristic about cargo types/classes, add a flag to https://newgrf-specs.tt-wiki.net/wiki/Action0/Industries#Special_industry_flags_to_define_special_behavior_.281A.29 for "cannot have a tunnel underneath" (and possibly also for "is considered a 'mine' for station names", replacing the original use of this function)

if we add this to default industries, and the NewGRF authors used property 8 in a sane way (which they maybe didn't) it should propagate to new industries properly

I looked into this but I ended up finding out that there is a flag for extractive industries already, and I wanted to prevent adding new flags since I would expect complains from people about it...

Are there any instructions on how to update regression files? They seem to fail with this change.

I looked into this but I ended up finding out that there is a flag for extractive industries already, and I wanted to prevent adding new flags since I would expect complains from people about it...

I suspect you're looking at the industry type, 0B. This suggestion is for a new special flag in 1A. #8079 is a recent precedent for adding flags to support NewGRF behaviors not used by vanilla industries.

Alternate Suggestion:
instead of relying on this heuristic about cargo types/classes, add a flag to https://newgrf-specs.tt-wiki.net/wiki/Action0/Industries#Special_industry_flags_to_define_special_behavior_.281A.29 for "cannot have a tunnel underneath" (and possibly also for "is considered a 'mine' for station names", replacing the original use of this function)
if we add this to default industries, and the NewGRF authors used property 8 in a sane way (which they maybe didn't) it should propagate to new industries properly

I looked into this but I ended up finding out that there is a flag for extractive industries already, and I wanted to prevent adding new flags since I would expect complains from people about it...

well, the main problem is that this "extractive" flag is more general than "mine", which makes this heuristic about cargo types/classes in this function necessary, which is problematic enough if you use it for one purpose (station name), but even more problematic if you use it for two unrelated purposes

Looked into it, that's not what I found yesterday so I will work on having it as a behavior actually, will update code change this week hopefully, thank you!

Hi @perezdidac ,

Thank you for your PR!

First of all, sorry you spend time on adding a setting for this, as that suggestion is not in line with what we maintainers of this game have as vision for the game. In general, we really frown upon new settings. OpenTTD already has many many many many settings, of which most are never used by anyone, and over the years we have found out that having this many settings always leads to more bug reports as in: but if I flip these 3 exotic settings, then your patch breaks! It is horrible :P So we try to stay away from settings in general, and as policy, we basically do not add settings, unless it really benefits a bigger group as a whole; not the itch of a few :)

That doesn't mean we add code that is "enabled for all", like the initial version of this PR. For this, we found that using either NewGRFs or GameScript is a much more appropriate solution. For example, if NewGRFs could control, as suggested by others, if a tunnel is allowed below them or not, that means a user can pick a NewGRF that does this or not. So the "setting" becomes part of the NewGRF you choose to download. This is much more maintainable for us, easier for the user to understand, and up to the content creator to have fun with :)

See our project goals for more details on this.

However, in this case, I truly wonder if we should add this to the base game. I am just one opinion, so take it with what-ever salt is needed, but my reasoning is as follow:

• If you want realism, simply do not build tunnels under mines. There is no need to enforce this, really.
• If you don't allow tunnels to be build under mines, you also have to add code that doesn't allow mines to be build over tunnels.
• If it is realism you are after, how high can a mine be on a hill before a tunnel is valid? Is there ever a moment? Feels kinda harsh if for all mines the height is the same. I can imagine that certain mines are shallow, while others are deep. Should this influence the behaviour? (honest questions; I do not know the answers :D)

To me this feels like a lot of change for only a very small group of people (but I can be completely wrong of course; I can be convinced otherwise :D). In short, in my opinion, if we do this, this PR should:

• Change the NewGRF specs, with a clear goal and plan
• Conditionally disallow tunnels to be build
• Conditionally disallow industries to be build because there is a tunnel

This increases the scope of this PR immensely. So I really wonder if that is worth it .. especially as such realism can also just be enforced by agreement, not by the game. A bit like role-playing .. nothing is holding you back from breaking character, but if you are true to yourself, you don't need a game to enforce it on you :)

What do you think? (again, read this more as thinking out loud than anything else; just trying to voice my opinion to start a discussion :D)

PS: on a personal opinion, this would annoy the hell out of me; I often had the case I was building a mainline, to have some industries exactly on top of it .. I was happy I could tunnel under it to continue my pretty mainline. The idea that I cannot under some industries would tick me off :P But that is really just a personal game-style opinion, and not as much relevant for this discussion :D

* If you want realism, simply do not build tunnels under mines. There is no need to enforce this, really.

i heavily oppose this opinion. in my history of playing this game, occasionally i have come across certain restrictions, that i would never even have considered before.

i'm a bit sceptical of offloading this to NewGRFs, because for every player type i can imagine, the decisions "should tunnels be restricted this way" and "should industry chains be different" are completely orthogonal.

as for the "bigger picture" approach: i do like the thought of combining this with a potential "bridges over everything", so my idea would be to add a z-extent property to houses and house-like things (objects, industrytiles, stations, etc.), that would define how many levels above and below ground level are blocked for other construction. in a distant relation this could also allow for airport runway approach/takeoff patterns to define how high buildings can be.

Are there any instructions on how to update regression files? They seem to fail with this change.

regression tests are there to find out whether you've inadvertendly broken something, and the output should be carefully checked whether that is the case, before you even consider updating the regression test itself.

Broken savegame - Invalid chunk size'

this probably means you forgot something while adding the setting, like put in invalid min/max savegame versions

Thanks everyone for all suggestions and information! This is awesome. I will hold on on this for now, I believe it might be hard to reach an agreement on this matter. For situations like this, is there a way to get consensus on developers and players somehow?

We talked it over some more with the developers, and how ever we twist or turn it, we don't see a place for this at the moment in OpenTTD. Not because we are against the feature itself, but because of the work involved in making it happen.

This for sure can and should be revisited later, especially when we are a bit further along in figuring out how we want to make other parts of the game scriptable. For a bit of context, we are looking how to make things like Towns scriptable, so people can make their own town-growth algorithms and stuff like that. There is some hope, but this might be wishful thinking, that this can extend to other places too, like: can you build here. That would be a far better place to fit in this feature :)

Either way, thank you for this Pull Request! I hope you understand our reasoning; if you feel up for more work on OpenTTD, our issue-tracker is full of small (and big) problems and bugs that need solving, as we are slowly working our way to a 1.11 release :) Feel free to hit me up on Discord if you have other ideas and want to talk over first if it fits in OpenTTD, or if you just have any other question in general :)

Tnx again!

PS: https://www.tt-forums.net/viewtopic.php?f=33&t=21438 :D Seems history has a tendency on coming back around :)