[CR] Diesel engines.

[desrik]

• V6, V8, and straight-6 diesel engines.
• Diesel fuel from pumps at gas stations
  ( One in six chance of replacing a normal gas pump with diesel. )
• Diesel fuel tanks in three flavors: normal, small, and external.
• Ability to siphon both gasoline or diesel fuels.
  ( Both through the vehicle GUI and by activating the rubber hose item )

[ghost]

For flavour, I'd love to see this be a straight-6 instead a V6/V8.

"Virtually every heavy duty over-the-road truck employs an inline-six diesel engine, as well as most medium duty and many light duty diesel trucks. Its virtues are superior low-end torque, very long service life, smooth operation and dependability. On-highway vehicle operators look for straight-six diesels, which are smooth-operating and quiet." https://en.wikipedia.org/wiki/Straight-six_engine#Straight-six_diesel_engines

[Wishbringer]

This seems about ready for testing so I'll include it in my FrankenMod.
I like the idea of a straight-six engine, adds more flavor.
Update: Using the "amt" variable doesn't actually work correctly so you may want to use:
(got < want ? ", draining the tank completely." : ", receiving tank is full.") );
Just like its done in "iuse.cpp".
You may also want to remove all instances of "amt" since it's no longer used.

[ghost]

Also, I noticed you set the epower for this engine to -200. Note that using a negative epower on combustion engines is used to simulate the power drain of the ignition system (e.g. spark plugs). However, diesel engines don't use spark plugs, and don't necessarily need any electricity to run at all. (Though modern diesels have electronics...)

[desrik]

@belenos-
Dont see why we couldn't add one in there. I was looking at the Cummings engines. They seem to be the first pick of the major truck (non-industrial) market. It would be cool to have a few V6 and V8 pickups and see a straight 6 in the Rig and Military trucks.

I didn't really know what that was for... is it a one time draw or is it constant? diesels do need electricity to start though... they dont have spark plugs they have glow plugs

@Wishbringer
amt variable works fine. vehicle::refill returns the amount left in the tank being siphoned from. If the return isn't 0, send the message about emptying the tank.

EDIT:: I also really need to figure out this biodiesel issue... How do guns have multiple accepted ammo types?

[Wishbringer]

PR: #7064
This code is already merged so you will get merge conflicts.
"amt" never is anything but 0, because you never get more than you want.
want = fillv->fuel_capacity("gasoline")-fillv->fuel_left("gasoline");
got = veh->drain("gasoline", want); <----------- HERE
"refill" returns the amount left over, otherwise 0.
You will always get the message "draining the tank completely" when transferring from car to car.
Besides why use an extra variable when you don't need it?
If it could return negative numbers, that would be a different story.
I tried that first, but I didn't dare use it because it could cause problems elsewhere.

[desrik]

I see what you mean. Changed it.

[ghost]

@desrik regarding l6 vs v6/v8, note that most diesel pickup trucks also use I6 diesels, not just heavy trucks. (But anyway, I'll stop pestering you on this :) )

Regarding negative epower on engines, it's a constant draw, but I just checked the code and only fuel_type_gasoline engines are checked for a epower draw, so it actually doesn't really matter what you set this to unless you want to changes to vehicle::power_parts().

Regarding engine start-up epower draw, this is handled separately in vehicle::start_engine(). Current start-up epower draw is set to 1/10th the engine power (to simulate the starter motor), but currently only for fuel_type_gasoline engines. You probably will want to add a case for fuel_type_diesel here as well, since diesel engines also use a starter motor. (I suggest an epower draw 1/8 engine power for diesel, since diesel engines need relatively heavier starter motors, plus have the glow plug draw you mentioned.)

Also, you probably want to check the vehicle class for any checks for 'fuel_type_gasoline' and see if you there also be a check made for fuel_type_diesel. I looked through the code quick, and you probably want to make changes in the following places:
vehicle::start_engine() [handle startup epower draw]
vehicle::can_mount() [allow alternators on diesel engines]
vehicle::safe_velocity()
vehicle::noise_and_smoke()
vehicle::consume_fuel()
vehicle::power_parts() [if you want the epower property to have effect for diesel]
vehicle::damage_direct() [diesel fuel tank explosions]

[ghost]

Looks like you made a typo here.

[desrik]

Thanks. :)

[desrik]

As far as I can tell this is done... If anyone has any thoughts on what the values should be on the engines as far as balancing let me know... I just kinda guessed.

[ghost]

Were you planning to add/modify any vehicles to use diesel as part of the PR? If so, according to wikipedia the Humvee uses a v8 diesel, so that could be an easy one to change.

Minor thing: a straight-6 engine can be abreviated as 'l6' or 'L6' if you want to keep the id strings short.

[Wishbringer]

Typo here : straigt_6_diesel should be straight_6_diesel.

[desrik]

@belenos- Damn sure forgot to do that :P It's done now. Straight-6 is now the I6 and used by the Schoolbus. The Semi Truck uses the V6. The Humvee, Military Cargo Truck, and the Armored Personnel Carrier use the V8.

[KA101]

So to be clear: buses and trucks now use diesel engines, but diesel's only in 1 of every 6 pumps and isn't craftable.

Uh, that's a pretty big nerf to big vehicles, I think. Holding on biodiesel.

[desrik]

@KA101 the one_in() can be changed... Would 1:4 be better? I was kind of aiming towards not having diesel available at every station generated, but I'm open for suggestions.

As for biodiesel... That's out of this PR. Tured out to be a bigger headache thatn I had originally planned, plus I met some resistance in IRC. It was suggested that the recipe for biodiesel could simply return regular diesel, but thats not really what I'm going for... I try to avoid "magic" functions... If you have any ideas on a way to implement biodiesel I'm all ears. That was the original reason for adding diesel to begin with.

[KA101]

1:4 seems better, yeah. Ideally there'd be a guaranteed pump at every station, and then the 1:6 or maybe 1:5 could kick in for additional pumps. Issue is that there have to be enough diesel pumps that you could actually believe diesel vehicles were routinely operating pre-Cataclysm.

(So, alternatively, military bunkers/outposts could have a diesel pump or two for humvees and miltrucks. Schools might have one around the back for the buses. Not sure whether that's a better solution: just an idea.)

[desrik]

Or possibly a truck stop? Big 2x2 store with gas pumps in the front and diesel in the back. Have a possibility for part of the store to be a fast food place.

I can see the outpost, but i can't see a bunker having a diesel pump.
As for the schools... Why not? Would be better if there was a school bus depot that always spawned within a few overmap tiles of the school.

[kevingranade]

You should be able to just have a few lines of code at the start that populate a std::string fuel_type with either "gasoline" or "disel", then use it where appropriate. There's no need to duplicate all this code.

[kevingranade]

Same comment as above x100, we do not want to duplicate code when we add stuff like this, it makes the code fragile because if we have to fix or change it later, we have to try and remember to do it in both places in the future.

[kevingranade]

No need to update these, they're for loading legacy saves, and hopefully we can get rid of them eventually.

[Rivet-the-Zombie]

It was suggested that the recipe for biodiesel could simply return regular diesel, but thats not really what I'm going for... I try to avoid "magic" functions... If you have any ideas on a way to implement biodiesel I'm all ears.

We don't bother to differentiate between grades of gasoline, or if it's E85 either. I don't see why it's an issue to call all forms of diesel the same here.