How to do Dual-mode Electro Diesels in NML

[NekoMaster]

I was wondering how one does Dual-Mode electro-diesels like the EMD FL9, the GE P32AC-DM, and the ALP-45DP

I would like to have them run as dual mode electro-diesels for Metro track (though NARS ADD-ON defaults to El. Rail if no metro/3rd track type is available)

I hope its not too hard or complicated as I still don't understand a lot of the more complex NML stuff even if I am using the 2cc Trains in NML code.

[PikkaBird]

Essentially, you code them as standard rail vehicles, then use the current_railtype variable to check for your powered railtypes and set the appropriate callback results (power, running_cost_factor, visual_effect_and_powered, etc). To use the current_railtype variable you need a railtypetable containing the labels you want to check for.

[andythenorth]

Code: Select all

    // -- power -- //
    switch (FEAT_TRAINS, SELF, double_juice_switch_power, current_railtype) {
                RAIL: return 3750;
                ELRL: return 6750;
             return 6750;
    }
   
item(FEAT_TRAINS, double_juice, 160) {
    property {
        name:                           string(STR_NAME_double_juice, string(STR_NAME_SUFFIX_ELECTRODIESEL));
        climates_available:             NO_CLIMATE; // nml constant
        engine_class:                   ENGINE_CLASS_DIESEL;
        visual_effect_and_powered:      visual_effect_and_powered(VISUAL_EFFECT_DISABLE, 0, DISABLE_WAGON_POWER);
        introduction_date:              date(2000,01,01); // consist just supplies intro year - openttd randomises intro dates a bit anyway
        cargo_capacity:                 0;
        sprite_id:                      SPRITE_ID_NEW_TRAIN; //enable new graphics - nml constant
        power:                          6750hp;
        speed:                          100mph;
        weight:                         120ton;
        tractive_effort_coefficient:    0.4;
        cost_factor:                    213.33333333333331;
        running_cost_base:              RUNNING_COST_DIESEL;
        running_cost_factor:            168.33333333333331;
        refit_cost:                     0; // btw this needs to be 0 if we want autorefit without using cb
        refittable_cargo_classes:       bitmask();
        non_refittable_cargo_classes:   bitmask(); // don't set non-refittable classes, increases likelihood of breaking cargo support
        cargo_allow_refit:              [];
        cargo_disallow_refit:           [];
        default_cargo_type:             PASS;
        cargo_age_period:               185;
        misc_flags:                     bitmask(TRAIN_FLAG_2CC); // nml constants
        dual_headed:                    0;
        model_life:                     VEHICLE_NEVER_EXPIRES;
        retire_early:                   36; // magic from Eddi
        reliability_decay:              20; // default value
        vehicle_life:                   40;
        length:                         2;
        track_type:                     RAIL;
    }
    graphics {
        default:                        double_juice_switch_graphics;
        purchase:                       double_juice_sg_purchase;
        power:                          double_juice_switch_power;
        purchase_power:                 double_juice_switch_power;
        visual_effect_and_powered:      double_juice_switch_visual_effect_and_powered;
        articulated_part: double_juice_articulated_cb_switch;
    }
}

[Leanden]

As Pikka says, you use a switch to check the current_railtype and return a different speed/power/etc.

My example is for dual-voltage electric but the principle is the same.

You then have a callback to that switch in the graphics block of the train.

Code: Select all

switch (FEAT_TRAINS, SELF,sw_BR395_speed, current_railtype) {                    
            ELRL: return 225;            
            BR_3RDR: return 160;                
        return 225;
    }

item (FEAT_TRAINS, item_BR395, 77) {
	property {
		name: 							string(STR_NAME_BR395);
		climates_available: 			ALL_CLIMATES;
		introduction_date:				date(2009,4,21);
		model_life:						8;
		retire_early:					1;
		vehicle_life:					50;
		reliability_decay:				7;
		refittable_cargo_classes:		0;
		cargo_allow_refit:				[PASS];
		loading_speed:					14;
		cost_factor:					107;
		running_cost_factor:			77;
		sprite_id:						SPRITE_ID_NEW_TRAIN;
		speed:							225 km/h;
		misc_flags:						TRAIN_FLAG_MU;
		refit_cost:						0;
		track_type:						BR_3RDC;
		ai_special_flag:				AI_FLAG_CARGO;
		power:							4480 hp;
		running_cost_base:				RUNNING_COST_ELECTRIC;
		dual_headed:					0;
		default_cargo_type:				PASS;
		cargo_capacity:					50;
		weight:							265 ton;
		engine_class:					ENGINE_CLASS_ELECTRIC;
		tractive_effort_coefficient:	0.3;
		air_drag_coefficient:			0.1;
		length:							8;
		effect_spawn_model_and_powered:	EFFECT_SPAWN_MODEL_ELECTRIC;
		extra_weight_per_wagon:			0;
		bitmask_vehicle_info:			0;
	}
	graphics {
	additional_text:					return(string(str_purchase_loco_with_liveries,string(str_purchase_type_emu),string(str_route_2),string(str_BR395_usage),string(str_BR395_eos),string(str_BR395_liveries)));
	can_attach_wagon:					CB_RESULT_ATTACH_ALLOW;
	cargo_subtype_text:					sw_BR395_cargo_subtype_text;
	articulated_part:        			switch_articulated_BR395;
	default: 							sw_BR395a;
	purchase:							spriteset_BR395_Purchase;
	colour_mapping: 					return PALETTE_CC_FIRST;
	speed:								sw_BR395_speed;
}
}

[supermop]

Not sure, but when we were discussing how to do this for dual-mode trucks on IRC, the conclusion was that the switch needs to check for every potential type of electrified road that you know of rather than just ELRD - and the understanding was that rail would behave the same way. Maybe Frosch or Wolf01 will be able to explain this better than me as they were the ones helping me get this working for Trolleybi.

[Leanden]

Thats why you have a railtype table.

So you dont have to switch for each railtype, instead you use the ones set in the table.

[PikkaBird]

Not sure, but when we were discussing how to do this for dual-mode trucks on IRC, the conclusion was that the switch needs to check for every potential type of electrified road that you know of rather than just ELRD - and the understanding was that rail would behave the same way. Maybe Frosch or Wolf01 will be able to explain this better than me as they were the ones helping me get this working for Trolleybi.

Yes. There's no way for the vehicle to know "this rail/roadtype is boosty" except the code explicitly telling it so. That's why the UKRS2 dual mode vehicles don't always work as expected with newer rail sets - the new sets use labels that didn't exist when UKRS2 was coded.

Rather than have a long list of compatible labels, Andy's Double Juice appears to assume every railtype except the default RAIL is electrified and provides full power. That's probably the right way to do things - I think it's safe to assume with dual-mode vehicles that most players want the higher stats all the time, with whatever rail set they're using, and the alternative mode is only there as flavour for detail-oriented or "realism" players.

[michael blunck]

There's no way for the vehicle to know "this rail/roadtype is boosty" except the code explicitly telling it so. [...]

There´s already a Standardized railtype scheme to avoid those problems. Still inventing 'own' railtype labels is a 'bad feature', isn´t it?

regards
Michael

[andythenorth]

Andy's Double Juice appears to assume every railtype except the default RAIL is electrified and provides full power.

I also gently disagree with the concept of railtype grfs being disconnected from train grfs. Arbitrary combinations are hard to support reliably. I only test and support Iron Horse with the Termite grf (and I'lll likely merge Termite into Iron Horse at some point).

[supermop]

There's no way for the vehicle to know "this rail/roadtype is boosty" except the code explicitly telling it so. [...]

There´s already a Standardized railtype scheme to avoid those problems. Still inventing 'own' railtype labels is a 'bad feature', isn´t it?

regards
Michael

That still has the problem of needing to enumerate every known 'should be powered' railtype in a long list, whether those types are standardized or not. There isn't a way currently to say 'extra power on ELRL' and have the newgrf determine what list of other rails provide power in the same manner as 'ELRL'.

Electric roads are a bit unique as well, as there is no 'standard types' list, however the author in question (me) happens to be the only one who has created and released any other than ELRD so far. So I have perfect knowledge of a de facto standard list at the moment, but as soon as the next author creates a new electric road type, my newgrf is 'broken'.

[michael blunck]

That still has the problem of needing to enumerate every known 'should be powered' railtype in a long list, whether those types are standardized or not.

Standardisation is the fundamental condition to tackle this problem in a comparatively easy way.

Since railtype labels are translated into numbers it is possible to set up an ordered railtype translation table with "electrified" resp "should be powered" tracks in a contiguous block:

Code: Select all

railtypetranslationtable(
        {"RAIL"}, {"MONO"}, {"MGLV"}, {"SABN"}, {"SACN"}, {"SADN"}, 
        {"ELRL"}, {"SABE"}, {"SACE"}, {"SADE"}, {"SAB3"}, {"SABZ"}  
)

Or something along these lines. Then, it´d would be easy to do something like this:

Code: Select all

def(3) veh_railtype(
         setspeed(100 km/h) if(ELRL .. SABZ) // increase speed if on electrified track
         cbfail() else
)

regards
Michael

[Wahazar]

Let me hook up to this thread. I have following idea: switching electric to diesel/steam and reverse (for example, by refitting in depot from passengers to mail and back, with 0 capacity).
I have a question: if such dual vehicle is refitted to electric (which results of 0 power for non-electrified track), how it will be handled by pathfinder?
Would such train be stuck in depot (or at last pathsignal before non-electrified track), or just will run blindly into non-electrified track?

[Transportman]

Let me hook up to this thread. I have following idea: switching electric to diesel/steam and reverse (for example, by refitting in depot from passengers to mail and back, with 0 capacity).
I have a question: if such dual vehicle is refitted to electric (which results of 0 power for non-electrified track), how it will be handled by pathfinder?
Would such train be stuck in depot (or at last pathsignal before non-electrified track), or just will run blindly into non-electrified track?

It would get stuck the moment it is refitted to a type for which it has no power at that railtype.

The pathfinder will happily take into account the possible power outputs, at least to the extent of not running a train onto a track on which it has no power. I do not know if the pathfinder includes some total power figure in the penalties, or only considers "does this train have power along this path?".