Feasibility of customising return guardian micro ai

[Spannerbag]

Hi,

Is there a way to customise the return guardian micro ai to specify different return_x,return_y for each unit?
And, maybe, tweak the behaviour (not sure until I playtest which is a long way off ).

Here, I presume, is the relevant code:

Code: Select all

function wesnoth.micro_ais.return_guardian(cfg)
	if (cfg.action ~= 'delete') then
		if (not cfg.id) and (not wml.get_child(cfg, "filter")) then
			wml.error("Return Guardian [micro_ai] tag requires either id= key or [filter] tag")
		end
		AH.get_named_loc_xy('return', cfg, 'Return guardian [micro_ai] tag')
	end
	local required_keys = {}
	local optional_keys = { id = 'string', filter = 'tag',
		return_loc = 'string', return_x = 'integer', return_y = 'integer'
	}
	local CA_parms = {
		ai_id = 'mai_return_guardian',
		{ ca_id = 'move', location = 'ca_return_guardian.lua', score = cfg.ca_score or 100100 }
	}
	return required_keys, optional_keys, CA_parms
end

Ideally return_x,return_y would be obtained from unit variables such as unit.variables.origin.x and unit.variables.origin.y.

Is this even feasible given the various dependencies on other lua files?
Alternatively is there another/better way (other than defining multiple micro_ais) of doing this?

Any advice gratefully received!

Cheers!

[Lord-Knightmare]

to specify different return_x,return_y for each unit?

Yes, this is possible.

(other than defining multiple micro_ais) of doing this?

This is the way to do it.

[Spannerbag]

to specify different return_x,return_y for each unit?

Yes, this is possible.

Great - just to be crystal clear the only code I need to change is the stuff I posted and nowhere else (i.e. there are no dependencies)?

(other than defining multiple micro_ais) of doing this?

This is the way to do it.

Trouble with multiple micro ais (mais) is that these units will be created by player action (although not player controlled) and I don't really want to limit them to a preset number of units... hmm ... will have a think. Should be possible to dynamically spawn multiple mais in WML, bit not sure if this will impact gameplay/performance if the player creates several units...

Will consider my options.

Thanks for the reply, appreciated!

[Lord-Knightmare]

Trouble with multiple micro ais (mais) is that these units will be created by player action (although not player controlled) and I don't really want to limit them to a preset number of units... hmm ... will have a think. Should be possible to dynamically spawn multiple mais in WML, bit not sure if this will impact gameplay/performance if the player creates several units...

I have seen scenarios function normally with around 120 guardian type MAI so this should be a "no issue". You can put the micro ai code in the [unit][ai] tag btw.

Great - just to be crystal clear the only code I need to change is the stuff I posted and nowhere else (i.e. there are no dependencies)?

Nothing is stopping you from making a customized return guardian MAI for your campaign and use that.

[Spannerbag]

Thanks again for the advice, much appreciated.

I think I'll look into multiple mais first as this seems the saner approach.

Cheers!

[gnombat]

And, maybe, tweak the behaviour (not sure until I playtest which is a long way off ).

You'll probably need to create your own AI eventually anyway then?

The Micro AIs are really just some pre-defined behaviors with a limited number of tweakable parameters... I think if you really want to customize the AI beyond that, it's generally expected that you'll create your own AI with Lua.

https://wiki.wesnoth.org/Creating_Custom_AIs#Creating_Custom_Candidate_Actions

[Spannerbag]

You'll probably need to create your own AI eventually anyway then?...

Thanks for the info, I have several options and am presently scoping out the complexity of each.
Ideally I would - at present anyway - prefer to have a custom/micro ai solution as I feel this would maximise gameplay interest and enjoyment IMHO.
However I'm not sure the additional effort is worth it given I can employ other implementations that would be a lot easier/simpler if also less close to what I envisage.

I'm not great at lua but will have a poke around and see what I can totally muck up cobble together.

Cheers!

[gnombat]

However I'm not sure the additional effort is worth it given I can employ other implementations that would be a lot easier/simpler if also less close to what I envisage.

It wouldn't be much additional effort since you would just copy the entire ca_return_guardian.lua file to your add-on. Then the only thing you would need to change (at first) would be the lines that call AH.get_named_loc_xy('return', cfg) since that is what looks for return_x and return_y, so you could replace that with your own logic.

https://github.com/wesnoth/wesnoth/blob/1.18.8/data/ai/micro_ais/cas/ca_return_guardian.lua#L18
https://github.com/wesnoth/wesnoth/blob/1.18.8/data/ai/micro_ais/cas/ca_return_guardian.lua#L31

[Spannerbag]

Having done a tiny bit of digging myself I'd come to a very similar conclusion; basically extend the existing logic by having the return guardian micro ai work as it does now plus enabling unit specific return x,y values that override the "global" values return_x,return_y / return_loc.

So in both :evaluation and :execution I'd need to test if the current guardian unit had unit variables set; probably unit.variables.return_guardian.return_x and unit.variables.return_guardian.return_y.

If both exist and are on-map then use these otherwise fallback to existing return_loc = AH.get_named_loc_xy('return', cfg).

However, it's been awhile since I worked with lua and I've forgotten a fair bit but it'll hopefully come back to me once I look into things a bit more.

Presently I think the logic would be something like:

1. Test unt variables, if either is null/undefined fallback to default/global values.
   Presumably these values would be visible in lua as guardian.return_guardian.return_x and guardian.return_guardian.return_y?
2. Test unit x,y values on map (presumably wesnoth.current.map.special_locations[loc_id]? Not explored options for this yet).
   If not on map then again fallback to default/global values as in 1. above.
3. Otherwise use unit values.

Think I've missed anything?

If not, this isn't anywhere near as complex as I'd imagined.

Thanks for the info, much appreciated!

Cheers!

[gnombat]

Test unt variables, if either is null/undefined fallback to default/global values.
Presumably these values would be visible in lua as guardian.return_guardian.return_x and guardian.return_guardian.return_y?

Custom unit variables should be in guardian.variables:

https://wiki.wesnoth.org/LuaAPI/types/unit#Unit_sub-tables

Test unit x,y values on map (presumably wesnoth.current.map.special_locations[loc_id]? Not explored options for this yet).

That's if you are using a named location loc_id to identify the location.

If you're using x and y values and you just want to check that they are valid, you could use wesnoth.current.map:on_board(x, y).

https://github.com/wesnoth/wesnoth/blob/1.18.8/data/ai/lua/ai_helper.lua#L776

[Spannerbag]

Custom unit variables should be in guardian.variables:

https://wiki.wesnoth.org/LuaAPI/types/unit#Unit_sub-tables

Forgot the "variables" bit.

...If you're using x and y values and you just want to check that they are valid, you could use wesnoth.current.map:on_board(x, y).

https://github.com/wesnoth/wesnoth/blob/1.18.8/data/ai/lua/ai_helper.lua#L776

Yes, that would be much simpler, thanks!

Thanks for the very helpful advice and links, much appreciated!

Cheers!

[Spannerbag]

Hi,
making progress but have a couple of queries.

None of this has been tested yet, responses to this post will determine if I test current code or mess things up even further simplify (if sensible) first

First I created a new mai return_guardian_uv (_uv for unit variables).

Code: Select all

-- mai_return_guardian_uv.lua

-- Modified return guardian mai with unit specific return co-ordinates
-- Many thanks to gnombat for advice and assistance

-- https://forums.wesnoth.org/viewtopic.php?t=60912
-- https://wiki.wesnoth.org/LuaAPI/types/unit#Unit_sub-tables
-- https://github.com/wesnoth/wesnoth/blob/1.18.8/data/ai/lua/ai_helper.lua#L776

-- If specified, unit variables can override return location specified in [micro_ai] tag.
-- These are: unit.variables.return_guardian_uv.return_x and unit.variables.return_guardian_uv.return_y

local AH = wesnoth.require "ai/lua/ai_helper.lua"

function wesnoth.micro_ais.return_guardian_uv(cfg)
	if (cfg.action ~= 'delete') then
		if (not cfg.id) and (not wml.get_child(cfg, "filter")) then
			wml.error("Return Guardian UV [micro_ai] tag requires either id= key or [filter] tag")
		end
		AH.get_named_loc_xy('return', cfg, 'Return guardian UV [micro_ai] tag')
	end
	local required_keys = {}
	local optional_keys = { id = 'string', filter = 'tag',
		return_loc = 'string', return_x = 'integer', return_y = 'integer'	-- May be overridden by unit variables
	}
	local CA_parms = {
		ai_id = 'mai_return_guardian_uv',
		{ ca_id = 'move', location = 'ca_return_guardian_uv.lua', score = cfg.ca_score or 100100 }
	}
	return required_keys, optional_keys, CA_parms
end

ORIGINAL ca_return_guardian:evaluation

Code: Select all

function ca_return_guardian:evaluation(cfg)
    local guardian = get_guardian(cfg)
    if guardian then
        local return_loc = AH.get_named_loc_xy('return', cfg)
        if (guardian.x == return_loc[1]) and (guardian.y == return_loc[2]) then
            return cfg.ca_score - 200
        else
            return cfg.ca_score
        end
    end

    return 0
end

My abomination:

Code: Select all

local AH = wesnoth.require "ai/lua/ai_helper.lua"

local function get_guardian_uv(cfg)
    local filter = wml.get_child(cfg, "filter") or { id = cfg.id }
    local guardian_uv = AH.get_units_with_moves {
        side = wesnoth.current.side,
        { "and", filter }
    }[1]

    return guardian_uv
end

local ca_return_guardian_uv = {}

function ca_return_guardian_uv:evaluation(cfg)
    local guardian_uv = get_guardian_uv(cfg)
    if guardian_uv then
        if guardian.variables.return_guardian.return_x and guardian.variables.return_guardian.return_y then
            if wesnoth.current.map:on_board(guardian.variables.return_guardian.return_x, guardian.variables.return_guardian.return_y) then
                if (guardian_uv.x == guardian.variables.return_guardian.return_x) and (guardian_uv.y == guardian.variables.return_guardian.return_y) then
                    return cfg.ca_score - 200
                else
                    return cfg.ca_score
                end
            else            
                wml.error("Unit return location not on map: guardian.variables.return_guardian.return_x,y=" .. guardian.variables.return_guardian.return_x .. ',' .. guardian.variables.return_guardian.return_y .. " " .. (required_for or ''))
            end
        else
            local return_loc = AH.get_named_loc_xy('return', cfg)
            if (guardian_uv.x == return_loc[1]) and (guardian_uv.y == return_loc[2]) then
                return cfg.ca_score - 200
            else
                return cfg.ca_score
            end
        end
    end

    return 0
end

However the thought occurs that a simpler method would be to simply reassign return_loc in get_guardian_uv if valid (on map) locations are specified in the current guardian_uv.
This would be passed back as a return value to overwrite the value specified in the definition.
As these are local variables they wouldn't (I presume) have any effect on the initial return_loc value passed from the definition?

Would this approach work and if so have I missed anything?

Thanks in advance!

Cheers!

[gnombat]

However the thought occurs that a simpler method would be to simply reassign return_loc in get_guardian_uv if valid (on map) locations are specified in the current guardian_uv.
This would be passed back as a return value to overwrite the value specified in the definition.
As these are local variables they wouldn't (I presume) have any effect on the initial return_loc value passed from the definition?

I'm not sure exactly what you have in mind... I would probably recommend just creating a new function, like this:

Code: Select all

local function get_guardian_uv_xy(cfg, guardian_uv)
    ...
end

function ca_return_guardian_uv:evaluation(cfg)
    local guardian_uv = get_guardian_uv(cfg)
    if guardian_uv then
        local return_loc = get_guardian_uv_xy(cfg, guardian_uv)
        if (guardian_uv.x == return_loc[1]) and (guardian_uv.y == return_loc[2]) then
            return cfg.ca_score - 200
        else
            return cfg.ca_score
        end
    end

    return 0
end

[Spannerbag]

...I'm not sure exactly what you have in mind... I would probably recommend just creating a new function...

Heh, at first glance your structure does pretty much what I was trying to express - and in a more elegant way.
To me, it does the same basic thing: assign the unit's return values to return_loc and leave the original logic more or less unchanged?

However your example clarifies a few structural uncertainties I had.

Will hopefully wreck things completely get this working over the next few days as time permits (rl is busy as ever ).

Thanks again for your help, much appreciated as always!

Cheers!

[Spannerbag]

Well, got it working much quicker (and more easily) than expected.

Not exhaustively tested but seems to work as expected plus no errors.

Only niggle was lua didn't like testing for the nonexistence of a variable inside a nonexistent container (fair enough I suppose) so I just tested for the container.

So, instead of:

if guardian_uv.variables.return_guardian.return_x and guardian_uv.variables.return_guardian.return_y then

I used

if guardian_uv.variables.return_guardian then

Only other minor query: I've not been able to find the internal structure of loc so guessed at how to assign return_loc_uv the relevant x,y values - is there a better way than what I did (line 6 of code below)? Just curious.

Code: Select all

local function get_guardian_uv_xy(cfg, guardian_uv)
    local return_loc_uv = AH.get_named_loc_xy('return', cfg)
--    if guardian_uv.variables.return_guardian.return_x and guardian_uv.variables.return_guardian.return_y then
    if guardian_uv.variables.return_guardian then
        if wesnoth.current.map:on_board(guardian_uv.variables.return_guardian.return_x, guardian_uv.variables.return_guardian.return_y) then
            return_loc_uv[1], return_loc_uv[2] = guardian_uv.variables.return_guardian.return_x, guardian_uv.variables.return_guardian.return_y
        end
    end
    return return_loc_uv
end

I don't think I'll bother with error trapping for where variables.return_guardian exists but doesn't contain return_x and/or return_y and just let the logic silently fallback to the return values specified in micro_ai].


Thanks again for your help and patience, really helpful.
Cheers!