LightFighter's Lua Lab

[Astoria]

I've experimented a bit with lua and came up with this macro/tag:

Code: Select all

    [lua]
        code = <<
            local function effects(f)
		local filtered = wesnoth.get_units { x,y = f.x,y or id = f.id or type = f.type or error("~wml:[imagemod] expects a filter.", 0) }
		wesnoth.add_modification(filtered, "object", { { "effect", { apply_to = "image_mod", replace = "f.image" } } { "effect", { apply_to = "ellipse", ellipse = "f.ellipse" } } } )
	    end
            wesnoth.register_wml_action("imagemod", effects)
        >>
    [/lua]

What happens in-game, is that it keeps showing me this error:

Code: Select all

[string "..."]:3: '}' expected near '='

Can somebody tell me what I'm doing wrong?

[Luther]

The 'x,y = f.x,y' is illegal. You would have to put in each element separately. I can post an example later.

EDIT:

Note that it's easier to put this all into a separate Lua file. It's a pain to edit Lua within WML.

I do not have 1.9 installed, so this code is very untested. I'm sure there are errors.

Code: Select all

--Make the code a bit shorter
H = wesnoth.require('lua/helper.lua')
T = H.set_wml_tag_metatable{}

local function effects(f)

  --Use a standard unit filter provided by the user. You might be able to pass
  --f directly to get_units, but I would require a [filter] tag to be safe. You
  --don't need an error message because a nil filter simply catches all units.
  local filtered = wesnoth.get_units(H.get_child(f, 'filter'))

  --add_modification can only work on one unit at a time.
  for i, unit in ipairs(filtered) do
    wesnoth.add_modification(
      unit,
      'object',
      {
        --Take advantage of set_wml_tag_metatable, which was called at the top.
        T.effect{
          apply_to = "image_mod",
          --You probably want a string provided by the user, not a string
          --literal.
          replace = f.image
        },
        T.effect{
          apply_to = "ellipse",
          ellipse = f.ellipse
        }
      }
    )
  end
end

wesnoth.register_wml_action("imagemod", effects)

Let us know how it works.

EDITED to add another comment.
EDITED to fix a syntax error.

[Astoria]

That also doesn't work, same sort of error.

Code: Select all

[string "..."]:7: '}' expected near 'T'

[Luther]

I forgot to put a comma between the two T tables. I've edited the code in my post. Try it again.

[Astoria]

Thanks, it worked!

[Astoria]

Another quick question: Is there a way to make an #ifdef in lua?

[Anonymissimus]

No. Lua isn't preprocessed.

EDIT
Well, if you "embed" it into wml it is, or can be, but it is very questionable whether that makes sense at all. You need to match the syntaxes of both wml and lua and must write lua as if it was wml which is pointless.

[Astoria]

Finished the (ugly) quantity variable stacker:

Code: Select all

function quantity(cfg)
	if easy
	then
		wesnoth.set_variable("quantity", cfg.easy)
	end
	if medium
	then
		wesnoth.set_variable("quantity", cfg.medium)
	end
	if hard
	then
		wesnoth.set_variable("quantity", cfg.hard)
	end
end
        wesnoth.register_wml_action("quantity", quantity)

Code: Select all

	[event]
		name=preload
		first_time_only=no
#workarounds here
		#ifdef EASY
			{VARIABLE easy yes}
		#endif
		#ifdef MEDIUM
			{VARIABLE medium yes}
		#endif
		#ifdef HARD
			{VARIABLE hard yes}
		#endif
		{WML_TAGS}
	[/event]

It is really simple, but it should work.

[AI]

That only allows you three difficulty levels.
Northern Rebirth, for one, uses 4. It needs its own macros because of that, but now it can't use this tag either...

[Astoria]

That only allows you three difficulty levels.
Northern Rebirth, for one, uses 4. It needs its own macros because of that, but now it can't use this tag either...

Code: Select all

function quantity(cfg)
   if easy
   then
      wesnoth.set_variable("quantity", cfg.easy)
   end
   if medium
   then
      wesnoth.set_variable("quantity", cfg.medium)
   end
   if hard
   then
      wesnoth.set_variable("quantity", cfg.hard)
   end
   if nightmare
   then
      wesnoth.set_variable("quantity", cfg.nightmare)
   end
end
        wesnoth.register_wml_action("quantity", quantity)

Code: Select all

   [event]
      name=preload
      first_time_only=no
#workarounds here
      #ifdef EASY
         {VARIABLE easy yes}
      #endif
      #ifdef MEDIUM
         {VARIABLE medium yes}
      #endif
      #ifdef HARD
         {VARIABLE hard yes}
      #endif
      #ifdef NIGHTMARE
         {VARIABLE nightmare yes}
      #endif
      {WML_TAGS}
   [/event]

Usage:

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[quantity]
easy=10
medium=20
hard=30
[/quantity]
[gold]
 side=1
 amount=$quantity
[/gold]

[AI]

Yes, but what if someone wants to use 5 difficulties, or different difficulty DEFINEs? Should they have to replace the tag or craft a macro to work around its shortcomings?

[Astoria]

Yes, but what if someone wants to use 5 difficulties, or different difficulty DEFINEs? Should they have to replace the tag or craft a macro to work around its shortcomings?

Yes, they have to, but this system will allow UMC designers to make another type of difficulty system, like making formulas.

[bigkahuna]

IIRC, Invasion from the Unknown uses a macro of this sort without any Lua.

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#ifdef EASY
#define DIFF _ON_EASY _ON_NORMAL _ON_HARD
{_ON_EASY}#enddef
#endif
#ifdef NORMAL
#define DIFF _ON_EASY _ON_NORMAL _ON_HARD
{_ON_NORMAL}#enddef
#endif
#ifdef HARD
#define DIFF _ON_EASY _ON_NORMAL _ON_HARD
{_ON_HARD}#enddef
#endif

Theoretically you could add:

#ifdef NIGHTMARE
#define DIFF _ON_EASY _ON_NORMAL _ON_HARD _ON_NIGHTMARE
{_ON_NIGHTMARE}

and alter the others accordingly. Usage:

{VARIABLE monkeys ({DIFF 12 14 16})}
or
[event]
name=turn {DIFF 2 4 6}

etc

[silene]

It is really simple, but it should work.

You can make it even simpler.

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#ifdef EASY
{VARIABLE difficulty easy}
#endif
...

wesnoth.register_wml_action("quantity", function(cfg)
  wesnoth.set_variable("quantity", cfg[wesnoth.get_variable "difficulty"])
end)

[Astoria]

New code (thank you silene!)

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wesnoth.register_wml_action("quantity", function(cfg)
  wesnoth.set_variable("cfg.save_in", cfg[wesnoth.get_variable "difficulty"])
end)

Usage:

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[quantity]
save_in=foo
easy=b
medium=a
hard=r
[/quantity]