Lua variables for terrain defense

[PsychoticKittens]

Exasperation, on request, coded this a-ways back for me to fix my problem with wesnoth crashing for my WML version of the code.
But I noted that the effect from his terrain-defense variable had no effect (I tested it by having a unit attack a target in grassland and forest, 20 and 30 respectively, and do the same damage)

Entire Code

Spoiler:

Code: Select all

# multiplies damage inflicted by hitter's current hp / max hp. First step in damage dealing. Should also calculate effect of Evade ability and put it into this event.

#define MDC_POPULATION
   # no need to have a dummy ability just for description, so I merged them
   [chance_to_hit]
      id=mdc-population
      name= _ "Population"
      name_inactive= _ "Population"
      description= _ "Population: This unit can encompass more than one physical unit. Damage is multiplied by Current Health divided by Maximum Health (which is the health of a single physical unit in the whole)"
      description_inactive= _ "Population: This unit can encompass more than one physical unit. Damage is multiplied by Current Health divided by Maximum Health (which is the health of a single physical unit in the whole)"
      apply_to=self
      value=100
   [/chance_to_hit]
#enddef

#define MDC_POPULATION_EVENT
[event]
   name=attack
   first_time_only=no

   # get evade and resistance values for units; much easier to get evade using lua
   [lua]
      code=<<
         local x, y = wesnoth.current.event_context.x1, wesnoth.current.event_context.y1
         local u, t = wesnoth.get_units({ x = x, y = y })[1], wesnoth.get_terrain(x, y)
         wesnoth.set_variable("popvars.e1", wesnoth.unit_defense(u, t))
         x, y = wesnoth.current.event_context.x2, wesnoth.current.event_context.y2
         u, t = wesnoth.get_units({ x = x, y = y })[1], wesnoth.get_terrain(x, y)
         wesnoth.set_variable("popvars.e2", wesnoth.unit_defense(u, t))
      >>
   [/lua]
   {VARIABLE popvars.r1 $unit.resistance.$second_weapon.type}
   {VARIABLE popvars.r2 $second_unit.resistance.$weapon.type}
   # find population numbers
   {VARIABLE popvars.n1 "$(($unit.hitpoints+$unit.max_hitpoints-1)/$unit.max_hitpoints)"}
   {VARIABLE popvars.n2 "$(($second_unit.hitpoints+$second_unit.max_hitpoints-1)/$second_unit.max_hitpoints)"}
   # store original damage
   {VARIABLE popvars.d1 $weapon.damage}
   {VARIABLE popvars.d2 $second_weapon.damage}
   # find base damages (adjusted for evade)
   {VARIABLE popvars.b1 "$(($weapon.damage*$popvars.e2+50)/100)"}
   {VARIABLE popvars.b2 "$(($second_weapon.damage*$popvars.e1+50)/100)"}
   # find and apply damage increments
   {VARIABLE popvars.i1 "$($popvars.b1*$popvars.n1-$weapon.damage)"}
   {VARIABLE popvars.i2 "$($popvars.b2*$popvars.n2-$second_weapon.damage)"}

   {IF_VAR popvars.i1 not_equals 0 (
      [then]
         [object]
            [filter]
               x=$x1
               y=$y1
            [/filter]
            [effect]
               apply_to=attack
               [filter_attack]
                  range=melee
               [/filter_attack]
               increase_damage=$popvars.i1
            [/effect]
            silent=yes
         [/object]
      [/then]
   )}

   {IF_VAR popvars.i2 not_equals 0 (
      [then]
         [object]
            [filter]
               x=$x2
               y=$y2
            [/filter]
            [effect]
               apply_to=attack
               [filter_attack]
                  range=melee
               [/filter_attack]
               increase_damage=$popvars.i2
            [/effect]
            silent=yes
         [/object]
      [/then]
   )}
[/event]
[event]
   name=attacker_hits
   first_time_only=no

   # if defender took damage, but survived
   {IF_VAR second_unit.hitpoints greater_than 0 (
      [and]
         {MDC_VARIABLE damage_inflicted greater_than 0}
      [/and]
      [then]
         # find how many survivors there were, and how much the damage needs to be adjusted by
         {VARIABLE popvars.s2 "$(($second_unit.hitpoints+$second_unit.max_hitpoints-1)/$second_unit.max_hitpoints)"}
         {VARIABLE popvars.i2 "$($popvars.b2*($popvars.s2-$popvars.n2))"}
         {VARIABLE popvars.n2 $popvars.s2}
         # apply damage adjustment if necessary
         {IF_VAR popvars.i2 not_equals 0 (
            [then]
               [object]
                  [filter]
                     x=$x2
                     y=$y2
                  [/filter]
                  [effect]
                     apply_to=attack
                     [filter_attack]
                        range=melee
                     [/filter_attack]
                     increase_damage=$popvars.i2
                  [/effect]
                  silent=yes
               [/object]
            [/then]
         )}
      [/then]
   )}
[/event]
[event]
   name=defender_hits
   first_time_only=no

   # same as previous event, but roles reversed
   {IF_VAR unit.hitpoints greater_than 0 (
      [and]
         {MDC_VARIABLE damage_inflicted greater_than 0}
      [/and]
      [then]
         {VARIABLE popvars.s1 "$(($unit.hitpoints+$unit.max_hitpoints-1)/$unit.max_hitpoints)"}
         {VARIABLE popvars.i1 "$($popvars.b1*($popvars.s1-$popvars.n1))"}
         {VARIABLE popvars.n1 $popvars.s1}

         {IF_VAR popvars.i1 not_equals 0 (
            [then]
               [object]
                  [filter]
                     x=$x1
                     y=$y1
                  [/filter]
                  [effect]
                     apply_to=attack
                     [filter_attack]
                        range=melee
                     [/filter_attack]
                     increase_damage=$popvars.i1
                  [/effect]
                  silent=yes
               [/object]
            [/then]
         )}
      [/then]
   )}
[/event]
[event]
   name=attack_end
   first_time_only=no

   # if attacker survived
   {IF_VAR unit.hitpoints greater_than 0 (
      # set damage back to original damage
      [then]
         {VARIABLE popvars.i1 "$($popvars.d1-$popvars.b1*$popvars.n1)"}
         {IF_VAR popvars.i1 not_equals 0 (
            [then]
               [object]
                  [filter]
                     x=$x1
                     y=$y1
                  [/filter]
                  [effect]
                     apply_to=attack
                     [filter_attack]
                        range=melee
                     [/filter_attack]
                     increase_damage=$popvars.i1
                  [/effect]
                  silent=yes
               [/object]
            [/then]
         )}
      [/then]
   )}
   # same for defender
   {IF_VAR second_unit.hitpoints greater_than 0 (
      [then]
         {VARIABLE popvars.i2 "$($popvars.d2-$popvars.b2*$popvars.n2)"}
         {IF_VAR popvars.i2 not_equals 0 (
            [then]
               [object]
                  [filter]
                     x=$x2
                     y=$y2
                  [/filter]
                  [effect]
                     apply_to=attack
                     [filter_attack]
                        range=melee
                     [/filter_attack]
                     increase_damage=$popvars.i2
                  [/effect]
                  silent=yes
               [/object]
            [/then]
         )}
      [/then]
   )}
   # clean up after variables
   {CLEAR_VARIABLE popvars}
[/event]
#enddef

Area that defines the variables, from what Exasperation Noted:

Code: Select all

   [lua]
      code=<<
         local x, y = wesnoth.current.event_context.x1, wesnoth.current.event_context.y1
         local u, t = wesnoth.get_units({ x = x, y = y })[1], wesnoth.get_terrain(x, y)
         wesnoth.set_variable("popvars.e1", wesnoth.unit_defense(u, t))
         x, y = wesnoth.current.event_context.x2, wesnoth.current.event_context.y2
         u, t = wesnoth.get_units({ x = x, y = y })[1], wesnoth.get_terrain(x, y)
         wesnoth.set_variable("popvars.e2", wesnoth.unit_defense(u, t))
      >>
   [/lua]

And the use of said terrain defense variables:

Code: Select all

   # find base damages (adjusted for evade)
   {VARIABLE popvars.b1 "$(($weapon.damage*$popvars.e2+50)/100)"}
   {VARIABLE popvars.b2 "$(($second_weapon.damage*$popvars.e1+50)/100)"}

Since I don't know a drop of Lua, all I've ever learned is WML, the most I get out of that is that it multiplies damage by popvars.e2/e1 (with an additional 50) divided by 100.

With 20 terrain defense, that would be 70/100, in essence multiplying by .7, 30 would be .8; I could be wrong, but that's not quite what I was going for. As the base damage (before being applied to resists on strike) would be weapon damage multiplied by 100 minus evasion, divided by 100. (thusly making .8 out of 20% defense, and .7 out of 30% defense).

Even then, There was no notable effect from the difference in terrain. So I'm at a loss.

[Anonymissimus]

Can't see something wrong in particular with the lua code when inspecting visually (and only that, you oughta deal with the wml formulas yourself). Make sure that the wml variables x1, x2, y1, y2 exist for the event type where the lua code appears. Also, the defenses in popvars should be wml defenses (100 - the defense shown in the topbar when you click on the unit).

EDIT
As ror the formulas - it seems you don't take mathematical priority rules into account. * binds tighter than + etc.