Item-based Upgrade System

Alright Myre, here it is. Just plug the code into your map (make sure the trigger names are exactly what I tell you to make them), fill out the values, and test away.

Code 1: "The Meat and Potatoes"
This code is what does all the work for you. It fires automatically, on its own. All you need to do is put it in the item + upgrade values in Code 2.

(Note: The trigger name MUST match the text following "scope" (first line). No spaces, either. So if the trigger name is "riffraff", the first line should be "scope riffraff".)

Code:

scope UpgradeComputer

globals
//The following are given their values in the "Set Values" trigger.
integer array ATK_ITEM_IDS[10] //The array of item IDs for attack upgrades
integer array DEF_ITEM_IDS[10] //Same as above, for defense upgrades
integer array HP_ITEM_IDS[10] //Same as above, for hp upgrades
integer array ATK_UPG_IDS[10] //Ids of the attack upgrades
integer array DEF_UPG_IDS[10] //Ids of the defense upgrades
integer array HP_UPG_IDS[10] //Ids of the hp upgrades

private constant integer COMPUTER_ID = 13 //The # of the computer player
//In JASS, player #'s start from 0. So it goes:
//0 == Player 1 (Red)
//1 == Player 2 (Blue)
//And so on. Just put the Computer's JASS-number (Player number - 1, really) in there.
endglobals


private function Conditions takes nothing returns boolean
  local integer i = 1
  local integer id = GetItemTypeId(GetManipulatedItem())
  loop
    exitwhen i > 10
    if id == ATK_ITEM_IDS[i] or id == DEF_ITEM_IDS[i] or id == HP_ITEM_IDS[i] then
      return true
    else
      set i = i + 1
    endif
   
    return false
endfunction

private function Actions takes nothing returns nothing
  local integer id = GetItemTypeId(GetManipulatedItem())
  local integer i = 1
  local integer upgrade = 0
  local boolean found = false
 
  //Checking the attack upgrades
  loop
  exitwhen i > 10 or found == true
  if id == ATK_ITEM_IDS[i] then
    set upgrade = ATK_UPG_IDS[i]
    set ATK_ITEM_IDS[i] = 0
    set found = true
  else
    set i = i + 1
  endif
  endloop
 
  //Wasn't an attack upgrade, checking for defense
  if found != true then
    set i = 1
    loop
    exitwhen i > 10 or found == true
    if id == DEF_ITEM_IDS[i] then
      set upgrade = DEF_UPG_IDS[i]
      set DEF_ITEM_IDS = 0
      set found = true
    else
      set i = i + 1
    endif
    endloop
  endif
 
  //Wasn't either of them, checking for HP now
  if found != true then
    set i = 1
    loop
    exitwhen i > 10 or found == true
    if id == HP_ITEM_IDS[i] then
      set upgrade = HP_UPG_IDS[i]
      set HP_ITEM_IDS[i] = 0
      set found = true
    else
      set i = i + 1
    endif
    endloop
  endif

  call SetPlayerTechResearched(COMPUTER_ID, upgrade, i)
endfunction

//===========================================================================
public function InitTrig takes nothing returns nothing
  local trigger t = CreateTrigger(  )
    call TriggerRegisterAnyUnitEventBJ(t, EVENT_PLAYER_UNIT_PICKUP_ITEM )
    call TriggerAddCondition(t, Condition( function Conditions ) )
    call TriggerAddAction(t, function Actions )
  set t = null
endfunction

endscope

Code 2: "The Broth"
Here, you set your values. The trigger name can be whatever you want, doesn't matter. What does, is two things:

1: You MUST call "Set_Values" at some point (1-2 seconds) after map initialization.
2: You need to set all the values (at least the ones you plan to use) for this to work. Instructions are included, and if you have any questions you can ask.

Code:

library
function Set_Values takes nothing returns nothing

//Replace the "Ixxx" with the rawcode ID of each upgrade item (not the upgrade), IN ORDER.
//The 0's are placeholders in case you wanna add more levels later
set ATK_ITEM_IDS[1] = 'Ixxx'
set ATK_ITEM_IDS[2] = 'Ixxx'
set ATK_ITEM_IDS[3] = 'Ixxx'
set ATK_ITEM_IDS[4] = 'Ixxx'
set ATK_ITEM_IDS[5] = 'Ixxx'
set ATK_ITEM_IDS[6] = 0
set ATK_ITEM_IDS[7] = 0
set ATK_ITEM_IDS[8] = 0
set ATK_ITEM_IDS[9] = 0
set ATK_ITEM_IDS[10] = 0

set DEF_ITEM_IDS[1] = 'Ixxx'
set DEF_ITEM_IDS[2] = 'Ixxx'
set DEF_ITEM_IDS[3] = 'Ixxx'
set DEF_ITEM_IDS[4] = 'Ixxx'
set DEF_ITEM_IDS[5] = 'Ixxx'
set DEF_ITEM_IDS[6] = 0
set DEF_ITEM_IDS[7] = 0
set DEF_ITEM_IDS[8] = 0
set DEF_ITEM_IDS[9] = 0
set DEF_ITEM_IDS[10] = 0

set HP_ITEM_IDS[1] = 'Ixxx'
set HP_ITEM_IDS[2] = 'Ixxx'
set HP_ITEM_IDS[3] = 'Ixxx'
set HP_ITEM_IDS[4] = 'Ixxx'
set HP_ITEM_IDS[5] = 'Ixxx'
set HP_ITEM_IDS[6] = 0
set HP_ITEM_IDS[7] = 0
set HP_ITEM_IDS[8] = 0
set HP_ITEM_IDS[9] = 0
set HP_ITEM_IDS[10] = 0


//The following are for the actual upgrades used, not the items to trigger them.
//The same stuff applies for the following as it does above.
set ATK_UPG_IDS[1] = 'Rxxx'
set ATK_UPG_IDS[2] = 'Rxxx'
set ATK_UPG_IDS[3] = 'Rxxx'
set ATK_UPG_IDS[4] = 'Rxxx'
set ATK_UPG_IDS[5] = 'Rxxx'
set ATK_UPG_IDS[6] = 0
set ATK_UPG_IDS[7] = 0
set ATK_UPG_IDS[8] = 0
set ATK_UPG_IDS[9] = 0
set ATK_UPG_IDS[10] = 0

set DEF_UPG_IDS[1] = 'Rxxx'
set DEF_UPG_IDS[2] = 'Rxxx'
set DEF_UPG_IDS[3] = 'Rxxx'
set DEF_UPG_IDS[4] = 'Rxxx'
set DEF_UPG_IDS[5] = 'Rxxx'
set DEF_UPG_IDS[6] = 0
set DEF_UPG_IDS[7] = 0
set DEF_UPG_IDS[8] = 0
set DEF_UPG_IDS[9] = 0
set DEF_UPG_IDS[10] = 0

set HP_UPG_IDS[1] = 'Rxxx'
set HP_UPG_IDS[2] = 'Rxxx'
set HP_UPG_IDS[3] = 'Rxxx'
set HP_UPG_IDS[4] = 'Rxxx'
set HP_UPG_IDS[5] = 'Rxxx'
set HP_UPG_IDS[6] = 0
set HP_UPG_IDS[7] = 0
set HP_UPG_IDS[8] = 0
set HP_UPG_IDS[9] = 0
set HP_UPG_IDS[10] = 0
endfunction

endlibrary

That should be it. If you have any questions, or if something doesn't work, let me know.

I know the code is for Myre, but I'm curious. what do these codes do?

It's for an upgrade system in BFaC's Last Stand. The version this is going to be in is going through a complete overhaul with new terrain and such, so it's going to take me a while to release a version with this implemented. Good news is though, BFaC's forces will stand a better chance further into the game. They'll still get owned though.