[Example] Check if spell is available with memory reading

[orby_tale]

Described method will help you to filter out spells which can’t be used due to the lack of mana (or holy power), wrong distance to target or other reasons. This will help to implement good combat rotations for your bot.

The main trick is in getting information from this function API IsUsableAction - WoWWiki - Your guide to the World of Warcraft
It seems that all prerequisites are calculated somewhere else and this function just checks two flags stored in memory. So we can easily do the same in our application.

This piece of code will show the example usage:

of_enabled_action_btns = $9EDC58;
of_no_mana_for_action_btns = $9EDA18;


//i - number of Action button.
is_available = mr.readUInt( mem_baseaddr + of_enabled_action_btns + i*4);
not_enough_mana = mr.readUInt( mem_baseaddr + of_no_mana_for_action_btns + i*4);

So here is the brief example code for building combat loop. First of all we need to prepare our action bar – rearrange spells in priority order. The spell with highest priority goes first. Here is example for retribution paladin:




Now the example code in Delphi (ya, really which will give you the idea of how to put it all together.

Credits for cooldown tracking goes to someone from mmowned.
//4.0.1

  SKILLS_BAR_FROM = 60;
  SKILLS_BAR_TO = 72;
of_action_toolbar_start = $9EE0D4;
of_spell_cooldowns = $980968;
of_enabled_action_btns = $9EDC58;
of_no_mana_for_action_btns = $9EDA18;



{*******************************************}
{**** SKILLS *******************************}
procedure s_Combat.use_spell();
var
  i : word;
  is_available, not_enough_mana : dword;
  x : byte;
  spid : dword;
  s : AnsiString;
begin

  update_cooldowns();
  if (on_gcd) then begin
    if (gcd_left > 200) then sleep( gcd_left - 200 );
    exit;
  end;
  x := 0;

  for i := SKILLS_BAR_FROM to SKILLS_BAR_TO do begin
    inc(x);
    is_available := mr.readUInt( mem_baseaddr + of_enabled_action_btns + i*4);
    not_enough_mana := mr.readUInt( mem_baseaddr + of_no_mana_for_action_btns + i*4);

    if (is_available = 1) and ( not_enough_mana <> 1 )    then begin
      //get spell ID from btn
      spid := mr.readUInt(mem_baseaddr + of_action_toolbar_start + (i+1)*4);

      if not( on_cooldown(spid) ) then begin
        log(' btn '+inttostr(x)+' available ('+inttostr(spid)+')');
        s := inttostr(x);
        SendKey( wow_hwnd, s[1] );
        break;
      end;
    end;
  end;
  
end;


procedure s_Combat.update_cooldowns();
var
  perfCount, frequency, currentTime: Int64;
  startTime, cooldown1, cooldown2, cooldownLength, globalLength, left: integer;
  curItem,spellId : dword;
begin
  n_cooldowns := 0;
  on_gcd := false;

  QueryPerformanceFrequency(frequency);
  QueryPerformanceCounter(perfCount);
  currentTime := round( (perfCount * 1000) / frequency );

  curItem := mr.readUInt(mem_baseaddr + of_spell_cooldowns + $8);
  while ((curItem <> 0) and ((curItem and 1) = 0)) do begin
    spellId := mr.readUInt(curItem + $8);
    startTime := mr.readInt(curItem + $10);
    cooldown1 := mr.readInt(curItem + $14);
    cooldown2 := mr.readInt(curItem + $20);
    globalLength  := mr.readInt( curItem + $2C );

    if ( (startTime + globalLength) > currentTime) then begin
      on_gcd := true;
      gcd_left :=  (startTime + globalLength) - currentTime;
      exit;
    end;


    cooldownLength := max(cooldown1, cooldown2);
    left := (startTime + cooldownLength) - currentTime ;
    if left > 0 then begin
      //log( Format(' +sp CD: %x %d', [spellId, left]) );
      inc(n_cooldowns);
      spells_on_cooldown[ n_cooldowns ] := spellId;
    end;
    curItem := mr.readUInt(curItem + 4);
  end;
end;


function s_Combat.on_cooldown(spid:dword) : boolean;
var
  i : word;
begin
  result := false;
  for i := 1 to n_cooldowns do begin
    if spells_on_cooldown[ i ] = spid then begin
      result := true;
      exit;
    end;
  end;
end;

[miceiken]

Very nice, I have been looking for something to check my cooldown out of process.
I edited it a bit and tried to convert the cooldown part into a simple bool check on given spellid whether it was on cooldown or not, please note that this code is unclean and not tested!

        [DllImport("kernel32.dll")]
        static extern bool QueryPerformanceCounter(out long lpPerformanceCounter);
        [DllImport("kernel32.dll")]
        static extern bool QueryPerformanceFrequency(out long lpFrequency);
        public static bool IsOnCooldown(int SpellId)
        {
            //long perfCount;
            long frequency;
            //QueryPerformanceFrequency(out perfCount);
            QueryPerformanceFrequency(out frequency);
            long perfCount = Memory.ReadRelative<long>(0x008A7F54);

            long currentTime = (perfCount * 1000) / frequency;

            var CurrentObject = Memory.ReadRelative<uint>(0x00980968 + 0x8);
            while ((CurrentObject != 0) && ((CurrentObject & 1) == 0))
            {
                var spellId = Memory.Read<uint>(CurrentObject + 0x8);
                if (spellId == SpellId)
                {
                    var startTime = Memory.Read<uint>(CurrentObject + 0x10);
                    var cooldown1 = Memory.Read<uint>(CurrentObject + 0x14);
                    var cooldown2 = Memory.Read<uint>(CurrentObject + 0x20);
                    var globalCooldown = Memory.Read<uint>(CurrentObject + 0x2C);

                    if ((startTime + globalCooldown) > currentTime)
                        return true; // On global cooldown

                    var cooldownLength = Math.Max(cooldown1, cooldown2);
                    if ((startTime + cooldownLength) - currentTime > 0)
                        return true; // On regular cooldown
                }

                CurrentObject = Memory.Read<uint>(CurrentObject + 0x4);
            }
            return false;
        }

Also note that instead of using QueryPerformanceCounter I read WoW's internal something, as suggested by Jujubosc here: http://www.mmowned.com/forums/world-...ml#post1970560
The above method is still there, but commented out, so you go ahead and check what works better