Calculate distance between inst and target

[Combustiblemon]

I was trying to make damage scaled to distance between target and attacker - make longer distance between them should deal more damage, but I can't find how to get distance.

inst._DoAttack = inst.components.combat.DoAttack
	inst.components.combat.DoAttack = function(self, targ, weapon, projectile, stimuli, instancemult)
		if weapon == nil then
			weapon = inst.components.combat:GetWeapon()
		end
		if weapon.components.weapon.attackrange and weapon.components.weapon.attackrange >= 4 then
			print("ya hav som range")
			instancemult = instancemult and instancemult + (weapon.components.weapon.attackrange - 4)/10 or 1 + (weapon.components.weapon.attackrange - 4)/10
		end
		inst._DoAttack(self, targ, weapon, projectile, stimuli, instancemult)
	end

this was first prototype one but this only used weapon's attack range, which is totally not my intention.

so I used Pythagoras' theorem to get distance like:

inst._DoAttack = inst.components.combat.DoAttack
	inst.components.combat.DoAttack = function(self, targ, weapon, projectile, stimuli, instancemult)
		if targ == nil then
			targ = inst
		end

		local atkx, atky, atkz = inst.Transform:GetWorldPosition()
		local tarx, tary, tarz = targ.Transform:GetWorldPosition()
  
		local distance = ((atkx - tarx)^2 + (atky - tary)^2 + (atkz - tarz)^2)^(1/2)
		--in most case y is zero, only flying thing could have y axis

		if distance then
			instancemult = instancemult and instancemult * (distance^(1/2)/10) or 1 + distance^(1/2)/10
		end
		inst._DoAttack(self, targ, weapon, projectile, stimuli, instancemult)
	end

it works!

It should give near 131% damage bonus when attack distance is 10(full range of blowdart).

only distance-getting-code is here if you need in case:

local function MeasureDistance(inst, targ)
	local tarx, tary, tarz = 0, 0, 0

	if targ then
		tarx, tary, tarz = targ.Transform:GetWorldPosition()
	else
		tarx, tary, tarz = inst.Transform:GetWorldPosition()
	end

	local stdx, stdy, stdz = inst.Transform:GetWorldPosition()
	local distance = ((stdx - tarx)^2 + (stdy - tary)^2 + (stdz - tarz)^2)^(1/2)
	--in most case y is zero, only flying thing could have y axis
	return distance
end

well at first I was asking how to get distance between inst and target but I somehow made it so I post it to help someone like me

 

edit: actually behaviours/follow.lua already has distance-measuring function, I should look more in codes. thanks for watching newb modder's code

Edited March 7, 2021 by Combustiblemon
already follow has dist

[-LukaS-]

You could measure distance to the enemy with

distsq(target, inst)

It's used it the combat component to check the distance to the target so the attack state can start.