//try to translate C code into lua
// https://wiki.srb2.org/wiki/A_AttractChase
if P_AttractLua
    return
end
rawset(_G, "P_AttractLua", function(source, dest, nightsgrab)
	//pretty quick copy & paste made by luigi budd
	
	--[[
		HOW TO USE:
		
		P_LookForPlayers(mobj_t actor, fixed dist, boolean allaround, boolean tracer?)
		if mobj.tracer
			P_AttractLua(mobj, mobj.tracer, boolean nightsgrab?)
		end
		
		Fill out P_LookForPlayers as normal, then once a tracer is found, call P_AttractLua.
		Usually used by rings.
		
	--]]
	
	local dist
	local ndist
	local speedmul
	local vangle
	
	local tx = dest.x
	local ty = dest.y
	local tz = dest.z + (dest.height/2) // Aim for center
	local xydist = P_AproxDistance(tx - source.x, ty - source.y)
	
	if ((not dest) or (dest.health <= 0) or (not dest.player) or (not source.tracer))
		return
	end
	
	// change angle
	source.angle = R_PointToAngle2(source.x, source.y, tx, ty)
	
	// change angle
	dist = P_AproxDistance(xydist, tz - source.z)
	
	if (dist < 1)
		dist = 1
	end
	
	if (nightsgrab and source.movefactor)
		source.movefactor = $ + (FRACUNIT/2)
		
		if (dist < source.movefactor)
			source.momx = 0
			source.momy = 0
			source.momz = 0
			P_TeleportMove(source, tx, ty, tz)
		else
			vangle = R_PointToAngle2(source.z, 0, tz, xydist)
			
			source.momx = FixedMul(FINESINE(vangle >> ANGLETOFINESHIFT), FixedMul(FINECOSINE(source.angle >> ANGLETOFINESHIFT), source.movefactor))
			source.momy = FixedMul(FINESINE(vangle >> ANGLETOFINESHIFT), FixedMul(FINESINE(source.angle >> ANGLETOFINESHIFT), source.movefactor))
			source.momz = FixedMul(FINECOSINE(vangle >> ANGLETOFINESHIFT), source.movefactor)
		end
	else
		if nightsgrab
			speedmul = P_AproxDistance(dest.momx, dest.momy) + FixedMul(8*FRACUNIT, source.scale)
		else
			speedmul = P_AproxDistance(dest.momx, dest.momy) + FixedMul(source.info.speed, source.scale)	
		end
		
		source.momx = FixedMul(FixedDiv(tx - source.x, dist), speedmul)
		source.momy = FixedMul(FixedDiv(ty - source.y, dist), speedmul)
		source.momz = FixedMul(FixedDiv(tz - source.z, dist), speedmul)
	end
	
	// Instead of just unsetting NOCLIP like an idiot, let's check the distance to our target.
	ndist = P_AproxDistance(P_AproxDistance(tx - (source.x+source.momx),
											ty - (source.y+source.momy)),
	                                        tz - (source.z+source.momz))

	if (ndist > dist) // gone past our target
		// place us on top of them then.
		source.momx = 0
		source.momy = 0
		source.momz = 0
		//i might need to translate this too
		// https://github.com/id-Software/DOOM-iOS/blob/master/code/prboom/p_maputl.c
		//P_UnsetThingPositionLua(source)
		P_TeleportMove(source, tx, ty, tx)
		//P_SetThingPositionLua(source)
		
		//don't need to translate the commented functions, since this works fine enough for me!
	end
end)