A* Pathfinding Bots: A "Public Project"

[MaximLaHaxim]

Hello everybody. I decided I'd make a "public project" for lack of a better word. Now, I've always wanted deathmatch-oriented bots in Garry's Mod. So, I decided to look into pathfinding and GMod's built-in navmesh functions.

The end result so far was this mess:

local testnodes = {}
for i = 1, #navmesh.GetAllNavAreas() do
	local area = navmesh.GetNavAreaByID( i )
		
	if area:IsValid() then
		testnodes[i] = {}
		testnodes[i].id = i
		testnodes[i].x = area:GetCenter().x
		testnodes[i].y = area:GetCenter().y
	end
end

function navmesh.FindExclude( excl, pos, radius, stepdown, stepup )
	local checked_areas = {}
	local unchecked_areas = navmesh.Find( pos, radius, stepdown, stepup )
	
	for _, v in pairs(unchecked_areas) do
		if v ~= excl then
			checked_areas[#checked_areas + 1] = v
		end
	end
	
	return checked_areas
end

nb_bots = {}

function nb_bots.GetAStarPath( ply )
	local nav_start = navmesh.GetNearestNavArea( ply:GetPos() )
	if !nav_start:IsValid() then return "nope" end
	
	local nav_goal = table.Random(navmesh.FindExclude( nav_start, Entity(1):GetPos(), 9999, 9999, 9999 ))
	if !nav_goal:IsValid() then return "nope" end
	
	return astar.path( testnodes[nav_start:GetID()], testnodes[nav_goal:GetID()], testnodes, true, function() return true end ) or "nope"
end

function nb_bots.DecideEnemy( ply )
	if ply.Enemy and ply.Enemy:Alive() and ply:Visible(ply.Enemy) then return end

	local found = {}
	
	for not_needed, playr in pairs( player.GetAll() ) do
		if playr ~= ply and playr:Alive() and ply:Visible( playr ) then
			found[#found + 1] = playr
		end
	end
	
	if #found == 0 and ply.Enemy ~= nil then ply.Enemy = nil return end
	
	ply.Enemy = table.Random( found )
end

function nb_bots.LookatPosXYZ( usercmd, ply, position )
	--[[local our_position = ply:GetPos()
	local distance = our_position:Distance( position )
	
	local pitch = math.atan2( -(position.z - our_position.z), distance )
	local yaw = math.deg(math.atan2(position.y - our_position.y, position.x - our_position.x))
	
	ply:SetEyeAngles( Angle( pitch, yaw, 0 ) )
	usercmd:SetViewAngles( Angle( pitch, yaw, 0 ) )]]
	
	local ang = ((ply:EyePos() - Vector(0,0,10))-(position - Vector(0,0,10))):AngleEx(Vector(0,0,0))
 
	local lClamp = ang + Angle(0,180,0)
	local ideal = Angle(math.Clamp(-lClamp.p,-180,180),lClamp.y,math.Clamp(lClamp.r,-180,180))
 
	ply:SetEyeAngles(ideal)
	usercmd:SetViewAngles(ideal)
end

function nb_bots.LookatPosXY( usercmd, ply, position )
	local our_position = ply:GetPos()
	local distance = our_position:Distance( position )
	
	local pitch = math.atan2( -(position.z - our_position.z), distance )
	local yaw = math.deg(math.atan2(position.y - our_position.y, position.x - our_position.x))
	
	ply:SetEyeAngles( Angle( pitch, yaw, 0 ) )
	usercmd:SetViewAngles( Angle( pitch, yaw, 0 ) )
end

hook.Add( "StartCommand", "Bots_Control", function( ply, cmd )
	if not ply:IsBot() then return end
	
	cmd:ClearMovement()
	cmd:ClearButtons()
	
	if not ply.AstarPath then ply.AstarPath = nb_bots.GetAStarPath( ply ) ply.CurSegment = 1 end
	
	if ply.CurSegment ~= (#ply.AstarPath+1) then
		if ply.AstarPath == "nope" then return end
		if math.Dist( ply:GetPos().x, ply:GetPos().y, ply.AstarPath[ply.CurSegment].x, ply.AstarPath[ply.CurSegment].y ) <= 1 then
			print("moving on!")
			ply.CurSegment = ply.CurSegment + 1
		else
			cmd:SetForwardMove( 200 )
		end
		if ply.CurSegment ~= #ply.AstarPath+1 then
			local vec = Vector( ply.AstarPath[ply.CurSegment].x, ply.AstarPath[ply.CurSegment].y, 0 )
			nb_bots.LookatPosXY( cmd, ply, vec )
		end
	else
		ply.CurSegment = 1
	end
	
	--[[local valid = IsValid(ply:GetActiveWeapon())
		
	if valid and ply:GetActiveWeapon():GetClass() ~= "weapon_ar2" then
		ply:SelectWeapon("weapon_ar2")
	end
	
	nb_bots.DecideEnemy( ply )
	
	if ply.Enemy then
		nb_bots.LookatPos(cmd, ply, ply.Enemy:EyePos())--:GetPos())
	
		if ply.Enemy:Alive() and ply:Visible(ply.Enemy) then
			--if ply:GetPos().z - enemy:GetPos().z <= -30 or ply:GetPos().z - enemy:GetPos().z >= 30 then return end
		
			--if valid and ply:GetActiveWeapon():Clip1() == 0 then
				--cmd:SetButtons( IN_RELOAD )
				--return
			--end
		
			cmd:SetSideMove(math.cos(RealTime())*400)
		
			if ply:GetPos():Distance(ply.Enemy:GetPos()) < 801 then
				cmd:SetButtons( IN_ATTACK )
			else
				cmd:SetForwardMove( 200 )
			end
		end
	
		--[[if not ply.path then
			local nav_area = table.Random( navmesh.Find( ply:GetPos(), 9000, 9000, 9000 ) )
			ply.path = nav_area:GetRandomPoint()
		end
	
		if ply.path and ply:GetPos():Distance( ply.path ) ~= 0 then
			nb_bots.Look_at_Position( cmd, ply, ply.path )
			cmd:SetForwardMove( 200 )
		else
			ply.CompletedMoving = true
		end]
	end]]
	
	
end )

(with this a* module [url]https://github.com/lattejed/a-star-lua[/url])

Now, I made this thread to bring awareness to it and also to start a discussion about it. I want to see if anyone is willing to help. I'm interested in seeing what we can do with this.

[editline]12th January 2016[/editline]

If anyone wants to help clean the code up/has any ideas, be sure to post here!