
AddCSLuaFile()

--
--
-- This is the default drive type for when you right click -> drive in sandbox
--
--

DEFINE_BASECLASS( "drive_base" );


drive.Register( "drive_sandbox", 
{
	--
	-- Called on creation
	--
	Init = function( self )

		self.CameraDist 	= 4
		self.CameraDistVel 	= 0.1

	end,

	--
	-- Calculates the view when driving the entity
	--
	CalcView =  function( self, view )

		--
		-- Use the utility method on drive_base.lua to give us a 3rd person view
		--
		local idealdist = math.max( 10, self.Entity:BoundingRadius() ) * self.CameraDist

		self:CalcView_ThirdPerson( view, idealdist, 2, { self.Entity } )

		view.angles.roll = 0

	end,
	
	SetupControls = function( self, cmd )				
	
		--
		-- If we're holding the reload key down then don't alter the view angles
		--
		if ( cmd:KeyDown( IN_RELOAD ) ) then

			cmd:SetViewAngles( EyeAngles() )

		end

		--
		-- Zoom out when we use the mouse wheel (this is completely clientside, so it's ok to use a lua var!!)
		--
		self.CameraDistVel = self.CameraDistVel + cmd:GetMouseWheel() * -0.5

		self.CameraDist = self.CameraDist + self.CameraDistVel * FrameTime()
		self.CameraDist = math.Clamp( self.CameraDist, 2, 20 )
		self.CameraDistVel = math.Approach( self.CameraDistVel, 0, self.CameraDistVel * FrameTime() * 2 )

	end,
	--
	-- Called before each move. You should use your entity and cmd to 
	-- fill mv with information you need for your move.
	--
	StartMove =  function( self, mv, cmd )

		--
		-- Set the observer mode to chase so that the entity is drawn
		--
		self.Player:SetObserverMode( OBS_MODE_CHASE )

		--
		-- Use (E) was pressed - stop it.
		--
		if ( mv:KeyReleased( IN_USE ) ) then
			self:Stop()
		end

		--
		-- Update move position and velocity from our entity
		--
		mv:SetOrigin( self.Entity:GetNetworkOrigin() )
		mv:SetVelocity( self.Entity:GetAbsVelocity() )
		mv:SetMoveAngles( self.Player:EyeAngles() )		-- Always move relative to the player's eyes

		local entity_angle		= self.Player:EyeAngles()
		entity_angle.roll		= self.Entity:GetAngles().roll

		--
		-- Right mouse button is down, don't change the angle of the object
		--
		if ( mv:KeyDown( IN_ATTACK2 ) || mv:KeyReleased( IN_ATTACK2 ) ) then
			entity_angle = self.Entity:GetAngles()
		end

		--
		-- If reload is down then spin the object around
		--
		if ( mv:KeyDown( IN_RELOAD ) ) then

			entity_angle.roll = entity_angle.roll + cmd:GetMouseX() * 0.01

		end

		--
		-- Right mouse button was released
		--
		if ( mv:KeyReleased( IN_ATTACK2 ) ) then
			self.Player:SetEyeAngles( self.Entity:GetAngles() )
		end

		mv:SetAngles( entity_angle )

	end,

	--
	-- Runs the actual move. On the client when there's 
	-- prediction errors this can be run multiple times.
	-- You should try to only change mv.
	--
	Move = function( self, mv )

		--
		-- Set up a speed, go faster if shift is held down
		--
		local speed = 0.0005 * FrameTime()
		if ( mv:KeyDown( IN_SPEED ) ) then speed = 0.005 * FrameTime() end

		--
		-- Get information from the movedata
		--
		local ang = mv:GetMoveAngles()
		local pos = mv:GetOrigin()
		local vel = mv:GetVelocity()

		-- Cancel out the roll
		ang.roll = 0

		--
		-- Add velocities. This can seem complicated. On the first line
		-- we're basically saying get the forward vector, then multiply it
		-- by our forward speed (which will be > 0 if we're holding W, < 0 if we're
		-- holding S and 0 if we're holding neither) - and add that to velocity.
		-- We do that for right and up too, which gives us our free movement.
		--
		vel = vel + ang:Forward()	* mv:GetForwardSpeed()	* speed
		vel = vel + ang:Right()		* mv:GetSideSpeed()		* speed
		vel = vel + ang:Up()		* mv:GetUpSpeed()		* speed

		--
		-- We don't want our velocity to get out of hand so we apply
		-- a little bit of air resistance. If no keys are down we apply
		-- more resistance so we slow down more.
		--
		if ( math.abs(mv:GetForwardSpeed()) + math.abs(mv:GetSideSpeed()) + math.abs(mv:GetUpSpeed()) < 0.1 ) then
			vel = vel * 0.90
		else
			vel = vel * 0.99
		end

		--
		-- Add the velocity to the position (this is the movement)
		--
		pos = pos + vel

		--
		-- We don't set the newly calculated values on the entity itself
		-- we instead store them in the movedata. These get applied in FinishMove.
		--
		mv:SetVelocity( vel )
		mv:SetOrigin( pos )

	end,

	--
	-- The move is finished. Use mv to set the new positions
	-- on your entities/players.
	--
	FinishMove =  function( self, mv )

		--
		-- Update our entity!
		--
		self.Entity:SetNetworkOrigin( mv:GetOrigin() )
		self.Entity:SetAbsVelocity( mv:GetVelocity() )
		self.Entity:SetAngles( mv:GetAngles() )

		--
		-- If we have a physics object update that too. But only on the server.
		--
		if ( SERVER && IsValid( self.Entity:GetPhysicsObject() ) ) then

			self.Entity:GetPhysicsObject():EnableMotion( true )
			self.Entity:GetPhysicsObject():SetPos( mv:GetOrigin() );
			self.Entity:GetPhysicsObject():Wake()
			self.Entity:GetPhysicsObject():EnableMotion( false )

		end

	end


}, "drive_base" );