wnsrc/gamemodes/sandbox/entities/weapons/gmod_tool/stools/camera.lua

--[[
| This file was obtained through the combined efforts
| of Madbluntz & Plymouth Antiquarian Society.
|
| Credits: lifestorm, Gregory Wayne Rossel JR.,
| 	Maloy, DrPepper10 @ RIP, Atle!
|
| Visit for more: https://plymouth.thetwilightzone.ru/
--]]


TOOL.Category = "Render"
TOOL.Name = "#tool.camera.name"

TOOL.ClientConVar[ "locked" ] = "0"
TOOL.ClientConVar[ "key" ] = "37"
TOOL.ClientConVar[ "toggle" ] = "1"

TOOL.Information = {
	{ name = "left" },
	{ name = "right" }
}

cleanup.Register( "cameras" )

local function CheckLimit( ply, key )

	-- TODO: Clientside prediction
	if ( CLIENT ) then return true end

	local found = false
	for id, camera in ipairs( ents.FindByClass( "gmod_cameraprop" ) ) do
		if ( !camera.controlkey || camera.controlkey != key ) then continue end
		if ( IsValid( camera:GetPlayer() ) && ply != camera:GetPlayer() ) then continue end
		found = true
		break
	end

	if ( !found && !ply:CheckLimit( "cameras" ) ) then
		return false
	end

	return true

end

local function MakeCamera( ply, key, locked, toggle, Data )
	if ( IsValid( ply ) && !CheckLimit( ply, key ) ) then return false end

	local ent = ents.Create( "gmod_cameraprop" )
	if ( !IsValid( ent ) ) then return false end

	duplicator.DoGeneric( ent, Data )

	if ( key ) then
		for id, camera in ipairs( ents.FindByClass( "gmod_cameraprop" ) ) do
			if ( !camera.controlkey || camera.controlkey != key ) then continue end
			if ( IsValid( ply ) && IsValid( camera:GetPlayer() ) && ply != camera:GetPlayer() ) then continue end
			camera:Remove()
		end

		ent:SetKey( key )
		ent.controlkey = key
	end

	ent:SetPlayer( ply )

	ent.toggle = toggle
	ent.locked = locked

	ent:Spawn()

	DoPropSpawnedEffect( ent )
	duplicator.DoGenericPhysics( ent, ply, Data )

	ent:SetTracking( NULL, Vector( 0 ) )
	ent:SetLocked( locked )

	if ( toggle == 1 ) then
		numpad.OnDown( ply, key, "Camera_Toggle", ent )
	else
		numpad.OnDown( ply, key, "Camera_On", ent )
		numpad.OnUp( ply, key, "Camera_Off", ent )
	end

	if ( IsValid( ply ) ) then
		ply:AddCleanup( "cameras", ent )
		ply:AddCount( "cameras", ent )
	end

	return ent

end

if ( SERVER ) then
	duplicator.RegisterEntityClass( "gmod_cameraprop", MakeCamera, "controlkey", "locked", "toggle", "Data" )
end

function TOOL:LeftClick( trace )

	local ply = self:GetOwner()
	local key = self:GetClientNumber( "key" )
	if ( key == -1 ) then return false end

	if ( !CheckLimit( ply, key ) ) then return false end

	if ( CLIENT ) then return true end

	local locked = self:GetClientNumber( "locked" )
	local toggle = self:GetClientNumber( "toggle" )

	local ent = MakeCamera( ply, key, locked, toggle, { Pos = trace.StartPos, Angle = ply:EyeAngles() } )
	if ( !IsValid( ent ) ) then return false end

	undo.Create( "Camera" )
		undo.AddEntity( ent )
		undo.SetPlayer( ply )
	undo.Finish()

	return true, ent

end

function TOOL:RightClick( trace )

	local _, camera = self:LeftClick( trace, true )

	if ( CLIENT ) then return true end

	if ( !IsValid( camera ) ) then return false end

	if ( trace.Entity:IsWorld() ) then

		trace.Entity = self:GetOwner()
		trace.HitPos = trace.Entity:GetPos()

	end

	-- We apply the view offset for players in camera entity
	if ( trace.Entity:IsPlayer() ) then
		trace.HitPos = trace.Entity:GetPos()
	end

	camera:SetTracking( trace.Entity, trace.Entity:WorldToLocal( trace.HitPos ) )

	return true

end

local ConVarsDefault = TOOL:BuildConVarList()

function TOOL.BuildCPanel( CPanel )

	CPanel:AddControl( "ComboBox", { MenuButton = 1, Folder = "camera", Options = { [ "#preset.default" ] = ConVarsDefault }, CVars = table.GetKeys( ConVarsDefault ) } )

	CPanel:AddControl( "Numpad", { Label = "#tool.camera.key", Command = "camera_key" } )
	CPanel:AddControl( "CheckBox", { Label = "#tool.camera.static", Command = "camera_locked", Help = true } )
	CPanel:AddControl( "CheckBox", { Label = "#tool.toggle", Command = "camera_toggle" } )

end