Add hot reloading support

Closes #11

CHANGELOG.md

@@ -4,8 +4,10 @@
 ### Added
 - Added `World:spawnAt` to spawn a new entity with a specified ID.
 - Added `World:__iter` to allow iteration over all entities in the world the world from a for loop.
+- Added `Loop:evictSystem(system)`, which removes a previously-scheduled system from the Loop. Evicting a system also cleans up any storage from hooks. This is intended to be used for hot reloading. Dynamically loading and unloading systems for gameplay logic is not recommended.
 ### Changed
 - The first entity ID is now `1` instead of `0`
+- Events that have no systems scheduled to run on them are no longer skipped upon calling `Loop:begin`.
 
 ## [0.2.0] - 2022-06-04
 ### Added

example.project.json

@@ -6,6 +6,9 @@
       "$className": "Workspace",
       "Terrain": {
         "$path": "example/terrain.rbxm"
+      },
+      "Level": {
+        "$path": "example/level.rbxm"
       }
     },
     "Lighting": {

example/client/init.client.lua

@@ -1,89 +1,7 @@
-local RunService = game:GetService("RunService")
 local ReplicatedStorage = game:GetService("ReplicatedStorage")
-local Packages = ReplicatedStorage.ExamplePackages
-local Matter = require(ReplicatedStorage.Packages.Matter)
-local Plasma = require(Packages.plasma)
-local Components = require(ReplicatedStorage.Game.components)
-local RemoteEvent = ReplicatedStorage:WaitForChild("MatterRemote")
+local start = require(ReplicatedStorage.Game.start)
+local receiveReplication = require(script.receiveReplication)
 
-local world = Matter.World.new()
-local state = {}
-local loop = Matter.Loop.new(world, state)
+local world, state = start(ReplicatedStorage.Game.clientSystems)
 
-local systems = {}
-for _, child in ipairs(script.systems:GetChildren()) do
-	if child:IsA("ModuleScript") then
-		table.insert(systems, require(child))
-	end
-end
-
-loop:scheduleSystems(systems)
-
-local plasmaNode = Plasma.new(workspace)
-
-loop:addMiddleware(function(nextFn)
-	return function()
-		Plasma.start(plasmaNode, nextFn)
-	end
-end)
-
-loop:begin({
-	default = RunService.Heartbeat,
-	RenderStepped = RunService.RenderStepped,
-})
-
-local entityIdMap = {}
-
-RemoteEvent.OnClientEvent:Connect(function(entities)
-	for serverEntityId, componentMap in entities do
-		local clientEntityId = entityIdMap[serverEntityId]
-
-		if clientEntityId and next(componentMap) == nil then
-			world:despawn(clientEntityId)
-			print(string.format("Despawn %ds%d", clientEntityId, serverEntityId))
-			continue
-		end
-
-		local componentsToInsert = {}
-		local componentsToRemove = {}
-
-		local insertNames = {}
-		local removeNames = {}
-
-		for name, container in componentMap do
-			if container.data then
-				table.insert(componentsToInsert, Components[name](container.data))
-				table.insert(insertNames, name)
-			else
-				table.insert(componentsToRemove, Components[name])
-				table.insert(removeNames, name)
-			end
-		end
-
-		if clientEntityId == nil then
-			clientEntityId = world:spawn(unpack(componentsToInsert))
-
-			entityIdMap[serverEntityId] = clientEntityId
-
-			print(string.format("Spawn %ds%d with %s", clientEntityId, serverEntityId, table.concat(insertNames, ",")))
-		else
-			if #componentsToInsert > 0 then
-				world:insert(clientEntityId, unpack(componentsToInsert))
-			end
-
-			if #componentsToRemove > 0 then
-				world:remove(clientEntityId, unpack(componentsToRemove))
-			end
-
-			print(
-				string.format(
-					"Modify %ds%d adding %s, removing %s",
-					clientEntityId,
-					serverEntityId,
-					if #insertNames > 0 then table.concat(insertNames, ", ") else "nothing",
-					if #removeNames > 0 then table.concat(removeNames, ", ") else "nothing"
-				)
-			)
-		end
-	end
-end)
+receiveReplication(world, state)

example/client/receiveReplication.lua

@@ -0,0 +1,71 @@
+local ReplicatedStorage = game:GetService("ReplicatedStorage")
+local Components = require(ReplicatedStorage.Game.components)
+local RemoteEvent = ReplicatedStorage:WaitForChild("MatterRemote")
+
+local function setupReplication(world, state)
+	local function debugPrint(...)
+		if state.debugEnabled then
+			print("Replication>", ...)
+		end
+	end
+
+	local entityIdMap = {}
+
+	RemoteEvent.OnClientEvent:Connect(function(entities)
+		for serverEntityId, componentMap in entities do
+			local clientEntityId = entityIdMap[serverEntityId]
+
+			if clientEntityId and next(componentMap) == nil then
+				world:despawn(clientEntityId)
+				debugPrint(string.format("Despawn %ds%d", clientEntityId, serverEntityId))
+				continue
+			end
+
+			local componentsToInsert = {}
+			local componentsToRemove = {}
+
+			local insertNames = {}
+			local removeNames = {}
+
+			for name, container in componentMap do
+				if container.data then
+					table.insert(componentsToInsert, Components[name](container.data))
+					table.insert(insertNames, name)
+				else
+					table.insert(componentsToRemove, Components[name])
+					table.insert(removeNames, name)
+				end
+			end
+
+			if clientEntityId == nil then
+				clientEntityId = world:spawn(unpack(componentsToInsert))
+
+				entityIdMap[serverEntityId] = clientEntityId
+
+				debugPrint(
+					string.format("Spawn %ds%d with %s", clientEntityId, serverEntityId, table.concat(insertNames, ","))
+				)
+			else
+				if #componentsToInsert > 0 then
+					world:insert(clientEntityId, unpack(componentsToInsert))
+				end
+
+				if #componentsToRemove > 0 then
+					world:remove(clientEntityId, unpack(componentsToRemove))
+				end
+
+				debugPrint(
+					string.format(
+						"Modify %ds%d adding %s, removing %s",
+						clientEntityId,
+						serverEntityId,
+						if #insertNames > 0 then table.concat(insertNames, ", ") else "nothing",
+						if #removeNames > 0 then table.concat(removeNames, ", ") else "nothing"
+					)
+				)
+			end
+		end
+	end)
+end
+
+return setupReplication

example/server/init.server.lua

@@ -1,68 +1,7 @@
-local RunService = game:GetService("RunService")
-local CollectionService = game:GetService("CollectionService")
 local ReplicatedStorage = game:GetService("ReplicatedStorage")
-local Packages = ReplicatedStorage.ExamplePackages
-local Matter = require(ReplicatedStorage.Packages.Matter)
-local Plasma = require(Packages.plasma)
-local Components = require(ReplicatedStorage.Game.components)
+local start = require(ReplicatedStorage.Game.start)
+local setupTags = require(ReplicatedStorage.Game.setupTags)
 
-local world = Matter.World.new()
-local state = {}
-local loop = Matter.Loop.new(world, state)
+local world = start(script.systems)
 
-local systems = {}
-for _, child in ipairs(script.systems:GetChildren()) do
-	if child:IsA("ModuleScript") then
-		table.insert(systems, require(child))
-	end
-end
-
-loop:scheduleSystems(systems)
-
-local plasmaNode = Plasma.new(workspace)
-
-loop:addMiddleware(function(nextFn)
-	return function()
-		Plasma.start(plasmaNode, nextFn)
-	end
-end)
-
-loop:begin({
-	default = RunService.Heartbeat,
-	RenderStepped = RunService.RenderStepped,
-})
-
-local boundTags = {
-	Spinner = Components.Spinner,
-}
-
-local function spawnBound(instance, component)
-	local id = world:spawn(
-		component(),
-		Components.Bind({
-			instance = instance,
-		}),
-		Components.Transform({
-			cframe = instance.CFrame,
-		})
-	)
-
-	instance:SetAttribute("entityId", id)
-end
-
-for tagName, component in pairs(boundTags) do
-	for _, instance in ipairs(CollectionService:GetTagged(tagName)) do
-		spawnBound(instance, component)
-	end
-
-	CollectionService:GetInstanceAddedSignal(tagName):Connect(function(instance)
-		spawnBound(instance, component)
-	end)
-
-	CollectionService:GetInstanceRemovedSignal(tagName):Connect(function(instance)
-		local id = instance:GetAttribute("entityId")
-		if id then
-			world:despawn(id)
-		end
-	end)
-end
+setupTags(world)

example/server/systems/replication.lua

@@ -7,14 +7,21 @@ local RemoteEvent = Instance.new("RemoteEvent")
 RemoteEvent.Name = "MatterRemote"
 RemoteEvent.Parent = ReplicatedStorage
 
-local replicatedComponents = {
-	Components.Roomba,
-	Components.Model,
-	Components.Health,
-	Components.Target,
-	Components.Mothership,
+local REPLICATED_COMPONENTS = {
+	"Roomba",
+	"Model",
+	"Health",
+	"Target",
+	"Mothership",
+	"Spinner",
 }
 
+local replicatedComponents = {}
+
+for _, name in REPLICATED_COMPONENTS do
+	replicatedComponents[Components[name]] = true
+end
+
 local function replication(world)
 	for _, player in useEvent(Players, "PlayerAdded") do
 		local payload = {}
@@ -24,7 +31,9 @@ local function replication(world)
 			payload[tostring(entityId)] = entityPayload
 
 			for component, componentData in entityData do
-				entityPayload[tostring(component)] = { data = componentData }
+				if replicatedComponents[component] then
+					entityPayload[tostring(component)] = { data = componentData }
+				end
 			end
 		end
 
@@ -34,7 +43,7 @@ local function replication(world)
 
 	local changes = {}
 
-	for _, component in replicatedComponents do
+	for component in replicatedComponents do
 		for entityId, record in world:queryChanged(component) do
 			local key = tostring(entityId)
 			local name = tostring(component)

example/client/systems/debugVision.lua → example/shared/clientSystems/debugVision.lua

@@ -1,9 +1,27 @@
-local HttpService = game:GetService("HttpService")
+local UserInputService = game:GetService("UserInputService")
 local ReplicatedStorage = game:GetService("ReplicatedStorage")
 local Components = require(ReplicatedStorage.Game.components)
 local template = ReplicatedStorage.Assets.BillboardGui
+local Matter = require(ReplicatedStorage.Packages.Matter)
+
+warn("Press F to toggle debug overlay")
+
+local function debugVision(world, state)
+	for _, input in Matter.useEvent(UserInputService, "InputBegan") do
+		if input.KeyCode == Enum.KeyCode.F then
+			state.debugEnabled = not state.debugEnabled
+		end
+	end
+
+	if not state.debugEnabled then
+		for id, debugLabel in world:query(Components.DebugLabel) do
+			debugLabel.label:Destroy()
+			world:remove(id, Components.DebugLabel)
+		end
+
+		return
+	end
 
-local function rainbowRoombas(world)
 	for id, model in world:query(Components.Model) do
 		local debugLabel = world:get(id, Components.DebugLabel)
 
@@ -42,4 +60,4 @@ local function rainbowRoombas(world)
 	end
 end
 
-return rainbowRoombas
+return debugVision

example/server/systems/roombasHurt.lua → example/shared/clientSystems/roombasHurt.lua

@@ -1,3 +1,4 @@
+local Players = game:GetService("Players")
 local ReplicatedStorage = game:GetService("ReplicatedStorage")
 local Components = require(ReplicatedStorage.Game.components)
 local Matter = require(ReplicatedStorage.Packages.Matter)
@@ -10,6 +11,16 @@ local function roombasHurt(world)
 				return
 			end
 
+			local player = Players:GetPlayerFromCharacter(touchedModel)
+
+			if not player then
+				return
+			end
+
+			if player ~= Players.LocalPlayer then
+				return
+			end
+
 			local humanoid = touchedModel:FindFirstChildWhichIsA("Humanoid")
 
 			if not humanoid then

example/shared/clientSystems/spinSpinners.lua

@@ -0,0 +1,10 @@
+local ReplicatedStorage = game:GetService("ReplicatedStorage")
+local Components = require(ReplicatedStorage.Game.components)
+
+local function spinSpinners(world)
+	for id, model in world:query(Components.Model, Components.Spinner) do
+		model.model.PrimaryPart.CFrame = model.model.PrimaryPart.CFrame * CFrame.Angles(0, math.rad(5), 0)
+	end
+end
+
+return spinSpinners

example/shared/components.lua

@@ -11,6 +11,7 @@ local COMPONENTS = {
 	"Mothership",
 	"Lasering",
 	"DebugLabel",
+	"Spinner",
 }
 
 local components = {}