From 3a975db66a3711f34e8b64bb27a8eaca79fdeca9 Mon Sep 17 00:00:00 2001
From: Alex Pickering <alex@cogarr.net>
Date: Sun, 1 Feb 2026 13:14:32 -0600
Subject: Initial commit

---
 src/ecs.moon | 184 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 184 insertions(+)
 create mode 100644 src/ecs.moon

(limited to 'src/ecs.moon')

diff --git a/src/ecs.moon b/src/ecs.moon
new file mode 100644
index 0000000..61b73a5
--- /dev/null
+++ b/src/ecs.moon
@@ -0,0 +1,184 @@
+win = require("window")
+log = require("log")
+world = require("world")
+Component = require("ecs.component")
+GraphicsComponent = require("ecs.graphics")
+NetworkedComponent = require("ecs.networked")
+PredictedComponent = require("ecs.predicted")
+ScriptComponent = require("ecs.script")
+CharacterControllerComponent = require("ecs.char_controller")
+shader_world = require("shaders.world")
+
+--win.scene:append(shader_world)
+--pp = am.postprocess({
+	--clear_color: vec4(0.2, 0.2, 0.3, 1),
+	--depth_buffer: true,
+	----stencil_buffer: true,
+	--width: win.width,
+	--height: win.height,
+--})
+pp = am.group!
+pp\append(shader_world.node)
+GraphicsComponent.node = pp
+ScriptComponent.node = pp
+PredictedComponent.node = pp
+NetworkedComponent.node = pp
+
+-- Base entity of our ECS
+class Entity
+	id: 1
+	new: (id, components) => -- [id], [components]
+		ent_reg = world.domain == "client" and world.level.entities or world.level_sync.ents
+		id_cur = id or #ent_reg + 1
+		@created_at = debug.traceback!
+		assert(id_cur < 10, "Got more then 10 entities")
+		while ent_reg[id_cur] != nil
+			id_cur += 1
+		log.debug("Want to create an entity with id" .. id_cur .. ", registry is:" .. tostring(ent_reg) .. "\n" .. debug.traceback(), {"ecs"})
+		assert(ent_reg[id_cur] == nil, "Attempted to create entity with the same id as one that already exists: " .. tostring(id_cur) .. ", entities were:" .. tostring(ent_reg))
+
+		log.info("Creating entity " .. id_cur .. " domain is: " .. world.domain, {"ecs"})
+		ent_reg[id_cur] = @
+		@reg = ent_reg
+		@id = id_cur
+		-- Bookkeeping for O(1) access for components
+		@c_by_type = {}
+		@c_by_name = {}
+		--Entity is responsible for the component -> entity link
+		@components = components or {}
+		for name, component in pairs(@components)
+			component.entity = @
+			@c_by_type[component.__class] = @c_by_type[component.__class] or {}
+			@c_by_type[component.__class][name] = component
+		for name, component in pairs(@components)
+			assert(component.join, "Component " .. name .. " does not have a join method.")
+			component\join(@)
+			component\post_join(@)
+	add: (component, cid) =>
+		assert(component, "Failed to find component:" .. tostring(component))
+		assert(type(component) == "table", "Component must be a table")
+		assert(component.__class, "Component must have a class")
+		component.entity = @
+		component\join(@, cid)
+		component\post_join(@, cid)
+		if cid == nil
+			cid = #@components + 1
+			while @components[cid]
+				cid += 1
+		assert(@components[cid] == nil, "Already had a component with id" .. tostring(cid))
+		@components[cid] = component
+		@c_by_type[component.__class] = @c_by_type[component.__class] or {}
+		@c_by_type[component.__class][cid] = component
+		assert(@c_by_name[component.name] == nil, "Duplicate components named" .. component.name)
+		@c_by_name[component.name] = component
+		@
+	remove: (cid) =>
+		component = @components[cid]
+		component.entity = nil
+		component\leave(@)
+		component
+		@components[cid] = nil
+		@c_by_type[component.__class][cid] = nil
+		@c_by_name[component.name] = nil
+	destroy: () =>
+		for name, component in pairs(@components)
+			@remove(name)
+		@reg[@id] = nil
+
+	get: (cid) =>
+		@components[cid]
+
+	serialize: () =>
+		components = {}
+		for i, component in pairs(@components)
+			component_name = component.__class.__name
+			if not component.serialize
+				log.warn("Component:" .. component_name .. " does not have a .serialize()", {"ecs"})
+				continue
+			component_data = component\serialize!
+			components[i] = string.format(
+				"%d\0%s%d\0%s",
+				#component_name, component_name,
+				#component_data, component_data
+			)
+		return table.concat(components, "\0")
+	
+	--@deserialize: (data) =>
+		--error("Deserialize called")
+		--log.info("Deserializing entity from data of length " .. tostring(data and #data or 0), {"ecs"})
+		--ent = @!
+		---- Empty payload -> empty entity
+		--if not data or #data == 0
+			--return ent
+		---- Map serialized component type names back to their classes
+		--component_types = {
+			--[GraphicsComponent.__name]: GraphicsComponent
+			--[NetworkedComponent.__name]: NetworkedComponent
+			--[PredictedComponent.__name]: PredictedComponent
+			--[ScriptComponent.__name]: ScriptComponent
+			--[CharacterControllerComponent.__name]: CharacterControllerComponent
+			--[PhysicsComponent.__name]: PhysicsComponent
+		--}
+		--pointer = 1
+		--len = #data
+		--while pointer <= len
+			---- Read component name length (digits up to first NUL)
+			--name_len_end = string.find(data, "\0", pointer)
+			--if not name_len_end
+				--break
+			--name_len_str = string.sub(data, pointer, name_len_end - 1)
+			--name_len = tonumber(name_len_str)
+			--if not name_len or name_len <= 0
+				--break
+			--pointer = name_len_end + 1
+			---- Read component type name
+			--component_name = string.sub(data, pointer, pointer + name_len - 1)
+			--pointer += name_len
+			---- Read component data length (digits up to next NUL)
+			--data_len_end = string.find(data, "\0", pointer)
+			--if not data_len_end
+				--break
+			--data_len_str = string.sub(data, pointer, data_len_end - 1)
+			--data_len = tonumber(data_len_str)
+			--if not data_len or data_len < 0
+				--break
+			--pointer = data_len_end + 1
+			---- Read component payload
+			--component_data = string.sub(data, pointer, pointer + data_len - 1)
+			--pointer += data_len
+			---- Skip inter-component separator if present
+			--if string.sub(data, pointer, pointer) == "\0"
+				--pointer += 1
+			--ctype = component_types[component_name]
+			--if not ctype
+				--log.warn("Unknown component type during deserialize: " .. tostring(component_name), {"ecs"})
+				--continue
+			--if not ctype.deserialize
+				--log.warn("Component type " .. tostring(component_name) .. " does not implement .deserialize()", {"ecs"})
+				--continue
+			---- Let the component class decide how to interpret its payload
+			--component = ctype.deserialize(component_data)
+			--if component
+				--ent\add(component)
+		--return ent
+
+	__tostring: () =>
+		components_str = tostring(@components)
+		return string.format("%s : {\n%s\n}\t%q",@@__name, components_str\gsub("^","\t"), @created_at)
+
+class PhysicsComponent extends Component
+	new: (name, properties) =>
+		assert(properties and properties.shape, "Failed to find a shape for physics component")
+		super(name, properties)
+
+{
+	:Component
+	:Entity
+	:NetworkedComponent
+	:PredictedComponent
+	:GraphicsComponent
+	:PhysicsComponent
+	:ScriptComponent
+	:CharacterControllerComponent
+	node: pp
+}
-- 
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