hammer/lib/command_buffer.luau
2024-09-21 19:12:15 +02:00

114 lines
2.7 KiB
Text

--!strict
--!optimize 2
local jecs = require("@pkg/jecs")
type entity<T = nil> = jecs.Entity<T>
type id<T = nil> = jecs.Id<T>
local world = require("./world").get()
--- `map<component_id, array<entity_id>>`
local add_commands: { [id]: { entity } } = {}
--- `map<component_id, array<entity_id, component_value>>`
local set_commands: { [id]: { [entity]: any } } = {}
--- `map<component_id, array<entity_id>>`
local remove_commands: { [id]: { entity } } = {}
--- `array<entity_id>`
local delete_commands: { entity } = {}
type command_buffer = {
--- Execute all buffered commands and clear the buffer
flush: () -> (),
--- Adds a component to the entity with no value
add: (entity: entity, component: id) -> (),
--- Assigns a value to a component on the given entity
set: <T>(entity: entity, component: id<T>, data: T) -> (),
--- Removes a component from the given entity
remove: (entity: entity, component: id) -> (),
--- Deletes an entity from the world
delete: (entity: entity) -> (),
}
local function flush()
local adds = add_commands
local sets = set_commands
local removes = remove_commands
local deletes = delete_commands
table.clear(add_commands)
table.clear(set_commands)
table.clear(remove_commands)
table.clear(delete_commands)
for _, id in deletes do
world:delete(id)
end
for component, ids in adds do
for _, id in ids do
if deletes[id] then
continue
end
world:add(id, component)
end
end
for component, ids in sets do
for id, value in ids do
if deletes[id] then
continue
end
world:set(id, component, value)
end
end
for component, ids in removes do
for _, id in ids do
if deletes[id] then
continue
end
world:remove(id, component)
end
end
end
local function add(entity: entity, component: id)
if not add_commands[component] then
add_commands[component] = {}
end
table.insert(add_commands[component], entity)
end
local function set<T>(entity: entity, component: id<T>, data: T)
if not set_commands[component] then
set_commands[component] = {}
end
set_commands[component][entity] = data
end
local function remove(entity: entity, component: id)
if not remove_commands[component] then
remove_commands[component] = {}
end
table.insert(remove_commands[component], entity)
end
local function delete(entity: entity)
table.insert(delete_commands, entity)
end
local command_buffer: command_buffer = {
flush = flush,
add = add,
set = set,
remove = remove,
delete = delete,
}
return command_buffer