1 files changed, 24 insertions, 0 deletions
diff --git a/src/state_machine.lua b/src/state_machine.lua
new file mode 100644
index 0000000..7aac1bc
--- /dev/null
+++ b/src/state_machine.lua
@@ -0,0 +1,24 @@
+register_comp("State_Machine", function(ent, default, states)
+  assert(states[default], "Entity does not have state '" .. default .. "'.")
+
+  ent.states = states
+  ent.state = default
+
+  for _, state in pairs(states) do
+    state.data = {}
+    try(state.init, state.data)
+  end
+end)
+
+function state_update_sys(ent, dt)
+  try(ent.states[ent.state].update, ent, ent.states[ent.state].data, dt)
+end
+
+function set_state(ent, to)
+  assert(has_comp(ent, "State_Machine"), "Entity must have a state machine.")
+  assert(ent.states[to], "Entity does not have state '" .. to .. "'.")
+
+  try(ent.states[ent.state].exit, ent, ent.states[ent.state].data, to)
+  ent.state = to
+  try(ent.states[ent.state].enter, ent, ent.states[ent.state].data)
+end