1 files changed, 37 insertions, 0 deletions
diff --git a/fsm/states.h b/fsm/states.h
new file mode 100644
index 0000000..156e6cf
--- /dev/null
+++ b/fsm/states.h
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+// fsm-states.h: State-handling functions for SpaghettiMonster.
+// Copyright (C) 2017-2023 Selene ToyKeeper
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#pragma once
+
+#include "fsm-adc.h"
+
+// typedefs
+typedef uint8_t State(Event event, uint16_t arg);
+typedef State * StatePtr;
+
+// top of the stack
+volatile StatePtr current_state;
+
+// stack for states, to allow shared utility states like "input a number"
+// and such, which return to the previous state after finishing
+#define STATE_STACK_SIZE 8
+StatePtr state_stack[STATE_STACK_SIZE];
+uint8_t state_stack_len = 0;
+
+void _set_state(StatePtr new_state, uint16_t arg,
+                Event exit_event, Event enter_event);
+int8_t push_state(StatePtr new_state, uint16_t arg);
+StatePtr pop_state();
+uint8_t set_state(StatePtr new_state, uint16_t arg);
+
+// if loop() needs to change state, use this instead of set_state()
+// (because this avoids race conditions)
+volatile StatePtr deferred_state;
+volatile uint16_t deferred_state_arg;
+void set_state_deferred(StatePtr new_state, uint16_t arg);
+
+#ifndef DONT_USE_DEFAULT_STATE
+uint8_t default_state(Event event, uint16_t arg);
+#endif
+