migrate Gravity firmware into a new dedicated firmware directory.

firmware/Gravity/app_state.h

@@ -0,0 +1,54 @@
+#ifndef APP_STATE_H
+#define APP_STATE_H
+
+#include <gravity.h>
+
+#include "channel.h"
+
+// Global state for settings and app behavior.
+struct AppState {
+    int tempo = Clock::DEFAULT_TEMPO;
+    bool encoder_reversed = false;
+    bool refresh_screen = true;
+    bool editing_param = false;
+    byte selected_param = 0;
+    byte selected_sub_param = 0;  // Temporary value for editing params.
+    byte selected_channel = 0;    // 0=tempo, 1-6=output channel
+    byte selected_swing = 0;
+    byte selected_save_slot = 0;  // The currently active save slot.
+    Clock::Source selected_source = Clock::SOURCE_INTERNAL;
+    Clock::Pulse selected_pulse = Clock::PULSE_PPQN_24;
+    Channel channel[Gravity::OUTPUT_COUNT];
+};
+
+extern AppState app;
+
+static Channel& GetSelectedChannel() {
+    return app.channel[app.selected_channel - 1];
+}
+
+enum ParamsMainPage : uint8_t {
+    PARAM_MAIN_TEMPO,
+    PARAM_MAIN_SOURCE,
+    PARAM_MAIN_PULSE,
+    PARAM_MAIN_ENCODER_DIR,
+    PARAM_MAIN_SAVE_DATA,
+    PARAM_MAIN_LOAD_DATA,
+    PARAM_MAIN_RESET_STATE,
+    PARAM_MAIN_LAST,
+};
+
+enum ParamsChannelPage : uint8_t {
+    PARAM_CH_MOD,
+    PARAM_CH_PROB,
+    PARAM_CH_DUTY,
+    PARAM_CH_OFFSET,
+    PARAM_CH_SWING,
+    PARAM_CH_EUC_STEPS,
+    PARAM_CH_EUC_HITS,
+    PARAM_CH_CV1_DEST,
+    PARAM_CH_CV2_DEST,
+    PARAM_CH_LAST,
+};
+
+#endif  // APP_STATE_H