izanagi-2022/src/packages/game/input/IZ_midi.c

#include "IZ_midi.h"

void IZ_MIDIInputHandleNoteOnOffEvents(IZ_MIDIInputState* state, IZ_Action* action, PmEvent e) {
	u32 message = e.message;
	u8 status = message & 0xF0u;
	u8 channel = message & 0x0Fu;
	u8 data1 = (message >> 8) & 0xFFu;
	// u8 data2 = (message >> 16) & 0xFFu;

	u8 control_index;
	for (control_index = 0; control_index < CONTROLS; control_index += 1) {
		if (
			data1 == state->config.control_mapping[control_index]
			&& (
				(state->config.channel < 16 && channel == state->config.channel)
				|| state->config.channel >= 16
			)
		) {
			const u16 bitflag = (0x1 << control_index);
			if (status == IZ_MIDI_NOTE_ON) {
				*action |= bitflag;
				return;
			}
			if (status == IZ_MIDI_NOTE_OFF) {
				*action &= ~bitflag;
				return;
			}
		}
	}
}

void IZ_MIDIInputHandleEvents(IZ_MIDIInputState(* state)[IZ_PLAYERS], IZ_Action(* action)[IZ_PLAYERS], PmEvent e) {
	u8 player_index;
	for (player_index = 0; player_index < IZ_PLAYERS; player_index += 1) {
		IZ_MIDIInputHandleNoteOnOffEvents(&(*state)[player_index], &(*action)[player_index], e);
	}
}

IZ_ProcedureResult IZ_MIDIInputSaveConfig(IZ_MIDIInputState(* state)[IZ_PLAYERS], const char* config_path) {
	u8 problem = 0;

	char control_mapping_section_name[27];
	char main_section_name[12];

	u8 player_index;
	u8 control_index;
	for (player_index = 0; player_index < IZ_PLAYERS; player_index += 1) {
		sprintf_s(control_mapping_section_name, 27, "MIDIInput.%d.ControlMapping", player_index);
		for (control_index = 0; control_index < CONTROLS; control_index += 1) {
			if (!ini_puts(
				control_mapping_section_name,
				ACTION_NAMES[control_index],
				IZ_MIDIGetNoteName((*state)[player_index].config.control_mapping[control_index]),
				config_path
			)) {
				problem |= (1 << player_index);
			}
		}

		sprintf_s(main_section_name, 12, "MIDIInput.%d", player_index);
		if (!ini_putl(
			main_section_name,
			"Channel",
			(*state)[player_index].config.channel,
			config_path
		)) {
			problem |= (1 << player_index);
		}

		if (!ini_putl(
			main_section_name,
			"DeviceID",
			(*state)[player_index].config.device_id,
			config_path
		)) {
			problem |= (1 << player_index);
		}
	}

	return problem;
}

void IZ_MIDIInputLoadConfig(IZ_MIDIInputState(* state)[IZ_PLAYERS], const char* config_path) {
	char buffer[128];
	char control_mapping_section_name[27];
	char main_section_name[12];

	u8 player_index;
	u8 control_index;
	for (player_index = 0; player_index < IZ_PLAYERS; player_index += 1) {
		sprintf_s(control_mapping_section_name, 27, "MIDIInput.%d.ControlMapping", player_index);
		for (control_index = 0; control_index < CONTROLS; control_index += 1) {
			ini_gets(
				control_mapping_section_name,
				ACTION_NAMES[control_index],
				IZ_MIDIGetNoteName(IZ_MIDI_INPUT_DEFAULT_STATE[player_index].config.control_mapping[control_index]),
				buffer,
				128,
				config_path
			);

			(*state)[player_index].config.control_mapping[control_index] = IZ_MIDIGetNoteFromName(buffer);
		}

		sprintf_s(main_section_name, 12, "MIDIInput.%d", player_index);
		(*state)[player_index].config.channel = ini_getl(main_section_name, "Channel", player_index, config_path);
		(*state)[player_index].config.device_id = ini_getl(main_section_name, "DeviceID", player_index, config_path);
	}
}

IZ_ProcedureResult IZ_MIDIInputInitialize(IZ_MIDIInputState(* state)[IZ_PLAYERS], const char* config_path, u8 argc, const char* argv[]) {
	if (Pm_Initialize()) {
		return 1;
	}

	SDL_memcpy(state, &IZ_MIDI_INPUT_DEFAULT_STATE, sizeof(IZ_MIDIInputState));
	IZ_MIDIInputLoadConfig(state, config_path);
	if (IZ_MIDIInputSaveConfig(state, config_path)) {
		return 2;
	}

	u8 player_index;
	u8 midi_devices_count = Pm_CountDevices();
	u8 input_midi_devices_count = 0;
	u8 device_index;
	for (device_index = 0; device_index < midi_devices_count; device_index += 1) {
		if (!Pm_GetDeviceInfo(device_index)->output) {
			continue;
		}

		// midi device can output messages for the app to receive
		input_midi_devices_count += 1;
	}

	for (player_index = 0; player_index < input_midi_devices_count; player_index += 1) {
		if (player_index >= IZ_PLAYERS) {
			break;
		}
		(*state)[player_index].device_info = Pm_GetDeviceInfo((*state)[player_index].config.device_id);
		(*state)[player_index].stream = NULL;
		Pm_OpenInput(
			&(*state)[player_index].stream,
			(*state)[player_index].config.device_id,
			NULL,
			MIDI_EVENT_BUFFER_SIZE,
			NULL,
			NULL
		);
	}

	return 0;
}

void IZ_MIDIInputTeardown(IZ_MIDIInputState(* state)[IZ_PLAYERS]) {
	u8 player_index;
	for (player_index = 0; player_index < IZ_PLAYERS; player_index += 1) {
		if (!(*state)[player_index].stream) {
			continue;
		}
		Pm_Close((*state)[player_index].stream);
	}
}