sdl2-hello-world/src/packages/game/input/IZ_joystick.c

#include "IZ_joystick.h"

void IZ_HandleJoystickDeviceEvents(SDL_Event e, IZ_JoystickState* state) {
	if (e.type == SDL_JOYDEVICEADDED) {
		if (SDL_NumJoysticks() <= PLAYERS && !state->joystick_instance) {
			state->joystick_instance = SDL_JoystickOpen(e.jdevice.which);
		}
	}

	if (e.type == SDL_JOYDEVICEREMOVED) {
		if (
			state->joystick_instance
			&& SDL_JoystickInstanceID(state->joystick_instance) == e.jdevice.which
			) {
			state->joystick_instance = NULL;
		}
	}
}

void IZ_HandleJoystickAxisEvents(SDL_Event e, IZ_JoystickState* state, IZ_Action* action) {
	if (e.type == SDL_JOYAXISMOTION) {
		if (
			e.jaxis.axis == IZ_JOYAXIS_DIRECTION_HORIZONTAL1
			|| e.jaxis.axis == IZ_JOYAXIS_DIRECTION_HORIZONTAL2
		) {
			*action &= ~(0x1 << IZ_ACTION_INDEX_RIGHT);
			*action &= ~(0x1 << IZ_ACTION_INDEX_LEFT);
			if (e.jaxis.value > state->config.axis_threshold) {
				*action |= (0x1 << IZ_ACTION_INDEX_RIGHT);
				return;
			}
			if (e.jaxis.value <= -state->config.axis_threshold) {
				*action |= (0x1 << IZ_ACTION_INDEX_LEFT);
			}
			return;
		}
		if (
			e.jaxis.axis == IZ_JOYAXIS_DIRECTION_VERTICAL1
			|| e.jaxis.axis == IZ_JOYAXIS_DIRECTION_VERTICAL2
		) {
			*action &= ~(0x1 << IZ_ACTION_INDEX_UP);
			*action &= ~(0x1 << IZ_ACTION_INDEX_DOWN);
			if (e.jaxis.value > state->config.axis_threshold) {
				*action |= (0x1 << IZ_ACTION_INDEX_DOWN);
				return;
			}
			if (e.jaxis.value <= -state->config.axis_threshold) {
				*action |= (0x1 << IZ_ACTION_INDEX_UP);
			}
		}
	}
}

void IZ_HandleJoystickHatEvents(SDL_Event e, IZ_Action* action) {
	if (e.type == SDL_JOYHATMOTION) {
		*action &= ~(0x1 << IZ_ACTION_INDEX_UP);
		*action &= ~(0x1 << IZ_ACTION_INDEX_RIGHT);
		*action &= ~(0x1 << IZ_ACTION_INDEX_DOWN);
		*action &= ~(0x1 << IZ_ACTION_INDEX_LEFT);
		if (e.jhat.value != 0) {
			*action |= e.jhat.value;
		}
	}
}

void IZ_HandleJoystickButtonEvents(SDL_Event e, IZ_JoystickState* state, IZ_Action* action) {
	for (uint8_t i = 4; i < CONTROLS; i += 1) {
		if (e.jbutton.button == state->config.control_mapping[i]) {
			const uint16_t bitflag = (0x1 << i);

			if (e.type == SDL_JOYBUTTONDOWN) {
				*action |= bitflag;
				break;
			}

			if (e.type == SDL_JOYBUTTONUP) {
				*action &= ~bitflag;
				break;
			}
		}
	}
}

void IZ_HandleJoystickEvents(SDL_Event e, IZ_JoystickState* state, IZ_Action* action) {
	IZ_HandleJoystickDeviceEvents(e, state);
	IZ_HandleJoystickAxisEvents(e, state, action);
	IZ_HandleJoystickHatEvents(e, action);
	IZ_HandleJoystickButtonEvents(e, state, action);
}

void IZ_LoadJoystickConfig(IZ_JoystickConfig* config, uint8_t p) {
	char config_path[128];
	IZ_GetConfigPath(config_path, 128);

	char joystick_control_mapping_section_name[] = "Joystick.0.ControlMapping";
	joystick_control_mapping_section_name[9] = (char) (48 + p);
	for (uint8_t i = 4; i < CONTROLS; i += 1) {
		config->control_mapping[i] = ini_getl(joystick_control_mapping_section_name, ACTION_NAMES[i], IZ_DEFAULT_JOYSTICK_CONTROLS[p][i], config_path);
	}

	char joystick_section_name[] = "Joystick.0";
	joystick_section_name[9] = (char) (48 + p);
	config->axis_threshold = ini_getl(joystick_section_name, "AxisThreshold", 8000, config_path);
}

void IZ_SaveJoystickConfig(IZ_JoystickConfig* config, uint8_t p) {
	char config_path[128];
	IZ_GetConfigPath(config_path, 128);

	char joystick_control_mapping_section_name[] = "Joystick.0.ControlMapping";
	joystick_control_mapping_section_name[9] = (char) (48 + p);
	for (uint8_t i = 4; i < CONTROLS; i += 1) {
		ini_putl(joystick_control_mapping_section_name, ACTION_NAMES[i], config->control_mapping[i], config_path);
	}

	char joystick_section_name[] = "Joystick.0";
	joystick_section_name[9] = (char) (48 + p);
	ini_putl(joystick_section_name, "AxisThreshold", config->axis_threshold, config_path);
}