goldberg_emulator/controller/gamepad.c

/**
 * Gamepad Input Library
 * Sean Middleditch
 * Copyright (C) 2010  Sean Middleditch
 * LICENSE: MIT/X
 */

#include <math.h>
#include <string.h>
#include <errno.h>
#include <malloc.h>

#define GAMEPAD_EXPORT 1
#include "gamepad.h"

/* Platform-specific includes */
#if defined(_WIN32)
#	define WIN32_LEAN_AND_MEAN 1
#	undef UNICODE
#	include "windows.h"
#	include "xinput.h"
#	pragma comment(lib, "XINPUT9_1_0.lib")
#elif defined(__linux__)
#	include <linux/joystick.h>
#	include <stdio.h>
#	include <fcntl.h>
#	include <unistd.h>
#	include <dirent.h>
#	include <sys/stat.h>
#	include <time.h>
#else
#	error "Unknown platform in gamepad.c"
#endif

#define BUTTON_TO_FLAG(b) (1 << (b))

/* Axis information */
typedef struct GAMEPAD_AXIS GAMEPAD_AXIS;
struct GAMEPAD_AXIS {
	int x, y;
	float nx, ny;
	float length;
	float angle;
	GAMEPAD_STICKDIR dirLast, dirCurrent;
};

/* Trigger value information */
typedef struct GAMEPAD_TRIGINFO GAMEPAD_TRIGINFO;
struct GAMEPAD_TRIGINFO {
	int value;
	float length;
	GAMEPAD_BOOL pressedLast, pressedCurrent;
};

/* Structure for state of a particular gamepad */
typedef struct GAMEPAD_STATE GAMEPAD_STATE;
struct GAMEPAD_STATE {
	GAMEPAD_AXIS stick[STICK_COUNT];
	GAMEPAD_TRIGINFO trigger[TRIGGER_COUNT];
	int bLast, bCurrent, flags;
#if defined(__linux__)
	char* device;
	int fd;
	int effect;
	double axis_min[ABS_MAX];
	double axis_max[ABS_MAX];
#endif
};

/* State of the four gamepads */
static GAMEPAD_STATE STATE[4];

/* Note whether a gamepad is currently connected */
#define FLAG_CONNECTED	(1<<0)
#define FLAG_RUMBLE		(1<<1)

/* Prototypes for utility functions */
static void GamepadResetState		(GAMEPAD_DEVICE gamepad);
static void GamepadUpdateCommon		(void);
static void GamepadUpdateDevice		(GAMEPAD_DEVICE gamepad);
static void GamepadUpdateStick		(GAMEPAD_AXIS* axis, float deadzone);
static void GamepadUpdateTrigger	(GAMEPAD_TRIGINFO* trig);

/* Various values of PI */
#define PI_1_4	0.78539816339744f
#define PI_1_2	1.57079632679489f
#define PI_3_4	2.35619449019234f
#define PI		3.14159265358979f

/* Platform-specific implementation code */
#if defined(_WIN32)

void GamepadInit(void) {
	int i;
	for (i = 0; i != GAMEPAD_COUNT; ++i) {
		STATE[i].flags = 0;
	}
}

void GamepadUpdate(void) {
	GamepadUpdateCommon();
}

static void GamepadUpdateDevice(GAMEPAD_DEVICE gamepad) {
	XINPUT_STATE xs;
	if (XInputGetState(gamepad, &xs) == 0) {
		/* reset if the device was not already connected */
		if ((STATE[gamepad].flags & FLAG_CONNECTED) == 0) {
			GamepadResetState(gamepad);
		}

		/* mark that we are connected w/ rumble support */
		STATE[gamepad].flags |= FLAG_CONNECTED|FLAG_RUMBLE;

		/* update state */
		STATE[gamepad].bCurrent = xs.Gamepad.wButtons;
		STATE[gamepad].trigger[TRIGGER_LEFT].value = xs.Gamepad.bLeftTrigger;
		STATE[gamepad].trigger[TRIGGER_RIGHT].value = xs.Gamepad.bRightTrigger;
		STATE[gamepad].stick[STICK_LEFT].x = xs.Gamepad.sThumbLX;
		STATE[gamepad].stick[STICK_LEFT].y = xs.Gamepad.sThumbLY;
		STATE[gamepad].stick[STICK_RIGHT].x = xs.Gamepad.sThumbRX;
		STATE[gamepad].stick[STICK_RIGHT].y = xs.Gamepad.sThumbRY;
	} else {
		/* disconnected */
		STATE[gamepad].flags &= ~FLAG_CONNECTED;
	}
}

void GamepadShutdown(void) {
	/* no Win32 shutdown required */
}

void GamepadSetRumble(GAMEPAD_DEVICE gamepad, float left, float right, unsigned int rumble_length_ms) {
	//TODO: rumble_length_ms
	if ((STATE[gamepad].flags & FLAG_RUMBLE) != 0) {
		XINPUT_VIBRATION vib;
		ZeroMemory(&vib, sizeof(vib));
		vib.wLeftMotorSpeed = (WORD)(left * 65535);
		vib.wRightMotorSpeed = (WORD)(right * 65535);
		XInputSetState(gamepad, &vib);
	}
}

#elif defined(__linux__)
#define test_bit(nr, addr) \
	(((1UL << ((nr) % (sizeof(long) * 8))) & ((addr)[(nr) / (sizeof(long) * 8)])) != 0)
#define NBITS(x) ((((x)-1)/(sizeof(long) * 8))+1)


static int IsGamepad(int fd, char *namebuf, const size_t namebuflen)
{
	struct input_id inpid;
	//uint16_t *guid16 = (uint16_t *)guid->data;

	/* When udev is enabled we only get joystick devices here, so there's no need to test them */
	unsigned long evbit[NBITS(EV_MAX)] = { 0 };
	unsigned long keybit[NBITS(KEY_MAX)] = { 0 };
	unsigned long absbit[NBITS(ABS_MAX)] = { 0 };

	if ((ioctl(fd, EVIOCGBIT(0, sizeof(evbit)), evbit) < 0) ||
		(ioctl(fd, EVIOCGBIT(EV_KEY, sizeof(keybit)), keybit) < 0) ||
		(ioctl(fd, EVIOCGBIT(EV_ABS, sizeof(absbit)), absbit) < 0)) {
		return (0);
	}

	if (!(test_bit(EV_KEY, evbit) && test_bit(EV_ABS, evbit) &&
		  test_bit(ABS_X, absbit) && test_bit(ABS_Y, absbit))) {
		return 0;
	}

	if (ioctl(fd, EVIOCGNAME(namebuflen), namebuf) < 0) {
		return 0;
	}

	if (ioctl(fd, EVIOCGID, &inpid) < 0) {
		return 0;
	}

	//printf("Joystick: %s, bustype = %d, vendor = 0x%.4x, product = 0x%.4x, version = %d\n", namebuf, inpid.bustype, inpid.vendor, inpid.product, inpid.version);

	//memset(guid->data, 0, sizeof(guid->data));

	/* We only need 16 bits for each of these; space them out to fill 128. */
	/* Byteswap so devices get same GUID on little/big endian platforms. */
/*
	*guid16++ = SDL_SwapLE16(inpid.bustype);
	*guid16++ = 0;

	if (inpid.vendor && inpid.product) {
		*guid16++ = SDL_SwapLE16(inpid.vendor);
		*guid16++ = 0;
		*guid16++ = SDL_SwapLE16(inpid.product);
		*guid16++ = 0;
		*guid16++ = SDL_SwapLE16(inpid.version);
		*guid16++ = 0;
	} else {
		strlcpy((char*)guid16, namebuf, sizeof(guid->data) - 4);
	}

	if (SDL_ShouldIgnoreJoystick(namebuf, *guid)) {
		return 0;
	}
*/
	return 1;
}

static void GamepadAddDevice(const char* devPath);
static void GamepadRemoveDevice(const char* devPath);

static void GamepadDetect()
{
	DIR *folder;
	struct dirent *dent;

	folder = opendir("/dev/input");
	if (folder) {
		while ((dent = readdir(folder))) {
			int len = strlen(dent->d_name);
			if (len > 5 && strncmp(dent->d_name, "event", 5) == 0) {
				char path[PATH_MAX];
				snprintf(path, sizeof(path), "/dev/input/%s", dent->d_name);
				GamepadAddDevice(path);
			}
		}

		closedir(folder);
	}

	for (int i = 0; i != GAMEPAD_COUNT; ++i) {
		if ((STATE[i].flags & FLAG_CONNECTED) && STATE[i].device) {
			struct stat sb;
			//printf("%s\n", STATE[i].device);
			if (stat(STATE[i].device, &sb) == -1) {
				GamepadRemoveDevice(STATE[i].device);
			}
		}
	}
}



/* Helper to add a new device */
static void GamepadAddDevice(const char* devPath) {
	int i;

	/* try to find a free controller */
	for (i = 0; i != GAMEPAD_COUNT; ++i) {
		if ((STATE[i].flags & FLAG_CONNECTED) == 0) {
			break;
		}

		if (STATE[i].device && strcmp(devPath, STATE[i].device) == 0) {
			return;
		}
	}

	if (i == GAMEPAD_COUNT) {
		return;
	}

	int fd = open(devPath, O_RDWR, 0);
	if (fd < 0) return;
	char namebuf[128];
	int is_gamepad = IsGamepad(fd, namebuf, sizeof (namebuf));
	if (!is_gamepad) {
		close(fd);
		return;
	}

	/* copy the device path */
	STATE[i].device = strdup(devPath);
	if (STATE[i].device == NULL) {
		return;
	}

	/* reset device state */
	GamepadResetState((GAMEPAD_DEVICE)i);

	fcntl(fd, F_SETFL, O_NONBLOCK);
	STATE[i].fd = fd;
	STATE[i].flags |= FLAG_CONNECTED;

	int controller = i;
	{
	int i, t;
	unsigned long keybit[NBITS(KEY_MAX)] = { 0 };
	unsigned long absbit[NBITS(ABS_MAX)] = { 0 };
	unsigned long relbit[NBITS(REL_MAX)] = { 0 };
	unsigned long ffbit[NBITS(FF_MAX)] = { 0 };

	/* See if this device uses the new unified event API */
	if ((ioctl(fd, EVIOCGBIT(EV_KEY, sizeof(keybit)), keybit) >= 0) &&
		(ioctl(fd, EVIOCGBIT(EV_ABS, sizeof(absbit)), absbit) >= 0) &&
		(ioctl(fd, EVIOCGBIT(EV_REL, sizeof(relbit)), relbit) >= 0)) {

		/* Get the number of buttons, axes, and other thingamajigs */
		for (i = BTN_JOYSTICK; i < KEY_MAX; ++i) {
			if (test_bit(i, keybit)) {
				//printf("Joystick has button: 0x%x\n", i);
			}
		}
		for (i = 0; i < BTN_JOYSTICK; ++i) {
			if (test_bit(i, keybit)) {
				//printf("Joystick has button: 0x%x\n", i);
			}
		}
		for (i = 0; i < ABS_MAX; ++i) {
			/* Skip hats */
			if (i == ABS_HAT0X) {
				i = ABS_HAT3Y;
				continue;
			}
			if (test_bit(i, absbit)) {
				struct input_absinfo absinfo;

				if (ioctl(fd, EVIOCGABS(i), &absinfo) < 0) {
					continue;
				}
/*
				printf("Joystick has absolute axis: 0x%.2x\n", i);
				printf("Values = { %d, %d, %d, %d, %d }\n",
					   absinfo.value, absinfo.minimum, absinfo.maximum,
					   absinfo.fuzz, absinfo.flat);
*/
				STATE[controller].axis_min[i] = absinfo.minimum;
				STATE[controller].axis_max[i] = absinfo.maximum;
			}
		}
		for (i = ABS_HAT0X; i <= ABS_HAT3Y; i += 2) {
			if (test_bit(i, absbit) || test_bit(i + 1, absbit)) {
				struct input_absinfo absinfo;
				int hat_index = (i - ABS_HAT0X) / 2;

				if (ioctl(fd, EVIOCGABS(i), &absinfo) < 0) {
					continue;
				}
/*
				printf("Joystick has hat %d\n", hat_index);
				printf("Values = { %d, %d, %d, %d, %d }\n",
					   absinfo.value, absinfo.minimum, absinfo.maximum,
					   absinfo.fuzz, absinfo.flat);
*/
				//joystick->hwdata->hats_indices[joystick->nhats++] = hat_index;
			}
		}
		if (test_bit(REL_X, relbit) || test_bit(REL_Y, relbit)) {
			//++joystick->nballs;
		}
	}

	if (ioctl(fd, EVIOCGBIT(EV_FF, sizeof(ffbit)), ffbit) >= 0) {
		if (test_bit(FF_RUMBLE, ffbit)) {
			STATE[controller].flags |= FLAG_RUMBLE;
		}
		if (test_bit(FF_SINE, ffbit)) {
			//printf("sine\n");
		}
	}
	}
}

/* Helper to remove a device */
static void GamepadRemoveDevice(const char* devPath) {
	int i;
	for (i = 0; i != GAMEPAD_COUNT; ++i) {
		if (STATE[i].device != NULL && strcmp(STATE[i].device, devPath) == 0) {
			if (STATE[i].fd != -1) {
				close(STATE[i].fd);
				STATE[i].fd = -1;
			}
			free(STATE[i].device);
			STATE[i].device = 0;
			STATE[i].flags = 0;
			break;
		}
	}
}

void GamepadInit(void) {
	struct udev_list_entry* devices;
	struct udev_list_entry* item;
	struct udev_enumerate* enu;
	int i;

	/* initialize connection state */
	for (i = 0; i != GAMEPAD_COUNT; ++i) {
		STATE[i].flags = 0;
		STATE[i].fd = STATE[i].effect = -1;
	}

	GamepadDetect();
}

void GamepadUpdate(void) {
	static unsigned long last = 0;
	unsigned long cur = time(NULL);

	if (last + 2 < cur) {
		GamepadDetect();
		last = cur;
	}

	GamepadUpdateCommon();
}

static int adjust_values_trigger(double min, double max, double value)
{
	return (((value + (0 - min)) / (max - min)) * 255.0);
}

static int adjust_values_stick(double min, double max, double value)
{
	return (((value + (0 - min)) / (max - min)) * (65535.0)) - 32768.0;
}

static void GamepadUpdateDevice(GAMEPAD_DEVICE gamepad) {
	if (STATE[gamepad].flags & FLAG_CONNECTED) {
		struct input_event events[32];
		int i, len;
		int code;

		while ((len = read(STATE[gamepad].fd, events, (sizeof events))) > 0) {
			len /= sizeof(events[0]);
			for (i = 0; i < len; ++i) {
				int button = 0;
				code = events[i].code;
				switch (events[i].type) {
				case EV_KEY:
					//printf("EV_KEY %i\n", code);
					switch (code) {
					case BTN_SOUTH: button = BUTTON_A; break;
					case BTN_EAST: button = BUTTON_B; break;
					case BTN_NORTH: button = BUTTON_X; break;
					case BTN_WEST: button = BUTTON_Y; break;
					case BTN_TL: button = BUTTON_LEFT_SHOULDER; break;
					case BTN_TR: button = BUTTON_RIGHT_SHOULDER; break;
					case BTN_SELECT: button = BUTTON_BACK; break;
					case BTN_START: button = BUTTON_START; break;
					case BTN_MODE: button = 0; break; /* XBOX button  */
					case BTN_THUMBL: button = BUTTON_LEFT_THUMB; break;
					case BTN_THUMBR: button = BUTTON_RIGHT_THUMB; break;
					default: button = 0; break;
					}
					if (events[i].value) {
						STATE[gamepad].bCurrent |= BUTTON_TO_FLAG(button);
					} else {
						STATE[gamepad].bCurrent ^= BUTTON_TO_FLAG(button);
					}
					break;
				case EV_ABS:
					switch (code) {
					case ABS_HAT0X:
					case ABS_HAT0Y:
					case ABS_HAT1X:
					case ABS_HAT1Y:
					case ABS_HAT2X:
					case ABS_HAT2Y:
					case ABS_HAT3X:
					case ABS_HAT3Y:
						//code -= ABS_HAT0X;
						//printf("ABS_HAT %i\n", code);
						switch(code) {
							case ABS_HAT0X:
								if (events[i].value < 0) {
									STATE[gamepad].bCurrent |= BUTTON_TO_FLAG(BUTTON_DPAD_LEFT);
									STATE[gamepad].bCurrent &= ~BUTTON_TO_FLAG(BUTTON_DPAD_RIGHT);
								} else if (events[i].value > 0) {
									STATE[gamepad].bCurrent |= BUTTON_TO_FLAG(BUTTON_DPAD_RIGHT);
									STATE[gamepad].bCurrent &= ~BUTTON_TO_FLAG(BUTTON_DPAD_LEFT);
								} else {
									STATE[gamepad].bCurrent &= ~BUTTON_TO_FLAG(BUTTON_DPAD_LEFT) & ~BUTTON_TO_FLAG(BUTTON_DPAD_RIGHT);
								}
								break;
							case ABS_HAT0Y:
								if (events[i].value < 0) {
									STATE[gamepad].bCurrent |= BUTTON_TO_FLAG(BUTTON_DPAD_UP);
									STATE[gamepad].bCurrent &= ~BUTTON_TO_FLAG(BUTTON_DPAD_DOWN);
								} else if (events[i].value > 0) {
									STATE[gamepad].bCurrent |= BUTTON_TO_FLAG(BUTTON_DPAD_DOWN);
									STATE[gamepad].bCurrent &= ~BUTTON_TO_FLAG(BUTTON_DPAD_UP);
								} else {
									STATE[gamepad].bCurrent &= ~BUTTON_TO_FLAG(BUTTON_DPAD_UP) & ~BUTTON_TO_FLAG(BUTTON_DPAD_DOWN);
								}
								break;
						}
						break;
					default:
						//printf("EV_ABS %i %i\n", code, events[i].value);
						if (code == ABS_Z || code == ABS_RZ) {
							int value = adjust_values_trigger(STATE[gamepad].axis_min[code], STATE[gamepad].axis_max[code], events[i].value);
							switch(code) {
								case ABS_Z :	STATE[gamepad].trigger[TRIGGER_LEFT].value = value; break;
								case ABS_RZ:	STATE[gamepad].trigger[TRIGGER_RIGHT].value = value; break;
							}
						} else {
							int value = adjust_values_stick(STATE[gamepad].axis_min[code], STATE[gamepad].axis_max[code], events[i].value);
							switch(code) {
								case ABS_X :	STATE[gamepad].stick[STICK_LEFT].x = value; break;
								case ABS_Y :	STATE[gamepad].stick[STICK_LEFT].y = -value; break;
								case ABS_RX:	STATE[gamepad].stick[STICK_RIGHT].x = value; break;
								case ABS_RY:	STATE[gamepad].stick[STICK_RIGHT].y = -value; break;
							}
						}
						break;
					}
					break;
				case EV_REL:
					switch (code) {
					case REL_X:
					case REL_Y:
						code -= REL_X;
						//printf("EV_REL %i %i\n", code, events[i].value);
						break;
					default:
						break;
					}
					break;
				case EV_SYN:
					switch (code) {
					case SYN_DROPPED :
						//printf("Event SYN_DROPPED detected\n");
						break;
					default:
						break;
					}
				default:
					break;
				}
			}
		}
	}
}

void GamepadShutdown(void) {
	int i;

	/* cleanup devices */
	for (i = 0; i != GAMEPAD_COUNT; ++i) {
		if (STATE[i].device != NULL) {
			free(STATE[i].device);
		}

		if (STATE[i].fd != -1) {
			close(STATE[i].fd);
		}
	}
}

void GamepadSetRumble(GAMEPAD_DEVICE gamepad, float left, float right, unsigned int rumble_length_ms) {
	if (STATE[gamepad].fd != -1) {
		struct input_event play;
		struct ff_effect ff;

		/* define an effect for this rumble setting */
		ff.type = FF_RUMBLE;
		ff.id = STATE[gamepad].effect;
		ff.u.rumble.strong_magnitude = (unsigned short)(left * 65535);
		ff.u.rumble.weak_magnitude = (unsigned short)(right * 65535);
		ff.replay.length = rumble_length_ms;
		ff.replay.delay = 0;

		/* upload the effect */
		if (ioctl(STATE[gamepad].fd, EVIOCSFF, &ff) != -1) {
			STATE[gamepad].effect = ff.id;
		}

		/* play the effect */
		play.type = EV_FF;
		play.code = STATE[gamepad].effect;
		play.value = 1;

		write(STATE[gamepad].fd, (const void*)&play, sizeof(play));
	}
}

#else /* !defined(_WIN32) && !defined(__linux__) */

#	error "Unknown platform in gamepad.c"

#endif /* end of platform implementations */

GAMEPAD_BOOL GamepadIsConnected(GAMEPAD_DEVICE device) {
	return (STATE[device].flags & FLAG_CONNECTED) != 0 ? GAMEPAD_TRUE : GAMEPAD_FALSE;
}

GAMEPAD_BOOL GamepadButtonDown(GAMEPAD_DEVICE device, GAMEPAD_BUTTON button) {
	return (STATE[device].bCurrent & BUTTON_TO_FLAG(button)) != 0 ? GAMEPAD_TRUE : GAMEPAD_FALSE;
}

GAMEPAD_BOOL GamepadButtonTriggered(GAMEPAD_DEVICE device, GAMEPAD_BUTTON button) {
	return ((STATE[device].bLast & BUTTON_TO_FLAG(button)) == 0 &&
			(STATE[device].bCurrent & BUTTON_TO_FLAG(button)) != 0) ? GAMEPAD_TRUE : GAMEPAD_FALSE;
}

GAMEPAD_BOOL GamepadButtonReleased(GAMEPAD_DEVICE device, GAMEPAD_BUTTON button) {
	return ((STATE[device].bCurrent & BUTTON_TO_FLAG(button)) == 0 &&
			(STATE[device].bLast & BUTTON_TO_FLAG(button)) != 0) ? GAMEPAD_TRUE : GAMEPAD_FALSE;
}

int GamepadTriggerValue(GAMEPAD_DEVICE device, GAMEPAD_TRIGGER trigger) {
	return STATE[device].trigger[trigger].value;
}

float GamepadTriggerLength(GAMEPAD_DEVICE device, GAMEPAD_TRIGGER trigger) {
	return STATE[device].trigger[trigger].length;
}

GAMEPAD_BOOL GamepadTriggerDown(GAMEPAD_DEVICE device, GAMEPAD_TRIGGER trigger) {
	return STATE[device].trigger[trigger].pressedCurrent;
}

GAMEPAD_BOOL GamepadTriggerTriggered(GAMEPAD_DEVICE device, GAMEPAD_TRIGGER trigger) {
	return (STATE[device].trigger[trigger].pressedCurrent &&
			!STATE[device].trigger[trigger].pressedLast) ? GAMEPAD_TRUE : GAMEPAD_FALSE;
}

GAMEPAD_BOOL GamepadTriggerReleased(GAMEPAD_DEVICE device, GAMEPAD_TRIGGER trigger) {
	return (!STATE[device].trigger[trigger].pressedCurrent &&
			STATE[device].trigger[trigger].pressedLast) ? GAMEPAD_TRUE : GAMEPAD_FALSE;
}

void GamepadStickXY(GAMEPAD_DEVICE device, GAMEPAD_STICK stick, int *outX, int *outY) {
	*outX = STATE[device].stick[stick].x;
	*outY = STATE[device].stick[stick].y;
}

float GamepadStickLength(GAMEPAD_DEVICE device, GAMEPAD_STICK stick) {
	return STATE[device].stick[stick].length;
}

void GamepadStickNormXY(GAMEPAD_DEVICE device, GAMEPAD_STICK stick, float *outX, float *outY) {
	*outX = STATE[device].stick[stick].nx;
	*outY = STATE[device].stick[stick].ny;
}

float GamepadStickAngle(GAMEPAD_DEVICE device, GAMEPAD_STICK stick) {
	return STATE[device].stick[stick].angle;
}

GAMEPAD_STICKDIR GamepadStickDir(GAMEPAD_DEVICE device, GAMEPAD_STICK stick) {
	return STATE[device].stick[stick].dirCurrent;
}

GAMEPAD_BOOL GamepadStickDirTriggered(GAMEPAD_DEVICE device, GAMEPAD_STICK stick, GAMEPAD_STICKDIR dir) {
	return (STATE[device].stick[stick].dirCurrent == dir &&
			STATE[device].stick[stick].dirCurrent != STATE[device].stick[stick].dirLast) ? GAMEPAD_TRUE : GAMEPAD_FALSE;
}

/* initialize common gamepad state */
static void GamepadResetState(GAMEPAD_DEVICE gamepad) {
	memset(STATE[gamepad].stick, 0, sizeof(STATE[gamepad].stick));
	memset(STATE[gamepad].trigger, 0, sizeof(STATE[gamepad].trigger));
	STATE[gamepad].bLast = STATE[gamepad].bCurrent = 0;
}

/* Update individual sticks */
static void GamepadUpdateCommon(void) {
	int i;
	for (i = 0; i != GAMEPAD_COUNT; ++i) {
		/* store previous button state */
		STATE[i].bLast = STATE[i].bCurrent;

		/* per-platform update routines */
		GamepadUpdateDevice((GAMEPAD_DEVICE)i);

		/* calculate refined stick and trigger values */
		if ((STATE[i].flags & FLAG_CONNECTED) != 0) {
			GamepadUpdateStick(&STATE[i].stick[STICK_LEFT], GAMEPAD_DEADZONE_LEFT_STICK);
			GamepadUpdateStick(&STATE[i].stick[STICK_RIGHT], GAMEPAD_DEADZONE_RIGHT_STICK);

			GamepadUpdateTrigger(&STATE[i].trigger[TRIGGER_LEFT]);
			GamepadUpdateTrigger(&STATE[i].trigger[TRIGGER_RIGHT]);
		}
	}
}

/* Update stick info */
static void GamepadUpdateStick(GAMEPAD_AXIS* axis, float deadzone) {
	// determine magnitude of stick
	axis->length = sqrtf((float)(axis->x*axis->x) + (float)(axis->y*axis->y));

	if (axis->length > deadzone) {
		// clamp length to maximum value
		if (axis->length > 32767.0f) {
			axis->length = 32767.0f;
		}

		// normalized X and Y values
		axis->nx = axis->x / axis->length;
		axis->ny = axis->y / axis->length;

		//fix special case
		if (axis->nx < -1.0) axis->nx = -1.0;
		if (axis->ny < -1.0) axis->ny = -1.0;

		// adjust length for deadzone and find normalized length
		axis->length -= deadzone;
		axis->length /= (32767.0f - deadzone);

		// find angle of stick in radians
		axis->angle = atan2f((float)axis->y, (float)axis->x);
	} else {
		axis->x = axis->y = 0;
		axis->nx = axis->ny = 0.0f;
		axis->length = axis->angle = 0.0f;
	}

	/* update the stick direction */
	axis->dirLast = axis->dirCurrent;
	axis->dirCurrent = STICKDIR_CENTER;

	/* check direction to see if it's non-centered */
	if (axis->length != 0.f) {
		if (axis->angle >= PI_1_4 && axis->angle < PI_3_4) {
			axis->dirCurrent = STICKDIR_UP;
		} else if (axis->angle >= -PI_3_4 && axis->angle < -PI_1_4) {
			axis->dirCurrent = STICKDIR_DOWN;
		} else if (axis->angle >= PI_3_4 || axis->angle < -PI_3_4) {
			axis->dirCurrent = STICKDIR_LEFT;
		} else /* if (axis->angle < PI_1_4 && axis->angle >= -PI_1_4) */ {
			axis->dirCurrent = STICKDIR_RIGHT;
		}
	}
}

/* Update trigger info */
static void GamepadUpdateTrigger(GAMEPAD_TRIGINFO* trig) {
	trig->pressedLast = trig->pressedCurrent;

	if (trig->value > GAMEPAD_DEADZONE_TRIGGER) {
		trig->length = ((trig->value - GAMEPAD_DEADZONE_TRIGGER) / (255.0f - GAMEPAD_DEADZONE_TRIGGER));
		trig->pressedCurrent = GAMEPAD_TRUE;
	} else {
		trig->value = 0;
		trig->length = 0.0f;
		trig->pressedCurrent = GAMEPAD_FALSE;
	}
}