RetroArch/wii/wiiuse/nunchuk.c

/* This source as presented is a modified version of original wiiuse for use 
 * with RetroArch, and must not be confused with the original software. */

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>

#include "dynamics.h"
#include "definitions.h"
#include "wiiuse_internal.h"
#include "nunchuk.h"
#include "io.h"

/**
 *	@brief Find what buttons are pressed.
 *
 *	@param nc		Pointer to a nunchuk_t structure.
 *	@param msg		The message byte specified in the event packet.
 */
static void nunchuk_pressed_buttons(struct nunchuk_t* nc, ubyte now) {
	/* message is inverted (0 is active, 1 is inactive) */
	now = ~now & NUNCHUK_BUTTON_ALL;

	/* preserve old btns pressed */
	nc->btns_last = nc->btns;

	/* pressed now & were pressed, then held */
	nc->btns_held = (now & nc->btns);

	/* were pressed or were held & not pressed now, then released */
	nc->btns_released = ((nc->btns | nc->btns_held) & ~now);

	/* buttons pressed now */
	nc->btns = now;
}

int nunchuk_handshake(struct wiimote_t *wm,struct nunchuk_t *nc,ubyte *data,uword len)
{
	//int i;
	int offset = 0;

	nc->btns = 0;
	nc->btns_held = 0;
	nc->btns_released = 0;
	nc->flags = &wm->flags;
	nc->accel_calib = wm->accel_calib;

	//for(i=0;i<len;i++) data[i] = (data[i]^0x17)+0x17;
	if(data[offset]==0xff) {
		if(data[offset+16]==0xff) {
			// try to read the calibration data again
			wiiuse_read_data(wm,data,WM_EXP_MEM_CALIBR,EXP_HANDSHAKE_LEN,wiiuse_handshake_expansion);
		} else
			offset += 16;
	}

	nc->accel_calib.cal_zero.x = (data[offset + 0]<<2)|((data[offset + 3]>>4)&3);
	nc->accel_calib.cal_zero.y = (data[offset + 1]<<2)|((data[offset + 3]>>2)&3);
	nc->accel_calib.cal_zero.z = (data[offset + 2]<<2)|(data[offset + 3]&3);
	nc->accel_calib.cal_g.x = (data[offset + 4]<<2)|((data[offset + 7]>>4)&3);
	nc->accel_calib.cal_g.y = (data[offset + 5]<<2)|((data[offset + 7]>>2)&3);
	nc->accel_calib.cal_g.z = (data[offset + 6]<<2)|(data[offset + 7]&3);
	nc->js.max.x = data[offset + 8];
	nc->js.min.x = data[offset + 9];
	nc->js.center.x = data[offset + 10];
	nc->js.max.y = data[offset + 11];
	nc->js.min.y = data[offset + 12];
	nc->js.center.y = data[offset + 13];

	// set to defaults (averages from 5 nunchuks) if calibration data is invalid
	if(nc->accel_calib.cal_zero.x == 0)
		nc->accel_calib.cal_zero.x = 499;
	if(nc->accel_calib.cal_zero.y == 0)
		nc->accel_calib.cal_zero.y = 509;
	if(nc->accel_calib.cal_zero.z == 0)
		nc->accel_calib.cal_zero.z = 507;
	if(nc->accel_calib.cal_g.x == 0)
		nc->accel_calib.cal_g.x = 703;
	if(nc->accel_calib.cal_g.y == 0)
		nc->accel_calib.cal_g.y = 709;
	if(nc->accel_calib.cal_g.z == 0)
		nc->accel_calib.cal_g.z = 709;
	if(nc->js.max.x == 0)
		nc->js.max.x = 223;
	if(nc->js.min.x == 0)
		nc->js.min.x = 27;
	if(nc->js.center.x == 0)
		nc->js.center.x = 126;
	if(nc->js.max.y == 0)
		nc->js.max.y = 222;
	if(nc->js.min.y == 0)
		nc->js.min.y = 30;
	if(nc->js.center.y == 0)
		nc->js.center.y = 131;

	wm->event = WIIUSE_NUNCHUK_INSERTED;
	wm->exp.type = EXP_NUNCHUK;

	return 1;
}

/**
 *	@brief The nunchuk disconnected.
 *
 *	@param nc		A pointer to a nunchuk_t structure.
 */
void nunchuk_disconnected(struct nunchuk_t* nc) 
{
	//printf("nunchuk_disconnected()\n");
	memset(nc, 0, sizeof(struct nunchuk_t));
}

/**
 *	@brief Handle nunchuk event.
 *
 *	@param nc		A pointer to a nunchuk_t structure.
 *	@param msg		The message specified in the event packet.
 */
void nunchuk_event(struct nunchuk_t* nc, ubyte* msg) {
	//int i;

	/* decrypt data */
	/*
	for (i = 0; i < 6; ++i)
		msg[i] = (msg[i] ^ 0x17) + 0x17;
	*/
	/* get button states */
	nunchuk_pressed_buttons(nc, msg[5]);

	nc->js.pos.x = msg[0];
	nc->js.pos.y = msg[1];

	/* extend min and max values to physical range of motion */
	if (nc->js.center.x) {
		if (nc->js.min.x > nc->js.pos.x) nc->js.min.x = nc->js.pos.x;
		if (nc->js.max.x < nc->js.pos.x) nc->js.max.x = nc->js.pos.x;
	}
	if (nc->js.center.y) {
		if (nc->js.min.y > nc->js.pos.y) nc->js.min.y = nc->js.pos.y;
		if (nc->js.max.y < nc->js.pos.y) nc->js.max.y = nc->js.pos.y;
	}

#ifndef GEKKO
	/* calculate joystick state */
	calc_joystick_state(&nc->js, nc->js.pos.x, nc->js.pos.y);
#endif
	/* calculate orientation */
	nc->accel.x = (msg[2]<<2) + ((msg[5]>>2)&3);
	nc->accel.y = (msg[3]<<2) + ((msg[5]>>4)&3);
	nc->accel.z = (msg[4]<<2) + ((msg[5]>>6)&3);
#ifndef GEKKO
	calculate_orientation(&nc->accel_calib, &nc->accel, &nc->orient, NUNCHUK_IS_FLAG_SET(nc, WIIUSE_SMOOTHING));
	calculate_gforce(&nc->accel_calib, &nc->accel, &nc->gforce);
#endif
}