dolphin/Externals/WiiUseSrc/Src/dynamics.cpp

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/*
* wiiuse
*
* Written By:
* Michael Laforest < para >
* Email: < thepara (--AT--) g m a i l [--DOT--] com >
*
* Copyright 2006-2007
*
* This file is part of wiiuse.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* $Header$
*
*/
/**
* @file
* @brief Handles the dynamics of the wiimote.
*
* The file includes functions that handle the dynamics
* of the wiimote. Such dynamics include orientation and
* motion sensing.
*/
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#ifdef WIN32
#include <float.h>
#endif
#include "definitions.h"
#include "wiiuse_internal.h"
#include "ir.h"
#include "dynamics.h"
/**
* @brief Calculate the roll, pitch, yaw.
*
* @param ac An accelerometer (accel_t) structure.
* @param accel [in] Pointer to a vec3b_t structure that holds the raw acceleration data.
* @param orient [out] Pointer to a orient_t structure that will hold the orientation data.
* @param rorient [out] Pointer to a orient_t structure that will hold the non-smoothed orientation data.
* @param smooth If smoothing should be performed on the angles calculated. 1 to enable, 0 to disable.
*
* Given the raw acceleration data from the accelerometer struct, calculate
* the orientation of the device and set it in the \a orient parameter.
*/
void calculate_orientation(struct accel_t* ac, struct vec3b_t* accel, struct orient_t* orient, int smooth) {
float xg, yg, zg;
float x, y, z;
/*
* roll - use atan(z / x) [ ranges from -180 to 180 ]
* pitch - use atan(z / y) [ ranges from -180 to 180 ]
* yaw - impossible to tell without IR
*/
/* yaw - set to 0, IR will take care of it if it's enabled */
orient->yaw = 0.0f;
/* find out how much it has to move to be 1g */
xg = (float)ac->cal_g.x;
yg = (float)ac->cal_g.y;
zg = (float)ac->cal_g.z;
/* find out how much it actually moved and normalize to +/- 1g */
x = ((float)accel->x - (float)ac->cal_zero.x) / xg;
y = ((float)accel->y - (float)ac->cal_zero.y) / yg;
z = ((float)accel->z - (float)ac->cal_zero.z) / zg;
/* make sure x,y,z are between -1 and 1 for the tan functions */
if (x < -1.0f) x = -1.0f;
else if (x > 1.0f) x = 1.0f;
if (y < -1.0f) y = -1.0f;
else if (y > 1.0f) y = 1.0f;
if (z < -1.0f) z = -1.0f;
else if (z > 1.0f) z = 1.0f;
/* if it is over 1g then it is probably accelerating and not reliable */
if (abs(accel->x - ac->cal_zero.x) <= ac->cal_g.x) {
/* roll */
x = RAD_TO_DEGREE(atan2f(x, z));
orient->roll = x;
orient->a_roll = x;
}
if (abs(accel->y - ac->cal_zero.y) <= ac->cal_g.y) {
/* pitch */
y = RAD_TO_DEGREE(atan2f(y, z));
orient->pitch = y;
orient->a_pitch = y;
}
/* smooth the angles if enabled */
if (smooth) {
apply_smoothing(ac, orient, SMOOTH_ROLL);
apply_smoothing(ac, orient, SMOOTH_PITCH);
}
}
/**
* @brief Calculate the gravity forces on each axis.
*
* @param ac An accelerometer (accel_t) structure.
* @param accel [in] Pointer to a vec3b_t structure that holds the raw acceleration data.
* @param gforce [out] Pointer to a gforce_t structure that will hold the gravity force data.
*/
void calculate_gforce(struct accel_t* ac, struct vec3b_t* accel, struct gforce_t* gforce) {
float xg, yg, zg;
/* find out how much it has to move to be 1g */
xg = (float)ac->cal_g.x;
yg = (float)ac->cal_g.y;
zg = (float)ac->cal_g.z;
/* find out how much it actually moved and normalize to +/- 1g */
gforce->x = ((float)accel->x - (float)ac->cal_zero.x) / xg;
gforce->y = ((float)accel->y - (float)ac->cal_zero.y) / yg;
gforce->z = ((float)accel->z - (float)ac->cal_zero.z) / zg;
}
/**
* @brief Calculate the angle and magnitude of a joystick.
*
* @param js [out] Pointer to a joystick_t structure.
* @param x The raw x-axis value.
* @param y The raw y-axis value.
*/
void calc_joystick_state(struct joystick_t* js, float x, float y) {
float rx, ry, ang;
/*
* Since the joystick center may not be exactly:
* (min + max) / 2
* Then the range from the min to the center and the center to the max
* may be different.
* Because of this, depending on if the current x or y value is greater
* or less than the assoicated axis center value, it needs to be interpolated
* between the center and the minimum or maxmimum rather than between
* the minimum and maximum.
*
* So we have something like this:
* (x min) [-1] ---------*------ [0] (x center) [0] -------- [1] (x max)
* Where the * is the current x value.
* The range is therefore -1 to 1, 0 being the exact center rather than
* the middle of min and max.
*/
if (x == js->center.x)
rx = 0;
else if (x >= js->center.x)
rx = ((float)(x - js->center.x) / (float)(js->max.x - js->center.x));
else
rx = ((float)(x - js->min.x) / (float)(js->center.x - js->min.x)) - 1.0f;
if (y == js->center.y)
ry = 0;
else if (y >= js->center.y)
ry = ((float)(y - js->center.y) / (float)(js->max.y - js->center.y));
else
ry = ((float)(y - js->min.y) / (float)(js->center.y - js->min.y)) - 1.0f;
/* calculate the joystick angle and magnitude */
ang = RAD_TO_DEGREE(atanf(ry / rx));
ang -= 90.0f;
if (rx < 0.0f)
ang -= 180.0f;
js->ang = absf(ang);
js->mag = (float) sqrt((rx * rx) + (ry * ry));
}
void apply_smoothing(struct accel_t* ac, struct orient_t* orient, int type) {
switch (type) {
case SMOOTH_ROLL:
{
/* it's possible last iteration was nan or inf, so set it to 0 if that happened */
if (isnan(ac->st_roll) || isinf(ac->st_roll))
ac->st_roll = 0.0f;
/*
* If the sign changes (which will happen if going from -180 to 180)
* or from (-1 to 1) then don't smooth, just use the new angle.
*/
if (((ac->st_roll < 0) && (orient->roll > 0)) || ((ac->st_roll > 0) && (orient->roll < 0))) {
ac->st_roll = orient->roll;
} else {
orient->roll = ac->st_roll + (ac->st_alpha * (orient->a_roll - ac->st_roll));
ac->st_roll = orient->roll;
}
return;
}
case SMOOTH_PITCH:
{
if (isnan(ac->st_pitch) || isinf(ac->st_pitch))
ac->st_pitch = 0.0f;
if (((ac->st_pitch < 0) && (orient->pitch > 0)) || ((ac->st_pitch > 0) && (orient->pitch < 0))) {
ac->st_pitch = orient->pitch;
} else {
orient->pitch = ac->st_pitch + (ac->st_alpha * (orient->a_pitch - ac->st_pitch));
ac->st_pitch = orient->pitch;
}
return;
}
}
}