m_filter_one_euro.c File Reference

The "One Euro Filter" for filtering interaction data. More...

#include "math/m_mathinclude.h"
#include "math/m_vec2.h"
#include "math/m_vec3.h"
#include "util/u_time.h"
#include "util/u_misc.h"
#include "m_filter_one_euro.h"

Include dependency graph for m_filter_one_euro.c:

Functions
static double	calc_smoothing_alpha (double Fc, double dt)
static double	exp_smooth (double alpha, float y, float prev_y)
static struct xrt_vec2	exp_smooth_vec2 (double alpha, struct xrt_vec2 y, struct xrt_vec2 prev_y)
static struct xrt_vec3	exp_smooth_vec3 (double alpha, struct xrt_vec3 y, struct xrt_vec3 prev_y)
static struct xrt_quat	exp_smooth_quat (double alpha, struct xrt_quat y, struct xrt_quat prev_y)
static void	filter_one_euro_init (struct m_filter_one_euro_base *f, double fc_min, double fc_min_d, double beta)
static bool	filter_one_euro_handle_first_sample (struct m_filter_one_euro_base *f, uint64_t ts, bool commit)
	Is this the first sample? If so, please set up the common things. More...
static double	filter_one_euro_compute_alpha_d (struct m_filter_one_euro_base *f, double *outDt, uint64_t ts, bool commit)
	Computes and outputs dt, updates the timestamp in the main structure if commit is true, and computes and returns alpha_d. More...
static double	filter_one_euro_compute_alpha (const struct m_filter_one_euro_base *f, double dt, double smoothed_derivative_magnitude)
	Computes and returns alpha. More...
void	m_filter_euro_f32_init (struct m_filter_euro_f32 *f, double fc_min, double fc_min_d, double beta)
void	m_filter_euro_f32_run (struct m_filter_euro_f32 *f, uint64_t ts, const float *in_y, float *out_y)
void	m_filter_euro_vec2_init (struct m_filter_euro_vec2 *f, double fc_min, double fc_min_d, double beta)
void	m_filter_euro_vec2_run (struct m_filter_euro_vec2 *f, uint64_t ts, const struct xrt_vec2 *in_y, struct xrt_vec2 *out_y)
void	m_filter_euro_vec2_run_no_commit (struct m_filter_euro_vec2 *f, uint64_t ts, const struct xrt_vec2 *in_y, struct xrt_vec2 *out_y)
void	m_filter_euro_vec3_init (struct m_filter_euro_vec3 *f, double fc_min, double fc_min_d, double beta)
void	m_filter_euro_vec3_run (struct m_filter_euro_vec3 *f, uint64_t ts, const struct xrt_vec3 *in_y, struct xrt_vec3 *out_y)
void	m_filter_euro_quat_init (struct m_filter_euro_quat *f, double fc_min, double fc_min_d, double beta)
void	m_filter_euro_quat_run (struct m_filter_euro_quat *f, uint64_t ts, const struct xrt_quat *in_y, struct xrt_quat *out_y)

Detailed Description

The "One Euro Filter" for filtering interaction data.

Author

Moses Turner moses.nosp@m.@col.nosp@m.labor.nosp@m.a.co.nosp@m.m

Jan Schmidt jan@c.nosp@m.entr.nosp@m.icula.nosp@m.r.co.nosp@m.m

Rylie Pavlik rylie.nosp@m..pav.nosp@m.lik@c.nosp@m.olla.nosp@m.bora..nosp@m.com

Based in part on https://github.com/thaytan/OpenHMD/blob/rift-kalman-filter/src/exponential-filter.c

Function Documentation

filter_one_euro_compute_alpha()

static double filter_one_euro_compute_alpha ( const struct m_filter_one_euro_base *  f, double  dt, double  smoothed_derivative_magnitude  )

static

Computes and returns alpha.

Parameters

[in]	f	filter base structure
	dt	Time change in seconds
	smoothed_derivative_magnitude	the magnitude of the smoothed derivative

Returns

alpha for filtering derivative

References m_filter_one_euro_base::beta, and m_filter_one_euro_base::fc_min.

filter_one_euro_compute_alpha_d()

static double filter_one_euro_compute_alpha_d ( struct m_filter_one_euro_base *  f, double *  outDt, uint64_t  ts, bool  commit  )

static

Computes and outputs dt, updates the timestamp in the main structure if commit is true, and computes and returns alpha_d.

Parameters

[in,out]	f	filter base structure
[out]	outDt	pointer where we should put dt (time since last sample) after computing it.
	ts	data timestamp
	commit	true to commit changes to the filter state

Returns

alpha_d for filtering derivative

References m_filter_one_euro_base::prev_ts, and U_TIME_1S_IN_NS.

Referenced by m_filter_euro_f32::m_filter_euro_f32_run(), m_filter_euro_quat::m_filter_euro_quat_run(), m_filter_euro_vec2::m_filter_euro_vec2_run(), m_filter_euro_vec2::m_filter_euro_vec2_run_no_commit(), and m_filter_euro_vec3::m_filter_euro_vec3_run().

filter_one_euro_handle_first_sample()

static bool filter_one_euro_handle_first_sample ( struct m_filter_one_euro_base *  f, uint64_t  ts, bool  commit  )

static

Is this the first sample? If so, please set up the common things.

References m_filter_one_euro_base::have_prev_y, and m_filter_one_euro_base::prev_ts.

Referenced by m_filter_euro_f32::m_filter_euro_f32_run(), m_filter_euro_quat::m_filter_euro_quat_run(), m_filter_euro_vec2::m_filter_euro_vec2_run(), m_filter_euro_vec2::m_filter_euro_vec2_run_no_commit(), and m_filter_euro_vec3::m_filter_euro_vec3_run().

m_filter_euro_quat_init()

void m_filter_euro_quat_init	(	struct m_filter_euro_quat *	f,
		double	fc_min,
		double	fc_min_d,
		double	beta
	)

Todo:

fix order of args