1
0
Fork 0
forked from NaxdyOrg/NaxGCC-FW
NaxGCC-FW/src/stick.rs

391 lines
12 KiB
Rust

// vast majority of this is taken from Phob firmware
use core::{f32::consts::PI, iter::Filter};
use defmt::Format;
use libm::{atan2f, fabs, powf};
use crate::{
input::{ControllerConfig, Stick},
stick,
};
/// fit order for the linearization
const FIT_ORDER: usize = 3;
const NUM_COEFFS: usize = FIT_ORDER + 1;
const NO_OF_NOTCHES: usize = 16;
const MAX_ORDER: usize = 20;
/// Filter gains for 800Hz, the ones for 1000Hz are provided by `get_norm_gains`
pub const FILTER_GAINS: FilterGains = FilterGains {
max_stick: 100.,
x_vel_decay: 0.1,
y_vel_decay: 0.1,
x_vel_pos_factor: 0.01,
y_vel_pos_factor: 0.01,
x_vel_damp: 0.125,
y_vel_damp: 0.125,
vel_thresh: 1.,
accel_thresh: 3.,
x_smoothing: 0.0,
y_smoothing: 0.0,
c_xsmoothing: 0.0,
c_ysmoothing: 0.0,
};
#[derive(Clone, Debug, Default, Format)]
pub struct StickParams {
// these are the linearization coefficients
pub fit_coeffs_x: [f32; NUM_COEFFS],
pub fit_coeffs_y: [f32; NUM_COEFFS],
// these are the notch remap parameters
pub affine_coeffs: [[f32; 16]; 4], // affine transformation coefficients for all regions of the stick
pub boundary_angles: [f32; 4], // angles at the boundaries between regions of the stick (in the plane)
}
#[derive(Clone, Debug, Default, Format)]
pub struct FilterGains {
/// What's the max stick distance from the center
pub max_stick: f32,
/// filtered velocity terms
/// how fast the filtered velocity falls off in the absence of stick movement.
/// Probably don't touch this.
pub x_vel_decay: f32, //0.1 default for 1.2ms timesteps, larger for bigger timesteps
pub y_vel_decay: f32,
/// how much the current position disagreement impacts the filtered velocity.
/// Probably don't touch this.
pub x_vel_pos_factor: f32, //0.01 default for 1.2ms timesteps, larger for bigger timesteps
pub y_vel_pos_factor: f32,
/// how much to ignore filtered velocity when computing the new stick position.
/// DO CHANGE THIS
/// Higher gives shorter rise times and slower fall times (more pode, less snapback)
pub x_vel_damp: f32, //0.125 default for 1.2ms timesteps, smaller for bigger timesteps
pub y_vel_damp: f32,
/// speed and accel thresholds below which we try to follow the stick better
/// These may need tweaking according to how noisy the signal is
/// If it's noisier, we may need to add additional filtering
/// If the timesteps are *really small* then it may need to be increased to get
/// above the noise floor. Or some combination of filtering and playing with
/// the thresholds.
pub vel_thresh: f32, //1 default for 1.2ms timesteps, larger for bigger timesteps
pub accel_thresh: f32, //5 default for 1.2ms timesteps, larger for bigger timesteps
/// This just applies a low-pass filter.
/// The purpose is to provide delay for single-axis ledgedashes.
/// Must be between 0 and 1. Larger = more smoothing and delay.
pub x_smoothing: f32,
pub y_smoothing: f32,
/// Same thing but for C-stick
pub c_xsmoothing: f32,
pub c_ysmoothing: f32,
}
#[derive(Clone, Debug, Default)]
struct LinearizeCalibrationOutput {
pub fit_coeffs_x: [f64; NUM_COEFFS],
pub fit_coeffs_y: [f64; NUM_COEFFS],
pub out_x: [f32; NO_OF_NOTCHES],
pub out_y: [f32; NO_OF_NOTCHES],
}
pub fn run_kalman(
x_z: f32,
y_z: f32,
controller_config: &ControllerConfig,
filter_gains: &FilterGains,
) -> (f32, f32) {
todo!()
}
/// Calculate the power of a number
fn curve_fit_power(base: f64, exponent: u32) -> f64 {
if exponent == 0 {
return 1.0;
}
let mut val = base;
for _ in 1..exponent {
val *= base;
}
val
}
/// Substitutes a column in a matrix with a vector
fn sub_col<const N: usize>(
matrix: &[[f64; N]; N],
t: &[f64; MAX_ORDER],
col: usize,
n: usize,
) -> [[f64; N]; N] {
let mut m = *matrix;
for i in 0..n {
m[i][col] = t[i];
}
m
}
/// Calculate the determinant of a matrix
fn det<const N: usize>(matrix: &[[f64; N]; N]) -> f64 {
let sign = trianglize(matrix);
if sign == 0 {
return 0.;
}
let mut p = 1f64;
for i in 0..N {
p *= matrix[i][i];
}
p * (sign as f64)
}
/// Trianglize a matrix
fn trianglize<const N: usize>(matrix: &[[f64; N]; N]) -> i32 {
let mut sign = 1;
let mut matrix = *matrix;
for i in 0..N {
let mut max = 0;
for row in i..N {
if fabs(matrix[row][i]) > fabs(matrix[max][i]) {
max = row;
}
}
if max > 0 {
sign = -sign;
let tmp = matrix[i];
matrix[i] = matrix[max];
matrix[max] = tmp;
}
if matrix[i][i] == 0. {
return 0;
}
for row in i + 1..N {
let factor = matrix[row][i] / matrix[i][i];
if factor == 0. {
continue;
}
for col in i..N {
matrix[row][col] -= factor * matrix[i][col];
}
}
}
sign
}
fn fit_curve<const N: usize, const NCOEFFS: usize>(
order: i32,
px: &[f64; N],
py: &[f64; N],
) -> [f64; NCOEFFS] {
let mut coeffs = [0f64; NCOEFFS];
if NCOEFFS != (order + 1) as usize {
panic!(
"Invalid coefficients length, expected {}, but got {}",
order + 1,
NCOEFFS
);
}
if NCOEFFS > MAX_ORDER || NCOEFFS < 2 {
panic!("Matrix size out of bounds");
}
if N < 1 {
panic!("Not enough points to fit");
}
let mut t = [0f64; MAX_ORDER];
let mut s = [0f64; MAX_ORDER * 2 + 1];
for i in 0..N {
let x = px[i];
let y = py[i];
for j in 0..NCOEFFS * 2 - 1 {
s[j] += curve_fit_power(x, j as u32);
}
for j in 0..NCOEFFS {
t[j] += y * curve_fit_power(x, j as u32);
}
}
//Master matrix LHS of linear equation
let mut matrix = [[0f64; NCOEFFS]; NCOEFFS];
for i in 0..NCOEFFS {
for j in 0..NCOEFFS {
matrix[i][j] = s[i + j];
}
}
let denom = det(&matrix);
for i in 0..NCOEFFS {
coeffs[NCOEFFS - i - 1] = det(&sub_col(&matrix, &t, i, NCOEFFS)) / denom;
}
coeffs
}
pub fn linearize(point: f32, coefficients: &[f32; 4]) -> f32 {
coefficients[0] * (point * point * point)
+ coefficients[1] * (point * point)
+ coefficients[2] * point
+ coefficients[3]
}
///
/// Generate a fit to linearize the stick response.
///
/// Inputs:
/// cleaned points X and Y, (must be 17 points for each of these, the first being the center, the others starting at 3 oclock and going around counterclockwise)
///
/// Outputs:
/// linearization fit coefficients for X and Y
pub fn linearize_calibration(in_x: &[f64; 17], in_y: &[f64; 17]) -> LinearizeCalibrationOutput {
let mut fit_points_x = [0f64; 5];
let mut fit_points_y = [0f64; 5];
fit_points_x[0] = in_x[8 + 1];
fit_points_x[1] = (in_x[6 + 1] + in_x[10 + 1]) / 2.0f64;
fit_points_x[2] = in_x[0];
fit_points_x[3] = (in_x[2 + 1] + in_x[14 + 1]) / 2.0f64;
fit_points_x[4] = in_x[0 + 1];
fit_points_y[0] = in_y[12 + 1];
fit_points_y[1] = (in_y[10 + 1] + in_y[14 + 1]) / 2.0f64;
fit_points_y[2] = in_y[0];
fit_points_y[3] = (in_y[6 + 1] + in_y[2 + 1]) / 2.0f64;
fit_points_y[4] = in_y[4 + 1];
let x_output: [f64; 5] = [27.5, 53.2537879754, 127.5, 201.7462120246, 227.5];
let y_output: [f64; 5] = [27.5, 53.2537879754, 127.5, 201.7462120246, 227.5];
let mut fit_coeffs_x = fit_curve::<5, NUM_COEFFS>(FIT_ORDER as i32, &fit_points_x, &x_output);
let mut fit_coeffs_y = fit_curve::<5, NUM_COEFFS>(FIT_ORDER as i32, &fit_points_y, &y_output);
let x_zero_error = linearize(fit_points_x[2] as f32, &fit_coeffs_x.map(|e| e as f32));
let y_zero_error = linearize(fit_points_y[2] as f32, &fit_coeffs_y.map(|e| e as f32));
fit_coeffs_x[3] = fit_coeffs_x[3] - x_zero_error as f64;
fit_coeffs_y[3] = fit_coeffs_y[3] - y_zero_error as f64;
let mut out_x = [0f32; NO_OF_NOTCHES];
let mut out_y = [0f32; NO_OF_NOTCHES];
for i in 0..=NO_OF_NOTCHES {
out_x[i] = linearize(in_x[i] as f32, &fit_coeffs_x.map(|e| e as f32));
out_y[i] = linearize(in_y[i] as f32, &fit_coeffs_y.map(|e| e as f32));
}
LinearizeCalibrationOutput {
fit_coeffs_x,
fit_coeffs_y,
out_x,
out_y,
}
}
pub fn notch_remap(
x_in: f32,
y_in: f32,
stick_params: &StickParams,
controller_config: &ControllerConfig,
which_stick: Stick,
) -> (f32, f32) {
//determine the angle between the x unit vector and the current position vector
let angle = match atan2f(y_in, x_in) {
//unwrap the angle based on the first region boundary
a if a < stick_params.boundary_angles[0] => a + PI * 2.0,
a => a,
};
//go through the region boundaries from lowest angle to highest, checking if the current position vector is in that region
//if the region is not found then it must be between the first and the last boundary, ie the last region
//we check GATE_REGIONS*2 because each notch has its own very small region we use to make notch values more consistent
let region = 'a: {
for i in 1..NO_OF_NOTCHES {
if angle < stick_params.boundary_angles[i] {
break 'a i - 1;
}
}
NO_OF_NOTCHES - 1
};
let stick_scale = match which_stick {
Stick::ControlStick => controller_config.astick_analog_scaler as f32 / 100.,
Stick::CStick => controller_config.cstick_analog_scaler as f32 / 100.,
};
let x_out = stick_scale
* (stick_params.affine_coeffs[region][0] * x_in
+ stick_params.affine_coeffs[region][1] * y_in);
let y_out = stick_scale
* (stick_params.affine_coeffs[region][2] * x_in
+ stick_params.affine_coeffs[region][3] * y_in);
// TODO: here, add calibration step shenanigans
(x_out, y_out)
}
fn vel_damp_from_snapback(snapback: i8) -> f32 {
match snapback {
a if a >= 0 => 0.125 * powf(2., (snapback - 4) as f32 / 3.0),
_ => 1. - 0.25 * powf(2., (snapback + 4) as f32 / 3.0),
}
}
/// Returns filter gains for 1000Hz polling rate
pub fn get_norm_gains(controller_config: &ControllerConfig) -> FilterGains {
let mut gains = FILTER_GAINS.clone();
gains.x_vel_damp = vel_damp_from_snapback(controller_config.x_snapback);
gains.y_vel_damp = vel_damp_from_snapback(controller_config.y_snapback);
gains.x_smoothing = controller_config.x_smoothing as f32 / 10.;
gains.y_smoothing = controller_config.y_smoothing as f32 / 10.;
gains.c_xsmoothing = controller_config.c_xsmoothing as f32 / 10.;
gains.c_ysmoothing = controller_config.c_ysmoothing as f32 / 10.;
// The below is assuming the sticks to be polled at 1000Hz
let time_factor = 1.0 / 1.2;
let time_divisor = 1.2 / 1.0;
let vel_thresh = 1.0 / (gains.vel_thresh * time_factor);
let accel_thresh = 1.0 / (gains.accel_thresh * time_factor);
FilterGains {
max_stick: gains.max_stick * gains.max_stick,
x_vel_decay: gains.x_vel_decay * time_factor,
y_vel_decay: gains.y_vel_decay * time_factor,
x_vel_pos_factor: gains.x_vel_pos_factor * time_factor,
y_vel_pos_factor: gains.y_vel_pos_factor * time_factor,
x_vel_damp: gains.x_vel_damp
* match controller_config.x_snapback {
a if a >= 0 => time_factor,
_ => 1.0,
},
y_vel_damp: gains.y_vel_damp
* match controller_config.y_snapback {
a if a >= 0 => time_factor,
_ => 1.0,
},
vel_thresh,
accel_thresh,
x_smoothing: powf(1.0 - gains.x_smoothing, time_divisor),
y_smoothing: powf(1.0 - gains.y_smoothing, time_divisor),
c_xsmoothing: powf(1.0 - gains.c_xsmoothing, time_divisor),
c_ysmoothing: powf(1.0 - gains.c_ysmoothing, time_divisor),
}
}