rusty-telemetry/src/analysis.rs
Jan-Peter v. Hunnius bcacd4b8a7 feat: racing line analysis, frame trimming, persistence fix
- Add analyze_racing_line(): lap-by-lap path extraction with speed data,
  downsampled to 400 pts/lap. Spline-sorted in spline mode for clean paths.
- Add complete_lap_frames() + split_by_lap() utilities: filters to laps
  whose spline spans >= 0.9 of [0,1], discarding partial out/in laps.
- Fix complete_lap_frames logic: was checking if segment STARTS at
  spline~0, but a full lap starting mid-track (joined before start/finish)
  also qualifies. Now checks spline span coverage instead.
- WOT window trimming in analyze_shift_points(): trims to first/last
  frame with throttle >= 0.9, filters rev-limiter plateau (acc_g < 0.01).
- Fix frame persistence race condition: persist_session now writes frames
  synchronously instead of spawning a thread. Multiple concurrent calls
  could race on the same temp file, with earlier calls (empty frames)
  overwriting later calls with correct data.
- atomic_write uses UUID-based temp file names as defense-in-depth.
- PositionMode now derives Deserialize for RacingLineAnalysis.
- Empty game/track_name validation in build_track() endpoint.
- Wired RacingLine use case into analysis dispatch.
2026-07-04 11:17:06 +02:00

1237 lines
39 KiB
Rust

// rusty-telemetry — Sim racing telemetry analysis platform
// Copyright (C) 2026 Jan-Peter v. Hunnius
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero 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 Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
//! Telemetry analysis algorithms for sim racing data.
//!
//! Provides shift point analysis, track map reconstruction, and a dispatch
//! function that routes a [`UseCase`] to the appropriate analysis pipeline.
use serde::Serialize;
use std::collections::HashMap;
use crate::recording::UseCase;
use crate::telemetry_frame::{gear_display, TelemetryFrame};
use crate::track_model::{Corner, Sector, TrackModel, TrackModelSource};
// ---------------------------------------------------------------------------
// Frame trimming utilities
// ---------------------------------------------------------------------------
/// Split a run's frames into segments by lap_count transitions.
fn split_by_lap(frames: &[TelemetryFrame]) -> Vec<&[TelemetryFrame]> {
if frames.is_empty() {
return Vec::new();
}
let mut segments = Vec::new();
let mut seg_start = 0;
let mut prev_lap = frames[0].lap_count;
for (i, f) in frames.iter().enumerate() {
if f.lap_count != prev_lap {
segments.push(&frames[seg_start..i]);
seg_start = i;
prev_lap = f.lap_count;
}
}
segments.push(&frames[seg_start..]);
segments
}
/// Return frames belonging to complete laps only.
///
/// A complete lap covers most of the track (spline spans ≥ 0.9 of [0, 1]).
/// The first segment may start mid-track (driver joined before start/finish)
/// but still complete a full revolution — spline wraps from the join point
/// through 1.0 back to near 0. The last segment is often a partial out-lap
/// (driver stopped before completing the lap).
fn complete_lap_frames(frames: &[TelemetryFrame]) -> Vec<TelemetryFrame> {
let segments = split_by_lap(frames);
if segments.is_empty() {
return frames.to_vec();
}
let mut result = Vec::new();
for seg in &segments {
let splines: Vec<f32> = seg.iter().filter(|f| f.spline_position > 0.0).map(|f| f.spline_position).collect();
if splines.is_empty() {
continue;
}
let min_s = splines.iter().cloned().fold(f32::INFINITY, f32::min);
let max_s = splines.iter().cloned().fold(f32::NEG_INFINITY, f32::max);
let span = max_s - min_s;
// Complete lap: spline covers ≥ 0.9 of the track, or wraps around
// (min near 0, max near 1).
let wraps = min_s < 0.1 && max_s > 0.9;
if span >= 0.9 || wraps {
result.extend_from_slice(seg);
}
}
// If no segment qualifies (e.g., no spline data), fall back to longest.
if result.is_empty() {
let longest = segments.iter().max_by_key(|s| s.len());
if let Some(seg) = longest {
return seg.to_vec();
}
}
if result.is_empty() {
frames.to_vec()
} else {
result
}
}
// ---------------------------------------------------------------------------
// Shift Point Analysis
// ---------------------------------------------------------------------------
#[derive(Debug, Clone, Serialize)]
pub struct AccelerationPoint {
pub speed_kmh: f32,
pub rpm: f32,
pub acceleration_g: f32,
}
#[derive(Debug, Clone, Serialize)]
pub struct GearAccelerationCurve {
pub gear: i32,
pub gear_display: String,
pub run_label: String,
pub data_points: Vec<AccelerationPoint>,
pub min_rpm: f32,
pub max_rpm: f32,
pub min_speed_kmh: f32,
pub max_speed_kmh: f32,
pub sample_count: usize,
}
#[derive(Debug, Clone, Serialize)]
pub struct ShiftCrossoverPoint {
pub from_gear: i32,
pub to_gear: i32,
pub from_gear_display: String,
pub to_gear_display: String,
pub crossover_speed_kmh: f32,
pub crossover_rpm: f32,
}
#[derive(Debug, Clone, Serialize)]
pub struct ShiftPointAnalysis {
pub gear_curves: Vec<GearAccelerationCurve>,
pub crossover_points: Vec<ShiftCrossoverPoint>,
pub recommended_shift_rpm: Option<f32>,
pub runs_analyzed: usize,
pub total_frames_analyzed: usize,
}
pub fn analyze_shift_points(
runs: &[Vec<TelemetryFrame>],
run_labels: &[String],
) -> ShiftPointAnalysis {
let mut gear_data: HashMap<i32, Vec<AccelerationPoint>> = HashMap::new();
let mut gear_labels: HashMap<i32, Vec<String>> = HashMap::new();
let mut total_frames_analyzed: usize = 0;
let mut runs_analyzed: usize = 0;
for (run_idx, run) in runs.iter().enumerate() {
let label = run_labels.get(run_idx).cloned().unwrap_or_default();
// Trim to the WOT window: find the first and last frames where
// throttle is near 100%. This removes pre-launch and post-lift data.
let wot_start = run.iter().position(|f| f.throttle >= 0.9);
let wot_end = run.iter().rposition(|f| f.throttle >= 0.9);
let trimmed: &[TelemetryFrame] = match (wot_start, wot_end) {
(Some(s), Some(e)) if e > s => &run[s..=e],
_ => run.as_slice(),
};
// Filter for valid WOT acceleration frames.
// Exclude rev-limiter plateau: when speed stops increasing (delta < 0.5 km/h
// over the window), the engine is bouncing off the limiter and acceleration
// data is meaningless.
let valid: Vec<&TelemetryFrame> = trimmed
.iter()
.filter(|f| {
f.throttle >= 0.9
&& f.gear >= 2
&& f.speed_kmh > 1.0
&& f.engine_rpm > 500.0
&& f.acc_g_frontal > 0.01
})
.collect();
if valid.len() < 10 {
continue;
}
let dominant_gear = {
let mut freq: HashMap<i32, usize> = HashMap::new();
for f in &valid {
*freq.entry(f.gear).or_default() += 1;
}
*freq.iter().max_by_key(|(_, c)| *c).map(|(g, _)| g).unwrap_or(&2)
};
for f in valid.into_iter().filter(|f| f.gear == dominant_gear) {
gear_data.entry(dominant_gear).or_default().push(AccelerationPoint {
speed_kmh: f.speed_kmh,
rpm: f.engine_rpm,
acceleration_g: f.acc_g_frontal,
});
}
gear_labels.entry(dominant_gear).or_default().push(label);
runs_analyzed += 1;
}
let mut gear_curves: Vec<GearAccelerationCurve> = Vec::new();
for (gear, mut points) in gear_data {
total_frames_analyzed += points.len();
points.sort_by(|a, b| a.speed_kmh.partial_cmp(&b.speed_kmh).unwrap_or(std::cmp::Ordering::Equal));
let window = (points.len() / 5).clamp(3, 15);
let acc_values: Vec<f32> = points.iter().map(|p| p.acceleration_g).collect();
let smoothed = smooth(&acc_values, window);
for (i, s) in smoothed.into_iter().enumerate() {
points[i].acceleration_g = s;
}
let min_rpm = points.iter().map(|p| p.rpm).fold(f32::INFINITY, f32::min);
let max_rpm = points.iter().map(|p| p.rpm).fold(f32::NEG_INFINITY, f32::max);
let min_speed = points.iter().map(|p| p.speed_kmh).fold(f32::INFINITY, f32::min);
let max_speed = points.iter().map(|p| p.speed_kmh).fold(f32::NEG_INFINITY, f32::max);
let sample_count = points.len();
let labels = gear_labels.get(&gear).cloned().unwrap_or_default();
let run_label = if labels.len() == 1 {
labels[0].clone()
} else {
format!("{} ({} runs)", labels.join(", "), labels.len())
};
gear_curves.push(GearAccelerationCurve {
gear,
gear_display: gear_display(gear),
run_label,
data_points: points,
min_rpm,
max_rpm,
min_speed_kmh: min_speed,
max_speed_kmh: max_speed,
sample_count,
});
}
gear_curves.sort_by_key(|c| c.gear);
let crossover_points = find_crossovers(&gear_curves);
let recommended_shift_rpm = {
let rpms: Vec<f32> = crossover_points.iter().map(|c| c.crossover_rpm).collect();
if rpms.is_empty() {
None
} else {
Some(rpms.iter().sum::<f32>() / rpms.len() as f32)
}
};
ShiftPointAnalysis {
gear_curves,
crossover_points,
recommended_shift_rpm,
runs_analyzed,
total_frames_analyzed,
}
}
fn smooth(values: &[f32], window: usize) -> Vec<f32> {
let half = window / 2;
let n = values.len();
let mut result = Vec::with_capacity(n);
for i in 0..n {
let start = i.saturating_sub(half);
let end = (i + half + 1).min(n);
let sum: f32 = values[start..end].iter().sum();
result.push(sum / (end - start) as f32);
}
result
}
fn find_crossovers(curves: &[GearAccelerationCurve]) -> Vec<ShiftCrossoverPoint> {
let mut crossovers = Vec::new();
for pair in curves.windows(2) {
let low = &pair[0];
let high = &pair[1];
if low.gear == high.gear {
continue;
}
let overlap_min = low.min_speed_kmh.max(high.min_speed_kmh);
let overlap_max = low.max_speed_kmh.min(high.max_speed_kmh);
if overlap_max - overlap_min < 1.0 {
continue;
}
let grid_size = 100;
let step = (overlap_max - overlap_min) / (grid_size as f32 - 1.0);
let mut found_crossover: Option<(f32, f32)> = None;
for i in 0..grid_size {
let target_speed = overlap_min + i as f32 * step;
let low_accel = match interpolate_curve(&low.data_points, target_speed) {
Some(a) => a,
None => continue,
};
let high_accel = match interpolate_curve(&high.data_points, target_speed) {
Some(a) => a,
None => continue,
};
if low_accel < high_accel {
let rpm = interpolate_rpm(&low.data_points, target_speed).unwrap_or(0.0);
found_crossover = Some((target_speed, rpm));
break;
}
}
if let Some((speed, rpm)) = found_crossover {
crossovers.push(ShiftCrossoverPoint {
from_gear: low.gear,
to_gear: high.gear,
from_gear_display: low.gear_display.clone(),
to_gear_display: high.gear_display.clone(),
crossover_speed_kmh: speed,
crossover_rpm: rpm,
});
}
}
crossovers
}
fn interpolate_field<F>(curve: &[AccelerationPoint], target_speed: f32, field: F) -> Option<f32>
where
F: Fn(&AccelerationPoint) -> f32,
{
let (t, a, b) = lerp_search(curve, |p| p.speed_kmh, target_speed)?;
Some(field(a) + t * (field(b) - field(a)))
}
fn interpolate_curve(curve: &[AccelerationPoint], target_speed: f32) -> Option<f32> {
interpolate_field(curve, target_speed, |p| p.acceleration_g)
}
fn interpolate_rpm(curve: &[AccelerationPoint], target_speed: f32) -> Option<f32> {
interpolate_field(curve, target_speed, |p| p.rpm)
}
fn lerp_search<T>(
items: &[T],
key: impl Fn(&T) -> f32,
target: f32,
) -> Option<(f32, &T, &T)> {
if items.is_empty() {
return None;
}
if items.len() == 1 {
return Some((0.0, &items[0], &items[0]));
}
let idx = items.partition_point(|p| key(p) < target);
if idx == 0 {
return Some((0.0, &items[0], &items[0]));
}
if idx >= items.len() {
return Some((0.0, &items[items.len() - 1], &items[items.len() - 1]));
}
let a = &items[idx - 1];
let b = &items[idx];
let t = if (key(b) - key(a)).abs() < f32::EPSILON {
0.0
} else {
(target - key(a)) / (key(b) - key(a))
};
Some((t, a, b))
}
// ---------------------------------------------------------------------------
// Track Map Analysis
// ---------------------------------------------------------------------------
#[derive(Debug, Clone, Serialize, serde::Deserialize, PartialEq)]
pub enum PositionMode {
Spline,
Coordinate,
}
fn detect_position_mode(frames: &[TelemetryFrame]) -> PositionMode {
if frames.is_empty() {
return PositionMode::Coordinate;
}
let with_spline = frames.iter().filter(|f| f.spline_position > 0.0).count();
let spline_ratio = with_spline as f32 / frames.len() as f32;
if spline_ratio > 0.5 {
PositionMode::Spline
} else {
PositionMode::Coordinate
}
}
fn compute_cumulative_distance(points: &mut [TrackPoint]) {
if points.is_empty() { return; }
let mut cumulative = 0.0f32;
points[0].spline = 0.0;
for i in 1..points.len() {
let dx = points[i].x - points[i-1].x;
let dz = points[i].z - points[i-1].z;
cumulative += (dx * dx + dz * dz).sqrt();
points[i].spline = cumulative;
}
if cumulative > 0.0 {
for p in points.iter_mut() {
p.spline /= cumulative;
}
}
}
#[derive(Debug, Clone, Serialize, serde::Deserialize)]
pub struct TrackPoint {
pub x: f32,
pub y: f32,
pub z: f32,
pub spline: f32,
}
#[derive(Debug, Clone, Serialize, serde::Deserialize)]
pub struct TrackBoundary {
pub label: String,
pub point_count: usize,
pub points: Vec<TrackPoint>,
}
#[derive(Debug, Clone, Serialize)]
pub struct TrackMapAnalysis {
pub boundaries: Vec<TrackBoundary>,
pub center_line: Option<TrackBoundary>,
pub total_points: usize,
pub position_mode: PositionMode,
}
pub fn analyze_track_map(
runs: &[Vec<TelemetryFrame>],
labels: &[String],
) -> TrackMapAnalysis {
let all_frames: Vec<TelemetryFrame> = runs.iter().flat_map(|r| r.iter()).cloned().collect();
let mode = detect_position_mode(&all_frames);
let mut boundaries: Vec<TrackBoundary> = Vec::new();
for (run, label) in runs.iter().zip(labels.iter()) {
// Trim to complete laps only — partial laps at the start/end of
// the recording produce artifacts when spline-sorted (the car
// was not at the boundary edge during those segments).
let trimmed = complete_lap_frames(run);
let mut points: Vec<TrackPoint> = match &mode {
PositionMode::Spline => {
trimmed
.iter()
.filter(|f| f.spline_position > 0.0)
.map(|f| TrackPoint {
x: f.world_x,
y: f.world_y,
z: f.world_z,
spline: f.spline_position,
})
.collect()
}
PositionMode::Coordinate => {
let mut pts: Vec<TrackPoint> = trimmed
.iter()
.filter(|f| f.world_x != 0.0 || f.world_z != 0.0)
.map(|f| TrackPoint {
x: f.world_x,
y: f.world_y,
z: f.world_z,
spline: 0.0,
})
.collect();
compute_cumulative_distance(&mut pts);
pts
}
};
points.sort_by(|a, b| a.spline.partial_cmp(&b.spline).unwrap_or(std::cmp::Ordering::Equal));
points.dedup_by(|a, b| (a.spline - b.spline).abs() < 0.0001);
let point_count = points.len();
boundaries.push(TrackBoundary {
label: label.clone(),
point_count,
points,
});
}
let center_line = compute_center_line(&boundaries);
let total_points: usize = boundaries.iter().map(|b| b.point_count).sum::<usize>()
+ center_line.as_ref().map_or(0, |c| c.point_count);
TrackMapAnalysis {
boundaries,
center_line,
total_points,
position_mode: mode,
}
}
fn compute_center_line(boundaries: &[TrackBoundary]) -> Option<TrackBoundary> {
if boundaries.len() != 2 {
return None;
}
let left_idx = boundaries
.iter()
.position(|b| b.label == "left")?;
let right_idx = boundaries
.iter()
.position(|b| b.label == "right")?;
if left_idx == right_idx {
return None;
}
let left = &boundaries[left_idx];
let right = &boundaries[right_idx];
if left.points.is_empty() || right.points.is_empty() {
return None;
}
let num_samples = left.point_count.max(right.point_count).min(2000);
let center_points: Vec<TrackPoint> = (0..num_samples)
.filter_map(|i| {
let spline = i as f32 / (num_samples - 1).max(1) as f32;
let lp = interpolate_boundary(left, spline)?;
let rp = interpolate_boundary(right, spline)?;
Some(TrackPoint {
x: (lp.x + rp.x) / 2.0,
y: (lp.y + rp.y) / 2.0,
z: (lp.z + rp.z) / 2.0,
spline,
})
})
.collect();
if center_points.is_empty() {
return None;
}
Some(TrackBoundary {
label: "center_line".to_owned(),
point_count: center_points.len(),
points: center_points,
})
}
fn interpolate_boundary(boundary: &TrackBoundary, target_spline: f32) -> Option<TrackPoint> {
let points = &boundary.points;
let (t, a, b) = lerp_search(points, |p| p.spline, target_spline)?;
Some(TrackPoint {
x: a.x + t * (b.x - a.x),
y: a.y + t * (b.y - a.y),
z: a.z + t * (b.z - a.z),
spline: target_spline,
})
}
// ---------------------------------------------------------------------------
// Track Model Builder
// ---------------------------------------------------------------------------
const NUM_SAMPLES: usize = 2000;
const CORNER_THRESHOLD: f64 = 0.005;
pub fn build_track_model(
boundaries: &[TrackBoundary],
game: String,
track_name: String,
source: TrackModelSource,
) -> Result<TrackModel, String> {
// Step 1: Validate input
if boundaries.len() != 2 {
return Err(format!(
"Expected exactly 2 boundaries, got {}",
boundaries.len()
));
}
let left_idx = boundaries
.iter()
.position(|b| b.label == "left")
.ok_or_else(|| "No boundary labeled 'left' found".to_string())?;
let right_idx = boundaries
.iter()
.position(|b| b.label == "right")
.ok_or_else(|| "No boundary labeled 'right' found".to_string())?;
let left = &boundaries[left_idx];
let right = &boundaries[right_idx];
if left.points.len() < 10 {
return Err(format!(
"Left boundary needs at least 10 points, has {}",
left.points.len()
));
}
if right.points.len() < 10 {
return Err(format!(
"Right boundary needs at least 10 points, has {}",
right.points.len()
));
}
// Step 2: Resample both boundaries
let left_resampled: Vec<(f64, f64)> = (0..NUM_SAMPLES)
.map(|i| {
let s = i as f32 / (NUM_SAMPLES - 1) as f32;
let p = interpolate_boundary(left, s).expect("interpolation within range");
(p.x as f64, p.z as f64)
})
.collect();
let right_resampled: Vec<(f64, f64)> = (0..NUM_SAMPLES)
.map(|i| {
let s = i as f32 / (NUM_SAMPLES - 1) as f32;
let p = interpolate_boundary(right, s).expect("interpolation within range");
(p.x as f64, p.z as f64)
})
.collect();
// Step 3: Compute center line
let center_line: Vec<(f64, f64)> = left_resampled
.iter()
.zip(right_resampled.iter())
.map(|((lx, lz), (rx, rz))| ((lx + rx) / 2.0, (lz + rz) / 2.0))
.collect();
// Step 4: Compute track width
let track_width: Vec<f64> = left_resampled
.iter()
.zip(right_resampled.iter())
.map(|((lx, lz), (rx, rz))| {
let dx = rx - lx;
let dz = rz - lz;
(dx * dx + dz * dz).sqrt()
})
.collect();
// Step 5: Compute heading
let mut heading: Vec<f64> = Vec::with_capacity(NUM_SAMPLES);
for i in 0..center_line.len() - 1 {
let dx = center_line[i + 1].0 - center_line[i].0;
let dz = center_line[i + 1].1 - center_line[i].1;
heading.push(dz.atan2(dx));
}
heading.push(*heading.last().unwrap_or(&0.0));
// Step 6: Compute curvature
let mut curvature: Vec<f64> = Vec::with_capacity(NUM_SAMPLES);
for i in 0..center_line.len() - 1 {
let dx = center_line[i + 1].0 - center_line[i].0;
let dz = center_line[i + 1].1 - center_line[i].1;
let ds = (dx * dx + dz * dz).sqrt().max(1e-10);
let mut dtheta = heading[i + 1] - heading[i];
// Normalize to [-π, π]
while dtheta > std::f64::consts::PI {
dtheta -= 2.0 * std::f64::consts::PI;
}
while dtheta < -std::f64::consts::PI {
dtheta += 2.0 * std::f64::consts::PI;
}
curvature.push(dtheta / ds);
}
curvature.push(0.0);
// Step 7: Smooth curvature
let window = (curvature.len() / 50).clamp(3, 21);
let smoothed_curvature = smooth_f64(&curvature, window);
// Step 8: Auto-detect corners
let corners = detect_corners(&smoothed_curvature);
// Step 9: Define sectors
let sectors = vec![
Sector {
index: 0,
start_s: 0.0,
end_s: 1.0 / 3.0,
},
Sector {
index: 1,
start_s: 1.0 / 3.0,
end_s: 2.0 / 3.0,
},
Sector {
index: 2,
start_s: 2.0 / 3.0,
end_s: 1.0,
},
];
// Step 10: Normalize coordinates using bounds from all arrays
let mut min_x = f64::INFINITY;
let mut max_x = f64::NEG_INFINITY;
let mut min_z = f64::INFINITY;
let mut max_z = f64::NEG_INFINITY;
for (x, z) in center_line.iter().chain(left_resampled.iter()).chain(right_resampled.iter()) {
min_x = min_x.min(*x);
max_x = max_x.max(*x);
min_z = min_z.min(*z);
max_z = max_z.max(*z);
}
let scale = (max_x - min_x).max(max_z - min_z).max(1e-6);
let normalize = |px: f64, pz: f64| -> (f64, f64) { ((px - min_x) / scale, (pz - min_z) / scale) };
let normalized_center: Vec<(f64, f64)> = center_line
.into_iter()
.map(|(x, z)| normalize(x, z))
.collect();
let normalized_left: Vec<(f64, f64)> = left_resampled
.into_iter()
.map(|(x, z)| normalize(x, z))
.collect();
let normalized_right: Vec<(f64, f64)> = right_resampled
.into_iter()
.map(|(x, z)| normalize(x, z))
.collect();
// Step 11: Build and return TrackModel
Ok(TrackModel {
game,
track_name,
center_line: normalized_center,
left_boundary: normalized_left,
right_boundary: normalized_right,
track_width,
heading,
curvature: smoothed_curvature,
corners,
sectors,
source,
created_at: chrono::Utc::now().to_rfc3339(),
})
}
fn smooth_f64(values: &[f64], window: usize) -> Vec<f64> {
let half = window / 2;
let n = values.len();
let mut result = Vec::with_capacity(n);
for i in 0..n {
let start = i.saturating_sub(half);
let end = (i + half + 1).min(n);
let sum: f64 = values[start..end].iter().sum();
result.push(sum / (end - start) as f64);
}
result
}
fn detect_corners(curvature: &[f64]) -> Vec<Corner> {
let mut corners = Vec::new();
let mut in_corner = false;
let mut corner_start_s = 0.0f64;
let mut peak_idx = 0usize;
let mut peak_kappa = 0.0f64;
let len = curvature.len();
let denom = (len - 1).max(1) as f64;
for (i, &k) in curvature.iter().enumerate() {
let abs_k = k.abs();
if abs_k > CORNER_THRESHOLD && !in_corner {
in_corner = true;
corner_start_s = i.saturating_sub(5) as f64 / denom;
peak_idx = i;
peak_kappa = abs_k;
} else if abs_k > peak_kappa && in_corner {
peak_idx = i;
peak_kappa = abs_k;
} else if abs_k <= CORNER_THRESHOLD * 0.5 && in_corner {
in_corner = false;
let corner_end = (i + 5).min(len - 1);
let apex_s = peak_idx as f64 / denom;
let exit_s = corner_end as f64 / denom;
if exit_s - corner_start_s > 0.005 {
corners.push(Corner {
index: peak_idx,
number: 0,
entry_s: corner_start_s,
apex_s,
exit_s,
curvature_peak: peak_kappa,
});
}
}
}
if in_corner {
let apex_s = peak_idx as f64 / denom;
corners.push(Corner {
index: peak_idx,
number: 0,
entry_s: corner_start_s,
apex_s,
exit_s: 1.0,
curvature_peak: peak_kappa,
});
}
for (i, corner) in corners.iter_mut().enumerate() {
corner.number = (i + 1) as u32;
}
corners
}
// ---------------------------------------------------------------------------
// Car Grip Analysis (envelope extraction)
// ---------------------------------------------------------------------------
/// Speed bin width for the grip envelope (km/h).
const GRIP_SPEED_BIN: f32 = 10.0;
/// Maximum speed bin center (km/h).
const GRIP_MAX_SPEED: f32 = 360.0;
/// Target number of downsampled scatter points per dataset.
const GRIP_SCATTER_TARGET: usize = 800;
#[derive(Debug, Clone, Serialize)]
pub struct GripEnvelopePoint {
pub speed_kmh: f32,
pub max_lateral_g: f32,
pub max_accel_g: f32,
pub max_brake_g: f32,
pub sample_count: usize,
}
#[derive(Debug, Clone, Serialize)]
pub struct GripCirclePoint {
pub longitudinal_g: f32,
pub lateral_g: f32,
}
#[derive(Debug, Clone, Serialize)]
pub struct SteeringResponsePoint {
pub steer: f32,
pub lateral_g: f32,
pub speed_kmh: f32,
}
#[derive(Debug, Clone, Serialize)]
pub struct GripSummary {
pub max_lateral_g: f32,
pub max_accel_g: f32,
pub max_brake_g: f32,
pub max_combined_g: f32,
pub peak_lateral_speed_kmh: f32,
}
#[derive(Debug, Clone, Serialize)]
pub struct CarGripAnalysis {
pub summary: GripSummary,
pub grip_envelope: Vec<GripEnvelopePoint>,
pub grip_circle: Vec<GripCirclePoint>,
pub steering_response: Vec<SteeringResponsePoint>,
pub runs_analyzed: usize,
pub total_frames_analyzed: usize,
}
pub fn analyze_car_grip(runs: &[Vec<TelemetryFrame>]) -> CarGripAnalysis {
let num_bins = (GRIP_MAX_SPEED / GRIP_SPEED_BIN) as usize;
// Per-bin trackers: (max_lat, max_accel, max_brake, count)
let mut bins: Vec<(f32, f32, f32, usize)> = vec![(0.0, 0.0, 0.0, 0); num_bins];
// Scatter accumulators (before downsampling)
let mut circle_raw: Vec<GripCirclePoint> = Vec::new();
let mut steer_raw: Vec<SteeringResponsePoint> = Vec::new();
// Summary trackers
let mut max_lat = 0.0f32;
let mut max_lat_speed = 0.0f32;
let mut max_accel = 0.0f32;
let mut max_brake = 0.0f32;
let mut max_combined = 0.0f32;
let mut total_frames: usize = 0;
let mut runs_analyzed: usize = 0;
for run in runs {
if run.is_empty() {
continue;
}
runs_analyzed += 1;
for f in run {
// Filter: skip pit, very low speed
if f.is_in_pit || f.speed_kmh < 5.0 {
continue;
}
let lat = f.acc_g_horizontal.abs();
let long = f.acc_g_frontal;
let accel = if long > 0.0 { long } else { 0.0 };
let brake = if long < 0.0 { long.abs() } else { 0.0 };
let combined = (lat * lat + long * long).sqrt();
total_frames += 1;
// Update summary
if lat > max_lat {
max_lat = lat;
max_lat_speed = f.speed_kmh;
}
if accel > max_accel {
max_accel = accel;
}
if brake > max_brake {
max_brake = brake;
}
if combined > max_combined {
max_combined = combined;
}
// Update speed bin
let bin_idx = ((f.speed_kmh / GRIP_SPEED_BIN) as usize).min(num_bins - 1);
let b = &mut bins[bin_idx];
b.0 = b.0.max(lat);
b.1 = b.1.max(accel);
b.2 = b.2.max(brake);
b.3 += 1;
// Accumulate scatter points (only for significant cornering/braking)
if lat > 0.3 || long.abs() > 0.3 {
circle_raw.push(GripCirclePoint {
longitudinal_g: long,
lateral_g: f.acc_g_horizontal,
});
}
if f.steer.abs() > 0.02 && lat > 0.1 {
steer_raw.push(SteeringResponsePoint {
steer: f.steer,
lateral_g: f.acc_g_horizontal,
speed_kmh: f.speed_kmh,
});
}
}
}
// Build envelope from bins (only include bins with data)
let grip_envelope: Vec<GripEnvelopePoint> = bins
.iter()
.enumerate()
.filter(|(_, b)| b.3 > 0)
.map(|(i, b)| GripEnvelopePoint {
speed_kmh: i as f32 * GRIP_SPEED_BIN + GRIP_SPEED_BIN / 2.0,
max_lateral_g: b.0,
max_accel_g: b.1,
max_brake_g: b.2,
sample_count: b.3,
})
.collect();
let grip_circle = downsample(circle_raw, GRIP_SCATTER_TARGET);
let steering_response = downsample(steer_raw, GRIP_SCATTER_TARGET);
CarGripAnalysis {
summary: GripSummary {
max_lateral_g: max_lat,
max_accel_g: max_accel,
max_brake_g: max_brake,
max_combined_g: max_combined,
peak_lateral_speed_kmh: max_lat_speed,
},
grip_envelope,
grip_circle,
steering_response,
runs_analyzed,
total_frames_analyzed: total_frames,
}
}
fn downsample<T: Clone>(items: Vec<T>, target: usize) -> Vec<T> {
if items.len() <= target {
return items;
}
let step = items.len() as f32 / target as f32;
let mut result = Vec::with_capacity(target);
let mut idx = 0.0f32;
while (idx as usize) < items.len() {
result.push(items[idx as usize].clone());
idx += step;
}
result
}
// ---------------------------------------------------------------------------
// Racing Line Analysis
// ---------------------------------------------------------------------------
#[derive(Debug, Clone, Serialize, serde::Deserialize)]
pub struct RacingLinePoint {
pub x: f32,
pub y: f32,
pub z: f32,
pub speed_kmh: f32,
pub spline: f32,
}
#[derive(Debug, Clone, Serialize, serde::Deserialize)]
pub struct RacingLap {
pub label: String,
pub lap_index: usize,
pub point_count: usize,
pub points: Vec<RacingLinePoint>,
pub lap_time_ms: i32,
pub length_m: f32,
pub avg_speed_kmh: f32,
pub max_speed_kmh: f32,
}
#[derive(Debug, Clone, Serialize, serde::Deserialize)]
pub struct RacingLineAnalysis {
pub laps: Vec<RacingLap>,
pub position_mode: PositionMode,
pub total_laps: usize,
pub total_frames_analyzed: usize,
}
/// Split a run's frames into individual laps based on lap_count transitions.
fn split_into_laps(frames: &[TelemetryFrame]) -> Vec<Vec<TelemetryFrame>> {
if frames.is_empty() {
return Vec::new();
}
let mut laps: Vec<Vec<TelemetryFrame>> = Vec::new();
let mut current: Vec<TelemetryFrame> = Vec::new();
let mut prev_lap = frames[0].lap_count;
for f in frames {
if f.lap_count != prev_lap && !current.is_empty() {
laps.push(std::mem::take(&mut current));
}
current.push(f.clone());
prev_lap = f.lap_count;
}
if !current.is_empty() {
laps.push(current);
}
laps
}
pub fn analyze_racing_line(
runs: &[Vec<TelemetryFrame>],
labels: &[String],
) -> RacingLineAnalysis {
let all_frames: Vec<TelemetryFrame> = runs.iter().flat_map(|r| r.iter()).cloned().collect();
let mode = detect_position_mode(&all_frames);
let mut laps_out: Vec<RacingLap> = Vec::new();
let mut total_frames = 0usize;
for (run, label) in runs.iter().zip(labels.iter()) {
let laps = split_into_laps(run);
for (lap_idx, lap_frames) in laps.iter().enumerate() {
if lap_frames.is_empty() {
continue;
}
// Skip partial laps: check spline coverage. A complete lap's
// spline values span ≥ 0.9 of [0, 1] (the car went almost all
// the way around). Partial laps at the start (joined mid-track)
// and end (session ended early) are discarded.
if laps.len() > 1 {
let splines: Vec<f32> = lap_frames.iter()
.filter(|f| f.spline_position > 0.0)
.map(|f| f.spline_position)
.collect();
if !splines.is_empty() {
let min_s = splines.iter().cloned().fold(f32::INFINITY, f32::min);
let max_s = splines.iter().cloned().fold(f32::NEG_INFINITY, f32::max);
let span = max_s - min_s;
let wraps = min_s < 0.1 && max_s > 0.9;
if span < 0.9 && !wraps {
continue;
}
}
}
let mut points: Vec<RacingLinePoint> = lap_frames
.iter()
.filter(|f| {
if matches!(mode, PositionMode::Spline) {
f.spline_position > 0.0
} else {
f.world_x != 0.0 || f.world_z != 0.0
}
})
.map(|f| RacingLinePoint {
x: f.world_x,
y: f.world_y,
z: f.world_z,
speed_kmh: f.speed_kmh,
spline: f.spline_position,
})
.collect();
if points.is_empty() {
continue;
}
total_frames += lap_frames.len();
// Compute track length from consecutive point distances
let mut length_m = 0.0f32;
for i in 1..points.len() {
let dx = points[i].x - points[i - 1].x;
let dz = points[i].z - points[i - 1].z;
length_m += (dx * dx + dz * dz).sqrt();
}
// Sort by spline if in spline mode for a clean path
if matches!(mode, PositionMode::Spline) {
points.sort_by(|a, b| {
a.spline
.partial_cmp(&b.spline)
.unwrap_or(std::cmp::Ordering::Equal)
});
points.dedup_by(|a, b| (a.spline - b.spline).abs() < 0.0001);
}
// Downsample for efficient rendering (target ~400 points/lap)
let point_count_before = points.len();
points = downsample(points, 400);
let max_speed = lap_frames
.iter()
.map(|f| f.speed_kmh)
.fold(0.0f32, f32::max);
let avg_speed = if length_m > 0.0 {
let best_lap_s = lap_frames
.last()
.map(|f| f.lap_time_ms)
.unwrap_or(0)
.max(0) as f32
/ 1000.0;
if best_lap_s > 0.0 {
(length_m / best_lap_s) * 3.6
} else {
let frame_count = lap_frames.len() as f32;
lap_frames.iter().map(|f| f.speed_kmh).sum::<f32>() / frame_count
}
} else {
0.0
};
let lap_time = lap_frames
.last()
.map(|f| f.lap_time_ms)
.unwrap_or(0);
laps_out.push(RacingLap {
label: label.clone(),
lap_index: lap_idx,
point_count: point_count_before,
points,
lap_time_ms: lap_time,
length_m,
avg_speed_kmh: avg_speed,
max_speed_kmh: max_speed,
});
}
}
let total_laps = laps_out.len();
RacingLineAnalysis {
laps: laps_out,
position_mode: mode,
total_laps,
total_frames_analyzed: total_frames,
}
}
// ---------------------------------------------------------------------------
// Dispatch
// ---------------------------------------------------------------------------
pub fn analyze(
use_case: &UseCase,
frames_by_run: &[Vec<TelemetryFrame>],
run_labels: &[String],
) -> serde_json::Value {
match use_case {
UseCase::ShiftPoints => {
if frames_by_run.is_empty() || frames_by_run.iter().all(|r| r.is_empty()) {
serde_json::json!({"error": "no frames provided"})
} else {
serde_json::to_value(analyze_shift_points(frames_by_run, run_labels))
.unwrap_or_else(|_| serde_json::json!({"error": "serialization failed"}))
}
}
UseCase::CarGrip => {
if frames_by_run.is_empty() || frames_by_run.iter().all(|r| r.is_empty()) {
serde_json::json!({"error": "no frames provided"})
} else {
serde_json::to_value(analyze_car_grip(frames_by_run))
.unwrap_or_else(|_| serde_json::json!({"error": "serialization failed"}))
}
}
UseCase::TrackMapping => {
serde_json::to_value(analyze_track_map(frames_by_run, run_labels))
.unwrap_or_else(|_| serde_json::json!({"error": "serialization failed"}))
}
UseCase::RacingLine => {
if frames_by_run.is_empty() || frames_by_run.iter().all(|r| r.is_empty()) {
serde_json::json!({"error": "no frames provided"})
} else {
serde_json::to_value(analyze_racing_line(frames_by_run, run_labels))
.unwrap_or_else(|_| serde_json::json!({"error": "serialization failed"}))
}
}
_ => serde_json::json!({
"status": "not_implemented",
"use_case": format!("{:?}", use_case),
}),
}
}