From 04f4332c4d795693243e1f1be51ffce59ad66137 Mon Sep 17 00:00:00 2001
From: Astro <astro@spaceboyz.net>
Date: Fri, 28 Jan 2022 21:43:58 +0100
Subject: [PATCH] beast: remove jitter buffer again

---
 beast/src/aircrafts.rs | 34 +++-------------------------------
 1 file changed, 3 insertions(+), 31 deletions(-)

diff --git a/beast/src/aircrafts.rs b/beast/src/aircrafts.rs
index f6e09a3..6c84f94 100644
--- a/beast/src/aircrafts.rs
+++ b/beast/src/aircrafts.rs
@@ -6,8 +6,6 @@ use tokio::sync::mpsc::channel;
 use adsb_deku::ICAO;
 use super::beast;
 
-const JITTER_WINDOW: usize = 9;
-
 #[derive(Default)]
 pub struct Entry {
     pub category: Option<(adsb_deku::adsb::TypeCoding, u8)>,
@@ -15,8 +13,7 @@ pub struct Entry {
     pub altitude: Option<u32>,
     cpr1: Option<adsb_deku::Altitude>,
     cpr2: Option<adsb_deku::Altitude>,
-    // jitter buffer
-    positions: [Option<adsb_deku::cpr::Position>; JITTER_WINDOW],
+    position: Option<adsb_deku::cpr::Position>,
     pub heading: Option<f64>,
     pub speed: Option<f64>,
     pub vertical_rate: Option<i16>,
@@ -52,12 +49,7 @@ impl Entry {
                             {
                                 eprintln!("invalid position: {:?}", pos);
                             } else {
-                                // shift previous positions in jitter buffer
-                                for i in 1..self.positions.len() {
-                                    self.positions[i - 1] = self.positions[i].take();
-                                }
-                                // add position to jitter buffer
-                                self.positions[self.positions.len() - 1] = Some(pos);
+                                self.position = Some(pos);
                                 self.seen_pos = Some(Instant::now());
                             }
                         }
@@ -90,27 +82,7 @@ impl Entry {
     }
 
     pub fn position(&self) -> Option<&adsb_deku::cpr::Position> {
-        let mut prev_lat = self.positions[0].as_ref()?.latitude;
-        let mut prev_lon = self.positions[0].as_ref()?.longitude;
-        for i in 1..self.positions.len() {
-            let lat = self.positions[i].as_ref()?.latitude;
-            let lon = self.positions[i].as_ref()?.longitude;
-            if lat < prev_lat - 1.0 ||
-                lat > prev_lat + 1.0 ||
-                lon < prev_lon - 1.0 ||
-                lon > prev_lon + 1.0
-            {
-                // erroneous jitter detected
-                eprintln!("{:?} error in: {:?}", self.callsign, self.positions.iter().filter_map(|pos| {
-                    pos.as_ref().map(|pos| (pos.latitude as i32, pos.longitude as i32))
-                }).collect::<Vec<_>>());
-                return None;
-            }
-            prev_lat = lat;
-            prev_lon = lon;
-        }
-
-        self.positions[self.positions.len() - 1].as_ref()
+        self.position.as_ref()
     }
 
     pub fn flight(&self) -> Option<&str> {