From 2e35f90a1949dfbf64702cd76722e6ce94be1fd4 Mon Sep 17 00:00:00 2001
From: yuni <hut@hut.pm>
Date: Sun, 17 Nov 2024 00:25:43 +0100
Subject: [PATCH] WIP crisper camera controls (prevent overshooting when
 braking)

---
 src/actor.rs | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/src/actor.rs b/src/actor.rs
index 551bf39..be89640 100644
--- a/src/actor.rs
+++ b/src/actor.rs
@@ -822,6 +822,7 @@ fn handle_wants_acceleration(
         let mut thruster_on = false;
         if let (Some(mut engine), Some(accel)) = (engine, accel) {
             let mut delta_v = DVec3::ZERO;
+            let mut allow_fullstop = false;
             let boost = engine.current_boost_factor;
             engine.currently_matching_velocity = false;
 
@@ -836,7 +837,11 @@ fn handle_wants_acceleration(
             }
 
             if accel.direction != DVec3::ZERO {
+                // Player is pressing AWSD keys
                 delta_v += (trans.rotation * accel.direction.as_vec3()).as_dvec3();
+            } else if accel.brake {
+                // Player is only pressing space
+                allow_fullstop = true;
             }
 
             if delta_v.length_squared() > 0.003 {
@@ -858,8 +863,25 @@ fn handle_wants_acceleration(
                     * ENGINE_SPEED_FACTOR as f64
                     * engine.current_boost_factor;
 
+                let final_accel = delta_v.normalize() * engine_factor * dt as f64;
+
                 // Apply acceleration to velocity
-                **v += delta_v.normalize() * engine_factor * dt as f64;
+                if allow_fullstop {
+                    if let Some(target_v) = closest_map.get(&entity) {
+                        // Prevent overshooting when matching velocity, which
+                        // would result in oscillating acceleration back and forth
+                        for axis in 0..3 {
+                            let original = v[axis];
+                            let target = target_v[axis];
+                            v[axis] += final_accel[axis];
+                            if (original - target).signum() != (v[axis] - target).signum() {
+                                v[axis] = target;
+                            }
+                        }
+                    }
+                } else {
+                    **v += final_accel;
+                }
 
                 // Visual effect
                 if engine.engine_type == EngineType::Monopropellant {