massivly decrease the effects of bigger tick times on the pos calculatuion by moving the block friction calcuation into the inner iterator

do physics always after character_behavior as this one is saying how the input should be handled

CHANGELOG.md

@@ -55,6 +55,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fixed an error where '{amount} Exp' floater did not use existing localizations
 - Fix villagers seeing cultists and familiar enemies through objects.
 - Menacing agents are now less spammy with their menacing messages
+- Reduced effects of slow/high FPS on physics like player speed by ~50%
 
 ## [0.12.0] - 2022-02-19
 

common/systems/src/lib.rs

@@ -27,8 +27,9 @@ pub fn add_local_systems(dispatch_builder: &mut DispatcherBuilder) {
     dispatch::<buff::Sys>(dispatch_builder, &[]);
     dispatch::<stats::Sys>(dispatch_builder, &[&buff::Sys::sys_name()]);
     dispatch::<phys::Sys>(dispatch_builder, &[
+        &character_behavior::Sys::sys_name(),
         &interpolation::Sys::sys_name(),
-        &controller::Sys::sys_name(),
+        //&controller::Sys::sys_name(), provided by character_behavior
         &mount::Sys::sys_name(),
         &stats::Sys::sys_name(),
     ]);

common/systems/src/phys.rs

@@ -1428,6 +1428,7 @@ fn box_voxel_collision<'a, T: BaseVol<Vox = Block> + ReadVol>(
     };
 
     let z_range = z_min..z_max;
+    let fric_mod = read.stats.get(entity).map_or(1.0, |s| s.friction_modifier);
 
     // Setup values for the loop below
     physics_state.on_ground = None;
@@ -1444,11 +1445,13 @@ fn box_voxel_collision<'a, T: BaseVol<Vox = Block> + ReadVol>(
     const MAX_INCREMENTS: usize = 100; // The maximum number of collision tests per tick
     let increments = ((pos_delta.map(|e| e.abs()).reduce_partial_max() / 0.3).ceil() as usize)
         .clamped(1, MAX_INCREMENTS);
+    let increment_dt = dt.0 / (increments as f32);
     let old_pos = pos.0;
     for _ in 0..increments {
         //prof_span!("increment");
         const MAX_ATTEMPTS: usize = 16;
-        pos.0 += pos_delta / increments as f32;
+        let increment_dpos = pos_delta / increments as f32;
+        pos.0 += increment_dpos;
 
         let try_colliding_block = |pos: &Pos| {
             //prof_span!("most colliding check");
@@ -1596,6 +1599,18 @@ fn box_voxel_collision<'a, T: BaseVol<Vox = Block> + ReadVol>(
             attempts += 1;
         }
 
+        // Apply on-ground-friction
+        let ground_fric = on_ground.map(|b| b.get_friction()).unwrap_or(0.0);
+        if ground_fric > 0.0 {
+            let fric_fac = (1.0 - ground_fric.min(1.0) * fric_mod).powf(increment_dt * 60.0);
+            vel.0 *= fric_fac;
+            // TODO: evaluate activate: undo part of the increment and adjust pos_delta by
+            // friction for the next step
+
+            // pos.0 -= increment_dpos * pos_delta * (1.0 - fric_fac);
+            pos_delta *= fric_fac;
+        }
+
         if attempts == MAX_ATTEMPTS {
             vel.0 = Vec3::zero();
             pos.0 = old_pos;
@@ -1710,7 +1725,6 @@ fn box_voxel_collision<'a, T: BaseVol<Vox = Block> + ReadVol>(
     }
 
     physics_state.on_wall = on_wall;
-    let fric_mod = read.stats.get(entity).map_or(1.0, |s| s.friction_modifier);
 
     // skating (ski)
     if !vel.0.xy().is_approx_zero()
@@ -1775,18 +1789,13 @@ fn box_voxel_collision<'a, T: BaseVol<Vox = Block> + ReadVol>(
         physics_state.skating_active = true;
         vel.0 = Vec3::new(new_ground_speed.x, new_ground_speed.y, 0.0);
     } else {
-        let ground_fric = physics_state
-            .on_ground
-            .map(|b| b.get_friction())
-            .unwrap_or(0.0);
-        let wall_fric = if physics_state.on_wall.is_some() && climbing {
-            FRIC_GROUND
-        } else {
-            0.0
-        };
-        let fric = ground_fric.max(wall_fric);
-        if fric > 0.0 {
-            vel.0 *= (1.0 - fric.min(1.0) * fric_mod).powf(dt.0 * 60.0);
+        // In contrast to ground_fric keep wall_fric outside the loop as its more costly
+        // and less noticeable
+        if physics_state.on_wall.is_some() && climbing {
+            vel.0 *= (1.0 - FRIC_GROUND * fric_mod).powf(dt.0 * 60.0);
+        }
+        // Set ground_vel when friction was applied.
+        if physics_state.on_wall.is_some() || physics_state.on_ground.is_some() {
             physics_state.ground_vel = ground_vel;
         }
         physics_state.skating_active = false;

common/systems/tests/phys/basic.rs

@@ -200,7 +200,7 @@ fn walk_max() -> Result<(), Box<dyn Error>> {
         utils::tick(&mut state, DT);
     }
     let (pos, vel, _) = utils::get_transform(&state, p1)?;
-    assert_relative_eq!(pos.0.x, 68.40794, epsilon = EPSILON);
+    assert_relative_eq!(pos.0.x, 68.51424, epsilon = EPSILON);
     assert_relative_eq!(vel.0.x, 9.695188, epsilon = EPSILON);
     for _ in 0..100 {
         utils::tick(&mut state, DT);
@@ -241,12 +241,12 @@ fn walk_dt_speed_diff() -> Result<(), Box<dyn Error>> {
     assert_relative_eq!(spos.0.y, 16.0);
     assert_relative_eq!(spos.0.z, 257.0);
     assert_relative_eq!(svel.0.x, 6.071788, epsilon = EPSILON);
-    assert_relative_eq!(fpos.0.x, 16.993896, epsilon = EPSILON);
+    assert_relative_eq!(fpos.0.x, 16.71537, epsilon = EPSILON);
     assert_relative_eq!(fpos.0.y, 16.0);
     assert_relative_eq!(fpos.0.z, 257.0);
     assert_relative_eq!(fvel.0.x, 3.7484815, epsilon = EPSILON);
 
-    assert_relative_eq!((spos.0.x - fpos.0.x).abs(), 0.5724735, epsilon = EPSILON);
+    assert_relative_eq!((spos.0.x - fpos.0.x).abs(), 0.29394722, epsilon = EPSILON);
     assert_relative_eq!((svel.0.x - fvel.0.x).abs(), 2.3233063, epsilon = EPSILON);
 
     for _ in 0..10 {
@@ -258,11 +258,11 @@ fn walk_dt_speed_diff() -> Result<(), Box<dyn Error>> {
     let (fpos, fvel, _) = utils::get_transform(&fstate, fp1)?;
     assert_relative_eq!(spos.0.x, 17.248621, epsilon = EPSILON);
     assert_relative_eq!(svel.0.x, 8.344364, epsilon = EPSILON);
-    assert_relative_eq!(fpos.0.x, 18.357212, epsilon = EPSILON);
+    assert_relative_eq!(fpos.0.x, 17.673855, epsilon = EPSILON);
     assert_relative_eq!(fvel.0.x, 5.1417327, epsilon = EPSILON);
 
     // Diff after 200ms
-    assert_relative_eq!((spos.0.x - fpos.0.x).abs(), 1.1085911, epsilon = EPSILON);
+    assert_relative_eq!((spos.0.x - fpos.0.x).abs(), 0.42523384, epsilon = EPSILON);
     assert_relative_eq!((svel.0.x - fvel.0.x).abs(), 3.2026315, epsilon = EPSILON);
 
     Ok(())