Final basic ground and jump physics tweaks.

src/components/PlayerPhysicsController.cs

@@ -3,28 +3,30 @@ using System;
 using System.Diagnostics;
 
 public partial class PlayerPhysicsController : CharacterBody2D {
-    [Export]
+    // [Export]
-    public float FloatingWalkAcceleration { get; set; } = 1f;
+    // public float RunMultiplier { get; set; } = 1.84f;
-    [Export]
-    public float RunMultiplier { get; set; } = 1.84f;
     [Export]
     public float WalkAcceleration { get; set; } = 3f;
+    [Export]
+    public float StoppingDeceleration { get; set; } = 8f;
+    [Export]
+    public float CancellationAcceleration { get; set; } = 4f;
 
     [Export]
     public float JumpHeight { get; set; } = 5.5f;
 
     private float PeakTime { get; set; } = 0.1f;
+    
+    [Export]
+    private float MaxFallSpeed { get; set; } = 8f;
 
     [Export]
-    public float DragArea { get; set; } = 4f;
+    private float MaxRiseSpeed { get; set; } = 16f;
 
     [Export]
-    public float AirDensity { get; set; } = 37.26982f;
+    private float MaxRunSpeed { get; set; } = 16f;
-
     [Export]
-    public float DragCoefficient { get; set; } = 1.3f;
+    private float MaxWalkSpeed { get; set; } = 8f;
-    [Export]
-    public float FloatingDragCoefficientMultiplier { get; set; } = 0.8f;
 
     [Export]
     public Label DebugTextLabel { get; set; }
@@ -42,33 +44,17 @@ public partial class PlayerPhysicsController : CharacterBody2D {
     [Export]
     public float UnitToPx { get; set; } = 32;
 
-    private float _lv = 0.0f;
+        private float _timeOffGround = 0.0f;
-    private float _invmass = 1/2f;
-    [Export]
-    public float Mass { get => 1/_invmass; set => _invmass = 1/value; }
 
-    private float epsilon = 10e-5f;
+    [Export]
+    public float CoyoteTiming { get; set; } = 0.1f;
+
+    private float _lv = 0.0f;
 
     private void RecalculateLv() {
         _lv = Mathf.Sqrt(Mathf.Pow(Gravity * PeakTime / 2, 2) + 2 * Gravity * JumpHeight);
     }
 
-    private float CalculateDrag(float velocity, float delta) {
-        var minopposing = Mathf.Abs(velocity * 0.99f);
-        return Mathf.Clamp(
-            0.5f * 
-            (this.IsOnFloor() ? DragCoefficient : DragCoefficient * FloatingDragCoefficientMultiplier) * 
-            (Mathf.Pow(TilesToMeters, 3) * AirDensity) * 
-            (Mathf.Pow(TilesToMeters, 2) * DragArea) * 
-            Mathf.Pow(velocity * PxToMeters, 2) * 
-            _invmass * 
-            -Mathf.Sign(velocity) *
-            delta *
-            (1f / TilesToMeters),
-            -minopposing,
-            minopposing);
-    }
-
     public override void _Ready() {
         RecalculateLv();
         base._Ready();
@@ -88,12 +74,16 @@ public partial class PlayerPhysicsController : CharacterBody2D {
                 < 300 => 4,
                 _ => 1
             };
+            if (!Sprite.IsPlaying())
+                Sprite.Play();
         } else {
             Sprite.SpeedScale = 1;
         }
         
         if (grounded && absvel.X < 0.1) {
             Sprite.Animation = "idle";
+            if (!Sprite.IsPlaying())
+                Sprite.Play();
         }
 
         if (!grounded && Velocity.Y > 0.1) {
@@ -105,11 +95,8 @@ public partial class PlayerPhysicsController : CharacterBody2D {
         }
     }
 
-    private float _timeOffGround = 0.0f;
-
     [Export]
-    public float CoyoteTiming { get; set; } = 0.1f;
+    public float Deadzone { get; set; } = 0.1f;
-
 
     public override void _PhysicsProcess(double delta) {
         var xAxis = Input.GetAxis("move_left", "move_right");
@@ -119,10 +106,10 @@ public partial class PlayerPhysicsController : CharacterBody2D {
         var lastCollision = this.IsOnCeiling();
         RecalculateLv();
 
-        float velx = (Velocity.X / UnitToPx) + CalculateDrag(Velocity.X, (float)delta);
+        float velx = (Velocity.X / UnitToPx);
-        float vely = (Velocity.Y / UnitToPx) + Gravity * (float)delta + CalculateDrag(Velocity.Y, (float)delta);
+        float vely = (Velocity.Y / UnitToPx) + Gravity * (float)delta;
 
-        if (Mathf.Abs(velx) < 0.3) velx = 0;
+        if (Mathf.Abs(velx) < 0.1) velx = 0;
 
         var grounded = this.IsOnFloor();
         var coyoteGrounded = _timeOffGround < CoyoteTiming;
@@ -138,32 +125,40 @@ public partial class PlayerPhysicsController : CharacterBody2D {
                 vely *= 1/4f;
             }
 
-            if (Input.IsActionPressed("run")) {
+            var accel = WalkAcceleration;
-                velx += xAxis * WalkAcceleration * (float)delta * RunMultiplier;
+            if (xAxis * Velocity.X < 0) accel = StoppingDeceleration;
-            } else {
+            velx += xAxis * accel * (float)delta;
-                velx += xAxis * WalkAcceleration * (float)delta;
-            }
         } else {
             if (Input.IsActionJustReleased("jump") && vely < 0) {
                 vely *= 1/4f;
             }
-
-            if (Input.IsActionPressed("run")) {
-                velx += xAxis * FloatingWalkAcceleration * (float)delta * RunMultiplier;
-            } else {
-                velx += xAxis * FloatingWalkAcceleration * (float)delta; 
-            }
         }
 
+        if (Mathf.Abs(xAxis) < Deadzone) {
+            var autostop = -Mathf.Sign(velx) * StoppingDeceleration * (float)delta;
+            if (Mathf.Abs(autostop) > Mathf.Abs(velx)) velx = 0f;
+            else velx += autostop;
+        }
+
+        var maxXSpeed = Input.IsActionPressed("run") ? MaxRunSpeed : MaxWalkSpeed;
+        var maxYSpeed = vely > 0 ? MaxFallSpeed : MaxRiseSpeed;
+        var (absvelx, absvely) = (Mathf.Abs(velx), Mathf.Abs(vely));
+        float xcancel = 0, ycancel = 0;
+        if (absvelx > maxXSpeed) xcancel = -Math.Sign(velx) * CancellationAcceleration * (float)delta;
+        if (absvely > maxYSpeed) ycancel = -Math.Sign(vely) * CancellationAcceleration * (float)delta;
+        if (Mathf.Abs(xcancel) + 0.1 > absvelx) velx = 0;
+        else velx += xcancel;
+        if (Mathf.Abs(ycancel) + 0.1 > absvely) vely = 0;
+        else vely += ycancel;
+
         DebugTextLabel.Text = 
             $"grounded: {grounded}\n" + 
             $"vely: {vely}\n" +
             $"velx: {velx}\n" +
-            $"lv  : {_lv:F2} or {_lv/(float)delta:F2}\n" +
+            $"lv  : {_lv:F2} or {_lv/(float)delta:F2}\n";
-            $"rd  : {CalculateDrag(Velocity.X, (float)delta):F2}, {CalculateDrag(Velocity.Y, (float)delta):F2}";
         // Force = new Vector2(0, forcey);
-        Velocity = new Vector2(velx, vely) * UnitToPx;
+        Velocity = new Vector2(velx, vely);
-
+        Velocity *= UnitToPx;
         MoveAndSlide();
     }
 }