From 14d36968054bc6a47e60529a122fb033505afb21 Mon Sep 17 00:00:00 2001
From: Nikolay Petrov <nikolay_petrov@gaijin.team>
Date: Tue, 6 Jan 2026 21:42:31 +0500
Subject: [PATCH] feat(movement): improve air control and ground snapping
 behavior

- Add directional air control modifier to prevent instant braking mid-air
  * Reduce control effectiveness by 50% when reversing direction (Dot < 0)
  * Allows side-to-side adjustments while maintaining forward momentum
- Remove input requirement for velocity projection on ground snap
  * Project velocity onto slope even without player input
  * Preserves momentum when landing on slopes
- Add KINDA_SMALL_NUMBER checks to prevent division by zero
- Add GetRenderLocation() Blueprint accessor for VFX positioning
- Clean up comments: translate Russian text to English

This makes air movement feel more realistic (less like flying) while
improving slope handling consistency.
---
 .../Movement/TengriMovementComponent.cpp      | 58 ++++++++++++-------
 .../Movement/TengriMovementComponent.h        |  4 ++
 2 files changed, 41 insertions(+), 21 deletions(-)

diff --git a/Source/TengriPlatformer/Movement/TengriMovementComponent.cpp b/Source/TengriPlatformer/Movement/TengriMovementComponent.cpp
index ca70e52..5eb00c1 100644
--- a/Source/TengriPlatformer/Movement/TengriMovementComponent.cpp
+++ b/Source/TengriPlatformer/Movement/TengriMovementComponent.cpp
@@ -313,33 +313,49 @@ void UTengriMovementComponent::TickPhysics(
     const float CurrentZ = PhysicsVelocity.Z;
     FVector HorizontalVelocity(PhysicsVelocity.X, PhysicsVelocity.Y, 0.f);
 
-    // Select Acceleration/Friction based on state
-    const float CurrentAccel = bIsGrounded 
-        ? MovementConfig->Acceleration 
-        : (MovementConfig->Acceleration * MovementConfig->AirControl);
-
     const float CurrentFriction = bIsGrounded 
         ? MovementConfig->Friction 
         : MovementConfig->AirFriction;
 
     if (!InputVector.IsNearlyZero())
     {
+        // Calculate directional air control modifier
+        // Reduce control when trying to reverse direction mid-air
+        const FVector VelocityDir = HorizontalVelocity.GetSafeNormal();
+        const float Dot = FVector::DotProduct(VelocityDir, InputVector);
+        
+        float FinalAirControl = MovementConfig->AirControl;
+        
+        // Reduce braking effectiveness in air (prevents instant direction changes)
+        if (Dot < 0.0f)
+        {
+            FinalAirControl *= 0.5f;
+        }
+
+        const float CurrentAccel = MovementConfig->Acceleration * FinalAirControl;
         const FVector TargetVelocity = InputVector * MovementConfig->MaxSpeed;
-        HorizontalVelocity = FMath::VInterpTo(
-            HorizontalVelocity,
-            TargetVelocity,
-            FixedDeltaTime,
-            CurrentAccel // <-- Uses Air Control if flying
-        );
+
+        if (CurrentAccel > KINDA_SMALL_NUMBER)
+        {
+            HorizontalVelocity = FMath::VInterpTo(
+                HorizontalVelocity,
+                TargetVelocity,
+                FixedDeltaTime,
+                CurrentAccel
+            );
+        }
     }
     else
     {
-        HorizontalVelocity = FMath::VInterpTo(
-            HorizontalVelocity,
-            FVector::ZeroVector,
-            FixedDeltaTime,
-            CurrentFriction // <-- Usually 0 in air
-        );
+        if (CurrentFriction > KINDA_SMALL_NUMBER)
+        {
+            HorizontalVelocity = FMath::VInterpTo(
+                HorizontalVelocity,
+                FVector::ZeroVector,
+                FixedDeltaTime,
+                CurrentFriction
+            );
+        }
     }
 
     PhysicsVelocity = HorizontalVelocity;
@@ -450,8 +466,8 @@ void UTengriMovementComponent::TickPhysics(
         FHitResult SnapHit;
         bJustSnapped = PerformGroundSnapping(PhysicsLocation, SnapHit);
         
-        // Project velocity onto slope if snapped
-        if (bJustSnapped && !InputVector.IsNearlyZero())
+        // Always project velocity onto slope when snapped (preserves momentum)
+        if (bJustSnapped)
         {
             PhysicsVelocity = UTengriCollisionResolver::ProjectVelocity(
                 PhysicsVelocity,
@@ -571,8 +587,8 @@ bool UTengriMovementComponent::PerformGroundSnapping(
 
 void UTengriMovementComponent::ForceRotation(const FRotator& NewRotation)
 {
-	// Обновляем все внутренние состояния, чтобы физика "подхватила" новый поворот
+	// Update all internal states so physics adopts new rotation immediately
 	PhysicsRotation = NewRotation;
 	RenderRotation = NewRotation;
-	PreviousPhysicsRotation = NewRotation; // Сбрасываем интерполяцию
+	PreviousPhysicsRotation = NewRotation; // Reset interpolation
 }
\ No newline at end of file
diff --git a/Source/TengriPlatformer/Movement/TengriMovementComponent.h b/Source/TengriPlatformer/Movement/TengriMovementComponent.h
index 0730958..de7aa05 100644
--- a/Source/TengriPlatformer/Movement/TengriMovementComponent.h
+++ b/Source/TengriPlatformer/Movement/TengriMovementComponent.h
@@ -32,6 +32,10 @@ class TENGRIPLATFORMER_API UTengriMovementComponent : public UActorComponent
 public:
 	UTengriMovementComponent();
 
+	/** Get interpolated render location */
+	UFUNCTION(BlueprintPure, Category = "Tengri Movement")
+	FVector GetRenderLocation() const { return RenderLocation; }
+
 	/** Event triggered when character lands (broadcast after physics loop completes) */
 	UPROPERTY(BlueprintAssignable, Category = "Tengri Movement|Events")
 	FOnTengriLandingSignature OnLanded;