Add attribute system with core stats and gameplay components

GameCore/Movement/GroundMovementSystem.cs

@@ -0,0 +1,61 @@
+using GameCore.Attributes;
+using GameCore.ECS;
+using GameCore.ECS.Interfaces;
+using GameCore.Input;
+using GameCore.Math;
+using GameCore.Physics;
+using Attribute = GameCore.Attributes.Attribute;
+
+namespace GameCore.Movement;
+
+public class GroundMovementSystem : ISystem
+{
+    public void Update(World world, float deltaTime)
+    {
+        var entities = world.GetEntitiesWith<InputStateComponent>();
+        foreach (var entity in entities)
+        {
+            var input = world.GetComponent<InputStateComponent>(entity);
+            var velocity = world.GetComponent<VelocityComponent>(entity);
+            var attributes = world.GetComponent<AttributeComponent>(entity);
+            var rotation = world.GetComponent<RotationComponent>(entity);
+
+            if (input == null || velocity == null || attributes == null || rotation == null)
+                continue;
+
+            var moveSpeed = attributes.GetValue(Attribute.MoveSpeed);
+            var acceleration = attributes.GetValue(Attribute.Acceleration);
+            var friction = attributes.GetValue(Attribute.Friction);
+
+            var yaw = rotation.Rotation.Y;
+            var rotatedDir = world.WorldQuery.RotateVectorByYaw(input.MoveDirection, yaw);
+
+            var targetVelocity = new Vector3(
+                rotatedDir.X * moveSpeed,
+                velocity.DesiredVelocity.Y,
+                rotatedDir.Z * moveSpeed
+            );
+
+            if (rotatedDir.Length() >= 0.1f)
+            {
+                velocity.DesiredVelocity =
+                    MoveToward(velocity.DesiredVelocity, targetVelocity, acceleration * deltaTime);
+            }
+            else
+            {
+                var frictionVec = new Vector3(velocity.DesiredVelocity.X, 0f, velocity.DesiredVelocity.Z);
+                frictionVec = MoveToward(frictionVec, Vector3.Zero, friction * deltaTime);
+                velocity.DesiredVelocity.X = frictionVec.X;
+                velocity.DesiredVelocity.Z = frictionVec.Z;
+            }
+        }
+    }
+
+    private Vector3 MoveToward(Vector3 from, Vector3 to, float delta)
+    {
+        var diff = to - from;
+        if (diff.Length() <= delta)
+            return to;
+        return from + diff.Normalize() * delta;
+    }
+}