riversong code showcase

Source/Riversong/Game/World/Agents/Intents/LookAtIntentExecutionLogic.cs

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+using System.Runtime.CompilerServices;
+using Cysharp.Threading.Tasks;
+using Unity.Burst;
+using Unity.Mathematics;
+using UnityEngine;
+
+namespace DanieleMarotta.RiversongCodeShowcase
+{
+    [BurstCompile]
+    public class LookAtIntentExecutionLogic : IntentExecutionLogic
+    {
+        private ITileSpace _tileSpace;
+
+        private float _rotationSpeed;
+
+        public override UniTask InitializeAsync(IServiceLocator serviceLocator)
+        {
+            _tileSpace = serviceLocator.GetService<ITileSpace>();
+            _rotationSpeed = serviceLocator.GetService<GameConfig>().Agents.RotationSpeed;
+
+            return UniTask.CompletedTask;
+        }
+
+        public override IntentExecutionResult Execute(Agent agent, in AgentIntent intent)
+        {
+            var lookAt = math.normalizesafe((float3)_tileSpace.TileToWorld(intent.Rect.Center) - agent.Position);
+            if (math.all(lookAt == 0)) return IntentExecutionResult.Success;
+
+            var step = math.radians(_rotationSpeed) * Time.deltaTime;
+            var heading = agent.Heading;
+            LookAt(ref heading, lookAt, step);
+            agent.Heading = heading;
+
+            return math.dot(heading, lookAt) > 0.995f ? IntentExecutionResult.Success : IntentExecutionResult.InProgress;
+        }
+
+        [BurstCompile]
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private static void LookAt(ref float3 heading, in float3 lookAt, float maxRadiansDelta)
+        {
+            var currentRotation = quaternion.LookRotationSafe(heading, math.up());
+            var targetRotation = quaternion.LookRotationSafe(lookAt, math.up());
+
+            var dot = math.dot(currentRotation, targetRotation);
+            if (dot < 0)
+            {
+                dot = -dot;
+                targetRotation.value = -targetRotation.value;
+            }
+            dot = math.clamp(dot, -1, 1);
+
+            var angle = math.acos(dot) * 2;
+            if (angle <= maxRadiansDelta)
+            {
+                heading = lookAt;
+                return;
+            }
+
+            currentRotation = math.slerp(currentRotation, targetRotation, maxRadiansDelta / angle);
+            heading = math.mul(currentRotation, math.forward());
+        }
+    }
+}