added ability to start initial animation on the different initial time

Author: am1goo

Editor/SpriteAnimator3000InspectorHelper.cs

@@ -2,7 +2,6 @@
 using UnityEditor;
 using UnityEditor.SceneManagement;
 using UnityEngine.SceneManagement;
-using Spritesheet3000;
 
 namespace Spritesheet3000.Editor
 {
@@ -12,6 +11,7 @@ public static class SpriteAnimator3000InspectorHelper
         private static readonly GUIContent _timeScaleLabel = new GUIContent("Time Scale");
         private static readonly GUIContent _flipXLabel = new GUIContent("Flip X");
         private static readonly GUIContent _flipYLabel = new GUIContent("Flip Y");
+        private static readonly GUIContent _randomStartLabel = new GUIContent("Random Start");
 
         public static void OnInspectorDraw<T>(SerializedObject serializedObject, BaseSpriteAnimator3000<T> anim, ref float currentTime, ref string[] currentClipOptions)
         {
@@ -30,6 +30,10 @@ public static void OnInspectorDraw<T>(SerializedObject serializedObject, BaseSpr
             if (timeScaleProp != null)
                 EditorGUILayout.PropertyField(timeScaleProp, _timeScaleLabel);
 
+            var randomStartProp = serializedObject.FindProperty("m_randomStart");
+            if (randomStartProp != null)
+                EditorGUILayout.PropertyField(randomStartProp, _randomStartLabel);
+
             var flipXProp = serializedObject.FindProperty("m_flip_x");
             if (flipXProp != null)
                 EditorGUILayout.PropertyField(flipXProp, _flipXLabel);

Runtime/BaseSpriteAnimator3000.cs

@@ -22,6 +22,10 @@ public abstract class BaseSpriteAnimator3000<T> : MonoBehaviour
         public float timeScale { get { return m_timeScale; } set { m_timeScale = value; } }
         public float totalTimeScale { get { return m_timeScale * SpriteAnimatorTimer3000.timeScale; } }
 
+        [SerializeField]
+        [HideInInspector]
+        private bool m_randomStart;
+
         [SerializeField]
         [HideInInspector]
         private bool m_flip_x = false;
@@ -47,7 +51,7 @@ public bool flipY
                 ChangeFlip(m_flip_x, m_flip_y);
             }
         }
-
+        
         private bool _playInEditor;
         public bool playInEditor { get => _playInEditor; set => _playInEditor = value; }
 
@@ -91,6 +95,16 @@ protected virtual void Awake()
             ChangeFlip(flipX, flipY);
         }
 
+        protected virtual void Start()
+        {
+            if (m_randomStart)
+            {
+                var l = clipLength;
+                if (l > 0)
+                    _clipTime = UnityEngine.Random.Range(0f, l);
+            }
+        }
+
         protected virtual void OnDestroy()
         {
             //do nothing
@@ -106,17 +120,18 @@ private void Update()
 
         private void Animation(SpriteAnimationClip3000 clip, float deltaTime)
         {
-            float dt = deltaTime;
-            if (dt < 0)
+            if (deltaTime < 0)
                 return;
 
             Sprite sprite = SampleByNormalizedTime(clip, normalizedTime);
             ChangeSprite(sprite);
 
-            _clipTime += dt;
-            if (_clipTime >= clipLength)
+            _clipTime += deltaTime;
+
+            var l = clipLength;
+            if (_clipTime >= l)
             {
-                _clipTime = 0;
+                _clipTime = Mathf.Repeat(_clipTime, l);
                 if (_callback != null)
                 {
                     _callback();