fix: TransitionFilter and GradationMode do not work correctly when the initial scale is 0

close #311

Author: mob-sakai

Packages/src/Runtime/UIEffectBase.cs

@@ -1,3 +1,4 @@
+using System;
 using System.Runtime.CompilerServices;
 using Coffee.UIEffectInternal;
 using UnityEngine;
@@ -21,6 +22,7 @@ public abstract class UIEffectBase : UIBehaviour, IMeshModifier, IMaterialModifi
         private Graphic _graphic;
         private Material _material;
         private UIEffectContext _context;
+        private Action _setVerticesDirtyIfVisible;
 
         public Graphic graphic => _graphic ? _graphic : _graphic = GetComponent<Graphic>();
         public virtual uint effectId => (uint)GetInstanceID();
@@ -52,13 +54,20 @@ protected override void OnEnable()
 
         protected override void OnDisable()
         {
+            if (_setVerticesDirtyIfVisible != null)
+            {
+                UIExtraCallbacks.onBeforeCanvasRebuild -= _setVerticesDirtyIfVisible;
+            }
+
             MaterialRepository.Release(ref _material);
             SetMaterialDirty();
             SetVerticesDirty();
         }
 
         protected override void OnDestroy()
         {
+            _setVerticesDirtyIfVisible = null;
+            _graphic = null;
             s_ContextPool.Return(ref _context);
         }
 
@@ -70,7 +79,27 @@ public virtual void ModifyMesh(VertexHelper vh)
         {
             if (!isActiveAndEnabled || context == null) return;
 
-            context.ModifyMesh(graphic, transitionRoot, vh, canModifyShape);
+            if (CanModifyMesh())
+            {
+                context.ModifyMesh(graphic, transitionRoot, vh, canModifyShape);
+            }
+            // If you can't modify the mesh, retry next frame.
+            else
+            {
+                UIExtraCallbacks.onBeforeCanvasRebuild += _setVerticesDirtyIfVisible ??= SetVerticesDirtyIfVisible;
+            }
+        }
+
+        private bool CanModifyMesh()
+        {
+            // The transitionRoot is same as the transform => true.
+            var root = transitionRoot;
+            if (transform == root) return true;
+
+            // The transitionRoot is not visible => false.
+            var scale1 = root.lossyScale;
+            var scale2 = transform.lossyScale;
+            return !Mathf.Approximately(scale1.x * scale1.y * scale2.x * scale2.y, 0);
         }
 
         public virtual Material GetModifiedMaterial(Material baseMaterial)
@@ -148,6 +177,15 @@ public virtual void SetVerticesDirty()
             }
         }
 
+        private void SetVerticesDirtyIfVisible()
+        {
+            if (CanModifyMesh())
+            {
+                UIExtraCallbacks.onBeforeCanvasRebuild -= _setVerticesDirtyIfVisible ??= SetVerticesDirtyIfVisible;
+                SetVerticesDirty();
+            }
+        }
+
         public virtual void SetMaterialDirty()
         {
             if (graphic)

Packages/src/Runtime/UIEffectContext.cs

@@ -462,8 +462,12 @@ public void ModifyMesh(Graphic graphic, RectTransform transitionRoot, VertexHelp
             if (transitionRoot)
             {
                 rect = transitionRoot.rect;
-                rectMatrix = transitionRoot.worldToLocalMatrix
-                             * graphic.transform.localToWorldMatrix;
+                if (transitionRoot != graphic.transform)
+                {
+                    rectMatrix = transitionRoot.worldToLocalMatrix
+                                 * graphic.transform.localToWorldMatrix;
+                }
+
                 rot *= Matrix4x4.Scale(new Vector3(1 / multiplier, 1 / multiplier, 1))
                        * rectMatrix;
             }