snapping first impl

Assets/IsoTools/Examples/Prefabs/Kenney/Building.prefab

@@ -164,7 +164,6 @@ MonoBehaviour:
   _position: {x: 0, y: 0, z: 0}
   _mode: 0
   _cacheRenderers: 1
-  _isAlignment: 1
   _isShowBounds: 0
 --- !u!212 &21224890
 SpriteRenderer:

Assets/IsoTools/Examples/Prefabs/Kenney/Building2.prefab

@@ -178,7 +178,6 @@ MonoBehaviour:
   _position: {x: 0, y: 0, z: 0}
   _mode: 0
   _cacheRenderers: 1
-  _isAlignment: 1
   _isShowBounds: 0
 --- !u!114 &11453236
 MonoBehaviour:

Assets/IsoTools/Examples/Prefabs/Kenney/Building3.prefab

@@ -164,7 +164,6 @@ MonoBehaviour:
   _position: {x: 0, y: 0, z: 0}
   _mode: 0
   _cacheRenderers: 1
-  _isAlignment: 1
   _isShowBounds: 0
 --- !u!212 &21269568
 SpriteRenderer:

Assets/IsoTools/Examples/Prefabs/Kenney/Fence.prefab

@@ -72,7 +72,6 @@ MonoBehaviour:
   _position: {x: 0, y: 0, z: 0}
   _mode: 0
   _cacheRenderers: 1
-  _isAlignment: 0
   _isShowBounds: 0
 --- !u!212 &21295688
 SpriteRenderer:

Assets/IsoTools/Examples/Prefabs/Kenney/Fence2.prefab

@@ -72,7 +72,6 @@ MonoBehaviour:
   _position: {x: 0, y: 0, z: 0}
   _mode: 0
   _cacheRenderers: 1
-  _isAlignment: 0
   _isShowBounds: 0
 --- !u!212 &21245702
 SpriteRenderer:

Assets/IsoTools/Examples/Prefabs/Kenney/Road.prefab

@@ -72,7 +72,6 @@ MonoBehaviour:
   _position: {x: 0, y: 0, z: 0}
   _mode: 0
   _cacheRenderers: 1
-  _isAlignment: 1
   _isShowBounds: 0
 --- !u!212 &21221408
 SpriteRenderer:

Assets/IsoTools/Examples/Prefabs/Kenney/Road2.prefab

@@ -72,7 +72,6 @@ MonoBehaviour:
   _position: {x: 0, y: 0, z: 0}
   _mode: 0
   _cacheRenderers: 1
-  _isAlignment: 1
   _isShowBounds: 0
 --- !u!212 &21228980
 SpriteRenderer:

Assets/IsoTools/Examples/Prefabs/Kenney/Road3.prefab

@@ -72,7 +72,6 @@ MonoBehaviour:
   _position: {x: 0, y: 0, z: 0}
   _mode: 0
   _cacheRenderers: 1
-  _isAlignment: 1
   _isShowBounds: 0
 --- !u!212 &21298190
 SpriteRenderer:

Assets/IsoTools/Examples/Prefabs/Kenney/Road4.prefab

@@ -72,7 +72,6 @@ MonoBehaviour:
   _position: {x: 0, y: 0, z: 0}
   _mode: 0
   _cacheRenderers: 1
-  _isAlignment: 1
   _isShowBounds: 0
 --- !u!212 &21274934
 SpriteRenderer:

Assets/IsoTools/Examples/Prefabs/Kenney/Tile.prefab

@@ -72,7 +72,6 @@ MonoBehaviour:
   _position: {x: 0, y: 0, z: 0}
   _mode: 0
   _cacheRenderers: 1
-  _isAlignment: 1
   _isShowBounds: 0
 --- !u!212 &21238442
 SpriteRenderer:

Assets/IsoTools/Examples/Prefabs/Kenney/Tree.prefab

@@ -72,7 +72,6 @@ MonoBehaviour:
   _position: {x: 0, y: 0, z: 0}
   _mode: 0
   _cacheRenderers: 1
-  _isAlignment: 0
   _isShowBounds: 0
 --- !u!212 &21283090
 SpriteRenderer:

Assets/IsoTools/Examples/Prefabs/Kenney/Water.prefab

@@ -72,7 +72,6 @@ MonoBehaviour:
   _position: {x: 0, y: 0, z: 0}
   _mode: 0
   _cacheRenderers: 1
-  _isAlignment: 1
   _isShowBounds: 0
 --- !u!212 &21257916
 SpriteRenderer:

Assets/IsoTools/Examples/Prefabs/Kenney/Water2.prefab

@@ -72,7 +72,6 @@ MonoBehaviour:
   _position: {x: 0, y: 0, z: 0}
   _mode: 0
   _cacheRenderers: 1
-  _isAlignment: 1
   _isShowBounds: 0
 --- !u!212 &21267074
 SpriteRenderer:

Assets/IsoTools/Examples/Prefabs/Kenney/Water3.prefab

@@ -72,7 +72,6 @@ MonoBehaviour:
   _position: {x: 0, y: 0, z: 0}
   _mode: 0
   _cacheRenderers: 1
-  _isAlignment: 1
   _isShowBounds: 0
 --- !u!212 &21210472
 SpriteRenderer:

Assets/IsoTools/Examples/Prefabs/Kenney/Water4.prefab

@@ -102,7 +102,6 @@ MonoBehaviour:
   _position: {x: 0, y: 0, z: 0}
   _mode: 0
   _cacheRenderers: 1
-  _isAlignment: 1
   _isShowBounds: 0
 --- !u!198 &19803878
 ParticleSystem:

Assets/IsoTools/Examples/Prefabs/Tests/Cube_1x1x1.prefab

@@ -44,7 +44,6 @@ MonoBehaviour:
   _position: {x: 0, y: 0, z: 0}
   _mode: 0
   _cacheRenderers: 1
-  _isAlignment: 1
   _isShowBounds: 0
 --- !u!212 &21217528
 SpriteRenderer:

Assets/IsoTools/Examples/Prefabs/Tests/Cube_1x3x1.prefab

@@ -44,7 +44,6 @@ MonoBehaviour:
   _position: {x: 0, y: 0, z: 0}
   _mode: 0
   _cacheRenderers: 1
-  _isAlignment: 1
   _isShowBounds: 0
 --- !u!212 &21253620
 SpriteRenderer:

Assets/IsoTools/Examples/Prefabs/Tests/Cube_3x1x1.prefab

@@ -44,7 +44,6 @@ MonoBehaviour:
   _position: {x: 0, y: 0, z: 0}
   _mode: 0
   _cacheRenderers: 1
-  _isAlignment: 1
   _isShowBounds: 0
 --- !u!212 &21262204
 SpriteRenderer:

Assets/IsoTools/Examples/Prefabs/Tests/Floor_3x3.prefab

@@ -44,7 +44,6 @@ MonoBehaviour:
   _position: {x: 0, y: 0, z: 0}
   _mode: 0
   _cacheRenderers: 1
-  _isAlignment: 1
   _isShowBounds: 0
 --- !u!212 &21253404
 SpriteRenderer:

Assets/IsoTools/Scripts/Internal/Editor/IsoObjectEditor.cs

@@ -8,10 +8,17 @@ namespace IsoTools.Internal {
 	class IsoObjectEditor : Editor {
 
 		IDictionary<IsoObject, Vector3> _positions       = new Dictionary<IsoObject, Vector3>();
-		IDictionary<IsoObject, float>   _iso_zpositions = new Dictionary<IsoObject, float>();
+		IDictionary<IsoObject, float>   _isoZPositions   = new Dictionary<IsoObject, float>();
+		IList<IsoObject>                _otherObjects    = new List<IsoObject>();
 		Vector3                         _center          = Vector3.zero;
 		Vector3                         _viewCenter      = Vector3.zero;
 
+		static public readonly float    SnappingDistance = 0.2f;
+
+		static bool IsSnappingEnabled() {
+			return !Event.current.control;
+		}
+
 		void GrabPositions() {
 			var iso_world = IsoWorld.Instance;
 			if ( iso_world ) {
@@ -19,7 +26,7 @@ namespace IsoTools.Internal {
 					.Where(p => p is IsoObject)
 					.Select(p => p as IsoObject)
 					.ToDictionary(p => p, p => p.transform.position);
-				_iso_zpositions = targets
+				_isoZPositions = targets
 					.Where(p => p is IsoObject)
 					.Select(p => p as IsoObject)
 					.ToDictionary(p => p, p => p.position.z);
@@ -29,6 +36,12 @@ namespace IsoTools.Internal {
 			}
 		}
 
+		void GrabOtherIsoObjects() {
+			_otherObjects = FindObjectsOfType<IsoObject>()
+				.Where(p => p.gameObject.activeInHierarchy && !targets.Contains(p))
+				.ToList();
+		}
+
 		void DirtyTargetPosition() {
 			if ( targets.Length == 1 && (target is IsoObject) && (target as IsoObject).gameObject.activeInHierarchy ) {
 				var position_prop = serializedObject.FindProperty("_position");
@@ -44,35 +57,79 @@ namespace IsoTools.Internal {
 			}
 		}
 
-		bool isAnyAlignment {
+		bool SnappingProcess(ref float min_a, float size_a, float min_b, float size_b) {
-			get { return _positions.Keys.Any(p => p.isAlignment); }
+			var max_a  = min_a + size_a;
+			var max_b  = min_b + size_b;
+			var result = false;
+			if ( IsSnappingIntersect(min_a, size_a, min_b, size_b) ) {
+				// |min_a max_a|min_b max_b|
+				if ( Mathf.Abs(max_a - min_b) < SnappingDistance ) {
+					min_a  = min_b - size_a;
+					result = true;
+				}
+				// |min_b max_b|min_a max_a|
+				if ( Mathf.Abs(max_b - min_a) < SnappingDistance ) {
+					min_a  = max_b;
+					result = true;
+				}
+				// |min_a_____max_a|
+				// |min_b__max_b|
+				if ( Mathf.Abs(min_a - min_b) < SnappingDistance ) {
+					min_a  = min_b;
+					result = true;
+				}
+				// |min_a_____max_a|
+				//    |min_b__max_b|
+				if ( Mathf.Abs(max_a - max_b) < SnappingDistance ) {
+					min_a  = max_b - size_a;
+					result = true;
+				}
+			}
+			return result;
 		}
 
-		void AlignmentSelection() {
+		bool IsSnappingIntersect(float min_a, float size_a, float min_b, float size_b) {
-			foreach ( var iso_object in _positions.Keys ) {
+			return
-				AlignmentIsoObject(iso_object);
+				min_a + size_a + SnappingDistance >= min_b &&
-			}
+				min_a - SnappingDistance <= min_b + size_b;
-			GrabPositions();
-		}
-
-		void AlignmentIsoObject(IsoObject iso_object) {
-			iso_object.position = iso_object.tilePosition;
-			iso_object.FixTransform();
 		}
 
 		float ZMoveIsoObjects(float delta) {
 			Undo.RecordObjects(
-				_iso_zpositions.Keys.ToArray(),
+				_isoZPositions.Keys.ToArray(),
-				_iso_zpositions.Count > 1 ? "Move IsoObjects" : "Move IsoObject");
+				_isoZPositions.Count > 1 ? "Move IsoObjects" : "Move IsoObject");
-			var is_any_alignment = isAnyAlignment;
+			if ( IsSnappingEnabled() ) {
-			return _iso_zpositions.Aggregate(0.0f, (AccIn, pair) => {
+				var snapping_z = false;
+				foreach ( var pair in _isoZPositions ) {
 					var iso_object = pair.Key;
 					var iso_orig_z = pair.Value;
-				iso_object.positionZ = iso_orig_z + delta;
+					var result_p_z = iso_orig_z + delta;
-				iso_object.FixTransform();
+					foreach ( var other in _otherObjects ) {
-				if ( is_any_alignment ) {
+						if ( IsSnappingIntersect(iso_object.positionX, iso_object.sizeX, other.positionX, other.sizeX) &&
-					AlignmentIsoObject(iso_object);
+							 IsSnappingIntersect(iso_object.positionY, iso_object.sizeY, other.positionY, other.sizeY) )
+						{
+							var new_snapping_z = !snapping_z && IsSnappingIntersect(result_p_z, iso_object.sizeZ, other.positionZ, other.sizeZ)
+								? SnappingProcess(ref result_p_z, iso_object.sizeZ, other.positionZ, other.sizeZ)
+								: false;
+							if ( new_snapping_z ) {
+								if ( new_snapping_z ) {
+									delta      = result_p_z - iso_orig_z;
+									snapping_z = true;
 								}
+							}
+						}
+					}
+					if ( snapping_z ) {
+						break;
+					}
+				}
+			}
+			return _isoZPositions.Aggregate(0.0f, (AccIn, pair) => {
+				var iso_object = pair.Key;
+				var iso_orig_z = pair.Value;
+				var result_p_z = iso_orig_z + delta;
+				iso_object.positionZ = result_p_z;
+				iso_object.FixTransform();
 				var z_delta = iso_object.position.z - iso_orig_z;
 				return Mathf.Abs(z_delta) > Mathf.Abs(AccIn) ? z_delta : AccIn;
 			});
@@ -82,15 +139,48 @@ namespace IsoTools.Internal {
 			Undo.RecordObjects(
 				_positions.Keys.ToArray(),
 				_positions.Count > 1 ? "Move IsoObjects" : "Move IsoObject");
-			var is_any_alignment = isAnyAlignment;
+			if ( IsSnappingEnabled() ) {
+				var snapping_x = false;
+				var snapping_y = false;
+				foreach ( var pair in _positions ) {
+					var iso_object     = pair.Key;
+					var iso_orig_p     = pair.Value;
+					var result_pos     = iso_orig_p + delta;
+					var result_pos_iso = IsoWorld.Instance.ScreenToIso(result_pos, iso_object.positionZ);
+					foreach ( var other in _otherObjects ) {
+						if ( IsSnappingIntersect(iso_object.positionZ, iso_object.sizeZ, other.positionZ, other.sizeZ) ) {
+							var new_snapping_x = !snapping_x && IsSnappingIntersect(result_pos_iso.y, iso_object.sizeY, other.positionY, other.sizeY)
+								? SnappingProcess(ref result_pos_iso.x, iso_object.sizeX, other.positionX, other.sizeX)
+								: false;
+							var new_snapping_y = !snapping_y && IsSnappingIntersect(result_pos_iso.x, iso_object.sizeX, other.positionX, other.sizeX)
+								? SnappingProcess(ref result_pos_iso.y, iso_object.sizeY, other.positionY, other.sizeY)
+								: false;
+							if ( new_snapping_x || new_snapping_y ) {
+								result_pos = IsoWorld.Instance.IsoToScreen(result_pos_iso);
+								if ( new_snapping_x ) {
+									delta.x    = result_pos.x - iso_orig_p.x;
+									delta.y    = result_pos.y - iso_orig_p.y;
+									snapping_x = true;
+								}
+								if ( new_snapping_y ) {
+									delta.x    = result_pos.x - iso_orig_p.x;
+									delta.y    = result_pos.y - iso_orig_p.y;
+									snapping_y = true;
+								}
+							}
+						}
+					}
+					if ( snapping_x && snapping_y ) {
+						break;
+					}
+				}
+			}
 			return _positions.Aggregate(Vector3.zero, (AccIn, pair) => {
 				var iso_object = pair.Key;
 				var iso_orig_p = pair.Value;
-				iso_object.transform.position = iso_orig_p + delta;
+				var result_pos = iso_orig_p + delta;
+				iso_object.transform.position = result_pos;
 				iso_object.FixIsoPosition();
-				if ( is_any_alignment ) {
-					AlignmentIsoObject(iso_object);
-				}
 				var pos_delta = iso_object.transform.position - iso_orig_p;
 				return pos_delta.magnitude > AccIn.magnitude ? pos_delta : AccIn;
 			});
@@ -150,6 +240,7 @@ namespace IsoTools.Internal {
 
 		void OnEnable() {
 			GrabPositions();
+			GrabOtherIsoObjects();
 		}
 
 		void OnDisable() {
@@ -174,6 +265,7 @@ namespace IsoTools.Internal {
 		public override void OnInspectorGUI() {
 			DrawDefaultInspector();
 			GrabPositions();
+			GrabOtherIsoObjects();
 			DirtyTargetPosition();
 		}
 	}

Assets/IsoTools/Scripts/IsoObject.cs

@@ -217,14 +217,8 @@ namespace IsoTools {
 		bool    _lastCacheRenderers = false;
 
 		[Space(10)]
-		[SerializeField] bool _isAlignment  = true;
 		[SerializeField] bool _isShowBounds = false;
 
-		public bool isAlignment {
-			get { return _isAlignment; }
-			set { _isAlignment = value; }
-		}
-
 		public bool isShowBounds {
 			get { return _isShowBounds; }
 			set { _isShowBounds = value; }
@@ -248,11 +242,6 @@ namespace IsoTools {
 		}
 
 		public void FixTransform() {
-		#if UNITY_EDITOR
-			if ( !Application.isPlaying && isAlignment ) {
-				_position = tilePosition;
-			}
-		#endif
 			if ( isoWorld ) {
 				transform.position = IsoUtils.Vec3ChangeZ(
 					isoWorld.IsoToScreen(position),