public static SnapResult CalculateSnapResult(GameObject root, Config snapConfig)
        {
            if (snapConfig.IgnoreDestObjects == null)
            {
                snapConfig.IgnoreDestObjects = new List <GameObject>();
            }

            List <GameObject> sourceObjects = root.GetAllChildrenAndSelf();

            if (sourceObjects.Count > MaxSourceObjects)
            {
                return(new SnapResult(SnapFailReson.MaxObjectsExceeded));
            }

            List <GameObject> sourceMeshObjects   = root.GetMeshObjectsInHierarchy();
            List <GameObject> sourceSpriteObjects = root.GetSpriteObjectsInHierarchy();

            if (sourceMeshObjects.Count == 0 && sourceSpriteObjects.Count == 0)
            {
                return(new SnapResult(SnapFailReson.InvalidSourceObjects));
            }

            ObjectBounds.QueryConfig boundsQConfig = new ObjectBounds.QueryConfig();
            boundsQConfig.ObjectTypes = GameObjectType.Mesh | GameObjectType.Sprite;

            Vector3             overlapSizeAdd     = Vector3.one * snapConfig.SnapRadius * 2.0f;
            List <BoxFace>      allSnapFaces       = BoxMath.AllBoxFaces;
            bool                tryMatchAreas      = (snapConfig.Prefs & Prefs.TryMatchArea) != 0;
            bool                foundMatchingAreas = false;
            List <SnapSortData> sortedSnapData     = new List <SnapSortData>(10);
            SnapSortData        sortData           = new SnapSortData();

            foreach (GameObject sourceObject in sourceObjects)
            {
                OBB overlapOBB = ObjectBounds.CalcWorldOBB(sourceObject, boundsQConfig);
                overlapOBB.Size = overlapOBB.Size + overlapSizeAdd;

                List <GameObject> nearbyObjects = RTScene.Get.OverlapBox(overlapOBB);
                nearbyObjects.RemoveAll(item => item.transform.IsChildOf(root.transform) ||
                                        snapConfig.IgnoreDestObjects.Contains(item) || !LayerEx.IsLayerBitSet(snapConfig.DestinationLayers, item.layer));
                if (nearbyObjects.Count == 0)
                {
                    continue;
                }

                Object2ObjectSnapData sourceSnapData = Object2ObjectSnapDataDb.Get.GetObject2ObjectSnapData(sourceObject);
                if (sourceSnapData == null)
                {
                    continue;
                }

                sortData.SrcObject = sourceObject;
                foreach (BoxFace srcSnapFace in allSnapFaces)
                {
                    BoxFaceAreaDesc srcAreaDesc   = sourceSnapData.GetWorldSnapAreaDesc(srcSnapFace);
                    OBB             srcAreaBounds = sourceSnapData.GetWorldSnapAreaBounds(srcSnapFace);
                    List <Vector3>  srcAreaPts    = srcAreaBounds.GetCenterAndCornerPoints();
                    sortData.SrcSnapFace = srcSnapFace;

                    foreach (GameObject destObject in nearbyObjects)
                    {
                        Object2ObjectSnapData destSnapData = Object2ObjectSnapDataDb.Get.GetObject2ObjectSnapData(destObject);
                        if (destSnapData == null)
                        {
                            continue;
                        }

                        sortData.DestObject = destObject;
                        foreach (BoxFace destSnapFace in allSnapFaces)
                        {
                            sortData.DestSnapFace = destSnapFace;
                            BoxFaceAreaDesc destAreaDesc = destSnapData.GetWorldSnapAreaDesc(destSnapFace);

                            sortData.FaceAreasMatch = false;

                            if (tryMatchAreas && destAreaDesc.AreaType == srcAreaDesc.AreaType)
                            {
                                sortData.FaceAreaDiff = Mathf.Abs(destAreaDesc.Area - srcAreaDesc.Area);
                                if (sortData.FaceAreaDiff <= 1000.0f)
                                {
                                    sortData.FaceAreasMatch = true;
                                }
                            }

                            OBB            destAreaBounds = destSnapData.GetWorldSnapAreaBounds(destSnapFace);
                            List <Vector3> destAreaPts    = destAreaBounds.GetCenterAndCornerPoints();

                            foreach (Vector3 srcPt in srcAreaPts)
                            {
                                sortData.SnapPivot = srcPt;
                                foreach (Vector3 destPt in destAreaPts)
                                {
                                    sortData.SnapDistance = (destPt - srcPt).magnitude;
                                    if (sortData.SnapDistance < snapConfig.SnapRadius)
                                    {
                                        sortData.SnapDest = destPt;
                                        sortedSnapData.Add(sortData);

                                        if (sortData.FaceAreasMatch)
                                        {
                                            foundMatchingAreas = true;
                                        }
                                    }
                                }
                            }
                        }
                    }
                }
            }

            if (sortedSnapData.Count != 0)
            {
                if (!tryMatchAreas || !foundMatchingAreas)
                {
                    sortedSnapData.Sort(delegate(SnapSortData s0, SnapSortData s1)
                    {
                        return(s0.SnapDistance.CompareTo(s1.SnapDistance));
                    });
                }
                else
                {
                    while (true)
                    {
                        if (!sortedSnapData[0].FaceAreasMatch)
                        {
                            sortedSnapData.RemoveAt(0);
                        }
                        else
                        {
                            break;
                        }
                    }

                    sortedSnapData.Sort(delegate(SnapSortData s0, SnapSortData s1)
                    {
                        return(s0.FaceAreaDiff.CompareTo(s1.FaceAreaDiff));
                    });
                }

                return(new SnapResult(sortedSnapData[0].SnapPivot, sortedSnapData[0].SnapDest, sortedSnapData[0].SnapDistance));
            }
            return(new SnapResult(SnapFailReson.NoDestinationFound));
        }
        public bool Initialize(GameObject gameObject)
        {
            if (gameObject == null || _gameObject != null)
            {
                return(false);
            }

            Mesh   mesh   = gameObject.GetMesh();
            Sprite sprite = gameObject.GetSprite();

            if (mesh == null && sprite == null)
            {
                return(false);
            }

            bool useMesh = true;

            if (mesh == null)
            {
                useMesh = false;
            }

            RTMesh rtMesh = null;

            if (useMesh)
            {
                Renderer meshRenderer = gameObject.GetMeshRenderer();
                if (meshRenderer == null || !meshRenderer.enabled)
                {
                    useMesh = false;
                }

                rtMesh = RTMeshDb.Get.GetRTMesh(mesh);
                if (rtMesh == null)
                {
                    useMesh = false;
                }
            }
            if (rtMesh == null && sprite == null)
            {
                return(false);
            }

            List <AABB> vertOverlapAABBs = BuildVertOverlapAABBs(gameObject, useMesh ? null : sprite, useMesh ? rtMesh : null);

            if (vertOverlapAABBs.Count == 0)
            {
                return(false);
            }

            AABB modelAABB = useMesh ? rtMesh.AABB : ObjectBounds.CalcSpriteModelAABB(gameObject);
            var  aabbFaces = BoxMath.AllBoxFaces;

            _gameObject = gameObject;
            if (useMesh)
            {
                foreach (var aabbFace in aabbFaces)
                {
                    AABB           overlapAABB     = vertOverlapAABBs[(int)aabbFace];
                    List <Vector3> overlappedVerts = rtMesh.OverlapModelVerts(overlapAABB);
                    Plane          facePlane       = BoxMath.CalcBoxFacePlane(modelAABB.Center, modelAABB.Size, Quaternion.identity, aabbFace);
                    overlappedVerts = facePlane.ProjectAllPoints(overlappedVerts);
                    _snapAreaBounds[(int)aabbFace] = new AABB(overlappedVerts);
                    _snapAreaDesc[(int)aabbFace]   = BoxMath.GetBoxFaceAreaDesc(_snapAreaBounds[(int)aabbFace].Size, aabbFace);
                }
            }
            else
            {
                foreach (var aabbFace in aabbFaces)
                {
                    if (aabbFace != BoxFace.Front && aabbFace != BoxFace.Back)
                    {
                        AABB           overlapAABB     = vertOverlapAABBs[(int)aabbFace];
                        List <Vector3> overlappedVerts = ObjectVertexCollect.CollectModelSpriteVerts(sprite, overlapAABB);
                        Plane          facePlane       = BoxMath.CalcBoxFacePlane(modelAABB.Center, modelAABB.Size, Quaternion.identity, aabbFace);
                        overlappedVerts = facePlane.ProjectAllPoints(overlappedVerts);
                        _snapAreaBounds[(int)aabbFace] = new AABB(overlappedVerts);
                        _snapAreaDesc[(int)aabbFace]   = BoxMath.GetBoxFaceAreaDesc(_snapAreaBounds[(int)aabbFace].Size, aabbFace);
                    }
                    else
                    {
                        _snapAreaBounds[(int)aabbFace] = AABB.GetInvalid();
                        _snapAreaDesc[(int)aabbFace]   = BoxFaceAreaDesc.GetInvalid();
                    }
                }
            }

            return(true);
        }