在固定网格上拖动对象的算法

我正在开发一个程序,用于绘制和播放流行的桌面游戏d&d:d,现在我正在开发基本功能,如拖动UI元素、捕捉网格和检查碰撞。

现在,从鼠标中释放的每个对象都会立即捕捉到最近的网格点。当类似于播放器对象的对象捕捉到具有墙或其他相邻的网格点时,这会导致问题。所以基本上,当玩家被扔下时,他们会被一些墙覆盖起来。这很好,可以按预期工作,但是问题是,现在每当你试图移动这个播放器时,我的碰撞检测就会被触发,因为它位于墙下,因此你不能再拖动它了。

相关代码如下:

void UIObj_MouseMove(object sender, MouseEventArgs e)  
{  
            blocked = false;  
            if (dragging)  
            {  
                foreach (UIElement o in ((Floor)Parent).Children)  
                {  
                    if (o.GetType() != GetType() && o.GetType().BaseType == typeof(UIObj) &&  
                        Math.Sqrt(Math.Pow(((UIObj)o).cX - cX, 2) + Math.Pow(((UIObj)o).cY - cY, 2)) <  
                        Math.Max(r.Height + ((UIObj)o).r.Height, r.Width + ((UIObj)o).r.Width))  
                    {  
                        double Y = e.GetPosition((Floor)Parent).Y;  
                        double X = e.GetPosition((Floor)Parent).X;  
                        Geometry newRect = new RectangleGeometry(new Rect(Margin.Left + (X - prevX),  
                        Margin.Top + (Y - prevY), Margin.Right + (X - prevX), Margin.Bottom + (Y - prevY)));  
                        GeometryHitTestParameters ghtp = new GeometryHitTestParameters(newRect);  
                        VisualTreeHelper.HitTest(o, null, new HitTestResultCallback(MyHitTestResultCallback), ghtp);  
                    }  
                }  
                if (!blocked)  
                {  
                    Margin = new Thickness(Margin.Left + (e.GetPosition((Floor)Parent).X - prevX),  
                        Margin.Top + (e.GetPosition((Floor)Parent).Y - prevY),  
                        Margin.Right + (e.GetPosition((Floor)Parent).X - prevX),  
                        Margin.Bottom + (e.GetPosition((Floor)Parent).Y - prevY));  
                    InvalidateVisual();  
                }
                prevX = e.GetPosition((Floor)Parent).X;  
                prevY = e.GetPosition((Floor)Parent).Y;  
                cX = Margin.Left + r.Width / 2;  
                cY = Margin.Top + r.Height / 2;  
            }  
        }  

internal virtual void SnapToGrid()  
        {  
            double xPos = Margin.Left;  
            double yPos = Margin.Top;  
            double xMarg =  xPos % ((Floor)Parent).cellDim;  
            double yMarg =  yPos % ((Floor)Parent).cellDim;  
            if (xMarg < ((Floor)Parent).cellDim / 2)  
            {  
                if (yMarg < ((Floor)Parent).cellDim / 2)  
                {  
                    Margin = new Thickness(xPos - xMarg, yPos - yMarg, xPos - xMarg + r.Width, yPos - yMarg + r.Height);
                    }  
                else  
                {  
                    Margin = new Thickness(xPos - xMarg, yPos - yMarg + ((Floor)Parent).cellDim, xPos - xMarg + r.Width,

                        yPos - yMarg + ((Floor)Parent).cellDim + r.Height);  
                }  
            }  
            else  
            {
                if (yMarg < ((Floor)Parent).cellDim / 2)
                {
                    Margin = new Thickness(xPos - xMarg + ((Floor)Parent).cellDim, yPos - yMarg,
                        xPos - xMarg + ((Floor)Parent).cellDim + r.Width, yPos - yMarg + r.Height);
                }
                else
                {
                    Margin = new Thickness(xPos - xMarg + ((Floor)Parent).cellDim, yPos - yMarg + ((Floor)Parent).cellDim,
                        xPos - xMarg + ((Floor)Parent).cellDim + r.Width, yPos - yMarg + ((Floor)Parent).cellDim + r.Height);
                }
            }
        }

本质上,我正在寻找一种简单的方法来修改现有的代码,以允许一个UI元素的移动,而另一个元素则位于该元素之上。谢谢!