WPF画布：旋转分组形状

Question

在我的WPF应用程序中，我试图在画布内旋转一组分组形状。我使用以下链接中提到的公式将形状对象顶部/左定位分组。

在2D中旋转一个点

如果旋转点（PX，PY）围绕点（ox，oy），theta会得到：

  p'x = cos(theta) * (px-ox) - sin(theta) * (py-oy) + ox
  p'y = sin(theta) * (px-ox) + cos(theta) * (py-oy) + oy

由于我的旋转对象是一个分组的对象，因此可以包含多级儿童。当我在画布中解开分组的形状时，我需要在同一位置上获取子形状的位置和角度，该位置可在父母分组的形状对象中可用。我如何计算子对象的位置。

样品分组的对象如下图所示：

• 矩形（父形）
  • 矩形（儿童形状1）
  • 三角形（儿童形状2）

canvas canvas gopted shape rotation rotation 左侧显示旋转的分组形状，而右侧则显示旋转的未分组的子形状。

对于所有组中的所有形状，我都有以下信息：

• 有关父X＆amp;的子形状位置； y（child_x＆amp; child_y）
• 儿童形状角度相对于父母组（child_angle）
• 父母群体角度和位置，尊重canvas（parent_x，parent_y＆amp _ parent_y＆parent_angle）
• 子女形状宽度和
• 父母身高的宽度和高度，是我如何塑造我如何塑造

我如何获得的。未分组后，儿童形状的位置和角度（矩形和三角形）？儿童形状应放在小组中时放置在帆布中的同一位置。我如何计算儿童形状的位置和角度，谢谢。

下面的代码我正在用于存储形状相关参数和分组和分组的逻辑。

/// <summary>
/// ShapeDiagram can be any shape like Rectangle/Triangle/Ellipse etc.
/// For now I am using only Rectangle template for 'ShapeDiagram' type.
/// </summary>
public class ShapeDiagram
{
    public double Left { get; set; }
    public double Top { get; set; }
    public double Angle { get; set; }
    public double Width { get; set; }
    public double Height { get; set; }
}

/// <summary>
/// Group can have more than one 'ShapeDiagram' elements. A custom shape can be created using child 'ShapeDiagram' elements.
/// User can rotate multiple 'ShapeDiagram' elements and create a group.
/// Group will have a rectangle border around the childrens as shown in the above image.
/// Group rectangle border is created using templates based on type like GroupShapeDigram or ShapeDiagram.
/// </summary>
public class GroupShapeDiagram : ShapeDiagram
{
    public ObservableCollection<ShapeDiagram> Childrens { get; set; }

}

/// <summary>
/// This class is binded to canvas and canvas child elements are binded to 'CanvasChildrens'
/// </summary>
public class ShapeHandler
{
    private ObservableCollection<ShapeDiagram> canvasChildrens;
    public ObservableCollection<ShapeDiagram> CanvasChildrens { get => canvasChildrens; set => canvasChildrens = value; }

    public ShapeHandler()
    {
        this.CanvasChildrens = new ObservableCollection<ShapeDiagram>();
    }

    public void AddCanvasChild(ShapeDiagram shape)
    {
        if(shape != null)
        {
            this.CanvasChildrens.Add(shape);
        }
    }

    public void RemoveCanvasChild(ShapeDiagram shape)
    {
        if (shape != null)
        {
            this.CanvasChildrens.Remove(shape);
        }
    }


    public GroupShapeDiagram DoGrouping(ObservableCollection<ShapeDiagram> childrens)
    {
        GroupShapeDiagram newGroup = new GroupShapeDiagram();

        newGroup.Childrens = childrens;
        newGroup.Angle = 0;
        newGroup.Top = 0;
        newGroup.Left = 0;
        newGroup.Width = GetNewGroupWidth(childrens);
        newGroup.Height = GetNewGroupHeight(childrens);

        // Add new group in the canvas child shapes collection
        this.CanvasChildrens.Add(newGroup);

        return newGroup;
    }

    public void DoUnGrouping(GroupShapeDiagram group)
    {
        // Remove selected group from the canvas child shapes collection
        this.CanvasChildrens.Remove(group);

        // TO-DO: Now adjust the group child shapes to correct location
        foreach(ShapeDiagram childShape in group.Childrens)
        {
            // *** This is where i am not getting correct values for Top/Left/Angle for child shapes after ungrouping
            childShape.Top += group.Top;
            childShape.Left += group.Left;
            childShape.Angle += group.Angle;
        }
    }

    private double GetNewGroupWidth(ObservableCollection<ShapeDiagram> childrens)
    {
        double maxWidth = 300;

        // TO-DO: Logic to get max width of all childrens with some buffer width, for now I am returning 300 as default group width

        return maxWidth;
    }

    private double GetNewGroupHeight(ObservableCollection<ShapeDiagram> childrens)
    {
        double maxHeight = 300;

        // TO-DO: Logic to get max heigth of all childrens with some buffer heigth, for now I am returning 300 as default group height

        return maxHeight;
    }

}

这是我正在使用的更新完整的示例代码，我正在使用该代码我的应用程序。 shapesdesignercode

谢谢 iamhum

Answer 1

我尚不清楚您如何旋转形状以及如何获得所需的值以执行计算以及实际需要什么意义。您仍然没有透露足够的细节来为您提供一个工作解决方案。

如果您需要在Canvas上的形状位置。

如果您需要形状左上角的新绝对位置，则可以使用矩阵来计算它们：

double rotationAngle;
Point rotationCenter;
Point shapePositionOnCanvas;
var transformationMatrix = new Matrix();
transformationMatrix.RotateAt(rotationAngle, rotationCenter.X, rotationCenter.Y);
Point topLeftShapePosition = transformationMatrix.Transform(shapePositionOnCanvas);