如何做好GDI +与实际测量的形状（英寸）旋转的形状命中测试？ [英] How to do Hit testing in GDI+ for rotated shapes with real shape measurements (inches)?

问题描述

由于我有一个包含许多形状的画布，可以说矩形现在。

Given I have a canvas that contains many shapes, lets say rectangles for now.

每个形状都有一个位置（英寸），尺寸（英寸）和旋转角度（度）。

Each shape has a location (inches), size(inches) and rotation angle(degrees).

当鼠标点击事件画布里面发生在像素位置（X，Y）。

When a mouse click event happen inside the canvas for a location (x,y) in pixels.

我要检查，如果点击鼠标的位置是在/特定形状中，考虑到旋转角度和测量单位转换。

I want to check if the clicked mouse position is inside/within a specific shape, considering the rotation angle and measurement unit conversion.

你能帮忙吗？

推荐答案

我找到了答案（我要人测量转换为像素，以确保它会正确计算）：

I found the answer (I have to convert al measurements to pixels to make sure it will calculate correctly):

public static bool HitTest(Rectangle bounds, float angle, Point location)
        {
            if (angle == 0) return bounds.Contains(location);

            using (Matrix matrix = new Matrix())
            {
                matrix.RotateAt(angle, Center(bounds));
                using (GraphicsPath path = new GraphicsPath())
                {
                    path.AddRectangle(bounds);
                    path.Transform(matrix);
                    return path.IsVisible(location.X, location.Y);
                }
            }
        }

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