首次提交：本地项目同步到Gitea

LibShapes/Core/PointTransform.cs

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+using System;
+using System.Collections.Generic;
+using System.Drawing;
+using System.Drawing.Drawing2D;
+using System.Linq;
+using System.Text;
+
+namespace Io.Github.Kerwinxu.LibShapes.Core
+{
+    /// <summary>
+    /// 这个是虚拟坐标跟画布上的坐标转换的
+    /// Offset 是偏移，而Zoom是放大倍数
+    /// </summary>
+    public class PointTransform
+    {
+        public float OffsetX { get; set; }
+
+        public float OffsetY { get; set; }
+
+        private float _zoom=1; // 默认值1
+
+        public float Zoom
+        {
+            get { return _zoom; }
+            set { _zoom= value; if (value <= 0) _zoom = 1; } // 如果小于等于0，就用默认值1吧。
+        }
+
+        /// <summary>
+        /// 这个转成画布的坐标
+        /// </summary>
+        /// <param name="pointF"></param>
+        /// <returns></returns>
+        public PointF CanvasToVirtualPoint(PointF pointF)
+        {
+            return new PointF() {
+                X = (pointF.X  - OffsetX) / Zoom ,          // 这个是加偏移
+                Y = (pointF.Y  - OffsetY) / Zoom
+            };
+        }
+
+        /// <summary>
+        /// 这个转成虚拟的坐标
+        /// </summary>
+        /// <param name="pointF"></param>
+        /// <returns></returns>
+        public PointF VirtualToCanvasPoint(PointF pointF)
+        {
+            return new PointF()
+            {
+                X = OffsetX + pointF.X * Zoom , 
+                Y = OffsetY + pointF.Y * Zoom
+            };
+        }
+
+
+        public Matrix GetMatrix()
+        {
+            Matrix matrix = new Matrix();
+            matrix.Translate(OffsetX, OffsetY);
+            matrix.Scale(Zoom, Zoom);
+            return matrix;
+        }
+
+        /// <summary>
+        /// 像素转成毫米
+        /// </summary>
+        /// <param name="g"></param>
+        /// <param name="pointF"></param>
+        /// <returns></returns>
+        public static PointF pixToMM(float dpiX, float dpiY,  PointF pointF)
+        {
+            return new  PointF(pointF.X/ dpiX * 25.4f,pointF.Y/ dpiY * 25.4f);
+        }
+
+    }
+}