Version 4.6.0: Own Point and Matrix to work around rounding errors in UWP

2026-04-05 14:37:01 +00:00 · 2018-03-06 22:22:58 +01:00 · 2018-03-06 22:22:58 +01:00 · a3542bf106
commit a3542bf106
parent 30a5b6d53f
30 changed files with 295 additions and 269 deletions
--- a/MapControl/UWP/Matrix.UWP.cs
+++ b/MapControl/UWP/Matrix.UWP.cs
@ -0,0 +1,101 @@
+// XAML Map Control - https://github.com/ClemensFischer/XAML-Map-Control
+// © 2018 Clemens Fischer
+// Licensed under the Microsoft Public License (Ms-PL)
+
+using System;
+
+namespace MapControl
+{
+    public struct Matrix
+    {
+        public double M11 { get; set; }
+        public double M12 { get; set; }
+        public double M21 { get; set; }
+        public double M22 { get; set; }
+        public double OffsetX { get; set; }
+        public double OffsetY { get; set; }
+
+        public static implicit operator Windows.UI.Xaml.Media.Matrix(Matrix m)
+        {
+            return new Windows.UI.Xaml.Media.Matrix(m.M11, m.M12, m.M21, m.M22, m.OffsetX, m.OffsetY);
+        }
+
+        public Matrix(double m11, double m12, double m21, double m22, double offsetX, double offsetY)
+        {
+            M11 = m11;
+            M12 = m12;
+            M21 = m21;
+            M22 = m22;
+            OffsetX = offsetX;
+            OffsetY = offsetY;
+        }
+
+        public Point Transform(Point p)
+        {
+            return new Point(M11 * p.X + M12 * p.Y + OffsetX, M21 * p.X + M22 * p.Y + OffsetY);
+        }
+
+        public void Translate(double x, double y)
+        {
+            OffsetX += x;
+            OffsetY += y;
+        }
+
+        public void Scale(double scaleX, double scaleY)
+        {
+            if (M12 != 0d || M21 != 0d)
+            {
+                throw new NotSupportedException("Scale not supported for rotated Matrix");
+            }
+
+            SetMatrix(scaleX * M11, 0d, 0d, scaleY * M22, scaleX * OffsetX, scaleY * OffsetY);
+        }
+
+        public void Rotate(double angle)
+        {
+            angle = (angle % 360d) / 180d * Math.PI;
+
+            if (angle != 0d)
+            {
+                var cos = Math.Cos(angle);
+                var sin = Math.Sin(angle);
+
+                SetMatrix(
+                    cos * M11 - sin * M12,
+                    sin * M11 + cos * M12,
+                    cos * M21 - sin * M22,
+                    sin * M21 + cos * M22,
+                    cos * OffsetX - sin * OffsetY,
+                    sin * OffsetX + cos * OffsetY);
+            }
+        }
+
+        public void Invert()
+        {
+            var invDet = 1d / (M11 * M22 - M12 * M21);
+
+            if (double.IsInfinity(invDet))
+            {
+                throw new InvalidOperationException("Matrix is not invertible");
+            }
+
+            SetMatrix(
+                invDet * M22,
+                invDet * -M12,
+                invDet * -M21,
+                invDet * M11,
+                invDet * (M21 * OffsetY - M22 * OffsetX),
+                invDet * (M12 * OffsetX - M11 * OffsetY));
+        }
+
+        private void SetMatrix(double m11, double m12, double m21, double m22, double offsetX, double offsetY)
+        {
+            M11 = m11;
+            M12 = m12;
+            M21 = m21;
+            M22 = m22;
+            OffsetX = offsetX;
+            OffsetY = offsetY;
+        }
+    }
+}