更新

WPFDark/Internals/DrawingContextExtensions.cs

@@ -0,0 +1,97 @@
+using System;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using System.Windows;
+using System.Windows.Media;
+using Jewelry.Collections;
+using WPFDark.Internals;
+
+namespace WPFDark.Internals
+{
+    internal static class DrawingContextExtensions
+    {
+        internal static void DrawBezier(this DrawingContext dc, ImmutableVec2_double[ /*4*/] bezierPoints, Pen pen)
+        {
+            var hashCode = MakeHashCode(bezierPoints);
+
+            if (_bezierCache.TryGetValue(hashCode, out var curve) == false)
+            {
+                curve = new StreamGeometry();
+
+                using (var ctx = curve.Open())
+                {
+                    ctx.BeginFigure(
+                        Unsafe.As<ImmutableVec2_double, Point>(ref bezierPoints[0]),
+                        false,
+                        false
+                    );
+
+                    ctx.BezierTo(
+                        Unsafe.As<ImmutableVec2_double, Point>(ref bezierPoints[1]),
+                        Unsafe.As<ImmutableVec2_double, Point>(ref bezierPoints[2]),
+                        Unsafe.As<ImmutableVec2_double, Point>(ref bezierPoints[3]),
+                        true,
+                        false);
+                }
+
+                curve.Freeze();
+
+                _bezierCache.Add(hashCode, curve);
+            }
+
+            dc.DrawGeometry(null, pen, curve);
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private static long MakeHashCode(Span<ImmutableVec2_double> src)
+        {
+            unchecked
+            {
+                var srcPrim = MemoryMarshal.Cast<ImmutableVec2_double, double>(src);
+
+                var p0X = Unsafe.As<double, long>(ref srcPrim[0]);
+                var p0Y = Unsafe.As<double, long>(ref srcPrim[1]);
+                var p1X = Unsafe.As<double, long>(ref srcPrim[2]);
+                var p1Y = Unsafe.As<double, long>(ref srcPrim[3]);
+                var p2X = Unsafe.As<double, long>(ref srcPrim[4]);
+                var p2Y = Unsafe.As<double, long>(ref srcPrim[5]);
+                var p3X = Unsafe.As<double, long>(ref srcPrim[6]);
+                var p3Y = Unsafe.As<double, long>(ref srcPrim[7]);
+
+                var hashCode = p0X;
+
+                hashCode = (hashCode * 397) ^ p0Y;
+                hashCode = (hashCode * 397) ^ p1X;
+                hashCode = (hashCode * 397) ^ p1Y;
+                hashCode = (hashCode * 397) ^ p2X;
+                hashCode = (hashCode * 397) ^ p2Y;
+                hashCode = (hashCode * 397) ^ p3X;
+                hashCode = (hashCode * 397) ^ p3Y;
+
+                return hashCode;
+            }
+        }
+
+        internal static void DrawCircle(this DrawingContext dc, Brush brush, Pen pen, Point pos, double radius)
+        {
+            var geom = new StreamGeometry
+            {
+                FillRule = FillRule.Nonzero
+            };
+
+            using (var ctx = geom.Open())
+            {
+                ctx.DrawEllipse(
+                    pos,
+                    radius,
+                    radius,
+                    true,
+                    true);
+            }
+
+            dc.DrawGeometry(brush, pen, geom);
+        }
+
+        private static readonly LruCache<long, StreamGeometry> _bezierCache = new LruCache<long, StreamGeometry>(10000);
+    }
+}