Implement DisplayNode drawing

Sources/SwiftUIMath/Internal/Display/GraphicsContext+DisplayNode.swift

@@ -0,0 +1,27 @@
+import SwiftUI
+
+extension GraphicsContext {
+  func draw(_ displayNode: Math.DisplayNode, size: CGSize, foregroundColor: Color) {
+    var context = self
+
+    context.translateBy(x: 0, y: size.height)
+    context.scaleBy(x: 1, y: -1)
+
+    let foregroundColor = foregroundColor.resolve(in: environment).cgColor
+
+    context.withCGContext { cgContext in
+      cgContext.draw(displayNode, foregroundColor: foregroundColor)
+    }
+  }
+
+  func draw(_ displayNode: Math.DisplayNode, size: CGSize, with shading: GraphicsContext.Shading) {
+    var context = self
+
+    context.fill(Path(CGRect(origin: .zero, size: size)), with: shading)
+    context.blendMode = .destinationIn
+
+    context.drawLayer {
+      $0.draw(displayNode, size: size, foregroundColor: .black)
+    }
+  }
+}