Add Environment.tolerance

Sources/SwiftSCAD/Environment/Tolerance.swift

@@ -0,0 +1,31 @@
+import Foundation
+
+private extension Environment {
+    static let key = Environment.ValueKey(rawValue: "SwiftSCAD.Tolerance")
+
+    func settingTolerance(_ tolerance: Double) -> Environment {
+        setting(key: Self.key, value: tolerance)
+    }
+}
+
+public extension Environment {
+    var tolerance: Double {
+        self[Self.key] as? Double ?? 0
+    }
+}
+
+public extension Geometry3D {
+    func withTolerance(_ tolerance: Double) -> any Geometry3D {
+        withEnvironment { enviroment in
+            enviroment.settingTolerance(tolerance)
+        }
+    }
+}
+
+public extension Geometry2D {
+    func withTolerance(_ tolerance: Double) -> any Geometry2D {
+        withEnvironment { enviroment in
+            enviroment.settingTolerance(tolerance)
+        }
+    }
+}