Context nullification, cached monitor nodes

libraries/bezier-rs/src/subpath/solvers.rs

@@ -486,6 +486,21 @@ impl<PointId: crate::Identifier> Subpath<PointId> {
 		None
 	}
 
+	pub fn center(&self) -> Option<DVec2> {
+		let len = self.manipulator_groups.len();
+		if len == 0 {
+			return None;
+		} else if len % 2 == 1 {
+			return Some(self.manipulator_groups[len / 2].anchor);
+		} else {
+			let p0 = self.manipulator_groups[len / 2 - 1].anchor;
+			let p1 = self.manipulator_groups[len / 2 - 1].out_handle;
+			let p2 = self.manipulator_groups[len / 2].in_handle;
+			let p3 = self.manipulator_groups[len / 2].anchor;
+			Some(0.125 * p0 + 0.375 * p1.unwrap_or(p0) + 0.375 * p2.unwrap_or(p3) + 0.125 * p3)
+		}
+	}
+
 	/// Returns the necessary information to create a round join with the provided center.
 	/// The returned items correspond to:
 	/// - The `out_handle` for the last manipulator group of `self`

libraries/dyn-any/src/lib.rs

@@ -123,6 +123,21 @@ pub fn downcast<'a, V: StaticType + 'a>(i: Box<dyn DynAny<'a> + 'a>) -> Result<B
 	}
 }
 
+#[cfg(feature = "alloc")]
+pub fn try_downcast<'a, V: StaticType + 'a>(i: Box<dyn DynAny<'a> + 'a>) -> Result<Box<V>, Box<dyn DynAny<'a> + 'a>> {
+	let type_id = DynAny::type_id(i.as_ref());
+	if type_id == core::any::TypeId::of::<<V as StaticType>::Static>() {
+		// SAFETY: caller guarantees that T is the correct type
+		let ptr = Box::into_raw(i) as *mut V;
+		Ok(unsafe { Box::from_raw(ptr) })
+	} else {
+		if type_id == core::any::TypeId::of::<&dyn DynAny<'static>>() {
+			panic!("downcast error: type_id == core::any::TypeId::of::<dyn DynAny<'a>>()");
+		}
+		Err(i)
+	}
+}
+
 pub unsafe trait StaticType {
 	type Static: 'static + ?Sized;
 	fn type_id(&self) -> core::any::TypeId {