Implement anchor and handle point rendering with the Path Tool (#353)

* Implement Path Tool

* Draw a red rectangle where the first point on the shape is

* Correctly render anchors, handles, and connecting lines

* Fix drain() which can panic

* Refactor frontend messages to work as return values not callbacks

* Reduce the number of unnecessary frontend updates

* Fix stack overflow by using a loop

* Group Document Render calls and put them at the end

* Speed hacks for dirtification

* Add performance

* Bunch folder changed updates

* Add triggers to redraw overlays to movement_handler

* Polish the pixel-perfect rendering of vector manipulators

* Restore scrollbars that were disabled

* Cleanup

* WIP Add shape outline rendering

* Fix compiling

* Add outlines to selected shapes

* Fix outlines rendering over handles and anchors

* Fix dirtification

* Add a comment

* Address code review feedback

* Formatting

* Small tweaks

Co-authored-by: Oliver Davies <oliver@psyfer.io>
Co-authored-by: Dennis Kobert <dennis@kobert.dev>

editor/src/frontend/frontend_message_handler.rs

@@ -4,8 +4,6 @@ use crate::tool::tool_options::ToolOptions;
 use crate::Color;
 use serde::{Deserialize, Serialize};
 
-pub type Callback = Box<dyn Fn(FrontendMessage)>;
-
 #[impl_message(Message, Frontend)]
 #[derive(PartialEq, Clone, Deserialize, Serialize, Debug)]
 pub enum FrontendMessage {
@@ -29,34 +27,3 @@ pub enum FrontendMessage {
 	SetCanvasZoom { new_zoom: f64 },
 	SetCanvasRotation { new_radians: f64 },
 }
-
-pub struct FrontendMessageHandler {
-	callback: crate::Callback,
-}
-
-impl FrontendMessageHandler {
-	pub fn new(callback: Callback) -> Self {
-		Self { callback }
-	}
-}
-
-impl MessageHandler<FrontendMessage, ()> for FrontendMessageHandler {
-	fn process_action(&mut self, message: FrontendMessage, _data: (), _responses: &mut VecDeque<Message>) {
-		(self.callback)(message)
-	}
-	advertise_actions!(
-		FrontendMessageDiscriminant;
-
-		DisplayError,
-		CollapseFolder,
-		ExpandFolder,
-		SetActiveTool,
-		UpdateCanvas,
-		UpdateScrollbars,
-		EnableTextInput,
-		DisableTextInput,
-		SetCanvasZoom,
-		SetCanvasRotation,
-		OpenDocumentBrowse,
-	);
-}

editor/src/frontend/mod.rs

@@ -1,4 +1,4 @@
 pub mod frontend_message_handler;
 pub mod layer_panel;
 
-pub use frontend_message_handler::{Callback, FrontendMessage, FrontendMessageDiscriminant, FrontendMessageHandler};
+pub use frontend_message_handler::{FrontendMessage, FrontendMessageDiscriminant};