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>

graphene/src/layers/simple_shape.rs

@@ -77,7 +77,16 @@ impl Shape {
 		transforms.iter().skip(start).cloned().reduce(|a, b| a * b).unwrap_or(DAffine2::IDENTITY)
 	}
 
-	pub fn shape(sides: u8, style: PathStyle) -> Self {
+	pub fn from_bez_path(bez_path: BezPath, style: PathStyle, solid: bool) -> Self {
+		Self {
+			path: bez_path,
+			style,
+			render_index: 1,
+			solid: solid,
+		}
+	}
+
+	pub fn ngon(sides: u8, style: PathStyle) -> Self {
 		use std::f64::consts::{FRAC_PI_2, TAU};
 		fn unit_rotation(theta: f64) -> DVec2 {
 			DVec2::new(theta.sin(), theta.cos())