Implement viewport selection (#178)

* Begin implementing viewport selection

* Implement viewport click and drag selection for ellipse and rectangle

* Begin implementing line selection

* Remove debug prints

* Run cargo format

* Use DVec2 instead of kurbo::Point

* Line and polyline intersection

* Run cargo format

* Add fix for missing layer panel update

* Replace point selection with box selection

* Formatting

Co-authored-by: Keavon Chambers <keavon@keavon.com>

core/document/src/layers/polyline.rs

@@ -1,3 +1,5 @@
+use crate::{intersection::intersect_quad_bez_path, LayerId};
+use glam::{DAffine2, DVec2};
 use serde::{Deserialize, Serialize};
 use std::fmt::Write;
 
@@ -17,7 +19,7 @@ impl PolyLine {
 }
 
 impl LayerData for PolyLine {
-	fn to_kurbo_path(&mut self, transform: glam::DAffine2, _style: style::PathStyle) -> kurbo::BezPath {
+	fn to_kurbo_path(&self, transform: glam::DAffine2, _style: style::PathStyle) -> kurbo::BezPath {
 		let mut path = kurbo::BezPath::new();
 		self.points
 			.iter()
@@ -27,6 +29,7 @@ impl LayerData for PolyLine {
 			.for_each(|(i, p)| if i == 0 { path.move_to(p) } else { path.line_to(p) });
 		path
 	}
+
 	fn render(&mut self, svg: &mut String, transform: glam::DAffine2, style: style::PathStyle) {
 		if self.points.is_empty() {
 			return;
@@ -40,6 +43,12 @@ impl LayerData for PolyLine {
 		}
 		let _ = write!(svg, r#""{} />"#, style.render());
 	}
+
+	fn intersects_quad(&self, quad: [DVec2; 4], path: &mut Vec<LayerId>, intersections: &mut Vec<Vec<LayerId>>, style: style::PathStyle) {
+		if intersect_quad_bez_path(quad, &self.to_kurbo_path(DAffine2::IDENTITY, style), false) {
+			intersections.push(path.clone());
+		}
+	}
 }
 
 #[cfg(test)]