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/document.rs

@@ -1,4 +1,4 @@
-use glam::DAffine2;
+use glam::{DAffine2, DVec2};
 
 use crate::{
 	layers::{self, style::PathStyle, Folder, Layer, LayerDataTypes, Line, PolyLine, Rect, Shape},
@@ -64,6 +64,19 @@ impl Document {
 		svg
 	}
 
+	/// Checks whether each layer under `path` intersects with the provided `quad` and adds all intersection layers as paths to `intersections`.
+	pub fn intersects_quad(&self, quad: [DVec2; 4], path: &mut Vec<LayerId>, intersections: &mut Vec<Vec<LayerId>>) {
+		self.document_folder(path).unwrap().intersects_quad(quad, path, intersections);
+		return;
+	}
+
+	/// Checks whether each layer under the root path intersects with the provided `quad` and returns the paths to all intersecting layers.
+	pub fn intersects_quad_root(&self, quad: [DVec2; 4]) -> Vec<Vec<LayerId>> {
+		let mut intersections = Vec::new();
+		self.intersects_quad(quad, &mut vec![], &mut intersections);
+		intersections
+	}
+
 	fn is_mounted(&self, mount_path: &[LayerId], path: &[LayerId]) -> bool {
 		path.starts_with(mount_path) && self.work_mounted
 	}

core/document/src/intersection.rs

@@ -0,0 +1,57 @@
+use glam::DVec2;
+use kurbo::{BezPath, Line, PathSeg, Point, Shape, Vec2};
+
+fn to_point(vec: DVec2) -> Point {
+	Point::new(vec.x, vec.y)
+}
+
+pub fn intersect_quad_bez_path(quad: [DVec2; 4], shape: &BezPath, closed: bool) -> bool {
+	let lines = vec![
+		Line::new(to_point(quad[0]), to_point(quad[1])),
+		Line::new(to_point(quad[1]), to_point(quad[2])),
+		Line::new(to_point(quad[2]), to_point(quad[3])),
+		Line::new(to_point(quad[3]), to_point(quad[0])),
+	];
+	// check if outlines intersect
+	for path_segment in shape.segments() {
+		for line in &lines {
+			if !path_segment.intersect_line(*line).is_empty() {
+				return true;
+			}
+		}
+	}
+	// check if selection is entirely within the shape
+	if closed && shape.contains(to_point(quad[0])) {
+		return true;
+	}
+	// check if shape is entirely within the selection
+	if let Some(shape_point) = get_arbitrary_point_on_path(shape) {
+		let mut pos = 0;
+		let mut neg = 0;
+		for line in lines {
+			if line.p0 == shape_point {
+				return true;
+			};
+			let line_vec = Vec2::new(line.p1.x - line.p0.x, line.p1.y - line.p0.y);
+			let point_vec = Vec2::new(line.p1.x - shape_point.x, line.p1.y - shape_point.y);
+			let cross = line_vec.cross(point_vec);
+			if cross > 0.0 {
+				pos += 1;
+			} else if cross < 0.0 {
+				neg += 1;
+			}
+			if pos > 0 && neg > 0 {
+				return false;
+			}
+		}
+	}
+	true
+}
+
+pub fn get_arbitrary_point_on_path(path: &BezPath) -> Option<Point> {
+	path.segments().next().map(|seg| match seg {
+		PathSeg::Line(line) => line.p0,
+		PathSeg::Quad(quad) => quad.p0,
+		PathSeg::Cubic(cubic) => cubic.p0,
+	})
+}

core/document/src/layers/ellipse.rs

@@ -1,5 +1,10 @@
+use glam::DAffine2;
+use glam::DVec2;
 use kurbo::Shape;
 
+use crate::intersection::intersect_quad_bez_path;
+use crate::LayerId;
+
 use super::style;
 use super::LayerData;
 
@@ -16,10 +21,17 @@ impl Ellipse {
 }
 
 impl LayerData for Ellipse {
-	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 {
-		kurbo::Ellipse::from_affine(kurbo::Affine::new(transform.to_cols_array())).to_path(0.1)
+		kurbo::Ellipse::from_affine(kurbo::Affine::new(transform.to_cols_array())).to_path(0.01)
 	}
+
 	fn render(&mut self, svg: &mut String, transform: glam::DAffine2, style: style::PathStyle) {
 		let _ = write!(svg, r#"<path d="{}" {} />"#, self.to_kurbo_path(transform, style).to_svg(), 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), true) {
+			intersections.push(path.clone());
+		}
+	}
 }

core/document/src/layers/folder.rs

@@ -1,3 +1,5 @@
+use glam::DVec2;
+
 use crate::{DocumentError, LayerId};
 
 use super::{style, Layer, LayerData, LayerDataTypes};
@@ -13,6 +15,10 @@ pub struct Folder {
 }
 
 impl LayerData for Folder {
+	fn to_kurbo_path(&self, _: glam::DAffine2, _: style::PathStyle) -> kurbo::BezPath {
+		unimplemented!()
+	}
+
 	fn render(&mut self, svg: &mut String, transform: glam::DAffine2, _style: style::PathStyle) {
 		let _ = writeln!(svg, r#"<g transform="matrix("#);
 		transform.to_cols_array().iter().enumerate().for_each(|(i, f)| {
@@ -26,8 +32,12 @@ impl LayerData for Folder {
 		let _ = writeln!(svg, "</g>");
 	}
 
-	fn to_kurbo_path(&mut self, _: glam::DAffine2, _: style::PathStyle) -> kurbo::BezPath {
+	fn intersects_quad(&self, quad: [DVec2; 4], path: &mut Vec<LayerId>, intersections: &mut Vec<Vec<LayerId>>, _style: style::PathStyle) {
-		unimplemented!()
+		for (layer, layer_id) in self.layers().iter().zip(&self.layer_ids) {
+			path.push(*layer_id);
+			layer.intersects_quad(quad, path, intersections);
+			path.pop();
+		}
 	}
 }
 

core/document/src/layers/line.rs

@@ -1,6 +1,10 @@
+use glam::DAffine2;
 use glam::DVec2;
 use kurbo::Point;
 
+use crate::intersection::intersect_quad_bez_path;
+use crate::LayerId;
+
 use super::style;
 use super::LayerData;
 
@@ -17,7 +21,7 @@ impl Line {
 }
 
 impl LayerData for Line {
-	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 {
 		fn new_point(a: DVec2) -> Point {
 			Point::new(a.x, a.y)
 		}
@@ -26,10 +30,17 @@ impl LayerData for Line {
 		path.line_to(new_point(transform.transform_point2(DVec2::ONE)));
 		path
 	}
+
 	fn render(&mut self, svg: &mut String, transform: glam::DAffine2, style: style::PathStyle) {
 		let [x1, y1] = transform.translation.to_array();
 		let [x2, y2] = transform.transform_point2(DVec2::ONE).to_array();
 
 		let _ = write!(svg, r#"<line x1="{}" y1="{}" x2="{}" y2="{}"{} />"#, x1, y1, x2, y2, 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());
+		}
+	}
 }

core/document/src/layers/mod.rs

@@ -19,12 +19,16 @@ pub use shape::Shape;
 
 pub mod folder;
 use crate::DocumentError;
+use crate::LayerId;
 pub use folder::Folder;
 use serde::{Deserialize, Serialize};
 
+pub const SELECTION_TOLERANCE: f64 = 5.0;
+
 pub trait LayerData {
 	fn render(&mut self, svg: &mut String, transform: glam::DAffine2, style: style::PathStyle);
-	fn to_kurbo_path(&mut self, transform: glam::DAffine2, style: style::PathStyle) -> BezPath;
+	fn to_kurbo_path(&self, transform: glam::DAffine2, style: style::PathStyle) -> BezPath;
+	fn intersects_quad(&self, quad: [DVec2; 4], path: &mut Vec<LayerId>, intersections: &mut Vec<Vec<LayerId>>, style: style::PathStyle);
 }
 
 #[derive(Debug, Clone, PartialEq, Deserialize, Serialize)]
@@ -51,6 +55,15 @@ macro_rules! call_kurbo_path {
 		}
 	};
 }
+
+macro_rules! call_intersects_quad {
+    ($self:ident.intersects_quad($quad:ident, $path:ident, $intersections:ident, $style:ident) { $($variant:ident),* }) => {
+		match $self {
+			$(Self::$variant(x) => x.intersects_quad($quad, $path, $intersections, $style)),*
+		}
+	};
+}
+
 impl LayerDataTypes {
 	pub fn render(&mut self, svg: &mut String, transform: glam::DAffine2, style: style::PathStyle) {
 		call_render! {
@@ -64,7 +77,7 @@ impl LayerDataTypes {
 			}
 		}
 	}
-	pub fn to_kurbo_path(&mut self, transform: glam::DAffine2, style: style::PathStyle) -> BezPath {
+	pub fn to_kurbo_path(&self, transform: glam::DAffine2, style: style::PathStyle) -> BezPath {
 		call_kurbo_path! {
 			self.to_kurbo_path(transform, style) {
 				Folder,
@@ -76,6 +89,19 @@ impl LayerDataTypes {
 			}
 		}
 	}
+
+	pub fn intersects_quad(&self, quad: [DVec2; 4], path: &mut Vec<LayerId>, intersections: &mut Vec<Vec<LayerId>>, style: style::PathStyle) {
+		call_intersects_quad! {
+			self.intersects_quad(quad, path, intersections, style) {
+				Folder,
+				Ellipse,
+				Rect,
+				Line,
+				PolyLine,
+				Shape
+			}
+		}
+	}
 }
 
 #[derive(Serialize, Deserialize)]
@@ -122,6 +148,20 @@ impl Layer {
 		self.cache.as_str()
 	}
 
+	pub fn intersects_quad(&self, quad: [DVec2; 4], path: &mut Vec<LayerId>, intersections: &mut Vec<Vec<LayerId>>) {
+		let inv_transform = self.transform.inverse();
+		let transformed_quad = [
+			inv_transform.transform_point2(quad[0]),
+			inv_transform.transform_point2(quad[1]),
+			inv_transform.transform_point2(quad[2]),
+			inv_transform.transform_point2(quad[3]),
+		];
+		if !self.visible {
+			return;
+		}
+		self.data.intersects_quad(transformed_quad, path, intersections, self.style)
+	}
+
 	pub fn render_on(&mut self, svg: &mut String) {
 		*svg += self.render();
 	}
@@ -129,12 +169,14 @@ impl Layer {
 	pub fn to_kurbo_path(&mut self) -> BezPath {
 		self.data.to_kurbo_path(self.transform, self.style)
 	}
+
 	pub fn as_folder_mut(&mut self) -> Result<&mut Folder, DocumentError> {
 		match &mut self.data {
 			LayerDataTypes::Folder(f) => Ok(f),
 			_ => Err(DocumentError::NotAFolder),
 		}
 	}
+
 	pub fn as_folder(&self) -> Result<&Folder, DocumentError> {
 		match &self.data {
 			LayerDataTypes::Folder(f) => Ok(&f),

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)]

core/document/src/layers/rect.rs

@@ -1,6 +1,10 @@
+use glam::DAffine2;
 use glam::DVec2;
 use kurbo::Point;
 
+use crate::intersection::intersect_quad_bez_path;
+use crate::LayerId;
+
 use super::style;
 use super::LayerData;
 
@@ -17,7 +21,7 @@ impl Rect {
 }
 
 impl LayerData for Rect {
-	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 {
 		fn new_point(a: DVec2) -> Point {
 			Point::new(a.x, a.y)
 		}
@@ -32,4 +36,10 @@ impl LayerData for Rect {
 	fn render(&mut self, svg: &mut String, transform: glam::DAffine2, style: style::PathStyle) {
 		let _ = write!(svg, r#"<path d="{}" {} />"#, self.to_kurbo_path(transform, style).to_svg(), 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), true) {
+			intersections.push(path.clone());
+		}
+	}
 }

core/document/src/layers/shape.rs

@@ -1,3 +1,8 @@
+use glam::DAffine2;
+use glam::DVec2;
+
+use crate::intersection::intersect_quad_bez_path;
+use crate::LayerId;
 use kurbo::BezPath;
 use kurbo::Vec2;
 
@@ -20,7 +25,7 @@ impl Shape {
 }
 
 impl LayerData for Shape {
-	fn to_kurbo_path(&mut self, transform: glam::DAffine2, _style: style::PathStyle) -> BezPath {
+	fn to_kurbo_path(&self, transform: glam::DAffine2, _style: style::PathStyle) -> BezPath {
 		fn unit_rotation(theta: f64) -> Vec2 {
 			Vec2::new(-theta.sin(), theta.cos())
 		}
@@ -66,4 +71,10 @@ impl LayerData for Shape {
 	fn render(&mut self, svg: &mut String, transform: glam::DAffine2, style: style::PathStyle) {
 		let _ = write!(svg, r#"<path d="{}" {} />"#, self.to_kurbo_path(transform, style).to_svg(), 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), true) {
+			intersections.push(path.clone());
+		}
+	}
 }

core/document/src/lib.rs

@@ -1,5 +1,6 @@
 pub mod color;
 pub mod document;
+pub mod intersection;
 pub mod layers;
 pub mod operation;
 pub mod response;

core/editor/src/document/document_message_handler.rs

@@ -281,6 +281,8 @@ impl MessageHandler<DocumentMessage, &InputPreprocessor> for DocumentMessageHand
 				for path in paths {
 					responses.extend(self.select_layer(&path));
 				}
+				// TODO: Correctly update layer panel in clear_selection instead of here
+				responses.extend(self.handle_folder_changed(Vec::new()));
 			}
 			Undo => {
 				// this is a temporary fix and will be addressed by #123

core/editor/src/input/input_mapper.rs

@@ -104,6 +104,12 @@ impl Default for Mapping {
 	fn default() -> Self {
 		let (up, down, pointer_move) = mapping![
 			entry! {action=DocumentMessage::PasteLayers, key_down=KeyV, modifiers=[KeyControl]},
+			// Select
+			entry! {action=SelectMessage::MouseMove, message=InputMapperMessage::PointerMove},
+			entry! {action=SelectMessage::DragStart, key_down=Lmb},
+			entry! {action=SelectMessage::DragStop, key_up=Lmb},
+			entry! {action=SelectMessage::Abort, key_down=Rmb},
+			entry! {action=SelectMessage::Abort, key_down=KeyEscape},
 			// Rectangle
 			entry! {action=RectangleMessage::Center, key_down=KeyAlt},
 			entry! {action=RectangleMessage::UnCenter, key_up=KeyAlt},

core/editor/src/tool/tools/select.rs

@@ -1,4 +1,11 @@
-use crate::input::InputPreprocessor;
+use document_core::color::Color;
+use document_core::layers::style::Fill;
+use document_core::layers::style::Stroke;
+use document_core::layers::{style, SELECTION_TOLERANCE};
+use document_core::Operation;
+use glam::{DAffine2, DVec2};
+
+use crate::input::{mouse::ViewportPosition, InputPreprocessor};
 use crate::tool::{DocumentToolData, Fsm, ToolActionHandlerData};
 use crate::{message_prelude::*, SvgDocument};
 
@@ -11,19 +18,29 @@ pub struct Select {
 #[impl_message(Message, ToolMessage, Select)]
 #[derive(PartialEq, Clone, Debug)]
 pub enum SelectMessage {
+	DragStart,
+	DragStop,
 	MouseMove,
+	Abort,
 }
 
 impl<'a> MessageHandler<ToolMessage, ToolActionHandlerData<'a>> for Select {
 	fn process_action(&mut self, action: ToolMessage, data: ToolActionHandlerData<'a>, responses: &mut VecDeque<Message>) {
 		self.fsm_state = self.fsm_state.transition(action, data.0, data.1, &mut self.data, data.2, responses);
 	}
-	advertise_actions!();
+	fn actions(&self) -> ActionList {
+		use SelectToolFsmState::*;
+		match self.fsm_state {
+			Ready => actions!(SelectMessageDiscriminant;  DragStart),
+			Dragging => actions!(SelectMessageDiscriminant; DragStop, MouseMove, Abort),
+		}
+	}
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 enum SelectToolFsmState {
 	Ready,
+	Dragging,
 }
 
 impl Default for SelectToolFsmState {
@@ -32,29 +49,96 @@ impl Default for SelectToolFsmState {
 	}
 }
 
-#[derive(Default)]
+#[derive(Clone, Debug, Default)]
-struct SelectToolData;
+struct SelectToolData {
+	drag_start: ViewportPosition,
+	drag_current: ViewportPosition,
+}
 
 impl Fsm for SelectToolFsmState {
 	type ToolData = SelectToolData;
 
-	fn transition(
+	fn transition(self, event: ToolMessage, document: &SvgDocument, tool_data: &DocumentToolData, data: &mut Self::ToolData, input: &InputPreprocessor, responses: &mut VecDeque<Message>) -> Self {
-		self,
+		let transform = document.root.transform;
-		event: ToolMessage,
-		_document: &SvgDocument,
-		_tool_data: &DocumentToolData,
-		_data: &mut Self::ToolData,
-		_input: &InputPreprocessor,
-		_responses: &mut VecDeque<Message>,
-	) -> Self {
 		use SelectMessage::*;
 		use SelectToolFsmState::*;
 		if let ToolMessage::Select(event) = event {
 			match (self, event) {
-				(Ready, MouseMove) => self,
+				(Ready, DragStart) => {
+					data.drag_start = input.mouse.position;
+					data.drag_current = input.mouse.position;
+					responses.push_back(Operation::MountWorkingFolder { path: vec![] }.into());
+					Dragging
+				}
+				(Dragging, MouseMove) => {
+					data.drag_current = input.mouse.position;
+
+					responses.push_back(Operation::ClearWorkingFolder.into());
+					responses.push_back(make_operation(data, tool_data, transform));
+
+					Dragging
+				}
+				(Dragging, DragStop) => {
+					data.drag_current = input.mouse.position;
+
+					responses.push_back(Operation::ClearWorkingFolder.into());
+
+					let (point_1, point_2) = if data.drag_start == data.drag_current {
+						let (x, y) = (data.drag_current.x as f64, data.drag_current.y as f64);
+						(
+							DVec2::new(x - SELECTION_TOLERANCE, y - SELECTION_TOLERANCE),
+							DVec2::new(x + SELECTION_TOLERANCE, y + SELECTION_TOLERANCE),
+						)
+					} else {
+						(
+							DVec2::new(data.drag_start.x as f64, data.drag_start.y as f64),
+							DVec2::new(data.drag_current.x as f64, data.drag_current.y as f64),
+						)
+					};
+
+					let quad = [
+						DVec2::new(point_1.x, point_1.y),
+						DVec2::new(point_2.x, point_1.y),
+						DVec2::new(point_2.x, point_2.y),
+						DVec2::new(point_1.x, point_2.y),
+					];
+
+					if data.drag_start == data.drag_current {
+						if let Some(intersection) = document.intersects_quad_root(quad).last() {
+							responses.push_back(DocumentMessage::SelectLayers(vec![intersection.clone()]).into());
+						} else {
+							responses.push_back(DocumentMessage::SelectLayers(vec![]).into());
+						}
+					} else {
+						responses.push_back(DocumentMessage::SelectLayers(document.intersects_quad_root(quad)).into());
+					}
+
+					Ready
+				}
+				(Dragging, Abort) => {
+					responses.push_back(Operation::DiscardWorkingFolder.into());
+
+					Ready
+				}
+				_ => self,
 			}
 		} else {
 			self
 		}
 	}
 }
+
+fn make_operation(data: &SelectToolData, _tool_data: &DocumentToolData, transform: DAffine2) -> Message {
+	let x0 = data.drag_start.x as f64;
+	let y0 = data.drag_start.y as f64;
+	let x1 = data.drag_current.x as f64;
+	let y1 = data.drag_current.y as f64;
+
+	Operation::AddRect {
+		path: vec![],
+		insert_index: -1,
+		transform: (transform.inverse() * glam::DAffine2::from_scale_angle_translation(DVec2::new(x1 - x0, y1 - y0), 0., DVec2::new(x0, y0))).to_cols_array(),
+		style: style::PathStyle::new(Some(Stroke::new(Color::from_rgb8(0x31, 0x94, 0xD6), 2.0)), Some(Fill::none())),
+	}
+	.into()
+}