Use an internal colission cecker for better performance

2022-02-01 17:58:06 +01:00
parent 188f6c15bf
commit 9253f3decd
3 changed files with 152 additions and 16 deletions
@@ -25,6 +25,11 @@ impl Point {
 		Self { x, y }
 	}

+	pub fn from_line_x(line: &Line, x: f64) -> Self {
+		let y = line.calc_y(x);
+		Self { x, y }
+	}
+
 	pub fn distance_to(&self, to: Point) -> f64 {
 		(self.y - to.y).hypot(self.x - to.x)
 	}
@@ -55,3 +60,128 @@ impl From<&JsPoint> for Point {
 		Self::new(point.x(), point.y())
 	}
 }
+
+#[derive(Debug, Copy, Clone)]
+pub struct Line {
+	pub m: f64,
+	pub b: f64,
+	pub p1: Point,
+}
+
+impl Line {
+	pub fn new(m: f64, b: f64, p1: Point) -> Self {
+		Self { m, b, p1 }
+	}
+
+	pub fn from_points(p1: Point, p2: Point) -> Self {
+		let m = (p1.y - p2.y) / (p1.x - p2.x);
+		let b = p1.y - m * p1.x;
+		Self { m, b, p1 }
+	}
+
+	pub fn from_point_and_angle(p1: Point, angle: f64) -> Self {
+		let p2 = Point {
+			x: p1.x - angle.cos(),
+			y: p1.y - angle.sin(),
+		};
+		Line::from_points(p1, p2)
+	}
+
+	pub fn is_vertical(&self) -> bool {
+		self.m.is_infinite()
+	}
+
+	pub fn is_horizontal(&self) -> bool {
+		self.m == 0.0
+	}
+
+	pub fn calc_x(&self, y: f64) -> f64 {
+		(y - self.b) / self.m
+	}
+
+	pub fn calc_y(&self, x: f64) -> f64 {
+		self.m * x + self.b
+	}
+
+	pub fn intersection(&self, other: &Line) -> Option<Point> {
+		// Are both lines vertical?
+		if self.is_vertical() && other.is_vertical() {
+			return None;
+		}
+
+		// Are the lines paralell?
+		if (self.m - other.m).abs() < 0.00000005 {
+			return None;
+		}
+
+		// Is one of the lines vertical?
+		if self.is_vertical() || other.is_vertical() {
+			let vertical;
+			let regular;
+			if self.is_vertical() {
+				vertical = self;
+				regular = other;
+			} else {
+				vertical = other;
+				regular = self;
+			}
+			return Some(Point::from_line_x(&regular, vertical.p1.x));
+		}
+
+		// Calculate x coordinate of intersection point between both lines
+		// Find intersection point: x * m1 + b1 = x * m2 + b2
+		// Solve for x: x = (b1 - b2) / (m2 - m1)
+		let x = (self.b - other.b) / (other.m - self.m);
+		if self.m.abs() < other.m.abs() {
+			Some(Point::from_line_x(&self, x))
+		} else {
+			Some(Point::from_line_x(&other, x))
+		}
+	}
+
+	pub fn get_perpendicular_through_point(&self, p: Point) -> Self {
+		let m = -1.0 / self.m;
+		let b = p.y - m * p.x;
+		Self { m, b, p1: p }
+	}
+}
+
+#[derive(Debug, Clone, Copy)]
+pub struct LineSegment {
+	pub p1: Point,
+	pub p2: Point,
+	pub line: Line,
+}
+
+impl LineSegment {
+	pub fn new(p1: Point, p2: Point) -> Self {
+		Self {
+			p1,
+			p2,
+			line: Line::from_points(p1, p2),
+		}
+	}
+
+	pub fn intersection(&self, other: &LineSegment) -> Option<Point> {
+		let intersection = self.line.intersection(&other.line);
+		intersection.filter(|intersection| {
+			self.is_intersection_on_segment(*intersection)
+				&& other.is_intersection_on_segment(*intersection)
+		})
+	}
+
+	fn is_intersection_on_segment(&self, intersection: Point) -> bool {
+		if intersection.is_same_as(&self.p1) || intersection.is_same_as(&self.p2) {
+			return true;
+		}
+		if self.line.is_vertical() || self.line.m.abs() > 1.0 {
+			return between(intersection.y, self.p1.y, self.p2.y);
+		}
+		between(intersection.x, self.p1.x, self.p2.x)
+	}
+}
+
+pub fn between<T: Copy + PartialOrd>(num: T, a: T, b: T) -> bool {
+	let (min, max) = if a < b { (a, b) } else { (b, a) };
+	num >= min && num <= max
+}
@@ -19,14 +19,6 @@ extern "C" {
 	pub fn log(s: &str);
 }

-#[wasm_bindgen(
-	inline_js = "export function collidesWithWall(p1, p2) { return canvas.walls.checkCollision(new Ray(p1, p2));}"
-)]
-extern "C" {
-	#[wasm_bindgen(js_name=collidesWithWall)]
-	pub fn collides_with_wall(p1: Point, p2: Point) -> bool;
-}
-
 #[wasm_bindgen]
 extern "C" {
 	pub type JsWall;
@@ -5,8 +5,8 @@ use wasm_bindgen::prelude::*;
 use rustc_hash::FxHashMap;

 use crate::{
-	geometry::Point,
-	js_api::{collides_with_wall, Wall},
+	geometry::{LineSegment, Point},
+	js_api::Wall,
 	ptr_indexed_hash_set::PtrIndexedHashSet,
 };

@@ -79,13 +79,16 @@ impl NodeStorage {
 		self.regular_nodes.push(node);
 	}

-	fn initialize_edges(&mut self, node: &NodePtr) {
+	fn initialize_edges(&mut self, node: &NodePtr, walls: &Vec<LineSegment>) {
 		if node.borrow().final_edge.is_none() {
 			let final_edge = self
 				.final_node
 				.as_ref()
 				.filter(|neighbor| {
-					!collides_with_wall(node.borrow().point, neighbor.borrow().point)
+					!self.collides_with_wall(
+						&LineSegment::new(node.borrow().point, neighbor.borrow().point),
+						walls,
+					)
 				})
 				.map(|neighbor| Edge {
 					target: neighbor.clone(),
@@ -104,7 +107,7 @@ impl NodeStorage {
 				continue;
 			}
 			let neighbor_point = neighbor.borrow().point;
-			if !collides_with_wall(point, neighbor_point) {
+			if !self.collides_with_wall(&LineSegment::new(point, neighbor_point), walls) {
 				let cost = point.distance_to(neighbor_point);
 				edges.push(Edge {
 					target: neighbor.clone(),
@@ -115,6 +118,10 @@ impl NodeStorage {
 		node.borrow_mut().edges = Some(edges);
 	}

+	fn collides_with_wall(&self, line: &LineSegment, walls: &Vec<LineSegment>) -> bool {
+		walls.iter().any(|wall| line.intersection(wall).is_some())
+	}
+
 	pub fn cleanup_final_edges(&mut self) {
 		for node in &self.regular_nodes {
 			node.borrow_mut().final_edge = None;
@@ -135,6 +142,8 @@ impl NodeStorage {
 pub struct Pathfinder {
 	#[wasm_bindgen(skip)]
 	pub nodes: NodeStorage,
+	#[wasm_bindgen(skip)]
+	pub walls: Vec<LineSegment>,
 }

 impl Pathfinder {
@@ -143,6 +152,7 @@ impl Pathfinder {
 		I: IntoIterator<Item = Wall>,
 	{
 		let mut endpoints = FxHashMap::<Point, Vec<f64>>::default();
+		let mut line_segments = Vec::new();
 		for wall in walls {
 			let x_diff = wall.p2.x - wall.p1.x;
 			let y_diff = wall.p2.y - wall.p1.y;
@@ -152,6 +162,7 @@ impl Pathfinder {
 				let angles = endpoints.entry(point).or_insert_with(Vec::new);
 				angles.push(angle);
 			}
+			line_segments.push(LineSegment::new(wall.p1, wall.p2));
 		}
 		endpoints
 			.values_mut()
@@ -175,7 +186,10 @@ impl Pathfinder {
 			nodes.push(calc_pathfinding_node(point, angle_between));
 		}
 		// TODO Eliminating nodes close to each other may improve performance
-		Self { nodes }
+		Self {
+			nodes,
+			walls: line_segments,
+		}
 	}

 	pub fn find_path(&mut self, from: Point, to: Point) -> Option<DiscoveredNodePtr> {
@@ -183,7 +197,7 @@ impl Pathfinder {
 		let mut nodes = self.nodes.clone();
 		nodes.final_node = Some(NodePtr::from(Node::new(from)));
 		let to_node = NodePtr::from(Node::new(to));
-		nodes.initialize_edges(&to_node);
+		nodes.initialize_edges(&to_node, &self.walls);
 		let to = DiscoveredNode {
 			node: to_node,
 			cost: 0.0,
@@ -216,7 +230,7 @@ impl Pathfinder {
 				if previous_nodes.contains(neighbor) {
 					continue;
 				}
-				nodes.initialize_edges(neighbor);
+				nodes.initialize_edges(neighbor, &self.walls);
 				let cost = current_node.borrow().cost + edge.cost;
 				let discovered_neighbor = DiscoveredNode {
 					node: neighbor.clone(),