Unify coordinate mapping

src/bin/flat/tube/mod.rs

@@ -3,6 +3,7 @@ use crate::riemann;
 use crate::riemann::Metric;
 use Subspace::{Boundary, Inner, Outer};
 use metric::Tube;
+use coords::Mapper;
 use crate::types::{FlatTraceResult, Hit, Location, Object, Ray};
 
 pub mod metric;
@@ -63,13 +64,14 @@ impl Space {
 
 	pub fn trace_inner(&self, ray: Ray) -> FlatTraceResult {
 		assert_eq!(self.which_subspace(ray.pos), Inner);
-		let cell = TubeInside { tube: self.tube };
-		let ray = cell.ray_to_local(ray);
+		let size = vec2(self.tube.inner_radius, self.tube.internal_halflength);
+		let ray = self.tube.outer_to_inner(ray);
+		assert!(ray.pos.abs().cmple(size).all());
 		let objs = self.list_objects_inner();
-		let dist = cell.to_boundary(ray).expect("Can't get outta here!");
+		let dist = Rect { size }.trace_out_of(ray).expect("Can't get outta here!");
 		FlatTraceResult {
-			end: Some(cell.ray_to_global(ray.forward(dist))),
-			objects: Self::hit_objects(objs.as_slice(), ray, dist, |pos| cell.pos_to_global(pos)),
+			end: Some(self.tube.inner_to_outer(ray.forward(dist))),
+			objects: Self::hit_objects(objs.as_slice(), ray, dist, |pos| self.tube.inner_to_outer(pos)),
 		}
 	}
 
@@ -151,11 +153,10 @@ impl Space {
 		match self.which_subspace(a) {
 			Outer => vec![b],
 			Inner => {
-				let cell = TubeInside { tube: self.tube };
 				let n = ((b - a).length() / step) as usize + 1;
-				let a = cell.pos_to_local(a);
-				let b = cell.pos_to_local(b);
-				(1..=n).map(|k| cell.pos_to_global(a.lerp(b, k as f32 / n as f32))).collect()
+				let a = self.tube.outer_to_inner(a);
+				let b = self.tube.outer_to_inner(b);
+				(1..=n).map(|k| self.tube.inner_to_outer(a.lerp(b, k as f32 / n as f32))).collect()
 			}
 			Boundary => panic!("Can't draw a line here!"),
 		}
@@ -223,44 +224,39 @@ fn test_rect() {
 	assert_eq!(r.trace_out_of(Ray { pos: vec2(2.0, 3.0), dir: vec2(1.0, 1.0) }), Some(0.0));
 }
 
-#[derive(Debug)]
-struct TubeInside {
-	tube: Tube,
-}
+mod coords {
+	use glam::{Vec2, vec2};
+	use crate::types::Ray;
+	use super::Tube;
 
-impl TubeInside {
-	fn is_inside(&self, pos: Vec2) -> bool {
-		pos.abs().cmple(self.size()).all()
+	pub trait Mapper<T> {
+		fn inner_to_outer(self, v: T) -> T;
+		fn outer_to_inner(self, v: T) -> T;
 	}
 
-	fn to_boundary(&self, ray: Ray) -> Option<f32> {
-		assert!(self.is_inside(ray.pos));
-		Rect { size: self.size() }.trace_out_of(ray)
-	}
+	impl Mapper<Vec2> for Tube {
+		fn inner_to_outer(self, pos: Vec2) -> Vec2 {
+			vec2(pos.x, self.y(pos.y))
+		}
 
-	fn pos_to_global(&self, pos: Vec2) -> Vec2 {
-		vec2(pos.x, self.tube.y(pos.y))
-	}
-
-	fn pos_to_local(&self, pos: Vec2) -> Vec2 {
-		vec2(pos.x, self.tube.v(pos.y))
-	}
-
-	fn ray_to_global(&self, ray: Ray) -> Ray {
-		Ray {
-			pos: self.pos_to_global(ray.pos),
-			dir: vec2(ray.dir.x, self.tube.dy(ray.pos.y) * ray.dir.y),
+		fn outer_to_inner(self, pos: Vec2) -> Vec2 {
+			vec2(pos.x, self.v(pos.y))
 		}
 	}
 
-	fn ray_to_local(&self, ray: Ray) -> Ray {
-		Ray {
-			pos: self.pos_to_local(ray.pos),
-			dir: vec2(ray.dir.x, self.tube.dv(ray.pos.y) * ray.dir.y),
+	impl Mapper<Ray> for Tube {
+		fn inner_to_outer(self, ray: Ray) -> Ray {
+			Ray {
+				pos: self.inner_to_outer(ray.pos),
+				dir: vec2(ray.dir.x, self.dy(ray.pos.y) * ray.dir.y),
+			}
+		}
+
+		fn outer_to_inner(self, ray: Ray) -> Ray {
+			Ray {
+				pos: self.outer_to_inner(ray.pos),
+				dir: vec2(ray.dir.x, self.dv(ray.pos.y) * ray.dir.y),
+			}
 		}
 	}
-
-	fn size(&self) -> Vec2 {
-		vec2(self.tube.inner_radius, self.tube.internal_halflength)
-	}
 }