From 1c96c87173f5498e0921f35b22a9a646a054f68d Mon Sep 17 00:00:00 2001
From: numzero <numzer0@yandex.ru>
Date: Sun, 30 Jun 2024 12:17:40 +0300
Subject: [PATCH] Unify FCS<Location>

---
 src/bin/flat/tube/mod.rs | 67 +++++++++++++++-------------------------
 1 file changed, 25 insertions(+), 42 deletions(-)

diff --git a/src/bin/flat/tube/mod.rs b/src/bin/flat/tube/mod.rs
index 41e6553..1681647 100644
--- a/src/bin/flat/tube/mod.rs
+++ b/src/bin/flat/tube/mod.rs
@@ -199,8 +199,31 @@ mod coords {
 		fn distance_to_boundary(&self, _ray: Ray) -> Option<f32> { None }
 	}
 
+	trait MetricCS {
+		fn global_metric(&self) -> &impl Metric;
+	}
+
+	impl<T: FlatCoordinateSystem<Vec2> + MetricCS> FlatCoordinateSystem<Location> for T {
+		fn flat_to_global(&self, loc: Location) -> Location {
+			let pos = self.flat_to_global(loc.pos);
+			Location {
+				pos,
+				rot: Mat2::from(self.global_metric().sqrt_at(pos).inverse()) * loc.rot,
+			}
+		}
+
+		fn global_to_flat(&self, loc: Location) -> Location {
+			Location {
+				pos: self.global_to_flat(loc.pos), // в плоской СК для Inner или её продолжении на Outer
+				rot: Mat2::from(self.global_metric().sqrt_at(loc.pos)) * loc.rot,
+			}
+		}
+	}
+
 	pub struct InnerCS(pub Tube);
 
+	impl MetricCS for InnerCS { fn global_metric(&self) -> &impl Metric { &self.0 } }
+
 	impl FlatCoordinateSystem<Vec2> for InnerCS {
 		fn flat_to_global(&self, pos: Vec2) -> Vec2 {
 			vec2(pos.x, self.0.y(pos.y))
@@ -228,23 +251,6 @@ mod coords {
 		}
 	}
 
-	impl FlatCoordinateSystem<Location> for InnerCS {
-		fn flat_to_global(&self, loc: Location) -> Location {
-			let pos = self.flat_to_global(loc.pos);
-			Location {
-				pos,
-				rot: Mat2::from(self.0.sqrt_at(pos).inverse()) * loc.rot,
-			}
-		}
-
-		fn global_to_flat(&self, loc: Location) -> Location {
-			Location {
-				pos: self.global_to_flat(loc.pos), // в плоской СК для Inner или её продолжении на Outer
-				rot: Mat2::from(self.0.sqrt_at(loc.pos)) * loc.rot,
-			}
-		}
-	}
-
 	impl FlatRegion for InnerCS {
 		fn distance_to_boundary(&self, ray: Ray) -> Option<f32> {
 			Rect { size: vec2(self.0.inner_radius, self.0.internal_halflength) }.trace_out_of(ray)
@@ -253,6 +259,8 @@ mod coords {
 
 	pub struct OuterCS(pub Tube);
 
+	impl MetricCS for OuterCS { fn global_metric(&self) -> &impl Metric { &self.0 } }
+
 	impl FlatCoordinateSystem<Vec2> for OuterCS {
 		fn flat_to_global(&self, pos: Vec2) -> Vec2 {
 			let inner = Rect { size: vec2(self.0.inner_radius + 1.0, self.0.external_halflength) };
@@ -279,31 +287,6 @@ mod coords {
 
 	impl FlatCoordinateSystem<Ray> for OuterCS {}
 
-	impl FlatCoordinateSystem<Location> for OuterCS {
-		fn flat_to_global(&self, loc: Location) -> Location {
-			let pos = self.flat_to_global(loc.pos);
-			Location {
-				pos,
-				rot: Mat2::from(self.0.sqrt_at(pos).inverse()) * loc.rot,
-			}
-		}
-
-		// NB: имеет разрыв в области Inner на y = 0.
-		fn global_to_flat(&self, loc: Location) -> Location {
-			let inner = Rect { size: vec2(self.0.inner_radius + 1.0, self.0.external_halflength) };
-			if inner.is_inside(loc.pos) {
-				let Vec2 { x: u, y } = loc.pos; // в основной СК
-				let v = self.0.v(y) + y.signum() * (self.0.external_halflength - self.0.internal_halflength);
-				Location {
-					pos: vec2(u, v), // в плоском продолжении СК Outer на область Inner
-					rot: Mat2::from(self.0.sqrt_at(loc.pos)) * loc.rot,
-				}
-			} else {
-				loc
-			}
-		}
-	}
-
 	impl FlatRegion for OuterCS {
 		fn distance_to_boundary(&self, ray: Ray) -> Option<f32> {
 			Rect { size: vec2(self.0.outer_radius, self.0.external_halflength) }.trace_into(ray)