Unify Ray and Location transforms

src/bin/flat/tube/mod.rs

@@ -185,7 +185,7 @@ fn test_rect() {
 
 mod coords {
 	use glam::{Mat2, Vec2, vec2};
-	use crate::riemann::Metric;
+	use crate::riemann::{Decomp2, Metric};
 	use crate::types::{Location, Ray};
 	use super::{Rect, Tube};
 
@@ -199,40 +199,47 @@ mod coords {
 		fn distance_to_boundary(&self, _ray: Ray) -> Option<f32> { None }
 	}
 
-	trait MetricCS {
+	trait MetricCS: FlatCoordinateSystem<Vec2> {
 		fn global_metric(&self) -> &impl Metric;
+		fn sqrt_at_global(&self, pos: Vec2) -> Decomp2 {
+			self.global_metric().sqrt_at(pos)
+		}
+		fn flat_to_global_tfm_at(&self, pos: Vec2) -> Mat2 {
+			self.sqrt_at_global(self.flat_to_global(pos)).inverse().into()
+		}
+		fn global_to_flat_tfm_at(&self, pos: Vec2) -> Mat2 {
+			self.sqrt_at_global(pos).into()
+		}
 	}
 
 	impl<T: FlatCoordinateSystem<Vec2> + MetricCS> FlatCoordinateSystem<Ray> for T {
 		fn flat_to_global(&self, ray: Ray) -> Ray {
-			let pos = self.flat_to_global(ray.pos);
 			Ray {
-				pos,
-				dir: Mat2::from(self.global_metric().sqrt_at(pos).inverse()) * ray.dir,
+				pos: self.flat_to_global(ray.pos),
+				dir: self.flat_to_global_tfm_at(ray.pos) * ray.dir,
 			}
 		}
 
 		fn global_to_flat(&self, ray: Ray) -> Ray {
 			Ray {
 				pos: self.global_to_flat(ray.pos),
-				dir: Mat2::from(self.global_metric().sqrt_at(ray.pos)) * ray.dir,
+				dir: self.global_to_flat_tfm_at(ray.pos) * ray.dir,
 			}
 		}
 	}
 
 	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,
+				pos: self.flat_to_global(loc.pos),
+				rot: self.flat_to_global_tfm_at(loc.pos) * 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,
+				rot: self.global_to_flat_tfm_at(loc.pos) * loc.rot,
 			}
 		}
 	}