From 95d46b24c8549b602a052a87c8e3a28ef09c9d3c Mon Sep 17 00:00:00 2001
From: numzero <numzer0@yandex.ru>
Date: Sun, 30 Jun 2024 11:52:37 +0300
Subject: [PATCH] Implement missing InnerCS APIs, and test them

---
 src/bin/flat/tube/mod.rs | 65 ++++++++++++++++++++++++++++++++++++----
 1 file changed, 60 insertions(+), 5 deletions(-)

diff --git a/src/bin/flat/tube/mod.rs b/src/bin/flat/tube/mod.rs
index 70b85cb..6237d4d 100644
--- a/src/bin/flat/tube/mod.rs
+++ b/src/bin/flat/tube/mod.rs
@@ -206,6 +206,8 @@ mod coords {
 		fn flat_to_global(&self, pos: Vec2) -> Vec2 {
 			vec2(pos.x, self.0.y(pos.y))
 		}
+
+		// Работает только при |pos.x| ≤ inner_radius или |pos.y| ≥ external_halflength.
 		fn global_to_flat(&self, pos: Vec2) -> Vec2 {
 			vec2(pos.x, self.0.v(pos.y))
 		}
@@ -229,13 +231,15 @@ mod coords {
 
 	impl FlatCoordinateSystem<Location> for InnerCS {
 		fn flat_to_global(&self, loc: Location) -> Location {
-			todo!()
+			Location {
+				pos: self.flat_to_global(loc.pos),
+				rot: Mat2::from(self.0.sqrt_at(loc.pos).inverse()) * loc.rot,
+			}
 		}
 
-		// NB: не работает для частей Outer с |y| < external_halflength. Но они и не нужны.
 		fn global_to_flat(&self, loc: Location) -> Location {
 			Location {
-				pos: vec2(loc.pos.x, self.0.v(loc.pos.y)), // в плоской СК для Inner или её продолжении на Outer
+				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,
 			}
 		}
@@ -282,10 +286,61 @@ mod coords {
 
 	#[cfg(test)]
 	mod test {
-		use super::{Location, Tube, OuterCS, FlatCoordinateSystem};
-		use glam::{Mat2, vec2};
+		use super::*;
+		use approx::{AbsDiffEq, assert_abs_diff_eq};
+		use glam::{Mat2, vec2, Vec2};
 		use itertools_num::linspace;
 
+		fn test_flat_region(region: &impl FlatRegion, range_global: (Vec2, Vec2), range_flat: (Vec2, Vec2)) {
+			const ε: f32 = 1e-3;
+			macro_rules! assert_eq_at {
+				($at: expr, $left: expr, $right: expr) => {
+					let at = $at;
+					let left = $left;
+					let right = $right;
+					assert!(left.abs_diff_eq(right, ε), "Assertion failed at {at}:\n  left: {left} = {}\n right: {right} = {}", stringify!($left), stringify!($right));
+				};
+			}
+			fn check_range(name_a: &str, a: Vec2, range_a: (Vec2, Vec2), name_b: &str, b: Vec2, range_b: (Vec2, Vec2)) {
+				assert!(b.cmpge(range_b.0 - ε).all() && b.cmple(range_b.1 + ε).all(), "Assertion failed:\nAt {name_a}: {a}, from range: {range_a:?}\nGot {name_b}: {b}, which is out of range {range_b:?}");
+				if a.x.abs_diff_eq(&range_a.0.x, ε) { assert_abs_diff_eq!(b.x, range_b.0.x, epsilon=ε); }
+				if a.y.abs_diff_eq(&range_a.0.y, ε) { assert_abs_diff_eq!(b.y, range_b.0.y, epsilon=ε); }
+				if a.x.abs_diff_eq(&range_a.1.x, ε) { assert_abs_diff_eq!(b.x, range_b.1.x, epsilon=ε); }
+				if a.y.abs_diff_eq(&range_a.1.y, ε) { assert_abs_diff_eq!(b.y, range_b.1.y, epsilon=ε); }
+			}
+			for x in linspace(range_global.0.x, range_global.1.x, 20) {
+				for y in linspace(range_global.0.y, range_global.1.y, 20) {
+					let pos_global = vec2(x, y);
+					let pos_flat = region.global_to_flat(pos_global);
+					check_range("global", pos_global, range_global, "flat", pos_flat, range_flat);
+					assert_eq_at!(pos_global, region.global_to_flat(Location { pos: pos_global, rot: Mat2::IDENTITY }).pos, pos_flat);
+					assert_eq_at!(pos_global, region.flat_to_global(pos_flat), pos_global);
+				}
+			}
+			for x in linspace(range_flat.0.x, range_flat.1.x, 20) {
+				for y in linspace(range_flat.0.y, range_flat.1.y, 20) {
+					let pos_flat = vec2(x, y);
+					let pos_global = region.flat_to_global(pos_flat);
+					check_range("flat", pos_flat, range_flat, "global", pos_global, range_global);
+					assert_eq_at!(pos_flat, region.flat_to_global(Location { pos: pos_flat, rot: Mat2::IDENTITY }).pos, pos_global);
+					assert_eq_at!(pos_flat, region.global_to_flat(pos_global), pos_flat);
+				}
+			}
+		}
+
+		#[test]
+		fn test_mapper_inner() {
+			let mapper = InnerCS(Tube {
+				inner_radius: 30.0,
+				outer_radius: 50.0,
+				internal_halflength: 100.0,
+				external_halflength: 300.0,
+			});
+			test_flat_region(&mapper, (vec2(-30.0, -300.0), vec2(30.0, 300.0)), (vec2(-30.0, -100.0), vec2(30.0, 100.0)));
+			test_flat_region(&mapper, (vec2(-60.0, -400.0), vec2(60.0, -300.0)), (vec2(-60.0, -200.0), vec2(60.0, -100.0)));
+			test_flat_region(&mapper, (vec2(-60.0, 300.0), vec2(60.0, 400.0)), (vec2(-60.0, 100.0), vec2(60.0, 200.0)));
+		}
+
 		#[test]
 		fn test_mapper_outer() {
 			let mapper = OuterCS(Tube {