Merge pull request #374 from hannobraun/math

Extract math code into dedicated crate

Cargo.lock

@@ -629,15 +629,14 @@ dependencies = [
  "approx 0.5.1",
  "bytemuck",
  "clap",
- "decorum",
  "figment",
  "fj",
+ "fj-math",
  "futures",
  "libloading",
  "map-macro",
  "nalgebra",
  "notify",
- "num-traits",
  "parking_lot 0.12.0",
  "parry2d-f64",
  "parry3d-f64",
@@ -652,6 +651,18 @@ dependencies = [
  "winit",
 ]
 
+[[package]]
+name = "fj-math"
+version = "0.5.0"
+dependencies = [
+ "approx 0.5.1",
+ "decorum",
+ "nalgebra",
+ "num-traits",
+ "parry2d-f64",
+ "parry3d-f64",
+]
+
 [[package]]
 name = "flate2"
 version = "1.0.22"

Cargo.toml

@@ -3,6 +3,7 @@ resolver = "2"
 members = [
     "fj",
     "fj-app",
+    "fj-math",
 
     "models/cuboid",
     "models/group",
@@ -11,4 +12,7 @@ members = [
 
     "release-operator",
 ]
-default-members = ["fj-app"]
+default-members = [
+    "fj-app",
+    "fj-math",
+]

fj-app/Cargo.toml

@@ -4,7 +4,7 @@ version = "0.5.0"
 edition = "2021"
 
 description = "The world needs another CAD program."
-readme      = "README.md"
+readme      = "../README.md"
 repository  = "https://github.com/hannobraun/fornjot"
 license     = "0BSD"
 keywords    = ["cad", "programmatic", "code-cad"]
@@ -15,13 +15,11 @@ categories  = ["mathematics", "rendering"]
 anyhow      = "1.0.56"
 approx      = "0.5.1"
 bytemuck    = "1.8.0"
-decorum     = "0.3.1"
 futures     = "0.3.21"
 libloading  = "0.7.2"
 map-macro   = "0.2.0"
 nalgebra    = "0.30.0"
 notify      = "5.0.0-pre.14"
-num-traits  = "0.2.14"
 parking_lot = "0.12.0"
 parry2d-f64 = "0.8.0"
 parry3d-f64 = "0.8.0"
@@ -45,6 +43,10 @@ features = ["env", "toml"]
 version = "0.5.0"
 path    = "../fj"
 
+[dependencies.fj-math]
+version = "0.5.0"
+path    = "../fj-math"
+
 [dependencies.serde]
 version  = "1.0.136"
 features = ["derive"]

fj-app/src/camera.rs

@@ -1,13 +1,11 @@
 use std::f64::consts::FRAC_PI_2;
 
+use fj_math::{Aabb, Scalar, Triangle};
 use nalgebra::{Point, TAffine, Transform, Translation, Vector};
 use parry3d_f64::query::{Ray, RayCast as _};
 use winit::dpi::PhysicalPosition;
 
-use crate::{
+use crate::window::Window;
-    math::{Aabb, Scalar, Triangle},
-    window::Window,
-};
 
 /// The camera abstraction
 ///

fj-app/src/graphics/config_ui.rs

@@ -1,13 +1,12 @@
 use std::collections::HashMap;
 
+use fj_math::Aabb;
 use wgpu::util::StagingBelt;
 use wgpu_glyph::{
     ab_glyph::{FontArc, InvalidFont},
     GlyphBrush, GlyphBrushBuilder, Section, Text,
 };
 
-use crate::math::Aabb;
-
 use super::draw_config::DrawConfig;
 
 #[derive(Debug)]
@@ -70,7 +69,7 @@ impl ConfigUi {
         }
 
         /* Render size of model bounding box */
-        let bbsize = aabb.size().components();
+        let bbsize = aabb.size().components;
         let info = format!(
             "Model bounding box size: {:0.1} {:0.1} {:0.1}",
             bbsize[0].into_f32(),

fj-app/src/graphics/geometries.rs

@@ -1,6 +1,6 @@
-use crate::math::Aabb;
 use std::convert::TryInto;
 
+use fj_math::Aabb;
 use wgpu::util::DeviceExt;
 
 use super::vertices::{Vertex, Vertices};

fj-app/src/graphics/renderer.rs

@@ -1,12 +1,13 @@
 use std::{io, mem::size_of};
 
+use fj_math::{Aabb, Point};
 use thiserror::Error;
 use tracing::debug;
 use wgpu::util::DeviceExt as _;
 use wgpu_glyph::ab_glyph::InvalidFont;
 use winit::dpi::PhysicalSize;
 
-use crate::{camera::Camera, math::Aabb, math::Point, window::Window};
+use crate::{camera::Camera, window::Window};
 
 use super::{
     config_ui::ConfigUi, draw_config::DrawConfig, drawables::Drawables,

fj-app/src/graphics/vertices.rs

@@ -1,9 +1,9 @@
 use bytemuck::{Pod, Zeroable};
+use fj_math::Triangle;
 use nalgebra::{vector, Point};
 
 use crate::{
     debug::DebugInfo,
-    math::Triangle,
     mesh::{Index, MeshMaker},
 };
 

fj-app/src/input/handler.rs

@@ -1,5 +1,6 @@
 use std::time::Instant;
 
+use fj_math::Triangle;
 use winit::{
     dpi::PhysicalPosition,
     event::{
@@ -10,7 +11,6 @@ use winit::{
 
 use crate::{
     camera::{Camera, FocusPoint},
-    math::Triangle,
     window::Window,
 };
 

fj-app/src/kernel/algorithms/approximation.rs

@@ -1,12 +1,11 @@
 use std::collections::HashSet;
 
-use crate::{
+use fj_math::{Point, Scalar, Segment};
-    kernel::topology::{
+
+use crate::kernel::topology::{
     edges::{Cycle, Edge},
     faces::Face,
     vertices::Vertex,
-    },
-    math::{Point, Scalar, Segment},
 };
 
 /// An approximation of an edge, multiple edges, or a face
@@ -132,15 +131,13 @@ fn approximate_edge(
 
 #[cfg(test)]
 mod tests {
+    use fj_math::{Point, Scalar, Segment};
     use map_macro::set;
 
-    use crate::{
+    use crate::kernel::{
-        kernel::{
         geometry::Surface,
         shape::Shape,
         topology::{edges::Cycle, faces::Face, vertices::Vertex},
-        },
-        math::{Point, Scalar, Segment},
     };
 
     use super::{approximate_edge, Approximation};

fj-app/src/kernel/algorithms/sweep.rs

@@ -1,7 +1,8 @@
 use std::collections::HashMap;
 
-use crate::{
+use fj_math::{Scalar, Transform, Triangle, Vector};
-    kernel::{
+
+use crate::kernel::{
     geometry::{surfaces::Swept, Surface},
     shape::{Handle, Shape},
     topology::{
@@ -9,8 +10,6 @@ use crate::{
         faces::Face,
         vertices::Vertex,
     },
-    },
-    math::{Scalar, Transform, Triangle, Vector},
 };
 
 use super::approximation::Approximation;
@@ -322,13 +321,12 @@ impl Relation {
 
 #[cfg(test)]
 mod tests {
-    use crate::{
+    use fj_math::{Point, Scalar, Vector};
-        kernel::{
+
+    use crate::kernel::{
         geometry::{surfaces::Swept, Surface},
         shape::{Handle, Shape},
         topology::{edges::Cycle, faces::Face, vertices::Vertex},
-        },
-        math::{Point, Scalar, Vector},
     };
 
     use super::sweep_shape;

fj-app/src/kernel/algorithms/triangulation.rs

@@ -1,7 +1,8 @@
+use fj_math::Scalar;
 use parry2d_f64::utils::point_in_triangle::{corner_direction, Orientation};
 use spade::HasPosition;
 
-use crate::{kernel::geometry, math::Scalar};
+use crate::kernel::geometry;
 
 /// Create a Delaunay triangulation of all points
 pub fn triangulate(

fj-app/src/kernel/geometry/curves/circle.rs

@@ -1,6 +1,6 @@
 use std::f64::consts::PI;
 
-use crate::math::{Point, Scalar, Transform, Vector};
+use fj_math::{Point, Scalar, Transform, Vector};
 
 /// A circle
 #[derive(Clone, Copy, Debug, Eq, PartialEq, Hash, Ord, PartialOrd)]
@@ -109,7 +109,7 @@ impl Circle {
 mod tests {
     use std::f64::consts::{FRAC_PI_2, PI};
 
-    use crate::math::{Point, Scalar, Vector};
+    use fj_math::{Point, Scalar, Vector};
 
     use super::Circle;
 

fj-app/src/kernel/geometry/curves/line.rs

@@ -1,4 +1,4 @@
-use crate::math::{Point, Transform, Vector};
+use fj_math::{Point, Transform, Vector};
 
 /// A line, defined by a point and a vector
 #[derive(Clone, Copy, Debug, Eq, PartialEq, Hash, Ord, PartialOrd)]
@@ -83,11 +83,10 @@ mod tests {
     use std::f64::consts::FRAC_PI_2;
 
     use approx::assert_abs_diff_eq;
+    use fj_math::{Point, Vector};
     use nalgebra::UnitQuaternion;
     use parry3d_f64::math::{Isometry, Translation};
 
-    use crate::math::{Point, Vector};
-
     use super::Line;
 
     #[test]

fj-app/src/kernel/geometry/curves/mod.rs

@@ -1,7 +1,7 @@
 mod circle;
 mod line;
 
-use crate::math::{Point, Scalar, Transform, Vector};
+use fj_math::{Point, Scalar, Transform, Vector};
 
 pub use self::{circle::Circle, line::Line};
 

fj-app/src/kernel/geometry/points.rs

@@ -1,6 +1,6 @@
 use std::ops::{Add, Sub};
 
-use crate::math::{self, Vector};
+use fj_math::Vector;
 
 /// A point that can be losslessly converted into its canonical form
 ///
@@ -13,7 +13,7 @@ pub struct Point<const D: usize> {
     /// The native form of the point is its representation in its native
     /// coordinate system. This could be a 1-dimensional curve, 2-dimensional
     /// surface, or 3-dimensional model coordinate system.
-    native: math::Point<D>,
+    native: fj_math::Point<D>,
 
     /// The canonical form of the point
     ///
@@ -21,7 +21,7 @@ pub struct Point<const D: usize> {
     /// kept here, unchanged, as the point is converted into other coordinate
     /// systems, it allows for a lossless conversion back into 3D coordinates,
     /// unaffected by floating point accuracy issues.
-    canonical: math::Point<3>,
+    canonical: fj_math::Point<3>,
 }
 
 impl<const D: usize> Point<D> {
@@ -29,23 +29,26 @@ impl<const D: usize> Point<D> {
     ///
     /// Both the native and the canonical form must be provide. The caller must
     /// guarantee that both of them match.
-    pub fn new(native: math::Point<D>, canonical: math::Point<3>) -> Self {
+    pub fn new(
+        native: fj_math::Point<D>,
+        canonical: fj_math::Point<3>,
+    ) -> Self {
         Self { native, canonical }
     }
 
     /// Access the point's native form
-    pub fn native(&self) -> math::Point<D> {
+    pub fn native(&self) -> fj_math::Point<D> {
         self.native
     }
 
     /// Access the point's canonical form
-    pub fn canonical(&self) -> math::Point<3> {
+    pub fn canonical(&self) -> fj_math::Point<3> {
         self.canonical
     }
 }
 
-impl From<math::Point<3>> for Point<3> {
+impl From<fj_math::Point<3>> for Point<3> {
-    fn from(point: math::Point<3>) -> Self {
+    fn from(point: fj_math::Point<3>) -> Self {
         Self::new(point, point)
     }
 }
@@ -54,7 +57,7 @@ impl From<math::Point<3>> for Point<3> {
 // `Point`, or the conversion back to 3D would be broken.
 
 impl<const D: usize> Add<Vector<D>> for Point<D> {
-    type Output = math::Point<D>;
+    type Output = fj_math::Point<D>;
 
     fn add(self, rhs: Vector<D>) -> Self::Output {
         self.native.add(rhs)
@@ -69,10 +72,10 @@ impl<const D: usize> Sub<Self> for Point<D> {
     }
 }
 
-impl<const D: usize> Sub<math::Point<D>> for Point<D> {
+impl<const D: usize> Sub<fj_math::Point<D>> for Point<D> {
     type Output = Vector<D>;
 
-    fn sub(self, rhs: math::Point<D>) -> Self::Output {
+    fn sub(self, rhs: fj_math::Point<D>) -> Self::Output {
         self.native.sub(rhs)
     }
 }

fj-app/src/kernel/geometry/surfaces/mod.rs

@@ -2,12 +2,10 @@ pub mod swept;
 
 pub use self::swept::Swept;
 
+use fj_math::{Point, Transform, Vector};
 use nalgebra::vector;
 
-use crate::{
+use crate::kernel::geometry;
-    kernel::geometry,
-    math::{Point, Transform, Vector},
-};
 
 use super::{Curve, Line};
 

fj-app/src/kernel/geometry/surfaces/swept.rs

@@ -1,7 +1,6 @@
-use crate::{
+use fj_math::{Point, Transform, Vector};
-    kernel::geometry::Curve,
+
-    math::{Point, Transform, Vector},
+use crate::kernel::geometry::Curve;
-};
 
 /// A surface that was swept from a curve
 #[derive(Clone, Copy, Debug, Eq, PartialEq, Hash, Ord, PartialOrd)]
@@ -56,10 +55,9 @@ impl Swept {
 #[cfg(test)]
 mod tests {
 
-    use crate::{
+    use fj_math::{Point, Vector};
-        kernel::geometry::{Curve, Line},
+
-        math::{Point, Vector},
+    use crate::kernel::geometry::{Curve, Line};
-    };
 
     use super::Swept;
 

fj-app/src/kernel/shape/geometry.rs

@@ -1,9 +1,8 @@
-use crate::{
+use fj_math::{Point, Transform};
-    kernel::{
+
+use crate::kernel::{
     geometry::{Curve, Surface},
     topology::faces::Face,
-    },
-    math::{Point, Transform},
 };
 
 use super::{

fj-app/src/kernel/shape/mod.rs

@@ -4,6 +4,8 @@ pub mod iter;
 pub mod topology;
 pub mod validate;
 
+use fj_math::{Point, Scalar};
+
 pub use self::{
     geometry::Geometry,
     handle::Handle,
@@ -12,8 +14,6 @@ pub use self::{
     validate::{ValidationError, ValidationResult},
 };
 
-use crate::math::{Point, Scalar};
-
 use super::{
     geometry::{Curve, Surface},
     topology::{

fj-app/src/kernel/shape/topology.rs

@@ -1,5 +1,7 @@
 use std::collections::HashSet;
 
+use fj_math::{Point, Scalar, Triangle, Vector};
+
 use crate::{
     debug::DebugInfo,
     kernel::{
@@ -10,7 +12,6 @@ use crate::{
             vertices::Vertex,
         },
     },
-    math::{Point, Scalar, Triangle, Vector},
 };
 
 use super::{
@@ -260,8 +261,9 @@ impl Topology<'_> {
 mod tests {
     use std::ops::{Deref, DerefMut};
 
-    use crate::{
+    use fj_math::{Point, Scalar};
-        kernel::{
+
+    use crate::kernel::{
         geometry::{Curve, Line, Surface},
         shape::{handle::Handle, Shape, ValidationError},
         topology::{
@@ -269,8 +271,6 @@ mod tests {
             faces::Face,
             vertices::Vertex,
         },
-        },
-        math::{Point, Scalar},
     };
 
     const MIN_DISTANCE: f64 = 5e-7;

fj-app/src/kernel/shapes/circle.rs

@@ -1,3 +1,5 @@
+use fj_math::{Aabb, Point, Scalar};
+
 use crate::{
     debug::DebugInfo,
     kernel::{
@@ -5,7 +7,6 @@ use crate::{
         shape::Shape,
         topology::{edges::Cycle, faces::Face},
     },
-    math::{Aabb, Point, Scalar},
 };
 
 use super::ToShape;

fj-app/src/kernel/shapes/difference_2d.rs

@@ -1,5 +1,7 @@
 use std::collections::HashMap;
 
+use fj_math::{Aabb, Scalar};
+
 use crate::{
     debug::DebugInfo,
     kernel::{
@@ -10,7 +12,6 @@ use crate::{
             vertices::Vertex,
         },
     },
-    math::{Aabb, Scalar},
 };
 
 use super::ToShape;

fj-app/src/kernel/shapes/group.rs

@@ -1,5 +1,7 @@
 use std::collections::HashMap;
 
+use fj_math::{Aabb, Scalar};
+
 use crate::{
     debug::DebugInfo,
     kernel::{
@@ -10,7 +12,6 @@ use crate::{
             vertices::Vertex,
         },
     },
-    math::{Aabb, Scalar},
 };
 
 use super::ToShape;

fj-app/src/kernel/shapes/mod.rs

@@ -5,10 +5,9 @@ pub mod sketch;
 pub mod sweep;
 pub mod transform;
 
-use crate::{
+use fj_math::{Aabb, Scalar};
-    debug::DebugInfo,
+
-    math::{Aabb, Scalar},
+use crate::debug::DebugInfo;
-};
 
 use super::shape::Shape;
 

fj-app/src/kernel/shapes/sketch.rs

@@ -1,3 +1,5 @@
+use fj_math::{Aabb, Point, Scalar};
+
 use crate::{
     debug::DebugInfo,
     kernel::{
@@ -5,7 +7,6 @@ use crate::{
         shape::Shape,
         topology::{edges::Cycle, faces::Face, vertices::Vertex},
     },
-    math::{Aabb, Point, Scalar},
 };
 
 use super::ToShape;

fj-app/src/kernel/shapes/sweep.rs

@@ -1,7 +1,8 @@
+use fj_math::{Aabb, Scalar, Vector};
+
 use crate::{
     debug::DebugInfo,
     kernel::{algorithms::sweep::sweep_shape, shape::Shape},
-    math::{Aabb, Scalar, Vector},
 };
 
 use super::ToShape;

fj-app/src/kernel/shapes/transform.rs

@@ -1,10 +1,7 @@
+use fj_math::{Aabb, Scalar, Transform};
 use parry3d_f64::math::Isometry;
 
-use crate::{
+use crate::{debug::DebugInfo, kernel::shape::Shape};
-    debug::DebugInfo,
-    kernel::shape::Shape,
-    math::{Aabb, Scalar, Transform},
-};
 
 use super::ToShape;
 

fj-app/src/kernel/topology/faces.rs

@@ -3,6 +3,7 @@ use std::{
     hash::{Hash, Hasher},
 };
 
+use fj_math::{Aabb, Scalar, Segment, Triangle};
 use parry2d_f64::query::{Ray as Ray2, RayCast as _};
 use parry3d_f64::query::Ray as Ray3;
 
@@ -15,7 +16,6 @@ use crate::{
         geometry::Surface,
         shape::Handle,
     },
-    math::{Aabb, Scalar, Segment, Triangle},
 };
 
 use super::edges::Cycle;

fj-app/src/kernel/topology/vertices.rs

@@ -1,6 +1,8 @@
 use std::hash::Hash;
 
-use crate::{kernel::shape::Handle, math::Point};
+use fj_math::Point;
+
+use crate::kernel::shape::Handle;
 
 /// A vertex
 ///

fj-app/src/main.rs

@@ -5,7 +5,6 @@ mod debug;
 mod graphics;
 mod input;
 mod kernel;
-mod math;
 mod mesh;
 mod model;
 mod window;
@@ -15,6 +14,7 @@ use std::ffi::OsStr;
 use std::path::PathBuf;
 use std::{collections::HashMap, sync::mpsc, time::Instant};
 
+use fj_math::Scalar;
 use futures::executor::block_on;
 use notify::Watcher as _;
 use tracing::trace;
@@ -25,7 +25,6 @@ use winit::{
     event_loop::{ControlFlow, EventLoop},
 };
 
-use crate::math::Scalar;
 use crate::{
     args::Args,
     camera::Camera,
@@ -105,7 +104,7 @@ fn main() -> anyhow::Result<()> {
             // look at the smallest non-zero extent of the bounding box and divide that
             // by some value.
             let mut min_extent = Scalar::MAX;
-            for extent in aabb.size().components() {
+            for extent in aabb.size().components {
                 if extent > Scalar::ZERO && extent < min_extent {
                     min_extent = extent;
                 }

fj-app/src/math/coordinates.rs

@@ -1,22 +0,0 @@
-use super::Scalar;
-
-/// 1-dimensional curve coordinates
-#[repr(C)]
-pub struct T {
-    pub t: Scalar,
-}
-
-/// 2-dimensional surface coordinates
-#[repr(C)]
-pub struct Uv {
-    pub u: Scalar,
-    pub v: Scalar,
-}
-
-/// 3-dimensional model coordinates
-#[repr(C)]
-pub struct Xyz {
-    pub x: Scalar,
-    pub y: Scalar,
-    pub z: Scalar,
-}

fj-app/src/math/mod.rs

@@ -1,13 +0,0 @@
-pub mod aabb;
-pub mod coordinates;
-pub mod point;
-pub mod scalar;
-pub mod segment;
-pub mod transform;
-pub mod triangle;
-pub mod vector;
-
-pub use self::{
-    aabb::Aabb, point::Point, scalar::Scalar, segment::Segment,
-    transform::Transform, triangle::Triangle, vector::Vector,
-};

fj-math/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+name    = "fj-math"
+version = "0.5.0"
+edition = "2021"
+
+description = "The world needs another CAD program."
+readme      = "../README.md"
+repository  = "https://github.com/hannobraun/fornjot"
+license     = "0BSD"
+keywords    = ["cad", "programmatic", "code-cad"]
+categories  = ["mathematics"]
+
+[dependencies]
+approx      = "0.5.1"
+decorum     = "0.3.1"
+nalgebra    = "0.30.0"
+num-traits  = "0.2.14"
+parry2d-f64 = "0.8.0"
+parry3d-f64 = "0.8.0"

fj-math/src/coordinates.rs

@@ -0,0 +1,31 @@
+use super::Scalar;
+
+/// 1-dimensional curve coordinates
+#[repr(C)]
+pub struct T {
+    /// The single coordinate of the 1-dimensional curve coordinates
+    pub t: Scalar,
+}
+
+/// 2-dimensional surface coordinates
+#[repr(C)]
+pub struct Uv {
+    /// The first coordinate of the 2-dimensional surface coordinates
+    pub u: Scalar,
+
+    /// The second coordinate of the 2-dimensional surface coordinates
+    pub v: Scalar,
+}
+
+/// 3-dimensional model coordinates
+#[repr(C)]
+pub struct Xyz {
+    /// The first coordinate of the 3-dimensional model coordinates
+    pub x: Scalar,
+
+    /// The second coordinate of the 3-dimensional model coordinates
+    pub y: Scalar,
+
+    /// The third coordinate of the 3-dimensional model coordinates
+    pub z: Scalar,
+}

fj-math/src/lib.rs

@@ -0,0 +1,48 @@
+//! Math primitives for the Fornjot ecosystem
+//!
+//! This crates provides basic math types for the Fornjot ecosystem. It is built
+//! on [nalgebra] and [Parry], but provides an interface that is specifically
+//! tailored to the needs of Fornjot.
+//!
+//! # Failing [`From`]/[`Into`] implementations
+//!
+//! Please note that any [`From`]/[`Into`] implementation that convert floating
+//! point numbers into [`Scalar`] can panic. These conversions call
+//! [`Scalar::from_f64`] internally and panic under the same conditions. This
+//! affects [`Scalar`] itself, but also any other types in this crate that
+//! provide conversions from types that involve `f64`.
+//!
+//! This explicitly goes against the mandate of [`From`]/[`Into`], whose
+//! documentation states that implementations must not fail. This is a
+//! deliberate design decision. The intended use case of `Scalar` is math code
+//! that considers NaN results a bug, not a recoverable error.
+//!
+//! For this use case, having easy conversions available is an advantage, and
+//! explicit `unwrap`/`expect` calls would add nothing. In addition, the
+//! [`From`]/[`Into`] documentation fails to provide any reasons for its
+//! mandate.
+//!
+//! [nalgebra]: https://nalgebra.org/
+//! [Parry]: https://www.parry.rs/
+
+#![deny(missing_docs)]
+
+mod aabb;
+mod coordinates;
+mod point;
+mod scalar;
+mod segment;
+mod transform;
+mod triangle;
+mod vector;
+
+pub use self::{
+    aabb::Aabb,
+    coordinates::{Uv, Xyz, T},
+    point::Point,
+    scalar::Scalar,
+    segment::Segment,
+    transform::Transform,
+    triangle::Triangle,
+    vector::Vector,
+};

fj-math/src/point.rs

@@ -7,14 +7,11 @@ use super::{
 
 /// An n-dimensional point
 ///
-/// The dimensionality is defined by the const generic argument `D`.
+/// The dimensionality of the point is defined by the const generic `D`
-///
+/// parameter.
-/// # Implementation Note
-///
-/// The goal of this type is to eventually implement `Eq` and `Hash`, making it
-/// easier to work with vectors. This is a work in progress.
 #[derive(Clone, Copy, Eq, PartialEq, Hash, Ord, PartialOrd)]
 pub struct Point<const D: usize> {
+    /// The coordinates of the point
     pub coords: Vector<D>,
 }
 

fj-math/src/scalar.rs

@@ -8,23 +8,6 @@ use decorum::R64;
 /// value is not NaN. This allows `Scalar` to provide implementations of [`Eq`],
 /// [`Ord`], and [`Hash`], enabling `Scalar` (and types built on top of it), to
 /// be used as keys in hash maps, hash sets, and similar types.
-///
-/// # Failing `From`/`Into` implementations
-///
-/// Please note that the [`From`]/[`Into`] implementation that convert floating
-/// point numbers into `Scalar` can panic. These conversions call
-/// [`Scalar::from_f64`] internally and panic under the same conditions.
-///
-/// This explicitly goes against the mandate of [`From`]/[`Into`], whose
-/// documentation mandate that implementations must not fail. This is a
-/// deliberate design decision. The intended use case of `Scalar` is math code
-/// that considers non-finite floating point values a bug, not a recoverable
-/// error.
-///
-/// For this use case, having easy conversions available is an advantage, and
-/// explicit `unwrap`/`expect` calls would add nothing. In addition, the mandate
-/// not to fail is not motivated in any way, in the [`From`]/[`Into`]
-/// documentation.
 #[derive(Clone, Copy)]
 pub struct Scalar(f64);
 
@@ -46,6 +29,8 @@ impl Scalar {
 
     /// Construct a `Scalar` from an `f64`
     ///
+    /// # Panics
+    ///
     /// Panics, if `scalar` is NaN.
     pub fn from_f64(scalar: f64) -> Self {
         if scalar.is_nan() {

fj-math/src/segment.rs

@@ -3,48 +3,56 @@ use std::fmt;
 use super::Point;
 
 /// A line segment, defined by its two end points
+///
+/// The dimensionality of the segment is defined by the const generic `D`
+/// parameter.
 #[derive(Clone, Copy, Eq, PartialEq, Hash, Ord, PartialOrd)]
 pub struct Segment<const D: usize> {
-    a: Point<D>,
+    points: [Point<D>; 2],
-    b: Point<D>,
 }
 
 impl<const D: usize> Segment<D> {
+    /// Construct a segment from two points
+    ///
+    /// # Panics
+    ///
+    /// Panics, if the points are coincident.
+    pub fn from_points(points: [Point<D>; 2]) -> Self {
+        let [a, b] = points;
+
+        assert!(a != b, "Invalid segment; both points are identical {a:?}");
+
+        Self { points }
+    }
+
     /// Access the points of the segment
     pub fn points(&self) -> [Point<D>; 2] {
-        [self.a, self.b]
+        self.points
     }
 }
 
 impl Segment<2> {
     /// Convert the 2-dimensional segment to a Parry segment
     pub fn to_parry(self) -> parry2d_f64::shape::Segment {
-        [self.a.to_na(), self.b.to_na()].into()
+        self.points.map(|point| point.to_na()).into()
     }
 }
 
 impl Segment<3> {
     /// Convert the 3-dimensional segment to a Parry segment
     pub fn to_parry(self) -> parry3d_f64::shape::Segment {
-        [self.a.to_na(), self.b.to_na()].into()
+        self.points.map(|point| point.to_na()).into()
     }
 }
 
 impl<const D: usize> From<[Point<D>; 2]> for Segment<D> {
     fn from(points: [Point<D>; 2]) -> Self {
-        let [a, b] = points;
+        Self::from_points(points)
-
-        assert!(a != b, "Invalid segment; both points are identical {a:?}");
-
-        Self {
-            a: points[0],
-            b: points[1],
-        }
     }
 }
 
 impl<const D: usize> fmt::Debug for Segment<D> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "[{:?} -> {:?}]", self.a, self.b)
+        write!(f, "[{:?} -> {:?}]", self.points[0], self.points[1])
     }
 }

fj-math/src/triangle.rs

@@ -1,6 +1,9 @@
 use super::{Point, Scalar};
 
 /// A triangle
+///
+/// The dimensionality of the triangle is defined by the const generic `D`
+/// parameter.
 #[derive(Clone, Copy, Debug, Eq, PartialEq, Hash, Ord, PartialOrd)]
 pub struct Triangle<const D: usize> {
     points: [Point<D>; 3],
@@ -8,6 +11,28 @@ pub struct Triangle<const D: usize> {
 }
 
 impl<const D: usize> Triangle<D> {
+    /// Construct a triangle from three points
+    ///
+    /// # Panics
+    ///
+    /// Panics, if the points don't form a triangle.
+    pub fn from_points(points: [Point<D>; 3]) -> Self {
+        let area = {
+            let [a, b, c] = points.map(Point::to_xyz);
+            (b - a).cross(&(c - a)).magnitude()
+        };
+
+        // A triangle is not valid if it doesn't span any area
+        if area != Scalar::from(0.0) {
+            Self {
+                points,
+                color: [255, 0, 0, 255],
+            }
+        } else {
+            panic!("Invalid Triangle specified");
+        }
+    }
+
     /// Access the triangle's points
     pub fn points(&self) -> [Point<D>; 3] {
         self.points
@@ -33,27 +58,15 @@ impl Triangle<3> {
 
 impl<const D: usize> From<[Point<D>; 3]> for Triangle<D> {
     fn from(points: [Point<D>; 3]) -> Self {
-        let area = {
+        Self::from_points(points)
-            let [a, b, c] = points.map(Point::to_xyz);
-            (b - a).cross(&(c - a)).magnitude()
-        };
-
-        // A triangle is not valid if it doesn't span any area
-        if area != Scalar::from(0.0) {
-            Self {
-                points,
-                color: [255, 0, 0, 255],
-            }
-        } else {
-            panic!("Invalid Triangle specified");
-        }
     }
 }
 
 #[cfg(test)]
 mod tests {
+    use crate::Point;
+
     use super::Triangle;
-    use crate::math::Point;
 
     #[test]
     fn valid_triangle_2d() {

fj-math/src/vector.rs

@@ -7,34 +7,42 @@ use super::{
 
 /// An n-dimensional vector
 ///
-/// The dimensionality is defined by the const generic argument `D`.
+/// The dimensionality of the vector is defined by the const generic `D`
-///
+/// parameter.
-/// # Implementation Note
-///
-/// The goal of this type is to eventually implement `Eq` and `Hash`, making it
-/// easier to work with vectors. This is a work in progress.
 #[derive(Clone, Copy, Eq, PartialEq, Hash, Ord, PartialOrd)]
-pub struct Vector<const D: usize>(pub [Scalar; D]);
+pub struct Vector<const D: usize> {
+    /// The vector components
+    pub components: [Scalar; D],
+}
 
 impl<const D: usize> Vector<D> {
-    /// Construct a `Vector` from an array
+    /// Construct a `Vector` from `f64` components
-    pub fn from_array(array: [f64; D]) -> Self {
+    ///
-        Self(array.map(Scalar::from_f64))
+    /// # Panics
+    ///
+    /// Panics, if the components can not be converted to [`Scalar`]. See
+    /// [`Scalar::from_f64`], which this method uses internally.
+    pub fn from_components_f64(components: [f64; D]) -> Self {
+        Self {
+            components: components.map(Scalar::from_f64),
+        }
     }
 
     /// Construct a `Vector` from an nalgebra vector
     pub fn from_na(vector: nalgebra::SVector<f64, D>) -> Self {
-        Self::from_array(vector.into())
+        Self::from_components_f64(vector.into())
     }
 
     /// Convert the vector into an nalgebra vector
     pub fn to_na(self) -> nalgebra::SVector<f64, D> {
-        self.0.map(Scalar::into_f64).into()
+        self.components.map(Scalar::into_f64).into()
     }
 
     /// Convert to a 1-dimensional vector
     pub fn to_t(self) -> Vector<1> {
-        Vector([self.0[0]])
+        Vector {
+            components: [self.components[0]],
+        }
     }
 
     /// Convert the vector into a 3-dimensional vector
@@ -47,14 +55,14 @@ impl<const D: usize> Vector<D> {
     pub fn to_xyz(self) -> Vector<3> {
         let zero = Scalar::ZERO;
 
-        let components = match self.0.as_slice() {
+        let components = match self.components.as_slice() {
             [] => [zero, zero, zero],
             &[t] => [t, zero, zero],
             &[u, v] => [u, v, zero],
             &[x, y, z, ..] => [x, y, z],
         };
 
-        Vector(components)
+        Vector { components }
     }
 
     /// Compute the magnitude of the vector
@@ -71,11 +79,6 @@ impl<const D: usize> Vector<D> {
     pub fn dot(&self, other: &Self) -> Scalar {
         self.to_na().dot(&other.to_na()).into()
     }
-
-    /// Access an iterator over the vector's components
-    pub fn components(&self) -> [Scalar; D] {
-        self.0
-    }
 }
 
 impl Vector<3> {
@@ -94,7 +97,7 @@ impl ops::Deref for Vector<1> {
     type Target = T;
 
     fn deref(&self) -> &Self::Target {
-        let ptr = self.0.as_ptr() as *const Self::Target;
+        let ptr = self.components.as_ptr() as *const Self::Target;
 
         // This is sound. We've created this pointer from a valid instance, that
         // has the same size and layout as the target.
@@ -106,7 +109,7 @@ impl ops::Deref for Vector<2> {
     type Target = Uv;
 
     fn deref(&self) -> &Self::Target {
-        let ptr = self.0.as_ptr() as *const Self::Target;
+        let ptr = self.components.as_ptr() as *const Self::Target;
 
         // This is sound. We've created this pointer from a valid instance, that
         // has the same size and layout as the target.
@@ -118,7 +121,7 @@ impl ops::Deref for Vector<3> {
     type Target = Xyz;
 
     fn deref(&self) -> &Self::Target {
-        let ptr = self.0.as_ptr() as *const Self::Target;
+        let ptr = self.components.as_ptr() as *const Self::Target;
 
         // This is sound. We've created this pointer from a valid instance, that
         // has the same size and layout as the target.
@@ -128,7 +131,7 @@ impl ops::Deref for Vector<3> {
 
 impl ops::DerefMut for Vector<1> {
     fn deref_mut(&mut self) -> &mut Self::Target {
-        let ptr = self.0.as_mut_ptr() as *mut Self::Target;
+        let ptr = self.components.as_mut_ptr() as *mut Self::Target;
 
         // This is sound. We've created this pointer from a valid instance, that
         // has the same size and layout as the target.
@@ -138,7 +141,7 @@ impl ops::DerefMut for Vector<1> {
 
 impl ops::DerefMut for Vector<2> {
     fn deref_mut(&mut self) -> &mut Self::Target {
-        let ptr = self.0.as_mut_ptr() as *mut Self::Target;
+        let ptr = self.components.as_mut_ptr() as *mut Self::Target;
 
         // This is sound. We've created this pointer from a valid instance, that
         // has the same size and layout as the target.
@@ -148,7 +151,7 @@ impl ops::DerefMut for Vector<2> {
 
 impl ops::DerefMut for Vector<3> {
     fn deref_mut(&mut self) -> &mut Self::Target {
-        let ptr = self.0.as_mut_ptr() as *mut Self::Target;
+        let ptr = self.components.as_mut_ptr() as *mut Self::Target;
 
         // This is sound. We've created this pointer from a valid instance, that
         // has the same size and layout as the target.
@@ -157,14 +160,14 @@ impl ops::DerefMut for Vector<3> {
 }
 
 impl<const D: usize> From<[Scalar; D]> for Vector<D> {
-    fn from(array: [Scalar; D]) -> Self {
+    fn from(components: [Scalar; D]) -> Self {
-        Self(array)
+        Self { components }
     }
 }
 
 impl<const D: usize> From<[f64; D]> for Vector<D> {
-    fn from(array: [f64; D]) -> Self {
+    fn from(components: [f64; D]) -> Self {
-        Self::from_array(array)
+        Self::from_components_f64(components)
     }
 }
 
@@ -176,19 +179,19 @@ impl<const D: usize> From<nalgebra::SVector<f64, D>> for Vector<D> {
 
 impl<const D: usize> From<Vector<D>> for [f32; D] {
     fn from(vector: Vector<D>) -> Self {
-        vector.0.map(|scalar| scalar.into_f32())
+        vector.components.map(|scalar| scalar.into_f32())
     }
 }
 
 impl<const D: usize> From<Vector<D>> for [f64; D] {
     fn from(vector: Vector<D>) -> Self {
-        vector.0.map(|scalar| scalar.into_f64())
+        vector.components.map(|scalar| scalar.into_f64())
     }
 }
 
 impl<const D: usize> From<Vector<D>> for [Scalar; D] {
     fn from(vector: Vector<D>) -> Self {
-        vector.0
+        vector.components
     }
 }
 
@@ -224,7 +227,7 @@ impl<const D: usize> ops::Div<Scalar> for Vector<D> {
 
 impl<const D: usize> fmt::Debug for Vector<D> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        self.0.fmt(f)
+        self.components.fmt(f)
     }
 }
 
@@ -236,13 +239,13 @@ impl<const D: usize> approx::AbsDiffEq for Vector<D> {
     }
 
     fn abs_diff_eq(&self, other: &Self, epsilon: Self::Epsilon) -> bool {
-        self.0.abs_diff_eq(&other.0, epsilon)
+        self.components.abs_diff_eq(&other.components, epsilon)
     }
 }
 
 #[cfg(test)]
 mod tests {
-    use crate::math::Vector;
+    use crate::Vector;
 
     #[test]
     fn to_xyz() {