Convert Color into a struct

crates/fj-interop/src/mesh.rs

@@ -107,4 +107,12 @@ pub struct Triangle {
 }
 
 /// RGBA color
-pub type Color = [u8; 4];
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash, Ord, PartialOrd)]
+pub struct Color(pub [u8; 4]);
+
+impl Default for Color {
+    fn default() -> Self {
+        // The default color is red. This is an arbitrary choice.
+        Self([255, 0, 0, 255])
+    }
+}

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

@@ -1,3 +1,4 @@
+use fj_interop::mesh::Color;
 use fj_math::{Point, Scalar, Transform, Triangle, Vector};
 
 use crate::{
@@ -16,7 +17,7 @@ pub fn sweep(
     source: Sketch,
     path: impl Into<Vector<3>>,
     tolerance: Tolerance,
-    color: [u8; 4],
+    color: Color,
 ) -> Solid {
     let path = path.into();
 
@@ -98,7 +99,7 @@ fn create_non_continuous_side_face(
     path: Vector<3>,
     is_sweep_along_negative_direction: bool,
     vertices_bottom: [GlobalVertex; 2],
-    color: [u8; 4],
+    color: Color,
     target: &mut Vec<Face>,
 ) {
     let vertices = {
@@ -168,7 +169,7 @@ fn create_continuous_side_face(
     edge: Edge,
     path: Vector<3>,
     tolerance: Tolerance,
-    color: [u8; 4],
+    color: Color,
     target: &mut Vec<Face>,
 ) {
     let translation = Transform::translation(path);
@@ -198,6 +199,7 @@ fn create_continuous_side_face(
 
 #[cfg(test)]
 mod tests {
+    use fj_interop::mesh::Color;
     use fj_math::{Point, Scalar, Vector};
 
     use crate::{
@@ -298,7 +300,7 @@ mod tests {
         let sketch = Sketch::from_faces([face]);
 
         let solid =
-            super::sweep(sketch, direction, tolerance, [255, 0, 0, 255]);
+            super::sweep(sketch, direction, tolerance, Color([255, 0, 0, 255]));
 
         let expected_vertices: Vec<_> = expected_vertices
             .into_iter()

crates/fj-kernel/src/builder.rs

@@ -1,5 +1,6 @@
 //! Convenient API to build objects
 
+use fj_interop::mesh::Color;
 use fj_math::Point;
 
 use crate::objects::{Cycle, Face, Surface};
@@ -10,7 +11,7 @@ pub struct FaceBuilder {
     surface: Surface,
     exterior: Option<Vec<Point<2>>>,
     interiors: Vec<Vec<Point<2>>>,
-    color: Option<[u8; 4]>,
+    color: Option<Color>,
 }
 
 impl FaceBuilder {
@@ -51,7 +52,7 @@ impl FaceBuilder {
     }
 
     /// Define the color of the face
-    pub fn with_color(mut self, color: [u8; 4]) -> Self {
+    pub fn with_color(mut self, color: Color) -> Self {
         self.color = Some(color);
         self
     }
@@ -72,7 +73,7 @@ impl FaceBuilder {
             interiors.push(cycle);
         }
 
-        let color = self.color.unwrap_or([255, 0, 0, 255]);
+        let color = self.color.unwrap_or_default();
 
         Face::new(surface, exteriors, interiors, color)
     }

crates/fj-kernel/src/objects/face.rs

@@ -17,7 +17,7 @@ impl Face {
         surface: Surface,
         exteriors: impl IntoIterator<Item = Cycle>,
         interiors: impl IntoIterator<Item = Cycle>,
-        color: [u8; 4],
+        color: Color,
     ) -> Self {
         let exteriors = exteriors.into_iter().collect();
         let interiors = interiors.into_iter().collect();
@@ -70,7 +70,7 @@ impl Face {
     }
 
     /// Access the color of the face
-    pub fn color(&self) -> [u8; 4] {
+    pub fn color(&self) -> Color {
         self.brep().color
     }
 
@@ -110,7 +110,7 @@ struct BRep {
     surface: Surface,
     exteriors: Vec<Cycle>,
     interiors: Vec<Cycle>,
-    color: [u8; 4],
+    color: Color,
 }
 
 type TriRep = Vec<(Triangle<3>, Color)>;

crates/fj-operations/src/difference_2d.rs

@@ -1,4 +1,4 @@
-use fj_interop::debug::DebugInfo;
+use fj_interop::{debug::DebugInfo, mesh::Color};
 use fj_kernel::{
     algorithms::Tolerance,
     iter::ObjectIters,
@@ -70,7 +70,12 @@ impl Shape for fj::Difference2d {
                 }
             }
 
-            faces.push(Face::new(*surface, exteriors, interiors, self.color()));
+            faces.push(Face::new(
+                *surface,
+                exteriors,
+                interiors,
+                Color(self.color()),
+            ));
         }
 
         let difference = Sketch::from_faces(faces);

crates/fj-operations/src/sketch.rs

@@ -1,4 +1,4 @@
-use fj_interop::debug::DebugInfo;
+use fj_interop::{debug::DebugInfo, mesh::Color};
 use fj_kernel::{
     algorithms::Tolerance,
     objects::{Cycle, Edge, Face, Sketch, Surface},
@@ -28,15 +28,15 @@ impl Shape for fj::Sketch {
                     Edge::circle_from_radius(Scalar::from_f64(circle.radius()));
                 let cycle = Cycle { edges: vec![edge] };
 
-                Face::new(surface, vec![cycle], Vec::new(), self.color())
+                Face::new(surface, vec![cycle], Vec::new(), Color(self.color()))
             }
             fj::Chain::PolyChain(poly_chain) => {
                 let points =
                     poly_chain.to_points().into_iter().map(Point::from);
 
                 Face::builder(surface)
                     .with_exterior_polygon(points)
-                    .with_color(self.color())
+                    .with_color(Color(self.color()))
                     .build()
             }
         };

crates/fj-operations/src/sweep.rs

@@ -1,4 +1,4 @@
-use fj_interop::debug::DebugInfo;
+use fj_interop::{debug::DebugInfo, mesh::Color};
 use fj_kernel::{
     algorithms::{sweep, Tolerance},
     objects::Solid,
@@ -22,7 +22,7 @@ impl Shape for fj::Sweep {
         let path = Vector::from(self.path());
         let color = self.shape().color();
 
-        let solid = sweep(sketch.into_inner(), path, tolerance, color);
+        let solid = sweep(sketch.into_inner(), path, tolerance, Color(color));
         validate(solid, config)
     }
 

crates/fj-viewer/src/graphics/vertices.rs

@@ -92,7 +92,7 @@ impl From<&Mesh<fj_math::Point<3>>> for Vertices {
             .map(|(vertex, normal, color)| Vertex {
                 position: vertex.into(),
                 normal: normal.into(),
-                color: color.map(|v| f32::from(v) / 255.0),
+                color: color.0.map(|v| f32::from(v) / 255.0),
             })
             .collect();