Add SetColor operation

Cargo.toml

@@ -10,6 +10,7 @@ members = [
     "crates/fj-window",
 
     "models/all",
+    "models/color",
     "models/cuboid",
     "models/holes",
     "models/spacer",

crates/fj-core/src/operations/mod.rs

@@ -43,6 +43,7 @@ pub mod holes;
 pub mod insert;
 pub mod join;
 pub mod merge;
+pub mod presentation;
 pub mod replace;
 pub mod reverse;
 pub mod split;

crates/fj-core/src/operations/presentation.rs

@@ -0,0 +1,21 @@
+//! Operations to control the presentation of objects
+
+use fj_interop::Color;
+
+use crate::objects::Region;
+
+/// Set the color of an object
+pub trait SetColor {
+    /// Set the color of the object
+    fn set_color(&self, color: impl Into<Color>) -> Self;
+}
+
+impl SetColor for Region {
+    fn set_color(&self, color: impl Into<Color>) -> Self {
+        Region::new(
+            self.exterior().clone(),
+            self.interiors().into_iter().cloned(),
+            Some(color.into()),
+        )
+    }
+}

models/color/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "color"
+version = "0.1.0"
+edition = "2021"
+
+
+[dependencies.cuboid]
+path = "../cuboid"
+
+[dependencies.fj]
+path = "../../crates/fj"

models/color/src/lib.rs

@@ -0,0 +1,28 @@
+use fj::core::{
+    objects::Solid,
+    operations::{
+        insert::Insert,
+        presentation::SetColor,
+        update::{UpdateFace, UpdateShell, UpdateSolid},
+    },
+    services::Services,
+    storage::Handle,
+};
+
+pub fn model(services: &mut Services) -> Handle<Solid> {
+    let size = 1.;
+    let cuboid = cuboid::model([size, size, size], services);
+
+    cuboid
+        .update_shell(cuboid.shells().only(), |shell| {
+            shell
+                .update_face(shell.faces().first(), |face| {
+                    face.update_region(|region| {
+                        region.set_color([0., 1., 0.]).insert(services)
+                    })
+                    .insert(services)
+                })
+                .insert(services)
+        })
+        .insert(services)
+}

models/color/src/main.rs

@@ -0,0 +1,8 @@
+use fj::{core::services::Services, handle_model};
+
+fn main() -> fj::Result {
+    let mut services = Services::new();
+    let model = color::model(&mut services);
+    handle_model(model, services)?;
+    Ok(())
+}