Move ShapeProcessor to fj-operations

It can't stay in `fj-app`, as the export code (which I intend to move
into its own crate) depends on it. I think `fj-operations` is a good
place for it, as the code that's already there has practically the same
dependencies as `ShapeProcessor`.

fj-app/src/main.rs

@@ -10,10 +10,7 @@ use std::time::Instant;
 
 use anyhow::anyhow;
 use fj_host::{Model, Parameters};
-use fj_interop::{debug::DebugInfo, mesh::Mesh};
+use fj_operations::shape_processor::ShapeProcessor;
-use fj_kernel::algorithms::{triangulate, Tolerance};
-use fj_math::{Aabb, Point, Scalar};
-use fj_operations::ToShape as _;
 use futures::executor::block_on;
 use tracing::{trace, warn};
 use tracing_subscriber::fmt::format;
@@ -224,50 +221,3 @@ fn main() -> anyhow::Result<()> {
         }
     });
 }
-
-struct ShapeProcessor {
-    tolerance: Option<Tolerance>,
-}
-
-impl ShapeProcessor {
-    fn process(&self, shape: &fj::Shape) -> ProcessedShape {
-        let aabb = shape.bounding_volume();
-
-        let tolerance = match self.tolerance {
-            None => {
-                // Compute a reasonable default for the tolerance value. To do
-                // this, we just 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 {
-                    if extent > Scalar::ZERO && extent < min_extent {
-                        min_extent = extent;
-                    }
-                }
-
-                let tolerance = min_extent / Scalar::from_f64(1000.);
-                Tolerance::from_scalar(tolerance).unwrap()
-            }
-            Some(user_defined_tolerance) => user_defined_tolerance,
-        };
-
-        let mut debug_info = DebugInfo::new();
-        let mesh = triangulate(
-            shape.to_shape(tolerance, &mut debug_info),
-            tolerance,
-            &mut debug_info,
-        );
-
-        ProcessedShape {
-            aabb,
-            mesh,
-            debug_info,
-        }
-    }
-}
-
-struct ProcessedShape {
-    aabb: Aabb<3>,
-    mesh: Mesh<Point<3>>,
-    debug_info: DebugInfo,
-}

fj-operations/src/lib.rs

@@ -6,6 +6,8 @@
 
 #![deny(missing_docs)]
 
+pub mod shape_processor;
+
 mod circle;
 mod difference_2d;
 mod group;

fj-operations/src/shape_processor.rs

@@ -0,0 +1,65 @@
+//! API for processing shapes
+
+use fj_interop::{debug::DebugInfo, mesh::Mesh};
+use fj_kernel::algorithms::{triangulate, Tolerance};
+use fj_math::{Aabb, Point, Scalar};
+
+use crate::ToShape as _;
+
+/// Processes an [`fj::Shape`] into a [`ProcessedShape`]
+pub struct ShapeProcessor {
+    /// The tolerance value used for creating the triangle mesh
+    pub tolerance: Option<Tolerance>,
+}
+
+impl ShapeProcessor {
+    /// Process an [`fj::Shape`] into [`ProcessedShape`]
+    pub fn process(&self, shape: &fj::Shape) -> ProcessedShape {
+        let aabb = shape.bounding_volume();
+
+        let tolerance = match self.tolerance {
+            None => {
+                // Compute a reasonable default for the tolerance value. To do
+                // this, we just 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 {
+                    if extent > Scalar::ZERO && extent < min_extent {
+                        min_extent = extent;
+                    }
+                }
+
+                let tolerance = min_extent / Scalar::from_f64(1000.);
+                Tolerance::from_scalar(tolerance).unwrap()
+            }
+            Some(user_defined_tolerance) => user_defined_tolerance,
+        };
+
+        let mut debug_info = DebugInfo::new();
+        let mesh = triangulate(
+            shape.to_shape(tolerance, &mut debug_info),
+            tolerance,
+            &mut debug_info,
+        );
+
+        ProcessedShape {
+            aabb,
+            mesh,
+            debug_info,
+        }
+    }
+}
+
+/// A processed shape
+///
+/// Created by [`ShapeProcessor::process`].
+pub struct ProcessedShape {
+    /// The axis-aligned bounding box of the shape
+    pub aabb: Aabb<3>,
+
+    /// The triangle mesh that approximates the original shape
+    pub mesh: Mesh<Point<3>>,
+
+    /// The debug info generated while processing the shape
+    pub debug_info: DebugInfo,
+}