Merge pull request #1050 from hannobraun/triangulate

Make triangulation more flexible

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

@@ -3,13 +3,10 @@
 //! Algorithmic code is collected in this module, to keep other modules focused
 //! on their respective purpose.
 
-mod triangulate;
-
 pub mod approx;
 pub mod intersect;
 pub mod reverse;
 pub mod sweep;
 pub mod transform;
+pub mod triangulate;
 pub mod validate;
-
-pub use self::triangulate::triangulate;

crates/fj-kernel/src/algorithms/triangulate/mod.rs

@@ -1,3 +1,5 @@
+//! Shape triangulation
+
 mod delaunay;
 mod polygon;
 
@@ -11,23 +13,64 @@ use self::{delaunay::TriangulationPoint, polygon::Polygon};
 use super::approx::{Approx, Tolerance};
 
 /// Triangulate a shape
-pub fn triangulate(
- faces: Vec<Face>,
- tolerance: Tolerance,
- debug_info: &mut DebugInfo,
-) -> Mesh<Point<3>> {
- let mut mesh = Mesh::new();
-
- for face in faces {
- if let Some(triangles) = face.triangles() {
+pub trait Triangulate: Sized {
+ /// Triangulate the shape
+ fn triangulate(
+ self,
+ tolerance: impl Into<Tolerance>,
+ debug_info: &mut DebugInfo,
+ ) -> Mesh<Point<3>> {
+ let mut mesh = Mesh::new();
+ self.triangulate_into_mesh(tolerance, &mut mesh, debug_info);
+ mesh
+ }
+
+ /// Triangulate a partial shape into the provided mesh
+ ///
+ /// This is a low-level method, intended for implementation of
+ /// `Triangulate`. Most callers should prefer [`Triangulate::triangulate`].
+ fn triangulate_into_mesh(
+ self,
+ tolerance: impl Into<Tolerance>,
+ mesh: &mut Mesh<Point<3>>,
+ debug_info: &mut DebugInfo,
+ );
+}
+
+impl<T> Triangulate for T
+where
+ T: IntoIterator<Item = Face>,
+{
+ fn triangulate_into_mesh(
+ self,
+ tolerance: impl Into<Tolerance>,
+ mesh: &mut Mesh<Point<3>>,
+ debug_info: &mut DebugInfo,
+ ) {
+ let tolerance = tolerance.into();
+
+ for face in self {
+ face.triangulate_into_mesh(tolerance, mesh, debug_info);
+ }
+ }
+}
+
+impl Triangulate for Face {
+ fn triangulate_into_mesh(
+ self,
+ tolerance: impl Into<Tolerance>,
+ mesh: &mut Mesh<Point<3>>,
+ debug_info: &mut DebugInfo,
+ ) {
+ if let Some(triangles) = self.triangles() {
  for &(triangle, color) in triangles {
  mesh.push_triangle(triangle, color);
  }
- continue;
+ return;
  }
 
- let surface = face.surface();
- let approx = face.approx(tolerance);
+ let surface = self.surface();
+ let approx = self.approx(tolerance.into());
 
  let points: Vec<_> = approx
  .points
@@ -62,11 +105,9 @@ pub fn triangulate(
 
  for triangle in triangles {
  let points = triangle.map(|point| point.point_global);
- mesh.push_triangle(points, face.color());
+ mesh.push_triangle(points, self.color());
  }
  }
-
- mesh
 }
 
 #[cfg(test)]
@@ -79,6 +120,8 @@ mod tests {
  objects::{Face, Surface},
  };
 
+ use super::Triangulate;
+
  #[test]
  fn simple() -> anyhow::Result<()> {
  let a = [0., 0.];
@@ -190,10 +233,6 @@ mod tests {
  let tolerance = Tolerance::from_scalar(Scalar::ONE)?;
 
  let mut debug_info = DebugInfo::new();
- Ok(super::triangulate(
- vec![face.into()],
- tolerance,
- &mut debug_info,
- ))
+ Ok(vec![face.into()].triangulate(tolerance, &mut debug_info))
  }
 }

crates/fj-operations/src/shape_processor.rs

@@ -3,7 +3,7 @@
 use fj_interop::{debug::DebugInfo, processed_shape::ProcessedShape};
 use fj_kernel::algorithms::{
  approx::{InvalidTolerance, Tolerance},
- triangulate,
+ triangulate::Triangulate,
  validate::{ValidationConfig, ValidationError},
 };
 use fj_math::Scalar;
@@ -42,7 +42,7 @@ impl ShapeProcessor {
  let config = ValidationConfig::default();
  let mut debug_info = DebugInfo::new();
  let shape = shape.compute_brep(&config, tolerance, &mut debug_info)?;
- let mesh = triangulate(shape.into_inner(), tolerance, &mut debug_info);
+ let mesh = shape.into_inner().triangulate(tolerance, &mut debug_info);
 
  Ok(ProcessedShape {
  aabb,