fix triangulator do not actually do delaunay

iTriangle/src/advanced/delaunay.rs

@@ -18,6 +18,16 @@ pub struct IntDelaunay {
     pub points: Vec<IntPoint>,
 }
 
+impl IntDelaunay {
+    #[inline]
+    pub(crate) fn into_raw(self) -> RawIntTriangulation {
+        RawIntTriangulation {
+            triangles: self.triangles,
+            points: self.points,
+        }
+    }
+}
+
 impl RawIntTriangulation {
     /// Converts an int triangle mesh into a Delaunay triangulation by applying edge flips.
     ///
@@ -28,12 +38,24 @@ impl RawIntTriangulation {
     /// A new [`IntDelaunay`] structure with updated triangle connectivity.
     #[inline]
     pub fn into_delaunay(self) -> IntDelaunay {
+        let mut buffer = DelaunayBuffer::new();
+        self.into_delaunay_with_buffer(&mut buffer)
+    }
+
+    /// Converts an int triangle mesh into a Delaunay triangulation by applying edge flips.
+    ///
+    /// Uses the provided scratch buffer to avoid repeated allocations across calls.
+    ///
+    /// # Returns
+    /// A new [`IntDelaunay`] structure with updated triangle connectivity.
+    #[inline]
+    pub fn into_delaunay_with_buffer(self, buffer: &mut DelaunayBuffer) -> IntDelaunay {
         let mut delaunay = IntDelaunay {
             triangles: self.triangles,
             points: self.points,
         };
 
-        delaunay.triangles.build();
+        delaunay.triangles.build_with_buffer(buffer);
 
         delaunay
     }

iTriangle/src/float/delaunay.rs

@@ -1,3 +1,4 @@
+use crate::advanced::buffer::DelaunayBuffer;
 use crate::advanced::delaunay::IntDelaunay;
 use crate::float::triangulation::{RawTriangulation, Triangulation};
 use crate::int::triangulation::IndexType;
@@ -18,8 +19,14 @@ pub struct Delaunay<P: FloatPointCompatible> {
 impl<P: FloatPointCompatible> RawTriangulation<P> {
     #[inline]
     pub fn into_delaunay(self) -> Delaunay<P> {
+        let mut buffer = DelaunayBuffer::new();
+        self.into_delaunay_with_buffer(&mut buffer)
+    }
+
+    #[inline]
+    pub fn into_delaunay_with_buffer(self, buffer: &mut DelaunayBuffer) -> Delaunay<P> {
         Delaunay {
-            delaunay: self.raw.into_delaunay(),
+            delaunay: self.raw.into_delaunay_with_buffer(buffer),
             adapter: self.adapter,
         }
     }

iTriangle/src/int/triangulation.rs

@@ -1,3 +1,4 @@
+use crate::advanced::delaunay::IntDelaunay;
 use crate::geom::triangle::IntTriangle;
 use alloc::vec::Vec;
 use i_overlay::i_float::int::point::IntPoint;
@@ -200,6 +201,16 @@ impl<I: IndexType> IntTriangulation<I> {
             .triangles
             .feed_indices(triangulation.points.len(), &mut self.indices);
     }
+
+    #[inline]
+    pub fn fill_with_delaunay(&mut self, delaunay: &IntDelaunay) {
+        self.points.clear();
+        self.points.extend_from_slice(&delaunay.points);
+
+        delaunay
+            .triangles
+            .feed_indices(delaunay.points.len(), &mut self.indices);
+    }
 }
 
 pub(crate) trait IndicesBuilder {

iTriangle/src/int/triangulator.rs

@@ -1,3 +1,4 @@
+use crate::advanced::buffer::DelaunayBuffer;
 use crate::int::earcut::earcut_64::Earcut64;
 use crate::int::monotone::triangulator::MonotoneTriangulator;
 use crate::int::triangulation::{IndexType, IntTriangulation, RawIntTriangulation};
@@ -17,6 +18,7 @@ pub struct IntTriangulator<I> {
     triangulator: MonotoneTriangulator,
     shapes_buffer: Option<IntTriangulation<I>>,
     raw_buffer: Option<RawIntTriangulation>,
+    delaunay_buffer: DelaunayBuffer,
 }
 
 impl<I: IndexType> IntTriangulator<I> {
@@ -30,6 +32,7 @@ impl<I: IndexType> IntTriangulator<I> {
             triangulator: MonotoneTriangulator::default(),
             raw_buffer: None,
             shapes_buffer: None,
+            delaunay_buffer: DelaunayBuffer::default(),
         }
     }
 }
@@ -137,8 +140,9 @@ impl<I: IndexType> IntTriangulator<I> {
                 self.triangulator
                     .contour_into_net_triangulation(contour, None, &mut raw);
             }
-            triangulation.fill_with_raw(&raw);
-            self.raw_buffer = Some(raw);
+            let delaunay = raw.into_delaunay_with_buffer(&mut self.delaunay_buffer);
+            triangulation.fill_with_delaunay(&delaunay);
+            self.raw_buffer = Some(delaunay.into_raw());
         } else if self.earcut && contour.is_earcut_compatible() {
             contour.earcut_flat_triangulate_into(triangulation);
         } else {
@@ -169,8 +173,9 @@ impl<I: IndexType> IntTriangulator<I> {
             let mut raw = self.raw_buffer.take().unwrap_or_default();
             self.triangulator
                 .shape_into_net_triangulation(shape, None, &mut raw);
-            triangulation.fill_with_raw(&raw);
-            self.raw_buffer = Some(raw);
+            let delaunay = raw.into_delaunay_with_buffer(&mut self.delaunay_buffer);
+            triangulation.fill_with_delaunay(&delaunay);
+            self.raw_buffer = Some(delaunay.into_raw());
         } else {
             self.triangulator
                 .shape_into_flat_triangulation(shape, triangulation);
@@ -236,9 +241,9 @@ impl<I: IndexType> IntTriangulator<I> {
                 self.triangulator
                     .flat_into_net_triangulation(flat, &mut raw);
             }
-
-            triangulation.fill_with_raw(&raw);
-            self.raw_buffer = Some(raw);
+            let delaunay = raw.into_delaunay_with_buffer(&mut self.delaunay_buffer);
+            triangulation.fill_with_delaunay(&delaunay);
+            self.raw_buffer = Some(delaunay.into_raw());
         } else if self.earcut && flat.is_earcut_compatible() {
             flat.as_first_contour()
                 .earcut_flat_triangulate_into(triangulation);