elalish · elalish · Jun 27, 2024 · Jun 16, 2024 · Jun 18, 2024 · Jun 18, 2024
diff --git a/bindings/c/include/manifoldc.h b/bindings/c/include/manifoldc.h
@@ -105,9 +105,8 @@ ManifoldManifold *manifold_trim_by_plane(void *mem, ManifoldManifold *m,
 
 // 3D to 2D
 
-ManifoldCrossSection *manifold_slice(void *mem, ManifoldManifold *m,
-                                     float height);
-ManifoldCrossSection *manifold_project(void *mem, ManifoldManifold *m);
+ManifoldPolygons *manifold_slice(void *mem, ManifoldManifold *m, float height);
+ManifoldPolygons *manifold_project(void *mem, ManifoldManifold *m);
 
 // Convex Hulls
 
@@ -157,11 +156,11 @@ ManifoldManifold *manifold_of_meshgl(void *mem, ManifoldMeshGL *mesh);
 ManifoldManifold *manifold_smooth(void *mem, ManifoldMeshGL *mesh,
                                   int *half_edges, float *smoothness,
                                   int n_idxs);
-ManifoldManifold *manifold_extrude(void *mem, ManifoldCrossSection *cs,
+ManifoldManifold *manifold_extrude(void *mem, ManifoldPolygons *cs,
                                    float height, int slices,
                                    float twist_degrees, float scale_x,
                                    float scale_y);
-ManifoldManifold *manifold_revolve(void *mem, ManifoldCrossSection *cs,
+ManifoldManifold *manifold_revolve(void *mem, ManifoldPolygons *cs,
                                    int circular_segments);
 ManifoldManifold *manifold_compose(void *mem, ManifoldManifoldVec *ms);
 ManifoldManifoldVec *manifold_decompose(void *mem, ManifoldManifold *m);

diff --git a/bindings/c/manifoldc.cpp b/bindings/c/manifoldc.cpp
@@ -192,15 +192,14 @@ ManifoldManifold *manifold_trim_by_plane(void *mem, ManifoldManifold *m,
   return to_c(new (mem) Manifold(trimmed));
 }
 
-ManifoldCrossSection *manifold_slice(void *mem, ManifoldManifold *m,
-                                     float height) {
+ManifoldPolygons *manifold_slice(void *mem, ManifoldManifold *m, float height) {
   auto poly = from_c(m)->Slice(height);
-  return to_c(new (mem) CrossSection(poly));
+  return to_c(new (mem) Polygons(poly));
 }
 
-ManifoldCrossSection *manifold_project(void *mem, ManifoldManifold *m) {
+ManifoldPolygons *manifold_project(void *mem, ManifoldManifold *m) {
   auto poly = from_c(m)->Project();
-  return to_c(new (mem) CrossSection(poly));
+  return to_c(new (mem) Polygons(poly));
 }
 
 ManifoldManifold *manifold_hull(void *mem, ManifoldManifold *m) {
@@ -382,7 +381,7 @@ ManifoldManifold *manifold_of_meshgl(void *mem, ManifoldMeshGL *mesh) {
   return to_c(new (mem) Manifold(m));
 }
 
-ManifoldManifold *manifold_extrude(void *mem, ManifoldCrossSection *cs,
+ManifoldManifold *manifold_extrude(void *mem, ManifoldPolygons *cs,
                                    float height, int slices,
                                    float twist_degrees, float scale_x,
                                    float scale_y) {
@@ -391,7 +390,7 @@ ManifoldManifold *manifold_extrude(void *mem, ManifoldCrossSection *cs,
   return to_c(new (mem) Manifold(m));
 }
 
-ManifoldManifold *manifold_revolve(void *mem, ManifoldCrossSection *cs,
+ManifoldManifold *manifold_revolve(void *mem, ManifoldPolygons *cs,
 
                                    int circular_segments) {
   auto m = Manifold::Revolve(*from_c(cs), circular_segments);

diff --git a/bindings/python/CMakeLists.txt b/bindings/python/CMakeLists.txt
@@ -20,7 +20,7 @@ nanobind_add_module(
   NB_STATIC STABLE_ABI LTO
   autogen_docstrings.inl
   manifold3d.cpp)
-target_link_libraries(manifold3d PRIVATE manifold sdf polygon)
+target_link_libraries(manifold3d PRIVATE manifold sdf polygon cross_section)
 target_compile_options(manifold3d PRIVATE ${MANIFOLD_FLAGS} -DMODULE_NAME=manifold3d)
 target_compile_features(manifold3d PUBLIC cxx_std_17)
 set_target_properties(manifold3d PROPERTIES OUTPUT_NAME "manifold3d")

diff --git a/bindings/python/manifold3d.cpp b/bindings/python/manifold3d.cpp
@@ -362,9 +362,18 @@ NB_MODULE(manifold3d, m) {
       .def("trim_by_plane", &Manifold::TrimByPlane, nb::arg("normal"),
            nb::arg("origin_offset"),
            manifold__trim_by_plane__normal__origin_offset)
-      .def("slice", &Manifold::Slice, nb::arg("height"),
-           manifold__slice__height)
-      .def("project", &Manifold::Project, manifold__project)
+      .def(
+          "slice",
+          [](const Manifold &self, float height) {
+            return CrossSection(self.Slice(height));
+          },
+          nb::arg("height"), manifold__slice__height)
+      .def(
+          "project",
+          [](const Manifold &self) {
+            return CrossSection(self.Project()).Simplify(self.Precision());
+          },
+          manifold__project)
       .def("status", &Manifold::Status, manifold__status)
       .def(
           "bounding_box",
@@ -402,14 +411,25 @@ NB_MODULE(manifold3d, m) {
       .def_static("cube", &Manifold::Cube, nb::arg("size") = glm::vec3{1, 1, 1},
                   nb::arg("center") = false, manifold__cube__size__center)
       .def_static(
-          "extrude", &Manifold::Extrude, nb::arg("crossSection"),
-          nb::arg("height"), nb::arg("n_divisions") = 0,
-          nb::arg("twist_degrees") = 0.0f,
+          "extrude",
+          [](const CrossSection &crossSection, float height, int nDivisions,
             float twistDegrees, glm::vec2 scaleTop) {
+            return Manifold::Extrude(crossSection.ToPolygons(), height,
+                                     nDivisions, twistDegrees, scaleTop);
+          },
+          nb::arg("crossSection"), nb::arg("height"),
+          nb::arg("n_divisions") = 0, nb::arg("twist_degrees") = 0.0f,
           nb::arg("scale_top") = std::make_tuple(1.0f, 1.0f),
           manifold__extrude__cross_section__height__n_divisions__twist_degrees__scale_top)
       .def_static(
-          "revolve", &Manifold::Revolve, nb::arg("crossSection"),
-          nb::arg("circular_segments") = 0, nb::arg("revolve_degrees") = 360.0,
+          "revolve",
+          [](const CrossSection &crossSection, int circularSegments,
+             float revolveDegrees) {
+            return Manifold::Revolve(crossSection.ToPolygons(),
+                                     circularSegments, revolveDegrees);
+          },
+          nb::arg("crossSection"), nb::arg("circular_segments") = 0,
+          nb::arg("revolve_degrees") = 360.0,
           manifold__revolve__cross_section__circular_segments__revolve_degrees)
       .def_static(
           "cylinder", &Manifold::Cylinder, nb::arg("height"),
@@ -688,13 +708,25 @@ NB_MODULE(manifold3d, m) {
                   cross_section__compose__cross_sections)
       .def("to_polygons", &CrossSection::ToPolygons, cross_section__to_polygons)
       .def(
-          "extrude", &Manifold::Extrude, nb::arg("height"),
-          nb::arg("n_divisions") = 0, nb::arg("twist_degrees") = 0.0f,
+          "extrude",
+          [](const CrossSection &self, float height, int nDivisions,
+             float twistDegrees, glm::vec2 scaleTop) {
+            return Manifold::Extrude(self.ToPolygons(), height, nDivisions,
+                                     twistDegrees, scaleTop);
+          },
+          nb::arg("height"), nb::arg("n_divisions") = 0,
+          nb::arg("twist_degrees") = 0.0f,
           nb::arg("scale_top") = std::make_tuple(1.0f, 1.0f),
           manifold__extrude__cross_section__height__n_divisions__twist_degrees__scale_top)
-      .def("revolve", &Manifold::Revolve, nb::arg("circular_segments") = 0,
-           nb::arg("revolve_degrees") = 360.0,
-           manifold__revolve__cross_section__circular_segments__revolve_degrees)
+      .def(
+          "revolve",
+          [](const CrossSection &self, int circularSegments,
+             float revolveDegrees) {
+            return Manifold::Revolve(self.ToPolygons(), circularSegments,
+                                     revolveDegrees);
+          },
+          nb::arg("circular_segments") = 0, nb::arg("revolve_degrees") = 360.0,
+          manifold__revolve__cross_section__circular_segments__revolve_degrees)
 
       .def_static("square", &CrossSection::Square, nb::arg("size"),
                   nb::arg("center") = false,

diff --git a/bindings/wasm/bindings.cpp b/bindings/wasm/bindings.cpp
@@ -139,7 +139,7 @@ EMSCRIPTEN_BINDINGS(whatever) {
       .function("_SplitByPlane", &man_js::SplitByPlane)
       .function("_TrimByPlane", &Manifold::TrimByPlane)
       .function("_Slice", &Manifold::Slice)
-      .function("project", &Manifold::Project)
+      .function("_Project", &Manifold::Project)
       .function("hull", select_overload<Manifold() const>(&Manifold::Hull))
       .function("_GetMeshJS", &js::GetMeshJS)
       .function("refine", &Manifold::Refine)

diff --git a/bindings/wasm/bindings.js b/bindings/wasm/bindings.js
@@ -165,14 +165,15 @@ Module.setup = function() {
       height, nDivisions = 0, twistDegrees = 0.0, scaleTop = [1.0, 1.0],
       center = false) {
     scaleTop = vararg2vec2([scaleTop]);
-    const man =
-        Module._Extrude(this, height, nDivisions, twistDegrees, scaleTop);
+    const man = Module._Extrude(
+        this._ToPolygons(), height, nDivisions, twistDegrees, scaleTop);
     return (center ? man.translate([0., 0., -height / 2.]) : man);
   };
 
   Module.CrossSection.prototype.revolve = function(
       circularSegments = 0, revolveDegrees = 360.0) {
-    return Module._Revolve(this, circularSegments, revolveDegrees);
+    return Module._Revolve(
+        this._ToPolygons(), circularSegments, revolveDegrees);
   };
 
   Module.CrossSection.prototype.add = function(other) {
@@ -283,7 +284,11 @@ Module.setup = function() {
   };
 
   Module.Manifold.prototype.slice = function(height = 0.) {
-    return this._Slice(height);
+    return Module.CrossSection(this._Slice(height));
+  };
+
+  Module.Manifold.prototype.project = function() {
+    return Module.CrossSection(this._Project()).simplify(this.precision());
   };
 
   Module.Manifold.prototype.split = function(manifold) {

diff --git a/samples/CMakeLists.txt b/samples/CMakeLists.txt
@@ -23,7 +23,7 @@ target_include_directories(samples
 )
 
 target_link_libraries(samples
-    PUBLIC manifold sdf
+    PUBLIC manifold sdf cross_section
 )
 
 target_compile_options(samples PRIVATE ${MANIFOLD_FLAGS})

diff --git a/samples/src/bracelet.cpp b/samples/src/bracelet.cpp
@@ -26,7 +26,7 @@ Manifold Base(float width, float radius, float decorRadius, float twistRadius,
 
   CrossSection circle =
       CrossSection::Circle(decorRadius, nDivision).Translate({twistRadius, 0});
-  Manifold decor = Manifold::Extrude(circle, width, nDivision, 180)
+  Manifold decor = Manifold::Extrude(circle.ToPolygons(), width, nDivision, 180)
                        .Scale({1.0f, 0.5f, 1.0f})
                        .Translate({0.0f, radius, 0.0f});
 

diff --git a/samples/src/knot.cpp b/samples/src/knot.cpp
@@ -50,7 +50,7 @@ Manifold TorusKnot(int p, int q, float majorRadius, float minorRadius,
       linearSegments > 2 ? linearSegments : n * q * majorRadius / threadRadius;
 
   CrossSection circle = CrossSection::Circle(1., n).Translate({2, 0});
-  Manifold knot = Manifold::Revolve(circle, m);
+  Manifold knot = Manifold::Revolve(circle.ToPolygons(), m);
 
   knot =
       knot.Warp([p, q, majorRadius, minorRadius, threadRadius](glm::vec3& v) {

diff --git a/src/manifold/CMakeLists.txt b/src/manifold/CMakeLists.txt
@@ -21,7 +21,7 @@ target_include_directories(${PROJECT_NAME} PUBLIC
     $<INSTALL_INTERFACE:include/${CMAKE_PROJECT_NAME}>
     $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>)
 target_link_libraries(${PROJECT_NAME}
-    PUBLIC utilities cross_section sdf
+    PUBLIC utilities sdf
     PRIVATE collider polygon ${MANIFOLD_INCLUDE} quickhull
 )
 

diff --git a/src/manifold/include/manifold.h b/src/manifold/include/manifold.h
@@ -16,7 +16,6 @@
 #include <functional>
 #include <memory>
 
-#include "cross_section.h"
 #include "public.h"
 #include "vec_view.h"
 
@@ -174,10 +173,10 @@ class Manifold {
                            float radiusHigh = -1.0f, int circularSegments = 0,
                            bool center = false);
   static Manifold Sphere(float radius, int circularSegments = 0);
-  static Manifold Extrude(const CrossSection& crossSection, float height,
+  static Manifold Extrude(const Polygons& crossSection, float height,
                           int nDivisions = 0, float twistDegrees = 0.0f,
                           glm::vec2 scaleTop = glm::vec2(1.0f));
-  static Manifold Revolve(const CrossSection& crossSection,
+  static Manifold Revolve(const Polygons& crossSection,
                           int circularSegments = 0,
                           float revolveDegrees = 360.0f);
   ///@}
@@ -279,8 +278,8 @@ class Manifold {
   /** @name 2D from 3D
    */
   ///@{
-  CrossSection Slice(float height = 0) const;
-  CrossSection Project() const;
+  Polygons Slice(float height = 0) const;
+  Polygons Project() const;
   ///@}
 
   /** @name Convex hull