From e2dfdf1600352924e7dbb3f58c5e8d0bd93fa70d Mon Sep 17 00:00:00 2001
From: Tanner Collin <git@tannercollin.com>
Date: Tue, 17 Feb 2026 17:52:17 -0700
Subject: [PATCH] feat: Generate faces from closed sketch wires

Co-authored-by: aider (gemini/gemini-2.5-pro) <aider@aider.chat>
---
 src/ApplicationController.cpp |   3 +
 src/SketchFeature.cpp         | 104 ++++++++++++++++++++++++++++++++++
 src/SketchFeature.h           |   2 +
 3 files changed, 109 insertions(+)

diff --git a/src/ApplicationController.cpp b/src/ApplicationController.cpp
index 43ae3d9..787dac6 100644
--- a/src/ApplicationController.cpp
+++ b/src/ApplicationController.cpp
@@ -158,6 +158,9 @@ void ApplicationController::addCircle(const gp_Pnt& center, double radius)
 
 void ApplicationController::endSketch()
 {
+    if (m_activeSketch) {
+        m_activeSketch->buildShape();
+    }
     m_activeSketch = nullptr;
     setActiveTool(ToolType::None);
     emit sketchModeEnded();
diff --git a/src/SketchFeature.cpp b/src/SketchFeature.cpp
index eae6d17..a10c6dc 100644
--- a/src/SketchFeature.cpp
+++ b/src/SketchFeature.cpp
@@ -2,6 +2,17 @@
 #include "SketchObject.h"
 #include "SketchLine.h"
 #include "SketchRectangle.h"
+#include "SketchCircle.h"
+
+#include <BRepBuilderAPI_MakeEdge.hxx>
+#include <BRepBuilderAPI_MakeWire.hxx>
+#include <BRepBuilderAPI_MakeFace.hxx>
+#include <BRep_Builder.hxx>
+#include <TopoDS_Compound.hxx>
+#include <TopoDS.hxx>
+#include <gp_Circ.hxx>
+#include <gp_Ax2.hxx>
+#include <TopExp_Explorer.hxx>
 
 #include <QJsonArray>
 
@@ -35,6 +46,99 @@ const TopoDS_Shape& SketchFeature::shape() const
     return m_shape;
 }
 
+void SketchFeature::buildShape()
+{
+    m_shape.Nullify();
+    QList<TopoDS_Edge> lineEdges;
+    QList<TopoDS_Face> faces;
+
+    for (SketchObject* obj : m_objects) {
+        if (auto line = dynamic_cast<SketchLine*>(obj)) {
+            lineEdges.append(BRepBuilderAPI_MakeEdge(line->startPoint(), line->endPoint()).Edge());
+        } else if (auto rect = dynamic_cast<SketchRectangle*>(obj)) {
+            const gp_Pnt& c1 = rect->corner1();
+            const gp_Pnt& c2 = rect->corner2();
+            gp_Pnt other_corner1, other_corner2;
+
+            if (m_plane == SketchPlane::XY) {
+                other_corner1.SetCoord(c1.X(), c2.Y(), c1.Z());
+                other_corner2.SetCoord(c2.X(), c1.Y(), c1.Z());
+            } else if (m_plane == SketchPlane::XZ) {
+                other_corner1.SetCoord(c1.X(), c1.Y(), c2.Z());
+                other_corner2.SetCoord(c2.X(), c1.Y(), c1.Z());
+            } else { // YZ
+                other_corner1.SetCoord(c1.X(), c1.Y(), c2.Z());
+                other_corner2.SetCoord(c1.X(), c2.Y(), c1.Z());
+            }
+
+            TopoDS_Edge e1 = BRepBuilderAPI_MakeEdge(c1, other_corner1).Edge();
+            TopoDS_Edge e2 = BRepBuilderAPI_MakeEdge(other_corner1, c2).Edge();
+            TopoDS_Edge e3 = BRepBuilderAPI_MakeEdge(c2, other_corner2).Edge();
+            TopoDS_Edge e4 = BRepBuilderAPI_MakeEdge(other_corner2, c1).Edge();
+            BRepBuilderAPI_MakeWire wireBuilder(e1, e2, e3, e4);
+            if (wireBuilder.IsDone()) {
+                BRepBuilderAPI_MakeFace faceBuilder(wireBuilder.Wire());
+                if (faceBuilder.IsDone()) {
+                    faces.append(faceBuilder.Face());
+                }
+            }
+        } else if (auto circle = dynamic_cast<SketchCircle*>(obj)) {
+            const gp_Pnt& center = circle->center();
+            double radius = circle->radius();
+            gp_Dir normal;
+            switch (m_plane) {
+                case SketchPlane::XY: normal = gp::DZ(); break;
+                case SketchPlane::XZ: normal = gp::DY(); break;
+                case SketchPlane::YZ: normal = gp::DX(); break;
+            }
+            gp_Ax2 axis(center, normal);
+            gp_Circ circ(axis, radius);
+            TopoDS_Edge edge = BRepBuilderAPI_MakeEdge(circ).Edge();
+            BRepBuilderAPI_MakeWire wireBuilder(edge);
+            if(wireBuilder.IsDone()) {
+                BRepBuilderAPI_MakeFace faceBuilder(wireBuilder.Wire());
+                if (faceBuilder.IsDone()) {
+                    faces.append(faceBuilder.Face());
+                }
+            }
+        }
+    }
+
+    if (!lineEdges.isEmpty()) {
+        BRepBuilderAPI_MakeWire wireBuilder;
+        wireBuilder.Add(lineEdges);
+        if (wireBuilder.IsDone()) {
+            TopoDS_Shape wiresShape = wireBuilder.Shape();
+            TopExp_Explorer explorer(wiresShape, TopAbs_WIRE);
+            for (; explorer.More(); explorer.Next()) {
+                TopoDS_Wire wire = TopoDS::Wire(explorer.Current());
+                if (wire.Closed()) {
+                    BRepBuilderAPI_MakeFace faceBuilder(wire);
+                    if (faceBuilder.IsDone()) {
+                        faces.append(faceBuilder.Face());
+                    }
+                }
+            }
+        }
+    }
+
+    if (faces.isEmpty()) {
+        return;
+    }
+
+    if (faces.size() == 1) {
+        m_shape = faces.first();
+    } else {
+        TopoDS_Compound compound;
+        BRep_Builder builder;
+        builder.MakeCompound(compound);
+        for (const auto& face : faces) {
+            builder.Add(compound, face);
+        }
+        m_shape = compound;
+    }
+}
+
 void SketchFeature::addObject(SketchObject* object)
 {
     m_objects.append(object);
diff --git a/src/SketchFeature.h b/src/SketchFeature.h
index 7af7e29..881c8b7 100644
--- a/src/SketchFeature.h
+++ b/src/SketchFeature.h
@@ -26,6 +26,8 @@ public:
 
     const TopoDS_Shape& shape() const;
 
+    void buildShape();
+
     void addObject(SketchObject* object);
     const QList<SketchObject*>& objects() const;