Work on modularizing files

src/ifcgeom/kernels/opencascade/extrusion.cpp

@@ -0,0 +1,85 @@
+#include "OpenCascadeKernel.h"
+
+#include <BRepPrimAPI_MakePrism.hxx>
+
+using namespace ifcopenshell::geometry;
+using namespace ifcopenshell::geometry::kernels;
+
+bool OpenCascadeKernel::convert(const taxonomy::extrusion* extrusion, TopoDS_Shape& shape) {
+	const double& height = extrusion->depth;
+
+	if (height < precision_) {
+		Logger::Error("Non-positive extrusion height encountered for:", extrusion->instance);
+		return false;
+	}
+
+	TopoDS_Shape face;
+	if (!convert(&extrusion->basis, face)) {
+		return false;
+	}
+
+	/*
+	// @todo we need to decide whether the matrix is kept on the taxonomy node or
+	// move the TopoDS_Shape, but obviously not both.
+	gp_GTrsf gtrsf;
+	if (!convert(&extrusion->matrix, gtrsf)) {
+		Logger::Error("Unable to move extrusion");
+	}
+	auto trsf = gtrsf.Trsf();
+	*/
+
+	const auto& fs = extrusion->direction.ccomponents();
+	gp_Dir dir(fs(0), fs(1), fs(2));
+
+	shape.Nullify();
+
+	if (face.ShapeType() == TopAbs_COMPOUND) {
+
+		// For compounds (most likely the result of a IfcCompositeProfileDef) 
+		// create a compound solid shape.
+
+		TopExp_Explorer exp(face, TopAbs_FACE);
+
+		TopoDS_CompSolid compound;
+		BRep_Builder builder;
+		builder.MakeCompSolid(compound);
+
+		int num_faces_extruded = 0;
+		for (; exp.More(); exp.Next(), ++num_faces_extruded) {
+			builder.Add(compound, BRepPrimAPI_MakePrism(exp.Current(), height*dir));
+		}
+
+		if (num_faces_extruded) {
+			shape = compound;
+		}
+
+	}
+
+	if (shape.IsNull()) {
+		shape = BRepPrimAPI_MakePrism(face, height*dir);
+	}
+
+	/*
+	if (!shape.IsNull()) {
+		// IfcSweptAreaSolid.Position (trsf) is an IfcAxis2Placement3D
+		// and therefore has a unit scale factor
+		shape.Move(trsf);
+	}
+	*/
+
+	return !shape.IsNull();
+}
+
+bool OpenCascadeKernel::convert_impl(const taxonomy::extrusion* extrusion, ifcopenshell::geometry::ConversionResults& results) {
+	TopoDS_Shape shape;
+	if (!convert(extrusion, shape)) {
+		return false;
+	}
+	results.emplace_back(ConversionResult(
+		extrusion->instance->data().id(),
+		extrusion->matrix,
+		new OpenCascadeShape(shape),
+		extrusion->surface_style
+	));
+	return true;
+}