First rough draft of alignment-based IfcFixedReferenceSweptAreaSolid

src/ifcgeom/mapping/IfcFixedReferenceSweptAreaSolid.cpp

@@ -0,0 +1,87 @@
+/********************************************************************************
+ *                                                                              *
+ * This file is part of IfcOpenShell.                                           *
+ *                                                                              *
+ * IfcOpenShell is free software: you can redistribute it and/or modify         *
+ * it under the terms of the Lesser GNU General Public License as published by  *
+ * the Free Software Foundation, either version 3.0 of the License, or          *
+ * (at your option) any later version.                                          *
+ *                                                                              *
+ * IfcOpenShell is distributed in the hope that it will be useful,              *
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of               *
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                 *
+ * Lesser GNU General Public License for more details.                          *
+ *                                                                              *
+ * You should have received a copy of the Lesser GNU General Public License     *
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.         *
+ *                                                                              *
+ ********************************************************************************/
+
+#include "mapping.h"
+#define mapping POSTFIX_SCHEMA(mapping)
+using namespace ifcopenshell::geometry;
+
+#ifdef SCHEMA_HAS_IfcFixedReferenceSweptAreaSolid
+
+taxonomy::ptr mapping::map_impl(const IfcSchema::IfcFixedReferenceSweptAreaSolid* inst) {
+	auto dir = map(inst->Directrix());
+	auto ref = taxonomy::cast<taxonomy::direction3>(map(inst->FixedReference()));
+	auto profile = taxonomy::cast<taxonomy::face>(map(inst->SweptArea()));
+
+	auto loft = taxonomy::make<taxonomy::loft>();
+	// @todo intialize as default
+	loft->axis = nullptr;
+
+	// @todo currently only the case is handled where directrix returns a piecewise_function
+	if (auto pwf = taxonomy::dcast<taxonomy::piecewise_function>(dir)) {
+		double start = 0;
+		double end = pwf->length();
+#ifdef SCHEMA_HAS_IfcDirectrixCurveSweptAreaSolid
+		// IfcDirectrixCurveSweptAreaSolid introduced in 4.3 changed attribute type
+		// from optional IfcParamValue to optional IfcCurveMeasureSelect.
+		// Invocation of mapping on pre-4.3 models can never result in a piecewise_function.
+		if (inst->StartParam()) { // && inst->StartParam()->as<IfcSchema::IfcLengthMeasure>()) {
+			double s = *inst->StartParam()->as<IfcSchema::IfcLengthMeasure>();
+			if (s > start) {
+				start = s;
+			}
+		}
+		if (inst->EndParam()) { // && inst->EndParam()->as<IfcSchema::IfcLengthMeasure>()) {
+			double e = *inst->EndParam()->as<IfcSchema::IfcLengthMeasure>();
+			if (e < end) {
+				end = e;
+			}
+		}
+#endif
+		auto len = end - start;
+		auto nsteps = (size_t)ceil(len);
+		for (size_t i = 0; i <= nsteps; ++i) {
+			auto m4 = pwf->evaluate(start + len / nsteps * i);
+			std::stringstream ss;
+			ss << m4;
+			auto s = ss.str();
+			std::wcout << s.c_str() << std::endl;
+
+			Eigen::Vector3d tangent = m4.col(0).head<3>().normalized();
+			Eigen::Vector3d proj = (ref->components() - tangent * tangent.dot(ref->components()));
+			proj.normalize();
+			auto ref = proj.cross(tangent);
+			auto pos = m4.col(3).head<3>();
+
+			Eigen::Matrix4d m4b = Eigen::Matrix4d::Identity();
+			m4b.col(0).head<3>() = ref;
+			m4b.col(1).head<3>() = proj;
+			m4b.col(2).head<3>() = tangent;
+			m4b.col(3).head<3>() = pos;
+
+			// @todo taxonomy::clone() does not actually clone. That's really confusing.
+			// loft->children.push_back(taxonomy::clone(profile));
+			loft->children.push_back(taxonomy::face::ptr(profile->clone_()));
+			loft->children.back()->matrix = taxonomy::make<taxonomy::matrix4>(m4b);
+		}
+	}
+
+	return loft;
+}
+
+#endif