option to write boolean operands to disk for debugging

src/ifcconvert/IfcConvert.cpp

@@ -218,6 +218,7 @@ int main(int argc, char** argv) {
 		("help,h", "display usage information")
 		("version", "display version information")
 		("verbose,v", po::value(&vcounter)->zero_tokens(), "more verbose log messages. Use twice (-vv) for debugging level.")
+		("debug,d", "write boolean operands to file in current directory for debugging purposes")
 		("quiet,q", "less status and progress output")
 #ifdef WITH_HDF5
 		("cache", "cache geometry creation. Use --cache-file to specify cache file path.")
@@ -793,6 +794,7 @@ int main(int argc, char** argv) {
 	settings.set(IfcGeom::IteratorSettings::EXCLUDE_SOLIDS_AND_SURFACES,  !include_model);
 	settings.set(IfcGeom::IteratorSettings::APPLY_LAYERSETS,              enable_layerset_slicing);
 	settings.set(IfcGeom::IteratorSettings::LAYERSET_FIRST,               layerset_first);
+	settings.set(IfcGeom::IteratorSettings::DEBUG_BOOLEAN,                vmap.count("debug"));
     settings.set(IfcGeom::IteratorSettings::NO_NORMALS, no_normals);
     settings.set(IfcGeom::IteratorSettings::GENERATE_UVS, generate_uvs);
 	settings.set(IfcGeom::IteratorSettings::EDGE_ARROWS, edge_arrows);

src/ifcgeom/IfcGeom.h

@@ -273,6 +273,9 @@ private:
 	double no_wire_intersection_check;
 	double no_wire_intersection_tolerance;
 	double precision_factor;
+	double boolean_debug_setting;
+
+	size_t operation_counter_ = 0;
 
 	// For stopping PlacementRelTo recursion in convert(const IfcSchema::IfcObjectPlacement* l, gp_Trsf& trsf)
 	const IfcParse::declaration* placement_rel_to_type_;

src/ifcgeom/IfcGeomFunctions.cpp

@@ -165,6 +165,7 @@
 #include "../ifcgeom/IfcGeomTree.h"
 
 #include <memory>
+#include <thread>
 
 #if OCC_VERSION_HEX < 0x60900
 #ifdef _MSC_VER
@@ -1487,6 +1488,9 @@ void IfcGeom::Kernel::setValue(GeomValue var, double value) {
 	case GV_NO_WIRE_INTERSECTION_TOLERANCE:
 		no_wire_intersection_tolerance = value;
 		break;
+	case GV_DEBUG_BOOLEAN:
+		boolean_debug_setting = value;
+		break;
 	default:
 		throw std::runtime_error("Invalid setting");
 	}
@@ -1522,6 +1526,8 @@ double IfcGeom::Kernel::getValue(GeomValue var) const {
 		return precision_factor;
 	case GV_NO_WIRE_INTERSECTION_TOLERANCE:
 		return no_wire_intersection_tolerance;
+	case GV_DEBUG_BOOLEAN:
+		return boolean_debug_setting;
 	}
 	throw std::runtime_error("Invalid setting");
 }
@@ -4260,6 +4266,15 @@ bool IfcGeom::Kernel::boolean_operation(const TopoDS_Shape& a, const TopoDS_Shap
 
 bool IfcGeom::Kernel::boolean_operation(const TopoDS_Shape& a_, const TopTools_ListOfShape& b__, BOPAlgo_Operation op, TopoDS_Shape& result, double fuzziness) {
 	
+	const bool debug = getValue(GV_DEBUG_BOOLEAN) > 0.;
+	std::string debug_identifier;
+	if (debug) {
+		std::stringstream ss;
+		ss << "bool-" << std::this_thread::get_id() << "-" << (operation_counter_++);
+		debug_identifier = ss.str();
+		Logger::Notice("Boolean debug identifier: " + debug_identifier);
+	}
+
 	if (fuzziness < 0.) {
 		fuzziness = getValue(GV_PRECISION) / 10.;
 	}
@@ -4314,8 +4329,22 @@ bool IfcGeom::Kernel::boolean_operation(const TopoDS_Shape& a_, const TopTools_L
 
 	const double fuzz = (std::min)(min_length_orig / 3., fuzziness);
 
+	Logger::Notice("Used fuzziness: " + std::to_string(fuzz));
+	
 	TopTools_ListOfShape s1s;
 	s1s.Append(copy_operand(a));
+
+	if (debug) {
+		TopTools_ListOfShape* lists[2] = { &s1s, &b };
+		static std::string operand_names[2] = { "a", "b" };
+		for (int i = 0; i < 2; ++i) {
+			TopTools_ListIteratorOfListOfShape it(*lists[i]);
+			for (int j = 0; it.More(); it.Next(), ++j) {
+				std::string fn = debug_identifier + "-" + operand_names[i] + "-" + std::to_string(j) + ".brep";
+				BRepTools::Write(it.Value(), fn.c_str());
+			}
+		}
+	}
 #if OCC_VERSION_HEX >= 0x70000
 	builder->SetNonDestructive(true);
 #endif

src/ifcgeom/IfcGeomIteratorImplementation.h

@@ -1167,6 +1167,12 @@ namespace IfcGeom {
 				: -1.0
 			);
 
+			kernel.setValue(IfcGeom::Kernel::GV_DEBUG_BOOLEAN,
+				settings.get(IteratorSettings::DEBUG_BOOLEAN)
+				? +1.0
+				: -1.0
+			);
+
 			if (settings.get(IteratorSettings::BUILDING_LOCAL_PLACEMENT)) {
 				if (settings.get(IteratorSettings::SITE_LOCAL_PLACEMENT)) {
 					Logger::Message(Logger::LOG_WARNING, "building-local-placement takes precedence over site-local-placement");

src/ifcgeom/IfcGeomIteratorSettings.h

@@ -111,8 +111,10 @@ namespace IfcGeom
 			/// Strictly use the tolerance from the IFC model. Typically this value is
 			/// increased 10-fold to have more reliable boolean subtraction results.
 			STRICT_TOLERANCE = 1 << 22,
+			/// Write boolean operands to file in current directory for debugging purposes
+			DEBUG_BOOLEAN = 1 << 23,
 			/// Number of different setting flags.
-			NUM_SETTINGS = 23,
+			NUM_SETTINGS = 24,
         };
 
         IteratorSettings()

src/ifcgeom_schema_agnostic/Kernel.h

@@ -76,6 +76,7 @@ namespace IfcGeom {
 			GV_NO_WIRE_INTERSECTION_CHECK,
 			GV_PRECISION_FACTOR,
 			GV_NO_WIRE_INTERSECTION_TOLERANCE,
+			GV_DEBUG_BOOLEAN
 		};
 
 		Kernel(IfcParse::IfcFile* file_ = 0);