Class RateRepresentationPredicate

code/AssetLib/IFC/IFCLoader.cpp:462–520

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// ------------------------------------------------------------------------------------------------
struct RateRepresentationPredicate {
    int Rate(const Schema_2x3::IfcRepresentation *r) const {
        // the smaller, the better

        if (!r->RepresentationIdentifier) {
            // neutral choice if no extra information is specified
            return 0;
        }

        const std::string &name = r->RepresentationIdentifier.Get();
        if (name == "MappedRepresentation") {
            if (!r->Items.empty()) {
                // take the first item and base our choice on it
                const Schema_2x3::IfcMappedItem *const m = r->Items.front()->ToPtr<Schema_2x3::IfcMappedItem>();
                if (m) {
                    return Rate(m->MappingSource->MappedRepresentation);
                }
            }
            return 100;
        }

        return Rate(name);
    }

    int Rate(const std::string &r) const {
        if (r == "SolidModel") {
            return -3;
        }

        // give strong preference to extruded geometry.
        if (r == "SweptSolid") {
            return -10;
        }

        if (r == "Clipping") {
            return -5;
        }

        // 'Brep' is difficult to get right due to possible voids in the
        // polygon boundaries, so take it only if we are forced to (i.e.
        // if the only alternative is (non-clipping) boolean operations,
        // which are not supported at all).
        if (r == "Brep") {
            return -2;
        }

        // Curves, bounding boxes - those will most likely not be loaded
        // as we can't make any use out of this data. So consider them
        // last.
        if (r == "BoundingBox" || r == "Curve2D") {
            return 100;
        }
        return 0;
    }

    bool operator()(const Schema_2x3::IfcRepresentation *a, const Schema_2x3::IfcRepresentation *b) const {
        return Rate(a) < Rate(b);
    }