IfcOpenShell/src/ifcopenshell-python/ifcopenshell/api/alignment/create_layout_segment.py

# IfcOpenShell - IFC toolkit and geometry engine
# Copyright (C) 2025 Thomas Krijnen <thomas@aecgeeks.com>
#
# This file is part of IfcOpenShell.
#
# IfcOpenShell is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 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
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.

import ifcopenshell
import ifcopenshell.api.alignment
import ifcopenshell.geom
from ifcopenshell import entity_instance
import math
from ifcopenshell import ifcopenshell_wrapper
import numpy as np

from ifcopenshell.api.alignment._add_segment_to_layout import _add_segment_to_layout


def create_layout_segment(
    file: ifcopenshell.file, layout: entity_instance, design_parameters: entity_instance
) -> np.array:
    """
    Creates a new IfcAlignmentSegment using the IfcAlignmentParameterSegment design parameters.
    The new segment is appended to the layout alignment and the corresponding IfcCurveSegment is created in the geometric representation

    :param layout: The layout to receive the new layout segment. This parameter is expected to be IfcAlignmentHorizontal, IfcAlignmentVertical or IfcAlignmentCant
    :param design_parameters: The parameters defining the segment. Expected to be the appropreate subclass of IfcAlignmentParameterSegment
    :return: 4x4 matrix at end of segment as np.array intended to be used as the start point geometry for the next segment.
    """
    expected_types = ["IfcAlignmentHorizontal", "IfcAlignmentVertical", "IfcAlignmentCant"]
    if not layout.is_a() in expected_types:
        raise TypeError(
            f"Expected entity type to be one of {[_ for _ in expected_types]}, instead received {layout.is_a()}"
        )

    if layout.is_a("IfcAlignmentHorizontal") and not design_parameters.is_a("IfcAlignmentHorizontalSegment"):
        raise TypeError("Expected design_parameters to be IfcAlignmentHorizontalSegment")
    elif layout.is_a("IfcAlignmentVertical") and not design_parameters.is_a("IfcAlignmentVerticalSegment"):
        raise TypeError("Expected design_parameters to be IfcAlignmentVerticalSegment")
    elif layout.is_a("IfcAlignmentCant") and not design_parameters.is_a("IfcAlignmentCantSegment"):
        raise TypeError("Expected design_parameters to be IfcAlignmentCantSegment")

    # create the segment and add it to the layout.
    segment = file.createIfcAlignmentSegment(GlobalId=ifcopenshell.guid.new(), DesignParameters=design_parameters)
    _add_segment_to_layout(file, layout, segment)  # adds to layout and geometric representation

    # compute the 4x4 matrix at the end of the segment so this information can be
    # returned and used when defining the next segment
    alignment = ifcopenshell.api.alignment.get_alignment(layout)
    curve = ifcopenshell.api.alignment.get_curve(alignment)

    if layout.is_a("IfcAlignmentHorizontal"):
        if curve.is_a("IfcGradientCurve"):
            curve = curve.BaseCurve
        elif curve.is_a("IfcSegmentedReferenceCurve"):
            curve = (
                curve.BaseCurve.BaseCurve
            )  # layout is horizontal and curve is segmented ref ... we want the curve's base curve
    elif layout.is_a("IfcAlignmentVertical"):
        if curve.is_a("IfcSegmentedReferenceCurve"):
            curve = curve.BaseCurve

    # the new segment is two from the end... the end segment is zero length
    curve_segment = curve.Segments[-2]

    settings = ifcopenshell.geom.settings()

    segment_fn = ifcopenshell_wrapper.map_shape(settings, curve_segment.wrapped_data)
    segment_evaluator = ifcopenshell_wrapper.function_item_evaluator(settings, segment_fn)
    e = segment_evaluator.evaluate(segment_fn.end())
    end = np.array(e)

    return end