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# Source code for silx.gui.plot3d.items.clipplane

    # /*##########################################################################
    #
    # Copyright (c) 2017-2018 European Synchrotron Radiation Facility
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    # The above copyright notice and this permission notice shall be included in
    # all copies or substantial portions of the Software.
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    # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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    """This module provides a scene clip plane class.
    """

    __authors__ = ["T. Vincent"]
    __license__ = "MIT"
    __date__ = "15/11/2017"

    import numpy

    from ..scene import primitives, utils

    from ._pick import PickingResult
    from .core import Item3D
    from .mixins import PlaneMixIn

    class ClipPlane(Item3D, PlaneMixIn):
        """Represents a clipping plane that clips following items within the group.

        For now only on clip plane is allowed at once in a scene.
        """

        def __init__(self, parent=None):
            plane = primitives.ClipPlane()
            Item3D.__init__(self, parent=parent, primitive=plane)
            PlaneMixIn.__init__(self)
            self._setPlane(plane)

        def __pickPreProcessing(self, context):
            """Common processing for :meth:`_pickPostProcess` and :meth:`_pickFull`

            :param PickContext context: Current picking context
            :return None or (bounds, intersection points, rayObject)
            """
            plane = self._getPlane()
            planeParent = plane.parent
            if planeParent is None:
                return None

            rayObject = context.getPickingSegment(frame=plane)
            if rayObject is None:
                return None

            bounds = planeParent.bounds(dataBounds=True)
            rayClip = utils.clipSegmentToBounds(rayObject[:, :3], bounds)
            if rayClip is None:
                return None  # Ray is outside parent's bounding box

            points = utils.segmentPlaneIntersect(
                rayObject[0, :3],
                rayObject[1, :3],
                planeNorm=self.getNormal(),
                planePt=self.getPoint(),
            )

            # A single intersection inside bounding box
            picked = (
                len(points) == 1
                and numpy.all(bounds[0] <= points[0])
                and numpy.all(points[0] <= bounds[1])
            )

            return picked, points, rayObject

        def _pick(self, context):
            # Perform picking before modifying context
            result = super(ClipPlane, self)._pick(context)

            # Modify context if needed
            if self.isVisible() and context.isEnabled():
                info = self.__pickPreProcessing(context)
                if info is not None:
                    picked, points, rayObject = info
                    plane = self._getPlane()

                    if picked:  # A single intersection inside bounding box
                        # Clip NDC z range for following brother items
                        ndcIntersect = plane.objectToNDCTransform.transformPoint(
                            points[0], perspectiveDivide=True
                        )
                        ndcNormal = plane.objectToNDCTransform.transformNormal(
                            self.getNormal()
                        )
                        if ndcNormal[2] < 0:
                            context.setNDCZRange(-1.0, ndcIntersect[2])
                        else:
                            context.setNDCZRange(ndcIntersect[2], 1.0)

                    else:
                        # TODO check this might not be correct
                        rayObject[:, 3] = 1.0  # Make sure 4h coordinate is one
                        if numpy.sum(rayObject[0] * self.getParameters()) < 0.0:
                            # Disable picking for remaining brothers
                            context.setEnabled(False)

            return result

        def _pickFastCheck(self, context):
            return True

        def _pickFull(self, context):
            """Perform picking in this item at given widget position.

            :param PickContext context: Current picking context
            :return: Object holding the results or None
            :rtype: Union[None,PickingResult]
            """
            info = self.__pickPreProcessing(context)
            if info is not None:
                picked, points, _ = info

                if picked:
                    return PickingResult(self, positions=[points[0]])

            return None