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# Source code for silx.gui.plot3d.scene.interaction

    # /*##########################################################################
    #
    # Copyright (c) 2015-2023 European Synchrotron Radiation Facility
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    # 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 interaction to plug on the scene graph."""

    __authors__ = ["T. Vincent"]
    __license__ = "MIT"
    __date__ = "25/07/2016"

    import logging
    import numpy

    from silx.gui import qt
    from silx.gui.plot.Interaction import (
        StateMachine,
        State,
        LEFT_BTN,
        RIGHT_BTN,
    )  # , MIDDLE_BTN

    from . import transform

    _logger = logging.getLogger(__name__)

    class ClickOrDrag(StateMachine):
        """Click or drag interaction for a given button."""

        # TODO: merge this class with silx.gui.plot.Interaction.ClickOrDrag

        DRAG_THRESHOLD_SQUARE_DIST = 5**2

        class Idle(State):
            def onPress(self, x, y, btn):
                if btn == self.machine.button:
                    self.goto("clickOrDrag", x, y)
                    return True

        class ClickOrDrag(State):

            def enterState(self, x, y):
                self.initPos = x, y

            def onMove(self, x, y):
                dx = (x - self.initPos[0]) ** 2
                dy = (y - self.initPos[1]) ** 2
                if (dx**2 + dy**2) >= self.machine.DRAG_THRESHOLD_SQUARE_DIST:
                    self.goto("drag", self.initPos, (x, y))

            def onRelease(self, x, y, btn):
                if btn == self.machine.button:
                    self.machine.click(x, y)
                    self.goto("idle")

        class Drag(State):

            def enterState(self, initPos, curPos):
                self.initPos = initPos
                self.machine.beginDrag(*initPos)
                self.machine.drag(*curPos)

            def onMove(self, x, y):
                self.machine.drag(x, y)

            def onRelease(self, x, y, btn):
                if btn == self.machine.button:
                    self.machine.endDrag(self.initPos, (x, y))
                    self.goto("idle")

        def __init__(self, button=LEFT_BTN):
            self.button = button
            states = {
                "idle": ClickOrDrag.Idle,
                "clickOrDrag": ClickOrDrag.ClickOrDrag,
                "drag": ClickOrDrag.Drag,
            }
            super(ClickOrDrag, self).__init__(states, "idle")

        def click(self, x, y):
            """Called upon a left or right button click.
            To override in a subclass.
            """
            pass

        def beginDrag(self, x, y):
            """Called at the beginning of a drag gesture with left button
            pressed.
            To override in a subclass.
            """
            pass

        def drag(self, x, y):
            """Called on mouse moved during a drag gesture.
            To override in a subclass.
            """
            pass

        def endDrag(self, x, y):
            """Called at the end of a drag gesture when the left button is
            released.
            To override in a subclass.
            """
            pass

    class CameraSelectRotate(ClickOrDrag):
        """Camera rotation using an arcball-like interaction."""

        def __init__(
            self, viewport, orbitAroundCenter=True, button=RIGHT_BTN, selectCB=None
        ):
            self._viewport = viewport
            self._orbitAroundCenter = orbitAroundCenter
            self._selectCB = selectCB
            self._reset()
            super(CameraSelectRotate, self).__init__(button)

        def _reset(self):
            self._origin, self._center = None, None
            self._startExtrinsic = None

        def click(self, x, y):
            if self._selectCB is not None:
                ndcZ = self._viewport._pickNdcZGL(x, y)
                position = self._viewport._getXZYGL(x, y)
                # This assume no object lie on the far plane
                # Alternative, change the depth range so that far is < 1
                if ndcZ != 1.0 and position is not None:
                    self._selectCB((x, y, ndcZ), position)

        def beginDrag(self, x, y):
            centerPos = None
            if not self._orbitAroundCenter:
                # Try to use picked object position as center of rotation
                ndcZ = self._viewport._pickNdcZGL(x, y)
                if ndcZ != 1.0:
                    # Hit an object, use picked point as center
                    centerPos = self._viewport._getXZYGL(x, y)  # Can return None

            if centerPos is None:
                # Not using picked position, use scene center
                bounds = self._viewport.scene.bounds(transformed=True)
                centerPos = 0.5 * (bounds[0] + bounds[1])

            self._center = transform.Translate(*centerPos)
            self._origin = x, y
            self._startExtrinsic = self._viewport.camera.extrinsic.copy()

        def drag(self, x, y):
            if self._center is None:
                return

            dx, dy = self._origin[0] - x, self._origin[1] - y

            if dx == 0 and dy == 0:
                direction = self._startExtrinsic.direction
                up = self._startExtrinsic.up
                position = self._startExtrinsic.position
            else:
                minsize = min(self._viewport.size)
                distance = numpy.sqrt(dx**2 + dy**2)
                angle = distance / minsize * numpy.pi

                # Take care of y inversion
                direction = dx * self._startExtrinsic.side - dy * self._startExtrinsic.up
                direction /= numpy.linalg.norm(direction)
                axis = numpy.cross(direction, self._startExtrinsic.direction)
                axis /= numpy.linalg.norm(axis)

                # Orbit start camera with current angle and axis
                # Rotate viewing direction
                rotation = transform.Rotate(numpy.degrees(angle), *axis)
                direction = rotation.transformDir(self._startExtrinsic.direction)
                up = rotation.transformDir(self._startExtrinsic.up)

                # Rotate position around center
                trlist = transform.StaticTransformList(
                    (self._center, rotation, self._center.inverse())
                )
                position = trlist.transformPoint(self._startExtrinsic.position)

            camerapos = self._viewport.camera.extrinsic
            camerapos.setOrientation(direction, up)
            camerapos.position = position

        def endDrag(self, x, y):
            self._reset()

    class CameraSelectPan(ClickOrDrag):
        """Picking on click and pan camera on drag."""

        def __init__(self, viewport, button=LEFT_BTN, selectCB=None):
            self._viewport = viewport
            self._selectCB = selectCB
            self._lastPosNdc = None
            super(CameraSelectPan, self).__init__(button)

        def click(self, x, y):
            if self._selectCB is not None:
                ndcZ = self._viewport._pickNdcZGL(x, y)
                position = self._viewport._getXZYGL(x, y)
                # This assume no object lie on the far plane
                # Alternative, change the depth range so that far is < 1
                if ndcZ != 1.0 and position is not None:
                    self._selectCB((x, y, ndcZ), position)

        def beginDrag(self, x, y):
            ndc = self._viewport.windowToNdc(x, y)
            ndcZ = self._viewport._pickNdcZGL(x, y)
            # ndcZ is the panning plane
            if ndc is not None and ndcZ is not None:
                self._lastPosNdc = numpy.array(
                    (ndc[0], ndc[1], ndcZ, 1.0), dtype=numpy.float32
                )
            else:
                self._lastPosNdc = None

        def drag(self, x, y):
            if self._lastPosNdc is not None:
                ndc = self._viewport.windowToNdc(x, y)
                if ndc is not None:
                    ndcPos = numpy.array(
                        (ndc[0], ndc[1], self._lastPosNdc[2], 1.0), dtype=numpy.float32
                    )

                    # Convert last and current NDC positions to scene coords
                    scenePos = self._viewport.camera.transformPoint(
                        ndcPos, direct=False, perspectiveDivide=True
                    )
                    lastScenePos = self._viewport.camera.transformPoint(
                        self._lastPosNdc, direct=False, perspectiveDivide=True
                    )

                    # Get translation in scene coords
                    translation = scenePos[:3] - lastScenePos[:3]
                    self._viewport.camera.extrinsic.position -= translation

                    # Store for next drag
                    self._lastPosNdc = ndcPos

        def endDrag(self, x, y):
            self._lastPosNdc = None

    class CameraWheel(object):
        """StateMachine like class, just handling wheel events."""

        # TODO choose scale of motion? Translation or Scale?
        def __init__(self, viewport, mode="center", scaleTransform=None):
            assert mode in ("center", "position", "scale")
            self._viewport = viewport
            if mode == "center":
                self._zoomTo = self._zoomToCenter
            elif mode == "position":
                self._zoomTo = self._zoomToPosition
            elif mode == "scale":
                self._zoomTo = self._zoomByScale
                self._scale = scaleTransform
            else:
                raise ValueError("Unsupported mode: %s" % mode)

        def handleEvent(self, eventName, *args, **kwargs):
            if eventName == "wheel":
                return self._zoomTo(*args, **kwargs)

        def _zoomToCenter(self, x, y, angleInDegrees):
            """Zoom to center of display.

            Only works with perspective camera.
            """
            direction = "forward" if angleInDegrees > 0 else "backward"
            self._viewport.camera.move(direction)
            return True

        def _zoomToPositionAbsolute(self, x, y, angleInDegrees):
            """Zoom while keeping pixel under mouse invariant.

            Only works with perspective camera.
            """
            ndc = self._viewport.windowToNdc(x, y)
            if ndc is not None:
                near = numpy.array((ndc[0], ndc[1], -1.0, 1.0), dtype=numpy.float32)

                nearscene = self._viewport.camera.transformPoint(
                    near, direct=False, perspectiveDivide=True
                )

                far = numpy.array((ndc[0], ndc[1], 1.0, 1.0), dtype=numpy.float32)
                farscene = self._viewport.camera.transformPoint(
                    far, direct=False, perspectiveDivide=True
                )

                dirscene = farscene[:3] - nearscene[:3]
                dirscene /= numpy.linalg.norm(dirscene)

                if angleInDegrees < 0:
                    dirscene *= -1.0

                # TODO which scale
                self._viewport.camera.extrinsic.position += dirscene
            return True

        def _zoomToPosition(self, x, y, angleInDegrees):
            """Zoom while keeping pixel under mouse invariant."""
            projection = self._viewport.camera.intrinsic
            extrinsic = self._viewport.camera.extrinsic

            if isinstance(projection, transform.Perspective):
                # For perspective projection, move camera
                ndc = self._viewport.windowToNdc(x, y)
                if ndc is not None:
                    ndcz = self._viewport._pickNdcZGL(x, y)

                    position = numpy.array((ndc[0], ndc[1], ndcz), dtype=numpy.float32)
                    positionscene = self._viewport.camera.transformPoint(
                        position, direct=False, perspectiveDivide=True
                    )

                    camtopos = extrinsic.position - positionscene

                    step = 0.2 * (1.0 if angleInDegrees < 0 else -1.0)
                    extrinsic.position += step * camtopos

            elif isinstance(projection, transform.Orthographic):
                # For orthographic projection, change projection borders
                ndcx, ndcy = self._viewport.windowToNdc(x, y, checkInside=False)

                step = 0.2 * (1.0 if angleInDegrees < 0 else -1.0)

                dx = (ndcx + 1) / 2.0
                stepwidth = step * (projection.right - projection.left)
                left = projection.left - dx * stepwidth
                right = projection.right + (1.0 - dx) * stepwidth

                dy = (ndcy + 1) / 2.0
                stepheight = step * (projection.top - projection.bottom)
                bottom = projection.bottom - dy * stepheight
                top = projection.top + (1.0 - dy) * stepheight

                projection.setClipping(left, right, bottom, top)

            else:
                raise RuntimeError("Unsupported camera", projection)
            return True

        def _zoomByScale(self, x, y, angleInDegrees):
            """Zoom by scaling scene (do not keep pixel under mouse invariant)."""
            scalefactor = 1.1
            if angleInDegrees < 0.0:
                scalefactor = 1.0 / scalefactor
            self._scale.scale = scalefactor * self._scale.scale

            self._viewport.adjustCameraDepthExtent()
            return True

    class FocusManager(StateMachine):
        """Manages focus across multiple event handlers

        On press an event handler can acquire focus.
        By default it looses focus when all buttons are released.
        """

        class Idle(State):
            def onPress(self, x, y, btn):
                for eventHandler in self.machine.currentEventHandler:
                    requestFocus = eventHandler.handleEvent("press", x, y, btn)
                    if requestFocus:
                        self.goto("focus", eventHandler, btn)
                        break

            def _processEvent(self, *args):
                for eventHandler in self.machine.currentEventHandler:
                    consumeEvent = eventHandler.handleEvent(*args)
                    if consumeEvent:
                        break

            def onMove(self, x, y):
                self._processEvent("move", x, y)

            def onRelease(self, x, y, btn):
                self._processEvent("release", x, y, btn)

            def onWheel(self, x, y, angle):
                self._processEvent("wheel", x, y, angle)

        class Focus(State):

            def enterState(self, eventHandler, btn):
                self.eventHandler = eventHandler
                self.focusBtns = {btn}  # Set

            def onPress(self, x, y, btn):
                self.focusBtns.add(btn)
                self.eventHandler.handleEvent("press", x, y, btn)

            def onMove(self, x, y):
                self.eventHandler.handleEvent("move", x, y)

            def onRelease(self, x, y, btn):
                self.focusBtns.discard(btn)
                requestfocus = self.eventHandler.handleEvent("release", x, y, btn)
                if len(self.focusBtns) == 0 and not requestfocus:
                    self.goto("idle")

            def onWheel(self, x, y, angleInDegrees):
                self.eventHandler.handleEvent("wheel", x, y, angleInDegrees)

        def __init__(self, eventHandlers=(), ctrlEventHandlers=None):
            self.defaultEventHandlers = eventHandlers
            self.ctrlEventHandlers = ctrlEventHandlers
            self.currentEventHandler = self.defaultEventHandlers

            states = {"idle": FocusManager.Idle, "focus": FocusManager.Focus}
            super(FocusManager, self).__init__(states, "idle")

        def onKeyPress(self, key):
            if key == qt.Qt.Key_Control and self.ctrlEventHandlers is not None:
                self.currentEventHandler = self.ctrlEventHandlers

        def onKeyRelease(self, key):
            if key == qt.Qt.Key_Control:
                self.currentEventHandler = self.defaultEventHandlers

        def cancel(self):
            for handler in self.currentEventHandler:
                handler.cancel()

    class RotateCameraControl(FocusManager):
        """Combine wheel and rotate state machine for left button
        and pan when ctrl is pressed
        """

        def __init__(
            self,
            viewport,
            orbitAroundCenter=False,
            mode="center",
            scaleTransform=None,
            selectCB=None,
        ):
            handlers = (
                CameraWheel(viewport, mode, scaleTransform),
                CameraSelectRotate(viewport, orbitAroundCenter, LEFT_BTN, selectCB),
            )
            ctrlHandlers = (
                CameraWheel(viewport, mode, scaleTransform),
                CameraSelectPan(viewport, LEFT_BTN, selectCB),
            )
            super(RotateCameraControl, self).__init__(handlers, ctrlHandlers)

    class PanCameraControl(FocusManager):
        """Combine wheel, selectPan and rotate state machine for left button
        and rotate when ctrl is pressed"""

        def __init__(
            self,
            viewport,
            orbitAroundCenter=False,
            mode="center",
            scaleTransform=None,
            selectCB=None,
        ):
            handlers = (
                CameraWheel(viewport, mode, scaleTransform),
                CameraSelectPan(viewport, LEFT_BTN, selectCB),
            )
            ctrlHandlers = (
                CameraWheel(viewport, mode, scaleTransform),
                CameraSelectRotate(viewport, orbitAroundCenter, LEFT_BTN, selectCB),
            )
            super(PanCameraControl, self).__init__(handlers, ctrlHandlers)

    class CameraControl(FocusManager):
        """Combine wheel, selectPan and rotate state machine."""

        def __init__(
            self,
            viewport,
            orbitAroundCenter=False,
            mode="center",
            scaleTransform=None,
            selectCB=None,
        ):
            handlers = (
                CameraWheel(viewport, mode, scaleTransform),
                CameraSelectPan(viewport, LEFT_BTN, selectCB),
                CameraSelectRotate(viewport, orbitAroundCenter, RIGHT_BTN, selectCB),
            )
            super(CameraControl, self).__init__(handlers)

    class PlaneRotate(ClickOrDrag):
        """Plane rotation using arcball interaction.

        Arcball ref.:
        Ken Shoemake. ARCBALL: A user interface for specifying three-dimensional
        orientation using a mouse. In Proc. GI '92. (1992). pp. 151-156.
        """

        def __init__(self, viewport, plane, button=RIGHT_BTN):
            self._viewport = viewport
            self._plane = plane
            self._reset()
            super(PlaneRotate, self).__init__(button)

        def _reset(self):
            self._beginNormal, self._beginCenter = None, None

        def click(self, x, y):
            pass  # No interaction

        @staticmethod
        def _sphereUnitVector(radius, center, position):
            """Returns the unit vector of the projection of position on a sphere.

            It assumes an orthographic projection.
            For perspective projection, it gives an approximation, but it
            simplifies computations and results in consistent arcball control
            in control space.

            All parameters must be in screen coordinate system
            (either pixels or normalized coordinates).

            :param float radius: The radius of the sphere.
            :param center: (x, y) coordinates of the center.
            :param position: (x, y) coordinates of the cursor position.
            :return: Unit vector.
            :rtype: numpy.ndarray of 3 floats.
            """
            center, position = numpy.array(center), numpy.array(position)

            # Normalize x and y on a unit circle
            spherecoords = (position - center) / float(radius)
            squarelength = numpy.sum(spherecoords**2)

            # Project on the unit sphere and compute z coordinates
            if squarelength > 1.0:  # Outside sphere: project
                spherecoords /= numpy.sqrt(squarelength)
                zsphere = 0.0
            else:  # In sphere: compute z
                zsphere = numpy.sqrt(1.0 - squarelength)

            spherecoords = numpy.append(spherecoords, zsphere)
            return spherecoords

        def beginDrag(self, x, y):
            # Makes sure the point defining the plane is at the center as
            # it will be the center of rotation (as rotation is applied to normal)
            self._plane.plane.point = self._plane.center

            # Store the plane normal
            self._beginNormal = self._plane.plane.normal

            _logger.debug("Begin arcball, plane center %s", str(self._plane.center))

            # Do the arcball on the screen
            radius = min(self._viewport.size)
            if self._plane.center is None:
                self._beginCenter = None

            else:
                center = self._plane.objectToNDCTransform.transformPoint(
                    self._plane.center, perspectiveDivide=True
                )
                self._beginCenter = self._viewport.ndcToWindow(
                    center[0], center[1], checkInside=False
                )

                self._startVector = self._sphereUnitVector(
                    radius, self._beginCenter, (x, y)
                )

        def drag(self, x, y):
            if self._beginCenter is None:
                return

            # Compute rotation: this is twice the rotation of the arcball
            radius = min(self._viewport.size)
            currentvector = self._sphereUnitVector(radius, self._beginCenter, (x, y))
            crossprod = numpy.cross(self._startVector, currentvector)
            dotprod = numpy.dot(self._startVector, currentvector)

            quaternion = numpy.append(crossprod, dotprod)
            # Rotation was computed with Y downward, but apply in NDC, invert Y
            quaternion[1] *= -1.0

            rotation = transform.Rotate()
            rotation.quaternion = quaternion

            # Convert to NDC, rotate, convert back to object
            normal = self._plane.objectToNDCTransform.transformNormal(self._beginNormal)
            normal = rotation.transformNormal(normal)
            normal = self._plane.objectToNDCTransform.transformNormal(normal, direct=False)
            self._plane.plane.normal = normal

        def endDrag(self, x, y):
            self._reset()

    class PlanePan(ClickOrDrag):
        """Pan a plane along its normal on drag."""

        def __init__(self, viewport, plane, button=LEFT_BTN):
            self._plane = plane
            self._viewport = viewport
            self._beginPlanePoint = None
            self._beginPos = None
            self._dragNdcZ = 0.0
            super(PlanePan, self).__init__(button)

        def click(self, x, y):
            pass

        def beginDrag(self, x, y):
            ndc = self._viewport.windowToNdc(x, y)
            ndcZ = self._viewport._pickNdcZGL(x, y)
            # ndcZ is the panning plane
            if ndc is not None and ndcZ is not None:
                ndcPos = numpy.array((ndc[0], ndc[1], ndcZ, 1.0), dtype=numpy.float32)
                scenePos = self._viewport.camera.transformPoint(
                    ndcPos, direct=False, perspectiveDivide=True
                )
                self._beginPos = self._plane.objectToSceneTransform.transformPoint(
                    scenePos, direct=False
                )
                self._dragNdcZ = ndcZ
            else:
                self._beginPos = None
                self._dragNdcZ = 0.0

            self._beginPlanePoint = self._plane.plane.point

        def drag(self, x, y):
            if self._beginPos is not None:
                ndc = self._viewport.windowToNdc(x, y)
                if ndc is not None:
                    ndcPos = numpy.array(
                        (ndc[0], ndc[1], self._dragNdcZ, 1.0), dtype=numpy.float32
                    )

                    # Convert last and current NDC positions to scene coords
                    scenePos = self._viewport.camera.transformPoint(
                        ndcPos, direct=False, perspectiveDivide=True
                    )
                    curPos = self._plane.objectToSceneTransform.transformPoint(
                        scenePos, direct=False
                    )

                    # Get translation in scene coords
                    translation = curPos[:3] - self._beginPos[:3]

                    newPoint = self._beginPlanePoint + translation

                    # Keep plane point in bounds
                    bounds = self._plane.parent.bounds(dataBounds=True)
                    if bounds is not None:
                        newPoint = numpy.clip(newPoint, a_min=bounds[0], a_max=bounds[1])

                        # Only update plane if it is in some bounds
                        self._plane.plane.point = newPoint

        def endDrag(self, x, y):
            self._beginPlanePoint = None

    class PlaneControl(FocusManager):
        """Combine wheel, selectPan and rotate state machine for plane control."""

        def __init__(self, viewport, plane, mode="center", scaleTransform=None):
            handlers = (
                CameraWheel(viewport, mode, scaleTransform),
                PlanePan(viewport, plane, LEFT_BTN),
                PlaneRotate(viewport, plane, RIGHT_BTN),
            )
            super(PlaneControl, self).__init__(handlers)

    class PanPlaneRotateCameraControl(FocusManager):
        """Combine wheel, pan plane and camera rotate state machine."""

        def __init__(self, viewport, plane, mode="center", scaleTransform=None):
            handlers = (
                CameraWheel(viewport, mode, scaleTransform),
                PlanePan(viewport, plane, LEFT_BTN),
                CameraSelectRotate(viewport, orbitAroundCenter=False, button=RIGHT_BTN),
            )
            super(PanPlaneRotateCameraControl, self).__init__(handlers)

    class PanPlaneZoomOnWheelControl(FocusManager):
        """Combine zoom on wheel and pan plane state machines."""

        def __init__(
            self,
            viewport,
            plane,
            mode="center",
            orbitAroundCenter=False,
            scaleTransform=None,
        ):
            handlers = (
                CameraWheel(viewport, mode, scaleTransform),
                PlanePan(viewport, plane, LEFT_BTN),
            )
            ctrlHandlers = (
                CameraWheel(viewport, mode, scaleTransform),
                CameraSelectRotate(viewport, orbitAroundCenter, LEFT_BTN),
            )
            super(PanPlaneZoomOnWheelControl, self).__init__(handlers, ctrlHandlers)