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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__)
[docs]
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
[docs]
class Idle(State):
def onPress(self, x, y, btn):
if btn == self.machine.button:
self.goto("clickOrDrag", x, y)
return True
[docs]
class ClickOrDrag(State):
[docs]
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")
[docs]
class Drag(State):
[docs]
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")
[docs]
def click(self, x, y):
"""Called upon a left or right button click.
To override in a subclass.
"""
pass
[docs]
def beginDrag(self, x, y):
"""Called at the beginning of a drag gesture with left button
pressed.
To override in a subclass.
"""
pass
[docs]
def drag(self, x, y):
"""Called on mouse moved during a drag gesture.
To override in a subclass.
"""
pass
[docs]
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
[docs]
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
[docs]
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)
[docs]
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()
[docs]
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
[docs]
def endDrag(self, x, y):
self._reset()
[docs]
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)
[docs]
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)
[docs]
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
[docs]
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
[docs]
def endDrag(self, x, y):
self._lastPosNdc = None
[docs]
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
[docs]
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.
"""
[docs]
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)
[docs]
class Focus(State):
[docs]
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()
[docs]
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)
[docs]
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)
[docs]
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)
[docs]
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
[docs]
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
[docs]
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)
)
[docs]
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
[docs]
def endDrag(self, x, y):
self._reset()
[docs]
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)
[docs]
def click(self, x, y):
pass
[docs]
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
[docs]
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
[docs]
def endDrag(self, x, y):
self._beginPlanePoint = None
[docs]
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)
[docs]
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)
[docs]
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)
