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Diffstat (limited to 'src/silx/gui/plot3d/scene/core.py')
| -rw-r--r-- | src/silx/gui/plot3d/scene/core.py | 343 |
1 files changed, 343 insertions, 0 deletions
diff --git a/src/silx/gui/plot3d/scene/core.py b/src/silx/gui/plot3d/scene/core.py new file mode 100644 index 0000000..43838fe --- /dev/null +++ b/src/silx/gui/plot3d/scene/core.py @@ -0,0 +1,343 @@ +# coding: utf-8 +# /*########################################################################## +# +# Copyright (c) 2015-2019 European Synchrotron Radiation Facility +# +# Permission is hereby granted, free of charge, to any person obtaining a copy +# of this software and associated documentation files (the "Software"), to deal +# in the Software without restriction, including without limitation the rights +# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +# copies of the Software, and to permit persons to whom the Software is +# furnished to do so, subject to the following conditions: +# +# The above copyright notice and this permission notice shall be included in +# all copies or substantial portions of the Software. +# +# 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 +# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +# THE SOFTWARE. +# +# ###########################################################################*/ +"""This module provides the base scene structure. + +This module provides the classes for describing a tree structure with +rendering and picking API. +All nodes inherit from :class:`Base`. +Nodes with children are provided with :class:`PrivateGroup` and +:class:`Group` classes. +Leaf rendering nodes should inherit from :class:`Elem`. +""" + +from __future__ import absolute_import, division, unicode_literals + +__authors__ = ["T. Vincent"] +__license__ = "MIT" +__date__ = "25/07/2016" + + +import itertools +import weakref + +import numpy + +from . import event +from . import transform + +from .viewport import Viewport + + +# Nodes ####################################################################### + +class Base(event.Notifier): + """A scene node with common features.""" + + def __init__(self): + super(Base, self).__init__() + self._visible = True + self._pickable = False + + self._parentRef = None + + self._transforms = transform.TransformList() + self._transforms.addListener(self._transformChanged) + + # notifying properties + + visible = event.notifyProperty('_visible', + doc="Visibility flag of the node") + pickable = event.notifyProperty('_pickable', + doc="True to make node pickable") + + # Access to tree path + + @property + def parent(self): + """Parent or None if no parent""" + return None if self._parentRef is None else self._parentRef() + + def _setParent(self, parent): + """Set the parent of this node. + + For internal use. + + :param Base parent: The parent. + """ + if parent is not None and self._parentRef is not None: + raise RuntimeError('Trying to add a node at two places.') + # Alternative: remove it from previous children list + self._parentRef = None if parent is None else weakref.ref(parent) + + @property + def path(self): + """Tuple of scene nodes, from the tip of the tree down to this node. + + If this tree is attached to a :class:`Viewport`, + then the :class:`Viewport` is the first element of path. + """ + if self.parent is None: + return self, + elif isinstance(self.parent, Viewport): + return self.parent, self + else: + return self.parent.path + (self, ) + + @property + def viewport(self): + """The viewport this node is attached to or None.""" + root = self.path[0] + return root if isinstance(root, Viewport) else None + + @property + def root(self): + """The root node of the scene. + + If attached to a :class:`Viewport`, this is the item right under it + """ + path = self.path + return path[1] if isinstance(path[0], Viewport) else path[0] + + @property + def objectToNDCTransform(self): + """Transform from object to normalized device coordinates. + + Do not forget perspective divide. + """ + # Using the Viewport's transforms property to proxy the camera + path = self.path + assert isinstance(path[0], Viewport) + return transform.StaticTransformList(elem.transforms for elem in path) + + @property + def objectToSceneTransform(self): + """Transform from object to scene. + + Combine transforms up to the Viewport (not including it). + """ + path = self.path + if isinstance(path[0], Viewport): + path = path[1:] # Remove viewport to remove camera transforms + return transform.StaticTransformList(elem.transforms for elem in path) + + # transform + + @property + def transforms(self): + """List of transforms defining the frame of this node relative + to its parent.""" + return self._transforms + + @transforms.setter + def transforms(self, iterable): + self._transforms.removeListener(self._transformChanged) + if isinstance(iterable, transform.TransformList): + # If it is a TransformList, do not create one to enable sharing. + self._transforms = iterable + else: + assert hasattr(iterable, '__iter__') + self._transforms = transform.TransformList(iterable) + self._transforms.addListener(self._transformChanged) + + def _transformChanged(self, source): + self.notify() # Broadcast transform notification + + # Bounds + + _CUBE_CORNERS = numpy.array(list(itertools.product((0., 1.), repeat=3)), + dtype=numpy.float32) + """Unit cube corners used to transform bounds""" + + def _bounds(self, dataBounds=False): + """Override in subclass to provide bounds in object coordinates""" + return None + + def bounds(self, transformed=False, dataBounds=False): + """Returns the bounds of this node aligned with the axis, + with or without transform applied. + + :param bool transformed: False to give bounds in object coordinates + (the default), True to apply this object's + transforms. + :param bool dataBounds: False to give bounds of vertices (the default), + True to give bounds of the represented data. + :return: The bounds: ((xMin, yMin, zMin), (xMax, yMax, zMax)) or None + if no bounds. + :rtype: numpy.ndarray of float + """ + bounds = self._bounds(dataBounds) + + if transformed and bounds is not None: + bounds = self.transforms.transformBounds(bounds) + + return bounds + + # Rendering + + def prepareGL2(self, ctx): + """Called before the rendering to prepare OpenGL resources. + + Override in subclass. + """ + pass + + def renderGL2(self, ctx): + """Called to perform the OpenGL rendering. + + Override in subclass. + """ + pass + + def render(self, ctx): + """Called internally to perform rendering.""" + if self.visible: + ctx.pushTransform(self.transforms) + self.prepareGL2(ctx) + self.renderGL2(ctx) + ctx.popTransform() + + def postRender(self, ctx): + """Hook called when parent's node render is finished. + + Called in the reverse of rendering order (i.e., last child first). + + Meant for nodes that modify the :class:`RenderContext` ctx to + reset their modifications. + """ + pass + + def pick(self, ctx, x, y, depth=None): + """True/False picking, should be fast""" + if self.pickable: + pass + + def pickRay(self, ctx, ray): + """Picking returning list of ray intersections.""" + if self.pickable: + pass + + +class Elem(Base): + """A scene node that does some rendering.""" + + def __init__(self): + super(Elem, self).__init__() + # self.showBBox = False # Here or outside scene graph? + # self.clipPlane = None # This needs to be handled in the shader + + +class PrivateGroup(Base): + """A scene node that renders its (private) childern. + + :param iterable children: :class:`Base` nodes to add as children + """ + + class ChildrenList(event.NotifierList): + """List of children with notification and children's parent update.""" + + def _listWillChangeHook(self, methodName, *args, **kwargs): + super(PrivateGroup.ChildrenList, self)._listWillChangeHook( + methodName, *args, **kwargs) + for item in self: + item._setParent(None) + + def _listWasChangedHook(self, methodName, *args, **kwargs): + for item in self: + item._setParent(self._parentRef()) + super(PrivateGroup.ChildrenList, self)._listWasChangedHook( + methodName, *args, **kwargs) + + def __init__(self, parent, children): + self._parentRef = weakref.ref(parent) + super(PrivateGroup.ChildrenList, self).__init__(children) + + def __init__(self, children=()): + super(PrivateGroup, self).__init__() + self.__children = PrivateGroup.ChildrenList(self, children) + self.__children.addListener(self._updated) + + @property + def _children(self): + """List of children to be rendered. + + This private attribute is meant to be used by subclass. + """ + return self.__children + + @_children.setter + def _children(self, iterable): + self.__children.removeListener(self._updated) + for item in self.__children: + item._setParent(None) + del self.__children # This is needed + self.__children = PrivateGroup.ChildrenList(self, iterable) + self.__children.addListener(self._updated) + self.notify() + + def _updated(self, source, *args, **kwargs): + """Listen for updates""" + if source is not self: # Avoid infinite recursion + self.notify(*args, **kwargs) + + def _bounds(self, dataBounds=False): + """Compute the bounds from transformed children bounds""" + bounds = [] + for child in self._children: + if child.visible: + childBounds = child.bounds( + transformed=True, dataBounds=dataBounds) + if childBounds is not None: + bounds.append(childBounds) + + if len(bounds) == 0: + return None + else: + bounds = numpy.array(bounds, dtype=numpy.float32) + return numpy.array((bounds[:, 0, :].min(axis=0), + bounds[:, 1, :].max(axis=0)), + dtype=numpy.float32) + + def prepareGL2(self, ctx): + pass + + def renderGL2(self, ctx): + """Render all children""" + for child in self._children: + child.render(ctx) + for child in reversed(self._children): + child.postRender(ctx) + + +class Group(PrivateGroup): + """A scene node that renders its (public) children.""" + + @property + def children(self): + """List of children to be rendered.""" + return self._children + + @children.setter + def children(self, iterable): + self._children = iterable |