#
# scene3dcanvas.py - The Scene3DCanvas class.
#
# Author: Paul McCarthy <pauldmccarthy@gmail.com>
#
"""This module provides the :class:`.Scene3DCanvas` class, which is used by
FSLeyes for its 3D view.
"""
import logging
import numpy as np
import OpenGL.GL as gl
import fsl.data.mesh as fslmesh
import fsl.data.image as fslimage
import fsl.utils.idle as idle
import fsl.transform.affine as affine
import fsleyes.gl.routines as glroutines
import fsleyes.gl.globject as globject
import fsleyes.displaycontext as fsldisplay
import fsleyes.displaycontext.canvasopts as canvasopts
log = logging.getLogger(__name__)
[docs]class Scene3DCanvas(object):
[docs] def __init__(self, overlayList, displayCtx):
self.__name = '{}_{}'.format(type(self).__name__, id(self))
self.__opts = canvasopts.Scene3DCanvasOpts()
self.__overlayList = overlayList
self.__displayCtx = displayCtx
self.__viewMat = np.eye(4)
self.__projMat = np.eye(4)
self.__invViewProjMat = np.eye(4)
self.__viewport = None
self.__resetLightPos = True
self.__glObjects = {}
overlayList.addListener('overlays',
self.__name,
self.__overlayListChanged)
displayCtx.addListener('bounds',
self.__name,
self.__displayBoundsChanged)
opts = self.opts
opts.addListener('pos', self.__name, self.Refresh)
opts.addListener('showCursor', self.__name, self.Refresh)
opts.addListener('cursorColour', self.__name, self.Refresh)
opts.addListener('bgColour', self.__name, self.Refresh)
opts.addListener('showLegend', self.__name, self.Refresh)
opts.addListener('occlusion', self.__name, self.Refresh)
opts.addListener('zoom', self.__name, self.Refresh)
opts.addListener('offset', self.__name, self.Refresh)
opts.addListener('rotation', self.__name, self.Refresh)
opts.addListener('highDpi', self.__name, self.__highDpiChanged)
[docs] def destroy(self):
"""
"""
self.__overlayList.removeListener('overlays', self.__name)
self.__displayCtx .removeListener('bounds', self.__name)
for ovl in list(self.__glObjects.keys()):
self.__deregisterOverlay(ovl)
self.__opts = None
self.__displayCtx = None
self.__overlayList = None
self.__glObjects = None
@property
def destroyed(self):
"""
"""
return self.__overlayList is None
@property
def opts(self):
"""Returns a reference to the :class:`.Scene3DCanvasOpts` instance.
"""
return self.__opts
@property
def resetLightPos(self):
"""By default, the :attr:`lightPos` is updated whenever the
:attr:`.DisplayContext.bounds` change. This flag can be used to
disable this behaviour.
"""
return self.__resetLightPos
@resetLightPos.setter
def resetLightPos(self, reset):
"""Control whether the :attr:`lightPos` property is reset whenever
the :attr:`.DisplayContext.bounds` change.
"""
self.__resetLightPos = reset
[docs] def defaultLightPos(self):
"""Resets the :attr:`lightPos` property to a sensible value. """
b = self.__displayCtx.bounds
centre = np.array([b.xlo + 0.5 * (b.xhi - b.xlo),
b.ylo + 0.5 * (b.yhi - b.ylo),
b.zlo + 0.5 * (b.zhi - b.zlo)])
self.opts.lightPos = centre + [b.xlen, b.ylen, 0]
@property
def viewMatrix(self):
"""Returns the view matrix for the current scene - this is an affine
matrix which encodes the current :attr:`.Scene3DCanvasOpts.offset`,
:attr:`.Scene3DCanvasOpts.zoom`,
:attr:`.Scene3DCanvasOpts.rotation` and camera settings.
See :meth:`__genViewMatrix`.
"""
return self.__viewMat
@property
def viewScale(self):
"""Returns an affine matrix which encodes the current
:attr:`.Scene3DCanvasOpts.zoom` setting.
"""
return self.__viewScale
@property
def viewOffset(self):
"""Returns an affine matrix which encodes the current
:attr:`.Scene3DCanvasOpts.offset` setting.
"""
return self.__viewOffset
@property
def viewRotation(self):
"""Returns an affine matrix which encodes the current
:attr:`.Scene3DCanvasOpts.rotation` setting.
"""
return self.__viewRotate
@property
def viewCamera(self):
"""Returns an affine matrix which encodes the current camera.
transformation. The initial camera orientation in the view shown by a
:class:`Scene3DCanvas` is located on the positive Y axis, is oriented
towards the positive Z axis, and is pointing towards the centre of the
:attr:`.DisplayContext.displayBounds`.
"""
return self.__viewCamera
@property
def projectionMatrix(self):
"""Returns the projection matrix. This is an affine matrix which
converts from normalised device coordinates (NDCs, coordinates between
-1 and +1) into viewport coordinates. The initial viewport for a
:class:`Scene3DCanvas` is configured by the :func:`.routines.ortho`
function.
See :meth:`__setViewport`.
"""
return self.__projMat
@property
def invViewProjectionMatrix(self):
"""Returns the inverse of the model-view-projection matrix, the
equivalent of:
``invert(projectionMatrix * viewMatrix)``
"""
return self.__invViewProjMat
@property
def viewport(self):
"""Returns a list of three ``(min, max)`` tuples which specify the
viewport limits of the currently displayed scene.
"""
return self.__viewport
[docs] def canvasToWorld(self, xpos, ypos, near=True):
"""Transform the given x/y canvas coordinates into the display
coordinate system. The calculated coordinates will be located on
the near clipping plane.
:arg near: If ``True`` (the default), the returned coordinate will
be located on the near clipping plane. Otherwise, the
coordinate will be located on the far clipping plane.
"""
width, height = self.GetSize()
# Normalise pixels to [-1, 1]
xp = -1 + 2.0 * xpos / width
yp = -1 + 2.0 * ypos / height
# We set the Z coord so the resulting
# coordinates will be located on either
# the near or clipping planes.
if near: pos = [xp, yp, -1]
else: pos = [xp, yp, 1]
# The first step is to convert mouse
# coordinates from [-1, 1] to viewport
# coodinates via the inverse projection
# matrix.
# The second step is to transform from
# viewport coords into model-view coords.
# This is easy - transform by the inverse
# MV matrix.
# We perform both of these steps in one
# by concatenating then inverting the
# view/projection matrices. This is
# calculated and cached for us in the
# __setViewport method.
pos = affine.transform(pos, self.__invViewProjMat)
return pos
[docs] def getGLObject(self, overlay):
"""Returns the :class:`.GLObject` associated with the given overlay,
or ``None`` if there is not one.
"""
return self.__glObjects.get(overlay, None)
[docs] def getGLObjects(self):
"""Returns two lists:
- A list of overlays to be drawn
- A list of corresponding :class:`GLObject` instances
The lists are in the order that they should be drawn.
This method also creates ``GLObject`` instances for any overlays
in the :class:`.OverlayList` that do not have one.
"""
overlays = self.__displayCtx.getOrderedOverlays()
surfs = [o for o in overlays if isinstance(o, fslmesh.Mesh)]
vols = [o for o in overlays if isinstance(o, fslimage.Image)]
other = [o for o in overlays if o not in surfs and o not in vols]
overlays = []
globjs = []
# If occlusion is on, we draw all surfaces first,
# so they are on the scene regardless of volume
# opacity.
#
# If occlusion is off, we draw all volumes
# (without depth testing) first, and draw all
# surfaces (with depth testing) afterwards.
# In this way, the surfaces will be occluded
# by the last drawn volume. I figure that this
# is better than being occluded by *all* volumes,
# regardless of depth or camera orientation.
#
# The one downside to this is that if a
# transparent volume is in front of a surface,
# the surface won't be shown.
#
# The only way to overcome this would be to
# sort by depth on every render which, given
# the possibility of volume clipping planes,
# is a bit too complicated for my liking.
if self.opts.occlusion: ovlOrder = surfs + vols + other
else: ovlOrder = vols + surfs + other
for ovl in ovlOrder:
globj = self.getGLObject(ovl)
# If there is no GLObject for this
# overlay, create one, but don't
# add it to the list (as creation
# is done asynchronously).
if globj is None:
self.__registerOverlay(ovl)
# Otherwise, if the value for this
# overlay evaluates to False, that
# means that it has been scheduled
# for creation, but is not ready
# yet.
elif globj:
overlays.append(ovl)
globjs .append(globj)
return overlays, globjs
[docs] def _initGL(self):
"""Called when the canvas is ready to be drawn on. """
self.__overlayListChanged()
self.__displayBoundsChanged()
def __overlayListChanged(self, *a):
"""Called when the :class:`.OverlayList` changes. Destroys/creates
:class:`.GLObject` instances as necessary.
"""
# Destroy any GL objects for overlays
# which are no longer in the list
for ovl, globj in list(self.__glObjects.items()):
if ovl not in self.__overlayList:
self.__deregisterOverlay(ovl)
# Create GLObjects for any
# newly added overlays
for ovl in self.__overlayList:
if ovl not in self.__glObjects:
self.__registerOverlay(ovl)
def __highDpiChanged(self, *a):
"""Called when the :attr:`.Scene3DCanvasOpts.highDpi` property
changes. Calls the :meth:`.GLCanvasTarget.EnableHighDPI` method.
"""
self.EnableHighDPI(self.opts.highDpi)
def __displayBoundsChanged(self, *a):
"""Called when the :attr:`.DisplayContext.bounds` change. Resets
the :attr:`.Scene3DCanvasOpts.lightPos` property.
"""
if self.resetLightPos:
self.defaultLightPos()
self.Refresh()
def __registerOverlay(self, overlay):
"""
"""
if not isinstance(overlay, (fslmesh.Mesh, fslimage.Image)):
return
log.debug('Registering overlay {}'.format(overlay))
display = self.__displayCtx.getDisplay(overlay)
if not self.__genGLObject(overlay):
return
display.addListener('enabled', self.__name, self.Refresh)
display.addListener('overlayType',
self.__name,
self.__overlayTypeChanged)
def __deregisterOverlay(self, overlay):
"""
"""
log.debug('Deregistering overlay {}'.format(overlay))
try:
display = self.__displayCtx.getDisplay(overlay)
display.removeListener('overlayType', self.__name)
display.removeListener('enabled', self.__name)
except fsldisplay.InvalidOverlayError:
pass
globj = self.__glObjects.pop(overlay, None)
if globj is not None:
globj.deregister(self.__name)
globj.destroy()
def __genGLObject(self, overlay):
"""
"""
if overlay in self.__glObjects:
return False
display = self.__displayCtx.getDisplay(overlay)
if display.overlayType not in ('volume', 'mesh'):
return False
self.__glObjects[overlay] = False
def create():
if not self or self.destroyed:
return
if overlay not in self.__glObjects:
return
if not self._setGLContext():
self.__glObjects.pop(overlay)
return
log.debug('Creating GLObject for {}'.format(overlay))
globj = globject.createGLObject(overlay,
self.__overlayList,
self.__displayCtx,
self,
True)
if globj is not None:
globj.register(self.__name, self.Refresh)
self.__glObjects[overlay] = globj
idle.idle(create)
return True
def __overlayTypeChanged(self, value, valid, display, name):
"""
"""
overlay = display.overlay
globj = self.__glObjects.pop(overlay, None)
if globj is not None:
globj.deregister(self.__name)
globj.destroy()
self.__genGLObject(overlay)
self.Refresh()
def __genViewMatrix(self, w, h):
"""Generate and return a transformation matrix to be used as the
model-view matrix. This includes applying the current :attr:`zoom`,
:attr:`rotation` and :attr:`offset` settings, and configuring
the camera. This method is called by :meth:`__setViewport`.
:arg w: Canvas width in pixels
:arg h: Canvas height in pixels
"""
opts = self.opts
b = self.__displayCtx.bounds
centre = [b.xlo + 0.5 * b.xlen,
b.ylo + 0.5 * b.ylen,
b.zlo + 0.5 * b.zlen]
# The MV matrix comprises (in this order):
#
# - A rotation (the rotation property)
#
# - Camera configuration. With no rotation, the
# camera will be looking towards the positive
# Y axis (i.e. +y is forwards), and oriented
# towards the positive Z axis (i.e. +z is up)
#
# - A translation (the offset property)
# - A scaling (the zoom property)
# Scaling and rotation matrices. Rotation
# is always around the centre of the
# displaycontext bounds (the bounding
# box which contains all loaded overlays).
scale = opts.zoom / 100.0
scale = affine.scaleOffsetXform([scale] * 3, 0)
rotate = affine.rotMatToAffine(opts.rotation, centre)
# The offset property is defined in x/y
# pixels, normalised to [-1, 1]. We need
# to convert them into viewport space,
# where the horizontal axis maps to
# (-xhalf, xhalf), and the vertical axis
# maps to (-yhalf, yhalf). See
# gl.routines.ortho.
offset = np.array(opts.offset[:] + [0])
xlen, ylen = glroutines.adjust(b.xlen, b.ylen, w, h)
offset[0] = xlen * offset[0] / 2
offset[1] = ylen * offset[1] / 2
offset = affine.scaleOffsetXform(1, offset)
# And finally the camera.
eye = list(centre)
eye[1] += 1
up = [0, 0, 1]
camera = glroutines.lookAt(eye, centre, up)
# Order is very important!
xform = affine.concat(offset, scale, camera, rotate)
np.array(xform, dtype=np.float32)
self.__viewOffset = offset
self.__viewScale = scale
self.__viewRotate = rotate
self.__viewCamera = camera
self.__viewMat = xform
def __setViewport(self):
"""Called by :meth:`_draw`. Configures the viewport and calculates
the model-view trasformation matrix.
:returns: ``True`` if the viewport was successfully configured,
``False`` otherwise.
"""
width, height = self.GetScaledSize()
b = self.__displayCtx.bounds
blo = [b.xlo, b.ylo, b.zlo]
bhi = [b.xhi, b.yhi, b.zhi]
zoom = self.opts.zoom / 100.0
if width == 0 or height == 0:
return False
# We allow one dimension to be
# flat, so we can display 2D
# meshes (e.g. flattened surfaces)
if np.sum(np.isclose(blo, bhi)) > 1:
return False
# Generate the view and projection matrices
self.__genViewMatrix(width, height)
projmat, viewport = glroutines.ortho(blo, bhi, width, height, zoom)
self.__projMat = projmat
self.__viewport = viewport
self.__invViewProjMat = affine.concat(self.__projMat, self.__viewMat)
self.__invViewProjMat = affine.invert(self.__invViewProjMat)
gl.glViewport(0, 0, width, height)
gl.glMatrixMode(gl.GL_PROJECTION)
gl.glLoadMatrixf(self.__projMat.ravel('F'))
gl.glMatrixMode(gl.GL_MODELVIEW)
gl.glLoadIdentity()
return True
[docs] def _draw(self):
"""Draws the scene to the canvas. """
if not self._setGLContext():
return
opts = self.opts
glroutines.clear(opts.bgColour)
if not self.__setViewport():
return
overlays, globjs = self.getGLObjects()
if len(overlays) == 0:
return
# If occlusion is on, we offset the
# depth of each overlay so that, where
# a depth collision occurs, overlays
# which are higher in the list will get
# drawn above (closer to the screen)
# than lower ones.
depthOffset = affine.scaleOffsetXform(1, [0, 0, 0.1])
depthOffset = np.array(depthOffset, dtype=np.float32, copy=False)
xform = np.array(self.__viewMat, dtype=np.float32, copy=False)
for ovl, globj in zip(overlays, globjs):
display = self.__displayCtx.getDisplay(ovl)
if not globj.ready():
continue
if not display.enabled:
continue
if opts.occlusion:
xform = affine.concat(depthOffset, xform)
elif isinstance(ovl, fslimage.Image):
gl.glClear(gl.GL_DEPTH_BUFFER_BIT)
log.debug('Drawing {} [{}]'.format(ovl, globj))
globj.preDraw( xform=xform)
globj.draw3D( xform=xform)
globj.postDraw(xform=xform)
if opts.showCursor:
with glroutines.enabled((gl.GL_DEPTH_TEST)):
self.__drawCursor()
if opts.showLegend:
self.__drawLegend()
# Testing click-to-near/far clipping plane transformation
if hasattr(self, 'points'):
colours = [(1, 0, 0, 1), (0, 0, 1, 1)]
gl.glPointSize(5)
gl.glBegin(gl.GL_LINES)
for i, p in enumerate(self.points):
gl.glColor4f(*colours[i % 2])
p = affine.transform(p, self.viewMatrix)
gl.glVertex3f(*p)
gl.glEnd()
def __drawCursor(self):
"""Draws three lines at the current :attr:`.DisplayContext.location`.
"""
opts = self.opts
b = self.__displayCtx.bounds
pos = opts.pos
points = np.array([
[pos.x, pos.y, b.zlo],
[pos.x, pos.y, b.zhi],
[pos.x, b.ylo, pos.z],
[pos.x, b.yhi, pos.z],
[b.xlo, pos.y, pos.z],
[b.xhi, pos.y, pos.z],
], dtype=np.float32)
points = affine.transform(points, self.__viewMat)
gl.glLineWidth(1)
r, g, b = opts.cursorColour[:3]
gl.glColor4f(r, g, b, 1)
gl.glBegin(gl.GL_LINES)
for p in points:
gl.glVertex3f(*p)
gl.glEnd()
def __drawLegend(self):
"""Draws a legend in the bottom left corner of the screen, showing
anatomical orientation.
"""
copts = self.opts
b = self.__displayCtx.bounds
w, h = self.GetSize()
xlen, ylen = glroutines.adjust(b.xlen, b.ylen, w, h)
# A line for each axis
vertices = np.zeros((6, 3), dtype=np.float32)
vertices[0, :] = [-1, 0, 0]
vertices[1, :] = [ 1, 0, 0]
vertices[2, :] = [ 0, -1, 0]
vertices[3, :] = [ 0, 1, 0]
vertices[4, :] = [ 0, 0, -1]
vertices[5, :] = [ 0, 0, 1]
# Each axis line is scaled to
# 60 pixels, and the legend is
# offset from the bottom-left
# corner by twice this amount.
scale = [xlen * 30.0 / w] * 3
offset = [-0.5 * xlen + 2.0 * scale[0],
-0.5 * ylen + 2.0 * scale[1],
0]
# Apply the current camera
# angle and rotation settings
# to the legend vertices. Offset
# anatomical labels off each
# axis line by a small amount.
rotation = affine.decompose(self.__viewMat)[2]
xform = affine.compose(scale, offset, rotation)
labelPoses = affine.transform(vertices * 1.2, xform)
vertices = affine.transform(vertices, xform)
# Draw the legend lines
gl.glDisable(gl.GL_DEPTH_TEST)
gl.glColor3f(*copts.cursorColour[:3])
gl.glLineWidth(2)
gl.glBegin(gl.GL_LINES)
gl.glVertex3f(*vertices[0])
gl.glVertex3f(*vertices[1])
gl.glVertex3f(*vertices[2])
gl.glVertex3f(*vertices[3])
gl.glVertex3f(*vertices[4])
gl.glVertex3f(*vertices[5])
gl.glEnd()
# Figure out the anatomical
# labels for each axis.
overlay = self.__displayCtx.getSelectedOverlay()
dopts = self.__displayCtx.getOpts(overlay)
labels = dopts.getLabels()[0]
# getLabels returns (xlo, ylo, zlo, xhi, yhi, zhi) -
# - rearrange them to (xlo, xhi, ylo, yhi, zlo, zhi)
labels = [labels[0],
labels[3],
labels[1],
labels[4],
labels[2],
labels[5]]
canvas = np.array([w, h])
view = np.array([xlen, ylen])
# Draw each label
for i in range(6):
# Calculate pixel x/y
# location for this label
xx, xy = canvas * (labelPoses[i, :2] + 0.5 * view) / view
# Calculate the size of the label
# in pixels, so we can centre the
# label
tw, th = glroutines.text2D(labels[i], (xx, xy), 10, (w, h),
calcSize=True)
# Draw the text
xx -= 0.5 * tw
xy -= 0.5 * th
gl.glColor3f(*copts.legendColour[:3])
glroutines.text2D(labels[i], (xx, xy), 10, (w, h))
def __drawLight(self):
opts = self.opts
lightPos = np.array(opts.lightPos)
lightPos *= (opts.zoom / 100.0)
gl.glColor4f(1, 1, 1, 1)
gl.glPointSize(10)
gl.glBegin(gl.GL_POINTS)
gl.glVertex3f(*lightPos)
gl.glEnd()
b = self.__displayCtx.bounds
centre = np.array([b.xlo + 0.5 * (b.xhi - b.xlo),
b.ylo + 0.5 * (b.yhi - b.ylo),
b.zlo + 0.5 * (b.zhi - b.zlo)])
centre = affine.transform(centre, self.__viewMat)
gl.glColor4f(1, 0, 1, 1)
gl.glBegin(gl.GL_LINES)
gl.glVertex3f(*lightPos)
gl.glVertex3f(*centre)
gl.glEnd()
def __drawBoundingBox(self):
b = self.__displayCtx.bounds
xlo, xhi = b.x
ylo, yhi = b.y
zlo, zhi = b.z
xlo += 0.1
xhi -= 0.1
vertices = np.array([
[xlo, ylo, zlo],
[xlo, ylo, zhi],
[xlo, yhi, zlo],
[xlo, yhi, zhi],
[xhi, ylo, zlo],
[xhi, ylo, zhi],
[xhi, yhi, zlo],
[xhi, yhi, zhi],
[xlo, ylo, zlo],
[xlo, yhi, zlo],
[xhi, ylo, zlo],
[xhi, yhi, zlo],
[xlo, ylo, zhi],
[xlo, yhi, zhi],
[xhi, ylo, zhi],
[xhi, yhi, zhi],
[xlo, ylo, zlo],
[xhi, ylo, zlo],
[xlo, ylo, zhi],
[xhi, ylo, zhi],
[xlo, yhi, zlo],
[xhi, yhi, zlo],
[xlo, yhi, zhi],
[xhi, yhi, zhi],
])
vertices = affine.transform(vertices, self.__viewMat)
gl.glLineWidth(2)
gl.glColor3f(0.5, 0, 0)
gl.glBegin(gl.GL_LINES)
for v in vertices:
gl.glVertex3f(*v)
gl.glEnd()