Source code for pyqtgraph.opengl.GLViewWidget
from ..Qt import QtCore, QtGui, QtOpenGL, QT_LIB
from OpenGL.GL import *
import OpenGL.GL.framebufferobjects as glfbo
import numpy as np
from .. import Vector
from .. import functions as fn
##Vector = QtGui.QVector3D
ShareWidget = None
[docs]class GLViewWidget(QtOpenGL.QGLWidget):
"""
Basic widget for displaying 3D data
- Rotation/scale controls
- Axis/grid display
- Export options
High-DPI displays: Qt5 should automatically detect the correct resolution.
For Qt4, specify the ``devicePixelRatio`` argument when initializing the
widget (usually this value is 1-2).
"""
[docs] def __init__(self, parent=None, devicePixelRatio=None):
global ShareWidget
if ShareWidget is None:
## create a dummy widget to allow sharing objects (textures, shaders, etc) between views
ShareWidget = QtOpenGL.QGLWidget()
QtOpenGL.QGLWidget.__init__(self, parent, ShareWidget)
self.setFocusPolicy(QtCore.Qt.ClickFocus)
self.opts = {
'devicePixelRatio': devicePixelRatio
}
self.reset()
self.items = []
self.noRepeatKeys = [QtCore.Qt.Key_Right, QtCore.Qt.Key_Left, QtCore.Qt.Key_Up, QtCore.Qt.Key_Down, QtCore.Qt.Key_PageUp, QtCore.Qt.Key_PageDown]
self.keysPressed = {}
self.keyTimer = QtCore.QTimer()
self.keyTimer.timeout.connect(self.evalKeyState)
self.makeCurrent()
[docs] def reset(self):
"""
Initialize the widget state or reset the current state to the original state.
"""
self.opts['center'] = Vector(0,0,0) ## will always appear at the center of the widget
self.opts['distance'] = 10.0 ## distance of camera from center
self.opts['fov'] = 60 ## horizontal field of view in degrees
self.opts['elevation'] = 30 ## camera's angle of elevation in degrees
self.opts['azimuth'] = 45 ## camera's azimuthal angle in degrees
## (rotation around z-axis 0 points along x-axis)
self.opts['viewport'] = None ## glViewport params; None == whole widget
self.setBackgroundColor('k')
def addItem(self, item):
self.items.append(item)
if hasattr(item, 'initializeGL'):
self.makeCurrent()
try:
item.initializeGL()
except:
self.checkOpenGLVersion('Error while adding item %s to GLViewWidget.' % str(item))
item._setView(self)
#print "set view", item, self, item.view()
self.update()
[docs] def removeItem(self, item):
"""
Remove the item from the scene.
"""
self.items.remove(item)
item._setView(None)
self.update()
[docs] def clear(self):
"""
Remove all items from the scene.
"""
for item in self.items:
item._setView(None)
self.items = []
self.update()
def initializeGL(self):
self.resizeGL(self.width(), self.height())
[docs] def setBackgroundColor(self, *args, **kwds):
"""
Set the background color of the widget. Accepts the same arguments as
pg.mkColor() and pg.glColor().
"""
self.opts['bgcolor'] = fn.glColor(*args, **kwds)
self.update()
def getViewport(self):
vp = self.opts['viewport']
dpr = self.devicePixelRatio()
if vp is None:
return (0, 0, int(self.width() * dpr), int(self.height() * dpr))
else:
return tuple([int(x * dpr) for x in vp])
def devicePixelRatio(self):
dpr = self.opts['devicePixelRatio']
if dpr is not None:
return dpr
if hasattr(QtOpenGL.QGLWidget, 'devicePixelRatio'):
return QtOpenGL.QGLWidget.devicePixelRatio(self)
else:
return 1.0
def resizeGL(self, w, h):
pass
#glViewport(*self.getViewport())
#self.update()
def setProjection(self, region=None):
m = self.projectionMatrix(region)
glMatrixMode(GL_PROJECTION)
glLoadIdentity()
a = np.array(m.copyDataTo()).reshape((4,4))
glMultMatrixf(a.transpose())
def projectionMatrix(self, region=None):
if region is None:
dpr = self.devicePixelRatio()
region = (0, 0, self.width() * dpr, self.height() * dpr)
x0, y0, w, h = self.getViewport()
dist = self.opts['distance']
fov = self.opts['fov']
nearClip = dist * 0.001
farClip = dist * 1000.
r = nearClip * np.tan(fov * 0.5 * np.pi / 180.)
t = r * h / w
## Note that X0 and width in these equations must be the values used in viewport
left = r * ((region[0]-x0) * (2.0/w) - 1)
right = r * ((region[0]+region[2]-x0) * (2.0/w) - 1)
bottom = t * ((region[1]-y0) * (2.0/h) - 1)
top = t * ((region[1]+region[3]-y0) * (2.0/h) - 1)
tr = QtGui.QMatrix4x4()
tr.frustum(left, right, bottom, top, nearClip, farClip)
return tr
def setModelview(self):
glMatrixMode(GL_MODELVIEW)
glLoadIdentity()
m = self.viewMatrix()
a = np.array(m.copyDataTo()).reshape((4,4))
glMultMatrixf(a.transpose())
def viewMatrix(self):
tr = QtGui.QMatrix4x4()
tr.translate( 0.0, 0.0, -self.opts['distance'])
tr.rotate(self.opts['elevation']-90, 1, 0, 0)
tr.rotate(self.opts['azimuth']+90, 0, 0, -1)
center = self.opts['center']
tr.translate(-center.x(), -center.y(), -center.z())
return tr
[docs] def itemsAt(self, region=None):
"""
Return a list of the items displayed in the region (x, y, w, h)
relative to the widget.
"""
region = (region[0], self.height()-(region[1]+region[3]), region[2], region[3])
#buf = np.zeros(100000, dtype=np.uint)
buf = glSelectBuffer(100000)
try:
glRenderMode(GL_SELECT)
glInitNames()
glPushName(0)
self._itemNames = {}
self.paintGL(region=region, useItemNames=True)
finally:
hits = glRenderMode(GL_RENDER)
items = [(h.near, h.names[0]) for h in hits]
items.sort(key=lambda i: i[0])
return [self._itemNames[i[1]] for i in items]
[docs] def paintGL(self, region=None, viewport=None, useItemNames=False):
"""
viewport specifies the arguments to glViewport. If None, then we use self.opts['viewport']
region specifies the sub-region of self.opts['viewport'] that should be rendered.
Note that we may use viewport != self.opts['viewport'] when exporting.
"""
if viewport is None:
glViewport(*self.getViewport())
else:
glViewport(*viewport)
self.setProjection(region=region)
self.setModelview()
bgcolor = self.opts['bgcolor']
glClearColor(*bgcolor)
glClear( GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT )
self.drawItemTree(useItemNames=useItemNames)
def drawItemTree(self, item=None, useItemNames=False):
if item is None:
items = [x for x in self.items if x.parentItem() is None]
else:
items = item.childItems()
items.append(item)
items.sort(key=lambda a: a.depthValue())
for i in items:
if not i.visible():
continue
if i is item:
try:
glPushAttrib(GL_ALL_ATTRIB_BITS)
if useItemNames:
glLoadName(i._id)
self._itemNames[i._id] = i
i.paint()
except:
from .. import debug
debug.printExc()
msg = "Error while drawing item %s." % str(item)
ver = glGetString(GL_VERSION)
if ver is not None:
ver = ver.split()[0]
if int(ver.split(b'.')[0]) < 2:
print(msg + " The original exception is printed above; however, pyqtgraph requires OpenGL version 2.0 or greater for many of its 3D features and your OpenGL version is %s. Installing updated display drivers may resolve this issue." % ver)
else:
print(msg)
finally:
glPopAttrib()
else:
glMatrixMode(GL_MODELVIEW)
glPushMatrix()
try:
tr = i.transform()
a = np.array(tr.copyDataTo()).reshape((4,4))
glMultMatrixf(a.transpose())
self.drawItemTree(i, useItemNames=useItemNames)
finally:
glMatrixMode(GL_MODELVIEW)
glPopMatrix()
def setCameraPosition(self, pos=None, distance=None, elevation=None, azimuth=None):
if pos is not None:
self.opts['center'] = pos
if distance is not None:
self.opts['distance'] = distance
if elevation is not None:
self.opts['elevation'] = elevation
if azimuth is not None:
self.opts['azimuth'] = azimuth
self.update()
[docs] def cameraPosition(self):
"""Return current position of camera based on center, dist, elevation, and azimuth"""
center = self.opts['center']
dist = self.opts['distance']
elev = self.opts['elevation'] * np.pi/180.
azim = self.opts['azimuth'] * np.pi/180.
pos = Vector(
center.x() + dist * np.cos(elev) * np.cos(azim),
center.y() + dist * np.cos(elev) * np.sin(azim),
center.z() + dist * np.sin(elev)
)
return pos
[docs] def orbit(self, azim, elev):
"""Orbits the camera around the center position. *azim* and *elev* are given in degrees."""
self.opts['azimuth'] += azim
self.opts['elevation'] = np.clip(self.opts['elevation'] + elev, -90, 90)
self.update()
[docs] def pan(self, dx, dy, dz, relative='global'):
"""
Moves the center (look-at) position while holding the camera in place.
============== =======================================================
**Arguments:**
*dx* Distance to pan in x direction
*dy* Distance to pan in y direction
*dz* Distance to pan in z direction
*relative* String that determines the direction of dx,dy,dz.
If "global", then the global coordinate system is used.
If "view", then the z axis is aligned with the view
direction, and x and y axes are inthe plane of the
view: +x points right, +y points up.
If "view-upright", then x is in the global xy plane and
points to the right side of the view, y is in the
global xy plane and orthogonal to x, and z points in
the global z direction.
============== =======================================================
Distances are scaled roughly such that a value of 1.0 moves
by one pixel on screen.
Prior to version 0.11, *relative* was expected to be either True (x-aligned) or
False (global). These values are deprecated but still recognized.
"""
# for backward compatibility:
relative = {True: "view-upright", False: "global"}.get(relative, relative)
if relative == 'global':
self.opts['center'] += QtGui.QVector3D(dx, dy, dz)
elif relative == 'view-upright':
cPos = self.cameraPosition()
cVec = self.opts['center'] - cPos
dist = cVec.length() ## distance from camera to center
xDist = dist * 2. * np.tan(0.5 * self.opts['fov'] * np.pi / 180.) ## approx. width of view at distance of center point
xScale = xDist / self.width()
zVec = QtGui.QVector3D(0,0,1)
xVec = QtGui.QVector3D.crossProduct(zVec, cVec).normalized()
yVec = QtGui.QVector3D.crossProduct(xVec, zVec).normalized()
self.opts['center'] = self.opts['center'] + xVec * xScale * dx + yVec * xScale * dy + zVec * xScale * dz
elif relative == 'view':
# pan in plane of camera
elev = np.radians(self.opts['elevation'])
azim = np.radians(self.opts['azimuth'])
fov = np.radians(self.opts['fov'])
dist = (self.opts['center'] - self.cameraPosition()).length()
fov_factor = np.tan(fov / 2) * 2
scale_factor = dist * fov_factor / self.width()
z = scale_factor * np.cos(elev) * dy
x = scale_factor * (np.sin(azim) * dx - np.sin(elev) * np.cos(azim) * dy)
y = scale_factor * (np.cos(azim) * dx + np.sin(elev) * np.sin(azim) * dy)
self.opts['center'] += QtGui.QVector3D(x, -y, z)
else:
raise ValueError("relative argument must be global, view, or view-upright")
self.update()
[docs] def pixelSize(self, pos):
"""
Return the approximate size of a screen pixel at the location pos
Pos may be a Vector or an (N,3) array of locations
"""
cam = self.cameraPosition()
if isinstance(pos, np.ndarray):
cam = np.array(cam).reshape((1,)*(pos.ndim-1)+(3,))
dist = ((pos-cam)**2).sum(axis=-1)**0.5
else:
dist = (pos-cam).length()
xDist = dist * 2. * np.tan(0.5 * self.opts['fov'] * np.pi / 180.)
return xDist / self.width()
def mousePressEvent(self, ev):
self.mousePos = ev.pos()
def mouseMoveEvent(self, ev):
diff = ev.pos() - self.mousePos
self.mousePos = ev.pos()
if ev.buttons() == QtCore.Qt.LeftButton:
if (ev.modifiers() & QtCore.Qt.ControlModifier):
self.pan(diff.x(), diff.y(), 0, relative='view')
else:
self.orbit(-diff.x(), diff.y())
elif ev.buttons() == QtCore.Qt.MidButton:
if (ev.modifiers() & QtCore.Qt.ControlModifier):
self.pan(diff.x(), 0, diff.y(), relative='view-upright')
else:
self.pan(diff.x(), diff.y(), 0, relative='view-upright')
def mouseReleaseEvent(self, ev):
pass
# Example item selection code:
#region = (ev.pos().x()-5, ev.pos().y()-5, 10, 10)
#print(self.itemsAt(region))
## debugging code: draw the picking region
#glViewport(*self.getViewport())
#glClear( GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT )
#region = (region[0], self.height()-(region[1]+region[3]), region[2], region[3])
#self.paintGL(region=region)
#self.swapBuffers()
def wheelEvent(self, ev):
delta = 0
if QT_LIB in ['PyQt4', 'PySide']:
delta = ev.delta()
else:
delta = ev.angleDelta().x()
if delta == 0:
delta = ev.angleDelta().y()
if (ev.modifiers() & QtCore.Qt.ControlModifier):
self.opts['fov'] *= 0.999**delta
else:
self.opts['distance'] *= 0.999**delta
self.update()
def keyPressEvent(self, ev):
if ev.key() in self.noRepeatKeys:
ev.accept()
if ev.isAutoRepeat():
return
self.keysPressed[ev.key()] = 1
self.evalKeyState()
def keyReleaseEvent(self, ev):
if ev.key() in self.noRepeatKeys:
ev.accept()
if ev.isAutoRepeat():
return
try:
del self.keysPressed[ev.key()]
except:
self.keysPressed = {}
self.evalKeyState()
def evalKeyState(self):
speed = 2.0
if len(self.keysPressed) > 0:
for key in self.keysPressed:
if key == QtCore.Qt.Key_Right:
self.orbit(azim=-speed, elev=0)
elif key == QtCore.Qt.Key_Left:
self.orbit(azim=speed, elev=0)
elif key == QtCore.Qt.Key_Up:
self.orbit(azim=0, elev=-speed)
elif key == QtCore.Qt.Key_Down:
self.orbit(azim=0, elev=speed)
elif key == QtCore.Qt.Key_PageUp:
pass
elif key == QtCore.Qt.Key_PageDown:
pass
self.keyTimer.start(16)
else:
self.keyTimer.stop()
[docs] def checkOpenGLVersion(self, msg):
"""
Give exception additional context about version support.
Only to be called from within exception handler.
As this check is only performed on error,
unsupported versions might still work!
"""
# Check for unsupported version
verString = glGetString(GL_VERSION)
ver = verString.split()[0]
# If not OpenGL ES...
if str(ver.split(b'.')[0]).isdigit():
verNumber = int(ver.split(b'.')[0])
# ...and version is supported:
if verNumber >= 2:
# OpenGL version is fine, raise the original exception
raise
# Print original exception
from .. import debug
debug.printExc()
# Notify about unsupported version
raise Exception(
msg + "\n" + \
"pyqtgraph.opengl: Requires >= OpenGL 2.0 (not ES); Found %s" % verString
)
[docs] def readQImage(self):
"""
Read the current buffer pixels out as a QImage.
"""
w = self.width()
h = self.height()
self.repaint()
pixels = np.empty((h, w, 4), dtype=np.ubyte)
pixels[:] = 128
pixels[...,0] = 50
pixels[...,3] = 255
glReadPixels(0, 0, w, h, GL_RGBA, GL_UNSIGNED_BYTE, pixels)
# swap B,R channels for Qt
tmp = pixels[...,0].copy()
pixels[...,0] = pixels[...,2]
pixels[...,2] = tmp
pixels = pixels[::-1] # flip vertical
img = fn.makeQImage(pixels, transpose=False)
return img
def renderToArray(self, size, format=GL_BGRA, type=GL_UNSIGNED_BYTE, textureSize=1024, padding=256):
w,h = map(int, size)
self.makeCurrent()
tex = None
fb = None
depth_buf = None
try:
output = np.empty((w, h, 4), dtype=np.ubyte)
fb = glfbo.glGenFramebuffers(1)
glfbo.glBindFramebuffer(glfbo.GL_FRAMEBUFFER, fb )
glEnable(GL_TEXTURE_2D)
tex = glGenTextures(1)
glBindTexture(GL_TEXTURE_2D, tex)
texwidth = textureSize
data = np.zeros((texwidth,texwidth,4), dtype=np.ubyte)
## Test texture dimensions first
glTexImage2D(GL_PROXY_TEXTURE_2D, 0, GL_RGBA, texwidth, texwidth, 0, GL_RGBA, GL_UNSIGNED_BYTE, None)
if glGetTexLevelParameteriv(GL_PROXY_TEXTURE_2D, 0, GL_TEXTURE_WIDTH) == 0:
raise Exception("OpenGL failed to create 2D texture (%dx%d); too large for this hardware." % shape[:2])
## create teture
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, texwidth, texwidth, 0, GL_RGBA, GL_UNSIGNED_BYTE, data.transpose((1,0,2)))
# Create depth buffer
depth_buf = glGenRenderbuffers(1)
glBindRenderbuffer(GL_RENDERBUFFER, depth_buf)
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, texwidth, texwidth)
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depth_buf)
self.opts['viewport'] = (0, 0, w, h) # viewport is the complete image; this ensures that paintGL(region=...)
# is interpreted correctly.
p2 = 2 * padding
for x in range(-padding, w-padding, texwidth-p2):
for y in range(-padding, h-padding, texwidth-p2):
x2 = min(x+texwidth, w+padding)
y2 = min(y+texwidth, h+padding)
w2 = x2-x
h2 = y2-y
## render to texture
glfbo.glFramebufferTexture2D(glfbo.GL_FRAMEBUFFER, glfbo.GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, tex, 0)
self.paintGL(region=(x, h-y-h2, w2, h2), viewport=(0, 0, w2, h2)) # only render sub-region
glBindTexture(GL_TEXTURE_2D, tex) # fixes issue #366
## read texture back to array
data = glGetTexImage(GL_TEXTURE_2D, 0, format, type)
data = np.fromstring(data, dtype=np.ubyte).reshape(texwidth,texwidth,4).transpose(1,0,2)[:, ::-1]
output[x+padding:x2-padding, y+padding:y2-padding] = data[padding:w2-padding, -(h2-padding):-padding]
finally:
self.opts['viewport'] = None
glfbo.glBindFramebuffer(glfbo.GL_FRAMEBUFFER, 0)
glBindTexture(GL_TEXTURE_2D, 0)
if tex is not None:
glDeleteTextures([tex])
if fb is not None:
glfbo.glDeleteFramebuffers([fb])
if depth_buf is not None:
glDeleteRenderbuffers(1, [depth_buf])
return output