from OpenGL.GL import * # noqa
import numpy as np
from ...Qt import QtGui
from ..GLGraphicsItem import GLGraphicsItem
__all__ = ['GLVolumeItem']
[docs]
class GLVolumeItem(GLGraphicsItem):
"""
**Bases:** :class:`GLGraphicsItem <pyqtgraph.opengl.GLGraphicsItem.GLGraphicsItem>`
Displays volumetric data.
"""
[docs]
def __init__(self, data, sliceDensity=1, smooth=True, glOptions='translucent', parentItem=None):
"""
============== =======================================================================================
**Arguments:**
data Volume data to be rendered. *Must* be 4D numpy array (x, y, z, RGBA) with dtype=ubyte.
sliceDensity Density of slices to render through the volume. A value of 1 means one slice per voxel.
smooth (bool) If True, the volume slices are rendered with linear interpolation
============== =======================================================================================
"""
self.sliceDensity = sliceDensity
self.smooth = smooth
self.data = None
self._needUpload = False
self.texture = None
super().__init__(parentItem=parentItem)
self.setGLOptions(glOptions)
self.setData(data)
def setData(self, data):
self.data = data
self._needUpload = True
self.update()
def _uploadData(self):
glEnable(GL_TEXTURE_3D)
if self.texture is None:
self.texture = glGenTextures(1)
glBindTexture(GL_TEXTURE_3D, self.texture)
if self.smooth:
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR)
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR)
else:
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_NEAREST)
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_NEAREST)
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER)
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER)
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_BORDER)
shape = self.data.shape
## Test texture dimensions first
glTexImage3D(GL_PROXY_TEXTURE_3D, 0, GL_RGBA, shape[0], shape[1], shape[2], 0, GL_RGBA, GL_UNSIGNED_BYTE, None)
if glGetTexLevelParameteriv(GL_PROXY_TEXTURE_3D, 0, GL_TEXTURE_WIDTH) == 0:
raise Exception("OpenGL failed to create 3D texture (%dx%dx%d); too large for this hardware." % shape[:3])
data = np.ascontiguousarray(self.data.transpose((2,1,0,3)))
glTexImage3D(GL_TEXTURE_3D, 0, GL_RGBA, shape[0], shape[1], shape[2], 0, GL_RGBA, GL_UNSIGNED_BYTE, data)
glDisable(GL_TEXTURE_3D)
self.lists = {}
for ax in [0,1,2]:
for d in [-1, 1]:
l = glGenLists(1)
self.lists[(ax,d)] = l
glNewList(l, GL_COMPILE)
self.drawVolume(ax, d)
glEndList()
self._needUpload = False
def paint(self):
if self.data is None:
return
if self._needUpload:
self._uploadData()
self.setupGLState()
glEnable(GL_TEXTURE_3D)
glBindTexture(GL_TEXTURE_3D, self.texture)
#glEnable(GL_DEPTH_TEST)
#glDisable(GL_CULL_FACE)
#glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)
#glEnable( GL_BLEND )
#glEnable( GL_ALPHA_TEST )
glColor4f(1,1,1,1)
view = self.view()
center = QtGui.QVector3D(*[x/2. for x in self.data.shape[:3]])
cam = self.mapFromParent(view.cameraPosition()) - center
#print "center", center, "cam", view.cameraPosition(), self.mapFromParent(view.cameraPosition()), "diff", cam
cam = np.array([cam.x(), cam.y(), cam.z()])
ax = np.argmax(abs(cam))
d = 1 if cam[ax] > 0 else -1
glCallList(self.lists[(ax,d)]) ## draw axes
glDisable(GL_TEXTURE_3D)
def drawVolume(self, ax, d):
imax = [0,1,2]
imax.remove(ax)
tp = [[0,0,0],[0,0,0],[0,0,0],[0,0,0]]
vp = [[0,0,0],[0,0,0],[0,0,0],[0,0,0]]
nudge = [0.5/x for x in self.data.shape]
tp[0][imax[0]] = 0+nudge[imax[0]]
tp[0][imax[1]] = 0+nudge[imax[1]]
tp[1][imax[0]] = 1-nudge[imax[0]]
tp[1][imax[1]] = 0+nudge[imax[1]]
tp[2][imax[0]] = 1-nudge[imax[0]]
tp[2][imax[1]] = 1-nudge[imax[1]]
tp[3][imax[0]] = 0+nudge[imax[0]]
tp[3][imax[1]] = 1-nudge[imax[1]]
vp[0][imax[0]] = 0
vp[0][imax[1]] = 0
vp[1][imax[0]] = self.data.shape[imax[0]]
vp[1][imax[1]] = 0
vp[2][imax[0]] = self.data.shape[imax[0]]
vp[2][imax[1]] = self.data.shape[imax[1]]
vp[3][imax[0]] = 0
vp[3][imax[1]] = self.data.shape[imax[1]]
slices = self.data.shape[ax] * self.sliceDensity
r = list(range(slices))
if d == -1:
r = r[::-1]
glBegin(GL_QUADS)
tzVals = np.linspace(nudge[ax], 1.0-nudge[ax], slices)
vzVals = np.linspace(0, self.data.shape[ax], slices)
for i in r:
z = tzVals[i]
w = vzVals[i]
tp[0][ax] = z
tp[1][ax] = z
tp[2][ax] = z
tp[3][ax] = z
vp[0][ax] = w
vp[1][ax] = w
vp[2][ax] = w
vp[3][ax] = w
glTexCoord3f(*tp[0])
glVertex3f(*vp[0])
glTexCoord3f(*tp[1])
glVertex3f(*vp[1])
glTexCoord3f(*tp[2])
glVertex3f(*vp[2])
glTexCoord3f(*tp[3])
glVertex3f(*vp[3])
glEnd()
## Interesting idea:
## remove projection/modelview matrixes, recreate in texture coords.
## it _sorta_ works, but needs tweaking.
#mvm = glGetDoublev(GL_MODELVIEW_MATRIX)
#pm = glGetDoublev(GL_PROJECTION_MATRIX)
#m = QtGui.QMatrix4x4(mvm.flatten()).inverted()[0]
#p = QtGui.QMatrix4x4(pm.flatten()).inverted()[0]
#glMatrixMode(GL_PROJECTION)
#glPushMatrix()
#glLoadIdentity()
#N=1
#glOrtho(-N,N,-N,N,-100,100)
#glMatrixMode(GL_MODELVIEW)
#glLoadIdentity()
#glMatrixMode(GL_TEXTURE)
#glLoadIdentity()
#glMultMatrixf(m.copyDataTo())
#view = self.view()
#w = view.width()
#h = view.height()
#dist = view.opts['distance']
#fov = view.opts['fov']
#nearClip = dist * .1
#farClip = dist * 5.
#r = nearClip * np.tan(fov)
#t = r * h / w
#p = QtGui.QMatrix4x4()
#p.frustum( -r, r, -t, t, nearClip, farClip)
#glMultMatrixf(p.inverted()[0].copyDataTo())
#glBegin(GL_QUADS)
#M=1
#for i in range(500):
#z = i/500.
#w = -i/500.
#glTexCoord3f(-M, -M, z)
#glVertex3f(-N, -N, w)
#glTexCoord3f(M, -M, z)
#glVertex3f(N, -N, w)
#glTexCoord3f(M, M, z)
#glVertex3f(N, N, w)
#glTexCoord3f(-M, M, z)
#glVertex3f(-N, N, w)
#glEnd()
#glDisable(GL_TEXTURE_3D)
#glMatrixMode(GL_PROJECTION)
#glPopMatrix()
