class Video(QWidget):
def __init__(self):
# init the widget
QWidget.__init__(self)
# set up the scene
self.scene=QGraphicsScene()
self.scene.setSceneRect(0,0,800,600)
# add a view of that scene
self.view = QGraphicsView()
self.view.setScene(self.scene)
self.view.setRenderHint(QPainter.Antialiasing)
self.view.setFixedSize(800,600)
self.view.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
self.view.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
# set the screen sync
val = "1"
# Set for nVidia linux
os.environ["__GL_SYNC_TO_VBLANK"] = val
# Set for recent linux Mesa DRI Radeon
os.environ["LIBGL_SYNC_REFRESH"] = val
qglf = QGLFormat()
qglf.setSampleBuffers(True)
#qglf.setSwapInterval(1)
self.glw = QGLWidget(qglf)
self.glw.setAutoBufferSwap(False)
self.view.setViewport(self.glw)
QTimer.singleShot(0,self.glw.swapBuffers)
def swapBuffers(self):
# first call the swap on the QGLWidget
self.glw.swapBuffers()
self.glw.makeCurrent()
# The following is taken from the PsychToolbox
# Draw a single pixel in left-top area of back-buffer.
# This will wait/stall the rendering pipeline
# until the buffer flip has happened, aka immediately after the VBL has started.
# We need the pixel as "synchronization token", so the following glFinish() really
# waits for VBL instead of just "falling through" due to the asynchronous nature of
# OpenGL:
glDrawBuffer(GL_BACK)
# We draw our single pixel with an alpha-value of zero - so effectively it doesn't
# change the color buffer - just the z-buffer if z-writes are enabled...
glColor4f(0.0,0.0,0.0,0.0)
glBegin(GL_POINTS)
glVertex2i(10,10)
glEnd()
# This glFinish() will wait until point drawing is finished, ergo backbuffer was ready
# for drawing, ergo buffer swap in sync with start of VBL has happened.
glFinish()
def show(self):
# shows the viewer widget
self.view.show()
class GUI():
def __init__(self):
# init the widget
#QWidget.__init__(self, parent)
# set up the scene
self.scene = QGraphicsScene()
self.scene.setSceneRect(0, 0, 800, 600)
# add a view of that scene
self.view = QGraphicsView()
self.view.setScene(self.scene)
self.view.setRenderHint(QPainter.Antialiasing)
self.view.setFixedSize(800, 600)
self.view.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
self.view.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
# set the screen sync to vertical retrace
val = "1"
# Set for nVidia linux
os.environ["__GL_SYNC_TO_VBLANK"] = val
# Set for recent linux Mesa DRI Radeon
os.environ["LIBGL_SYNC_REFRESH"] = val
qglf = QGLFormat()
qglf.setSampleBuffers(True)
self.glw = QGLWidget(qglf)
self.glw.setAutoBufferSwap(False)
self.view.setViewport(self.glw)
#self.view.showFullScreen()
self.view.show()
self.last_finish = 0
QTimer.singleShot(0, self.glw.swapBuffers)
def swapBuffers(self):
# first call the swap on the QGLWidget
start = long(now() * 1000)
self.glw.swapBuffers()
#self.glw.makeCurrent()
# The following is taken from the PsychToolbox
# Draw a single pixel in left-top area of back-buffer.
# This will wait/stall the rendering pipeline
# until the buffer flip has happened, aka immediately after the VBL has started.
# We need the pixel as "synchronization token", so the following glFinish() really
# waits for VBL instead of just "falling through" due to the asynchronous nature of
# OpenGL:
glDrawBuffer(GL_BACK)
# We draw our single pixel with an alpha-value of zero - so effectively it doesn't
# change the color buffer - just the z-buffer if z-writes are enabled...
glColor4f(0.0, 0.0, 0.0, 0.0)
glBegin(GL_POINTS)
glVertex2i(10, 10)
glEnd()
# This glFinish() will wait until point drawing is finished, ergo backbuffer was ready
# for drawing, ergo buffer swap in sync with start of VBL has happened.
glFinish()
finish = long(now() * 1000)
fdiff = finish - self.last_finish
self.last_finish = finish
return (start, finish - start, fdiff)
