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)