QGLBuffer.allocate messes with QGLWidget.renderText

srossross

When I call QGLBuffer.allocate QGLWidget.renderText stops working entirely. (simplest demo of issue)

In fact all QPainter functionality stops working, even if you overload the QGLwidget.paintEvent method.
Even native openGL calls to allocate a VBO cause this issue to persist. eg. @glBufferData@

The following PySide code demonstrates the issue. It will open two QGLwidget windows:

One window calls QGLBuffer.allocate and you can not see the text.
The other works fine.

Code:
@
from PySide.QtGui import *
from PySide.QtOpenGL import *
from OpenGL.GL import *
import sys

class GLWidget(QGLWidget):

    def __init__(self, alloc=False):
        QGLWidget.__init__(self)
        self.alloc = alloc
        
    def initializeGL(self):
        self.buffer = buffer = QGLBuffer(QGLBuffer.VertexBuffer)
        buffer.create()
        buffer.bind()
        buffer.setUsagePattern(QGLBuffer.StaticDraw)
        
        if self.alloc: # If true text will not be drawn
            buffer.allocate(80)
    
    def resizeGL(self, h, w):
        glViewport(0, 0, h, w)
        
    def paintGL(self):
        
        glClearColor(1, 1, 1, 1)
        glClear(GL_COLOR_BUFFER_BIT)
        
        glColor(0, 0, 0, 1)
        self.renderText(50, 50, "Text to Render")

def main(argv):

    app = QApplication(argv)
    
    widget = GLWidget(alloc=True)
    widget.show()
    
    widget2 = GLWidget(alloc=False)
    widget2.show()
    
    app.exec_()
    
if __name__ == '__main__':
    main(sys.argv)

@

Can anyone point me in the right direction?

Thanks in advance.

srossross

Solved it. I needed to call QGLBuffer.release() before calls to QPainter.