Hello

I'm using OpenGL in a QGraphicScene with drawBackground(

I create a simple shader that just change the pixel's color of a Qpainter rect
The shader works only the second time I use it


Qt Code: 
  1. void drawBackground( QPainter *pPainter, const QRectF &pRect )
  2. {
  3. 	glClearColor( mBackGroundColor.redF(), mBackGroundColor.greenF(), mBackGroundColor.blueF(), 1.0f );
  4.  
  5.     	glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
  6.     	glClearDepth(1.0f);
  7.  
  8.     	glMatrixMode( GL_PROJECTION );
  9.     	glPushMatrix();
  10. 	glLoadIdentity();
  11.  
  12. 	lViewAngle =  lViewAngle * 360.0 / M_PI;
  13. 	gluPerspective( lViewAngle, width() / height(), 0.1, 200 );
  14.  
  15. 	glMatrixMode( GL_MODELVIEW );
  16.  
  17. 	//OPENGL STUFF		
  18.  
  19.         glPopMatrix();
  20.         glMatrixMode( GL_PROJECTION );  
  21.     	pPainter->endNativePainting();	
  22.  
  23. 	//shader doesn't work
  24. 	shader.bind();
  25. 	pPainter->fillRect(0, 0, 128, 128, Qt::black);
  26.     	shader.release();
  27.  
  28. 	//shader work
  29.    	shader.bind();
  30.      	pPainter->fillRect(100, 100, 128, 128, Qt::black);
  31.     	shader.release();
  32. }
To copy to clipboard, switch view to plain text mode 

Thanks for your help