matrix=[.. sx ,0.0 ,0.0 ,0.0,.. 0.0 ,-sy ,0.0 ,0.0,.. 0.0 ,0.0 ,2.0/depth ,0.0,.. -1-(1.0/width),1+(1.0/height),1.0,1.0]
sx and sy are the matrix position or camera position (in your case the camera is pointed directly at the center of the view), depth = depth of view (only objects within this depth will be rendered). height and width are the size of your view on the world.