When you make a window in glut using glutCreateWindow it puts a top to the window? What if I want to do some OpenGL rendering without a window top?
This probably doesn't make much sense without a picture:
Essentially I want to remove this from the window.
The proper terminology for what you want is "undecorated window" or "borderless window". Unfortunately, I can't find any GLUT calls which let you control window decorations.
The closest I was able to find was glutFullScreen
which, on X11 platforms, is often implemented by maximizing an undecorated window... but it'll re-decorate it if you un-maximize it.
This forum thread seems to confirm my conclusions.
Use GLUT_BORDERLESS and GLUT_CAPTIONLESS as additional parameters to the glutInitDisplayMode() to get rid of window border and caption as follow:
glutInitDisplayMode(GLUT_RGBA|GLUT_DOUBLE|GLUT_DEPTH|GLUT_BORDERLESS|GLUT_CAPTIONLESS);
At least it works pretty good with freeglut 2.8.1 on Windows.