add antialiasing

[ijontichy]

Should be relatively simple to add support for anti-aliasing. The following OpenGL functions would be relevant:

glHint(GL_LINE_SMOOTH, GL_NICEST); glHint(GL_POLYGON_SMOOTH, GL_NICEST);

glEnable(GL_LINE_SMOOTH); glEnable(GL_POLYGON_SMOOTH); glEnable(GL_BLEND);