Isn''t glViewport supposed to limit the area where OpenGL will display to? If I use the following code the entire Windows client area turns green rather than just the (0,0)-(100,100) area. Is the glClear(GL_Color_Buffer_Bit) not restricted to just the viewport? glViewport(0, 0, 100, 100); glClearColor(0.0, 1.0, 0.0, 1.0); glClear(GL_Color_Buffer_Bit); (I''m using Delphi) Thanks for any help, Bruce

no, clear affects the whole buffer...
the viewport is used in the transformations of coordinates...

Use glScissor if you want to restrict drawing to a specific rectangle...