I’m trying to make 3 sub windows in a main window. I used glutCreateWindow to create the main window size about 587x459.

I want to create 3 subwindows …
2 windows side by side on the upper portion each with size 256x256.
3rd window at the bottom portion of the main window with size 256* 128

there is 25 gap size between the windows… thus the weird size of (256*2+75)587x459 (256+128+75).

I used glutCreateSubWindow(window_name,x,y,width, height) …
However, the window that comes out isn’t right. It seems more like the height of the 2 upper subwindow(s) (side by side)is equal to 1/2 height of the main window, such that there is a large blank space at the lower portion of the main window. ( because the height of the lower (3rd) subwindow is suppose to be only 128.

Can someone please state what the parameters stand for? I might have misunderstood the use of glutCreateSubWindow. Else, does anyone have any idea what went wrong?