Help with window height?

I am very new to OpenGL and graphical programming altogether. I created my OpenGL window (with help from websites…) and modified it to tile the window with textures.

However, my textures always cut off screen or display with blackness around them, I don’t understand why… the width is fine when I change it, but the height is the main culprit. Whenever I modify the screens height from the code it just resizes my tile grid to meet the new height, not fixing the problem… how can I get OpenGL to stop automatically resizing by height?

You mean you get a wrong aspect ratio ?

Or that the vertical field of view is fixed, whereas you would prefer to pin the horizontal field of view ?

Anyway it depends on how you define your projection …