# Parts of OpenGL rendering area missing/transparent until resize

I am having a weird transparency issue when running my game in windowed mode. Parts of the window, left and top parts in normal window mode, right and bottom when in maximised window, become transparent. It is full transparency not just an uncleared buffer as I can see movement from other windows behind. The size of the area that is transparent varies slightly between runs. I'm pretty sure it worked in January when I last worked on the game.

If I resize or iconify/restore the window either manually or programmatically with GLFW it fixes itself and renders the full window as expected.

glfwGetFramebufferSize, glfwGetWindowSize and glGetIntegerv(GL11.GL_VIEWPORT) all report the same correct values before and after a resize. Calling glViewport does not fix the issue. I am not getting any relevant openGL errors.

If I start the game window maximised on the displays connected to the old graphics card R9 290X I do not get this problem but window maximised on newer RX 5700 XT display still has the problem but in bottom right instead of top left. Full screen works fine on all displays.

Have not seen any problems with other games I have but I always run them in fullscreen and they are mostly DirectX or Vulcan.

Has anyone encountered this problem before? I would rather not have to programmatically modify the window size by 1 pixel each start as that is an ugly fix.

If anyone wants to test on their system to see if it is a code or driver error run either the full packaged jar (in sandbox preferably) or checkout minimal error example yourself and execute "./gradlew run".

• Windows 7
• GDX 1.9.11 (also tried 1.9.10)
• LWJGL 3.2.3 (also tried 3.2.2)