Good discussion here, which I stumbled upon after some searching.
Sorry for the slight necro, but I believe this is all still relevant, even with GMS2.
Thanks to Josua for pointing out "window_get_visible_rects()"
It seems there's still no way to toggle "borderless" mode via script? (can only set it on or off for the entire lifetime of the app via the settings window)
Did anyone get something working acceptably, using mentioned techniques or otherwise, in either GMS1 or GMS2?
eg. true fullscreen on primary display, "fake borderless fullscreen" on any other connected display, while still being able to support windowed mode with (potentially sizeable) border
No need to dig out code/examples. Just wondered whether it was feasible, or if there are any other surprises lurking, before I embark on a similar path.
Thanks!
EDIT: Oh, I also found this more recent (but only slightly-related) thread, RE: the IDE always launching the runner on the primary display. I guess the root issue is the same though...
https://forum.yoyogames.com/index.p...-from-ide-is-always-on-primary-monitor.16019/