It is not uncommon for clients to redundantly set the window size and position, either as a holdover from an SDL 1 port, when this was required, due to any window state change triggering a universal update function that sets all window state, even if unnecessary (e.g. always calling SDL_SetWindowSize(), even if the window is fullscreen), or due to the use of compatability layers. Historically, these clients expect that their behavior won't override the base window state, which is an assumption that the windowing changes in SDL 3 broke by caching size and position changes that can't be applied immediately.
This change drops size and position requests when the window is in the maximized and fullscreen states (fullscreen-desktop windows will be repositioned, but the non-fullscreen floating position will not be overwritten), which is behavior more in line with existing client assumptions, and should ease the porting process, as well as prevent annoying bugs when older software is run via sdl2-compat.
In the process of making these changes, pending window state has been moved to separate variables in the SDL_Window struct, as this fixes bugs regarding fullscreen display selection and centering windows immediately after resize on asynchronous platforms, which had issues due to pending state possibly being overwritten.
- make all of function pointers static
- make EGLint context_attribs[] static
- comment out unused function pointer ov_wglGetCurrentContext
- remove unused SDL_DisplayMode openvr_dm_default
- move SDL_VideoDisplay openvr_vd_default to OPENVR_VideoInit()
context and eliminate its C99 initializers
- replace atoi() calls with SDL_atoi()
- replace atof() calls with SDL_atof()
