Fixes DPI awareness of testdrawchessboard (previously, the surface was
being created in points instead of pixels, resulting in the demo app
only drawing in a corner of the screen on High-DPI displays)
*_CreateWindowFramebuffer()/*_UpdateWindowFramebuffer(): are updated
to use SDL_GetWindowSizeInPixels instead of SDL_GetWindowSize() or
window->w/window->h.
Most of the _CreateWindowFramebuffer backends are untested except
for Windows.
Fixes#7047
(cherry picked from commit 67c91353e01f6f2c0cc80c17eeddbad6def7cb01)
- This allows looking up the display index for an arbitrary location rather than requiring an active window to do so.
- This change also reimplements the fallback display lookup that found the display with center closest to the window's center to instead find the display rect edge
closest to the window center (this was done in the almost identical display lookup used in SDL_windowsmodes.c, which now uses `SDL_GetPointDisplayIndex`). In
practice this should almost never be hit as it requires the window's center to not be enclosed by any display rect.
Extend the SDL_WINDOW_ALLOW_HIGHDPI flag documentation to stress the importance of querying the window drawable size after every window event to avoid rendering issues in a mixed-DPI environment.
This API and implementation comes from the Unreal Engine branch of SDL, which
originally called this "SDL_ConfineCursor".
Some minor cleanup and changes for consistency with the rest of SDL_video, but
there are two major changes:
1. The coordinate system has been changed so that `rect` is _window_ relative
and not _screen_ relative, making it easier to implement without having
global access to the display.
2. The UE version unset all rects when passing `NULL` as a parameter for
`window`, this has been removed as it was an unused feature anyhow.
Currently this is only implemented for X, but can be supported on Wayland and
Windows at minimum too.
If you hide a window on Mutter, for example, the compositor never requests
new frames, which will cause Mesa to block forever in eglSwapBuffers to
satisfy the swap interval.
We now always set the swap interval to 0 and manage this ourselves, handing
the frame to Wayland when it requests a new one, and timing out at 10fps just
to keep apps moving if the compositor wants no frames at all.
My understanding is that other protocols are coming that might improve upon
this solution, but for now it solves the total hang.
Fixes#4335.
