Some applications (and embarrassingly, testime is one of them) call
SDL_StartTextInput() or SDL_SetTextInputRect() every frame. On KDE/KWin
with fcitx5, this causes there to be several preedit events every frame
(particularly given some of the workarounds in Wayland_StartTextInput),
which slows testime down to an unusable crawl.
Instead, make SDL_StartTextInput() a no-op if text input is already
enabled, and cache the input rect, only changing it when the new rect is
actually different.
With these changes, we only get preedit events (and hence
SDL_TEXTEDITING events) when the preedit string actually changes. This
matches the behaviour under XWayland, and works very smoothly.
This needs to check what our deployment target is, not what SDK
is available, since this is a linker symbol and not an enum
value or whatever.
Also removed a copy/paste error that mentioned CoreAudio in
the haptic subsystem.
Fixes#6534.
The XKB_KEY_* and XK_* macros resolve to the same constant values, so use the raw values and note what keys they correspond to in the comments, as is done for the other keysym values in this file.
This completely eliminates the need for any X or XKB system headers along with the if/else defines.
Most of these are probably harmless, but the changes to SDL_immdevice.c and SDL_pixels.c appear to have fixed genuine bugs.
SDL_audiocvt.c: By separating the calculation of the divisor, I got rid of the suspicion that dividing a double by an integer led to loss of precision.
SDL_immdevice.c: Added a missing test, one that could have otherwise led to dereferencing a null pointer.
SDL_events.c, SDL_gamecontroller.c, SDL_joystick.c, SDL_malloc.c, SDL_video.c: Made it clear the return values weren't used.
SDL_hidapi_shield.c: The size is zero, so nothing bad would have happened, but the SDL_memset() was still being given an address outside of the array's range.
SDL_dinputjoystick.c: Initialize local data, just in case IDirectInputDevice8_GetProperty() isn't guaranteed to write to it.
SDL_render_sw.c: drawstate.viewport could be null (as seen on line 691).
SDL.c: SDL_MostSignificantBitIndex32() could return -1, though I don't know if you want to cope with that (what I did) or SDL_assert() that it can't happen.
SDL_hints.c: Replaced boolean tests on pointer values with comparisons to NULL.
SDL_pixels.c: Looks like the switch is genuinely missing a break!
SDL_rect_impl.h: The MacOS static checker pointed out issues with the X comparisons that were handled by assertions; I added assertions for the Y comparisons.
SDL_yuv.c, SDL_windowskeyboard.c, SDL_windowswindow.c: Checked error-result returns.
This reverts commit 04b50f6c6b.
It turns out OpenGL vsync has broken again in macOS 12, so
we're reintroducing our CVDisplayLink code to deal with it,
again.
Reference Issue #4918.
