This has been better fixed by b28ed02 or another related relative mouse mode change of @slouken in SDL 2.0.17 and as such can be reverted to reduce unneeded processing in WM_MOUSEMOVE
This will still happen occasionally as the mouse is whipped around, if there is a window overlapping the game window, but it should happen less often now. This could even happen with the original code that warped the mouse every frame, so this should be a good compromise where we don't warp the mouse continously and we still keep the mouse in the safe area of the game window.
Note that notifications can be any size, so the safe area may need to be adjusted or even dynamically defined via a hint.
* Fixed: Whitespace being striped from the end of IME strings incorrectly
* Fixed: Google IME Candidate Window not placing correctly
* Why are PostBuild events stored in the vcxproj and not a user file?
* Revert SDL.vcxproj properly...
* Remove whitespace as per code review
* Fix Werror=declaration-after-statement error in code
This was the original intent (note SDL_UpdateWindowGrab() in SDL_OnWindowFocusGained() and SDL_OnWindowFocusLost()) and fixes a bug where relative motion unexpectedly stops if the task bar is covering the bottom of the game window and the mouse happens to move over it while relative mode is enabled.
Another alternative would be to confine the mouse when relative mode is enabled, but that generates mouse motion which would need to be ignored, and it's possible for the user moving the mouse to combine with the mouse moving into the confined area so you can't easily tell whether to ignore the mouse motion. See https://github.com/libsdl-org/SDL/issues/4165 for a case where this is problematic.
When hint SDL_HINT_OPENGL_ES_DRIVER is set to "1" (e.g. for ANGLE support), assertion due to !_this->gl_config.driver_loaded can be causes while EGL is available.
The implementation of clip logic for relative mode seemed to
unnecessarily limit the usable area to the middle of the window, in a
2x2 pixel region. This has the adverse side effect of moving the
operating system cursor to that location, even if it is in a valid
location in the window.
While in most scenarios this is handled correctly (by storing the
original position of the cursor in the window and restoring when leaving
relative mode), there are edge cases where this clip operation can cause
WM_MOUSEMOVE to fire at a point in time where it counts as a relative
delta from SDL's perspective.
When possible use native os functions to make a blocking call waiting for
an incoming event. Previous behavior was to continuously poll the event
queue with a small delay between each poll.
The blocking call uses a new optional video driver event,
WaitEventTimeout, if available. It is called only if an window
already shown is available. If present the window is designated
using the variable wakeup_window to receive a wakeup event if
needed.
The WaitEventTimeout function accept a timeout parameter. If
positive the call will wait for an event or return if the timeout
expired without any event. If the timeout is zero it will
implement a polling behavior. If the timeout is negative the
function will block indefinetely waiting for an event.
To let the main thread sees events sent form a different thread
a "wake-up" signal is sent to the main thread if the main thread
is in a blocking state. The wake-up event is sent to the designated
wakeup_window if present.
The wake-up event is sent only if the PushEvent call is coming
from a different thread. Before sending the wake-up event
the ID of the thread making the blocking call is saved using the
variable blocking_thread_id and it is compared to the current
thread's id to decide if the wake-up event should be sent.
Two new optional video device methods are introduced:
WaitEventTimeout
SendWakeupEvent
in addition the mutex
wakeup_lock
which is defined and initialized but only for the drivers supporting the
methods above.
If the methods are not present the system behaves as previously
performing a periodic polling of the events queue.
The blocking call is disabled if a joystick or sensor is detected
and falls back to previous behavior.
Details:
Currently doing 4 system calls per WM_INPUT message, which can cause the thread handling the message loop to be swapped out several times:
* GetProp - to get window data from the window handle
* GetRawInputData - to retrieve the raw input data
* 2 calls to GetMessageExtraInfo - to ignore synthetic mouse events generated for touchscreens
In this change:
* Replaced GetProp by iterating the list of windows maintained by SDL (with a fallback to GetProp). Note that this will affect all messages and not just WM_INPUT
* only calling GetMessageExtraInfo if a touchscreen has been detected
Fix for https://jira.valve.org/browse/CSGO-4855
@saml
On windows, when toggling the state of RelativeMode rapidly, there is a
high chance that SDL_WINDOWEVENT_ENTER / SDL_WINDOWEVENT_LEAVE events
will stop firing indefinitely.
This aims to resolve that shortcoming by ensuring mouse focus state is
correctly updated via WM_MOUSELEAVE events arriving via the windows
event hook.
