Adds hint "SDL_WINDOWS_DPI_SCALING" which can be set to "1" to
change the SDL coordinate system units to be DPI-scaled points, rather
than pixels everywhere.
This means windows will be appropriately sized, even when created on
high-DPI displays with scaling.
e.g. requesting a 640x480 window from SDL, on a display with 125%
scaling in Windows display settings, will create a window with an
800x600 client area (in pixels).
Setting this to "1" implicitly requests process DPI awareness
(setting SDL_WINDOWS_DPI_AWARENESS is unnecessary),
and forces SDL_WINDOW_ALLOW_HIGHDPI on all windows.
The hint allows setting a specific DPI awareness ("unaware", "system", "permonitor", "permonitorv2").
This is the first part of High-DPI support on Windows ( https://github.com/libsdl-org/SDL/issues/2119 ).
It doesn't implement a virtualized SDL coordinate system, which will be
addressed in a later commit. (This hint could be useful for SDL apps
that want 1 SDL unit = 1 pixel, though.)
Detecting and behaving correctly under per-monitor V2
(calling AdjustWindowRectExForDpi where needed) should fix the
following issues:
https://github.com/libsdl-org/SDL/issues/3286https://github.com/libsdl-org/SDL/issues/4712
* Fixes for IME Composition Truncation + Addition of SDL_ClearComposition, SDL_IsTextInputShown
* Fixed: Documentation and code style issues raised during code review.
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.
This gives us flexibility to add others hints to control keyboard grab behavior
without having to touch all of the backends. It also allows us to possibly
expose keyboard grab separately from mouse grab for applications that want to
manage those independently.
- explicitly use UNICODE versions of DrawText, EnumDisplaySettings,
EnumDisplayDevices, and CreateDC: the underlying structures have
WCHAR strings.
- change WIN_UpdateDisplayMode and WIN_GetDisplayMode() to accept
LPCWSTR instead of LPCTSTR for the same reason.
- change WIN_StringToUTF8 and WIN_UTF8ToString to the explicit 'W'
versions where appropriate.
The two are only ever called together, and combining them makes it possible
to eliminate redundant symbol loading and redundant attempts to connect
to a display server.
Creating a full-screen SDL renderer on Windows will keep the screensaver
suspended by DirectX, as is default for full-screen DX applications. However,
for applications that render in windowed-mode, the screensaver will
still kick in, even if SDL_DisableScreenSaver() is called or
SDL_HINT_VIDEO_ALLOW_SCREENSAVER is set to 0 (default). Implementing
a SuspendScreenSaver() function for Win32 fixes this behavior.
First: disable d'n'd events by default; most apps don't need these at all, and
if an app doesn't explicitly handle these, each drop on the window will cause
a memory leak if the events are enabled. This follows the guidelines we have
for SDL_TEXTINPUT events already.
Second: when events are enabled or disabled, signal the video layer, as it
might be able to inform the OS, causing UI changes or optimizations (for
example, dropping a file icon on a Cocoa app that isn't accepting drops will
cause macOS to show a rejection animation instead of the drop operation just
vanishing into the ether, X11 might show a different cursor when dragging
onto an accepting window, etc).
Third: fill in the drop event details in the test library and enable the
events in testwm.c for making sure this all works as expected.
SDL now builds with gcc 7.2 with the following command line options:
-Wall -pedantic-errors -Wno-deprecated-declarations -Wno-overlength-strings --std=c99
Ismael Ferreras Morezuelas (Swyter)
As a new year gift I have implemented the Windows version of SDL_GetWindowBordersSize(). I needed it for auto-selecting a cozy window size for the game I'm currently working on and noticed that it only worked under X11, so I thought it could be a good excuse to contribute back more stuff. The Mercurial patch is attached as a .diff file. Let me know what you think.
Happy 2018 to all the SDL2 devs and users!
--
PS: Keep in mind that Windows 10 includes the 8px invisible grip borders as part of the frame. There's a way of detecting if Aero/DWM is being used and ask only for the visible rect, but I believe that GetWindowRect() is doing that for a reason and working as intended, so I haven't changed it. (See [2])
References:
[1]: http://www.firststeps.ru/mfc/winapi/r.php?72
[2]: https://stackoverflow.com/a/34143777/674685
[3]: https://stackoverflow.com/a/431548/674685
[4]: https://wiki.libsdl.org/SDL_GetWindowBordersSize
Simon Hug
Some code in SDL loads libraries with SDL_LoadObject to get more information or use newer APIs. SDL_LoadObject may fail, set an error message and SDL will continue with some fallback code. Since SDL will overwrite the error or exit the function with a return value that indicates success, the error form SDL_LoadObject for the optional stuff might as well be cleared right away.
This is currently implemented for X11, Cocoa, Windows, and DirectFB.
This patch is based on work in Unreal Engine 4's fork of SDL,
compliments of Epic Games.
The internal function SDL_EGL_LoadLibrary() did not delete and remove a mostly
uninitialized data structure if loading the library first failed. A later try to
use EGL then skipped initialization and assumed it was previously successful
because the data structure now already existed. This led to at least one crash
in the internal function SDL_EGL_ChooseConfig() because a NULL pointer was
dereferenced to make a call to eglBindAPI().
