Modern C runtimes have well optimized memset and memcpy, so use those instead of dispatching into SDL's versions. In addition, some compilers can analyze memset and memcpy calls and directly turn them into optimized assembly.
Add the ability to import and wrap external surfaces from external toolkits such as Qt and GTK.
Wayland surfaces and windows are more intrinsically tied to the client library than other windowing systems, so it is necessary to provide a way to initialize SDL with an existing wl_display object, which needs to be set prior to video system initialization, or export the internal SDL wl_display object for use by external applications or toolkits. For this, the global property SDL_PROPERTY_GLOBAL_VIDEO_WAYLAND_WL_DISPLAY_POINTER is used.
A Wayland example was added to testnative, and a basic example of Qt 6 interoperation is provided in the Wayland readme to demonstrate the use of external windows with both SDL owning the wl_display, and an external toolkit owning it.
Allow for the creation of SDL windows with a roleless surface that applications can use for their own purposes, such as with a windowing protocol other than XDG toplevel.
The property `wayland.surface_role_custom` will create a window with a surface that SDL can render to and handles input for, but is not associated with a toplevel window, so applications can use it for their own, custom purposes (e.g. wlr_layer_shell).
A test/minimal example is included in tests/testwaylandcustom.c
A Wayland registry object can only have one listener attached at a time, so an application attempting to use the backend SDL registry object for its own purposes will just result in an error. Remove this property, as it is of no use to applications and will only result in errors.
If an application needs the registry, it needs to get the wl_display object via `SDL.window.wayland.display` and use wl_display_get_registry() to create a new registry object that it can attach its own listeners to.
It would be easy to assume that all APIs that reference
SDL_JOYSTICK_AXIS_MAX work the same way, but they do not: triggers
generally use the full signed 16-bit range in the lower-level joystick
API, but are normalized to be non-negative by the higher-level gamepad
API.
We also never said explicitly which direction is positive here.
Experimentally, it's right (X), down (Y), and pressed (triggers).
Resolves: https://github.com/libsdl-org/SDL/issues/8793
Signed-off-by: Simon McVittie <smcv@collabora.com>
The ARM926EJ-S Technical Reference Manual states:
> You can only access CP15 registers with MRC and MCR instructions in a
> privileged mode. CDP, LDC, STC, MCRR, and MRRC instructions, and unprivileged
> MRC or MCR instructions to CP15 cause the Undefined instruction exception to
> be taken.
Furthermore, `MCR p15, 0, <Rd>, c7, c10, 5` (later called Data Memory Barrier)
is not specified for the ARM926. Thus, SDL should not use these cache
instructions on ARMv5.