Wayland environments can expose more than one seat for multiple collections of input devices, which can include multiple, simultaneously active, desktop pointers and keyboards with independent layouts. The Wayland input backend previously presumed that only one seat could exist, which caused broken behavior if the compositor exposed more than one, which is possible on wlroots based compositors such as Sway. This introduces support for handling multiple seats, including proper handling of dynamically added and removed seats and capabilities at run time.
The SDL Wayland input system was accreted over time, and the assumption that only one seat will ever exist resulted in state and related objects not always being tied to their most appropriate owner in a multi-seat scenario, so refactoring was required to manage several bits of state per-seat, instead of per-window or globally.
As Wayland keyboards can have per-seat layouts, fast keymap switching is required when multiplexing input from multiple seats to the global SDL keyboard device. A parameter was added to the keymap creation function to specify if the keymap lifetime should be externally managed to facilitate keymap reuse, and some layout info was moved from the global keyboard state to the keymap state to avoid unnecessarily redetermining it whenever a reused keymap is bound. This reduces the overhead of switching keymaps to setting a single pointer.
Multiple seats also means that multiple windows can have keyboard and/or mouse focus at the same time on some compositors, but this is not currently a well-handled case in SDL, and will require more work to support, if necessary.
Adds support for Mod3, which is usually Level 5 shift, but can vary, as well as not altering the functionality of the more esoteric modifier keys, such as meta and hyper.
There are many recoverable errors that may happen internally and can be safely ignored if the public API doesn't return an error code. Seeing them causes lots of developer anxiety and they generally aren't helpful.
Fixes https://github.com/libsdl-org/SDL/issues/11813
It's too close the 3.2.0 release for an API change like this.
If/when we re-add these, some things for consideration:
* What use cases does this enable that aren't currently possible?
* What cross-platform API guarantees do we make about the availability of these events? e.g. do we try to simulate them where raw input isn't actually available?
* How is this different from the existing relative mode, and how do we clearly explain when you want these events vs wanting relative mode?
Notes from @expikr:
First observation: the reason I originally passed denominators instead of multipliers was because some rational values cannot be exactly represented by floats (e.g 1/120) so instead let the end-developer decide how to do the dividing themselves. It was the reason why it was using split values with an integer numerator to begin with, instead of having both as floats or even just normalize it in advance.
On the other hand, passing them as multipliers might have hypothetical uses for dynamically passing end-user controlled scaling in a transparent manner without coupling? (Though in that case why not just do that as additional fields appended to `motion` structs in an API-compatible layout?)
So it’s somewhat of a philosophical judgement of what this API of optional availability do we intend for it to present itself as:
- should it be a bit-perfect escape hatch with the absolute minimally-denominal abstraction over platform details just enough to be able to serve the full information (á la HIDPIAPI),
- or a renewed ergonomic API for splitting relative motion from cursor motion (in light of The Great Warping Purge) so that it is unburdened by legacy RelativeMode state machines, in which case it would be more appropriate to just call it `RELATIVE` instead of `RAW` and should be added alongside another new event purely for cursor events?
This alternate API stream was conceived in the context of preserving compatibility of the existing RelativeMode state machine by adding an escape hatch. So given the same context, my taste leans towards the former designation.
However, as The Great Warping Purge has made it potentially viable to do so, if I were allowed to break ABI by nuking the RelativeMode state machine entirely, I would prefer the latter designation unified as one of three separate components split from the old state machine, each independently controlled by platform-dependent availability without any state switching of a leaky melting pot:
- cursor visibility controls (if platform has cursor)
- cursor motion events (if platform has cursor)
- relative motion events (if the platform reports hardware motion)
This is sent when the device is lost and can't be recovered.
Also fixed the vulkan renderer so it returns errors appropriately and will log and break if debug mode is enabled.
Now we render directly to the window, scaling as appropriate. This fixes some
concerns the render target introduced, like the quality of the final scaled
output, how to step outside of the logical size temporarily to draw some
things sharply at the native resolution, and loss of sub-pixel precision.
Fixes#8736.
We require stdbool.h in the build environment, so we might as well use the plain bool type.
If your environment doesn't have stdbool.h, this simple replacement will suffice:
typedef signed char bool;
Also marked the existing functions as unsafe, as they can cause crashes if used in multi-threaded applications.
As a bonus, since the new functions are hashtable based, hint environment lookups are much faster.
