Add support for SDL3 joystick input driver

Made possible by EIREXE, xsellier and the SDL team.

This commit includes statically linked SDL3 for Windows, Linux and macOS.
The vendored copy of SDL3 was setup to only build the required subsystems
for gamepad/joystick support, with some patches to be able to make it as
minimal as possible and reduce the impact on binary size and code size.

Co-authored-by: Álex Román Núñez <eirexe123@gmail.com>
Co-authored-by: Xavier Sellier <xsellier@gmail.com>
Co-authored-by: Rémi Verschelde <rverschelde@gmail.com>

thirdparty/sdl/update-sdl.sh

@@ -0,0 +1,87 @@
+#!/bin/bash -e
+
+VERSION=3.2.16
+
+target=$(dirname "$(realpath $0)")
+pushd $target
+
+rm -rf atomic core events haptic hidapi include io joystick libm loadso \
+  sensor stdlib thread timer *.c *.h CREDITS.md LICENSE.txt
+rm -rf *.tar.gz tmp
+
+mkdir tmp && pushd tmp
+
+echo "Updating SDL3 to version:" $VERSION
+curl -L -O https://github.com/libsdl-org/SDL/archive/release-$VERSION.tar.gz
+
+tar --strip-components=1 -xvf release-$VERSION.tar.gz
+rm release-$VERSION.tar.gz
+
+# We aim to copy only the minimum amount of files needed, so we don't need to
+# vendor and compile more source code than necessary.
+
+cp -v CREDITS.md LICENSE.txt $target
+
+# Includes.
+# For build config, we use a single private one in the driver.
+# We might reconsider as we make more platforms use SDL.
+cp -rv include $target
+rm -f $target/include/build_config/{*.cmake,SDL_build_config_*.h} $target
+rm -f $target/include/SDL3/SDL_{egl,gpu,oldnames,opengl*,test*,vulkan}.h $target
+
+pushd src
+
+# Shared dependencies
+
+cp -rv *.{c,h} atomic libm stdlib $target
+rm -f $target/stdlib/*.masm
+
+# Only some files needed
+
+mkdir $target/events
+cp -v events/SDL_{event*.{c,h},mouse_c.h} $target/events
+
+mkdir $target/io
+cp -v io/SDL_iostream*.{c,h} $target/io
+
+# Platform specific
+
+mkdir $target/core
+cp -rv core/{linux,unix,windows} $target/core
+rm -f $target/core/windows/version.rc
+
+mkdir $target/haptic
+cp -rv haptic/{*.{c,h},darwin,linux,windows} $target/haptic
+
+mkdir $target/joystick
+cp -rv joystick/{*.{c,h},apple,darwin,hidapi,linux,windows} $target/joystick
+
+mkdir $target/loadso
+cp -rv loadso/dlopen $target/loadso
+
+mkdir $target/sensor
+cp -rv sensor/{*.{c,h},dummy} $target/sensor
+
+mkdir $target/thread
+cp -rv thread/{*.{c,h},generic,pthread,windows} $target/thread
+rm -f $target/thread/generic/SDL_{sysmutex*.{c,h},systls.c}
+
+mkdir $target/timer
+cp -rv timer/{*.{c,h},unix,windows} $target/timer
+
+# HIDAPI
+
+mkdir -p $target/hidapi
+cp -v hidapi/{*.{c,h},AUTHORS.txt,LICENSE.txt,LICENSE-bsd.txt,VERSION} $target/hidapi
+for dir in hidapi linux mac windows; do
+  mkdir $target/hidapi/$dir
+  cp -v hidapi/$dir/*.{c,h} $target/hidapi/$dir
+done
+
+popd
+popd
+rm -rf tmp
+popd
+
+echo "SDL3 source code copied successfully. Review 'git status' for potential new files to compile or remove."
+echo "Make sure to re-apply patches from the 'patches' folder if any are provided."