joystick interposer support for evdev and SDL

Author: danisla

addons/js-interposer/.gitignore

@@ -1 +1,2 @@
-*.so
+*.so
+sdl_joystick_reader

addons/js-interposer/Makefile

@@ -1,10 +1,43 @@
 PREFIX ?= /usr
 
-all:
+all: build build32
+
+deps:
+	@sudo apt-get update
+	@sudo apt-get install -y build-essential evtest strace joystick libsdl2-dev gcc-multilib libevdev-dev
+
+build:
 	gcc -shared -fPIC -o selkies_joystick_interposer.so joystick_interposer.c -ldl
 
-install: all
+build32:
+	gcc -m32 -shared -fPIC -o selkies_joystick_interposer_i386.so joystick_interposer.c -ldl
+
+install: build
 	mkdir -p $(PREFIX)/lib/$(gcc -print-multiarch | sed -e 's/i.*86/i386/')
 	cp *.so $(PREFIX)/lib/$(gcc -print-multiarch | sed -e 's/i.*86/i386/')/
 clean:
-	rm -f *.so
+	rm -f *.so
+	sudo rm -f /dev/input/js0 /dev/input/event1000
+
+fake-devices:
+	@sudo touch /dev/input/js0 && sudo chmod 777 /dev/input/js0
+	@sudo touch /dev/input/event1000 && sudo chmod 777 /dev/input/event1000
+
+py-js-test:
+	python3 js-interposer-test.py /tmp/selkies_js0.sock
+
+py-ev-test:
+	python3 js-interposer-test.py /tmp/selkies_event1000.sock
+
+jstest: build
+	LD_PRELOAD=$(PWD)/selkies_joystick_interposer.so jstest /dev/input/js0
+
+evtest: build fake-devices
+	LD_PRELOAD=$(PWD)/selkies_joystick_interposer.so evtest /dev/input/event1000
+
+sdltest: build fake-devices
+	gcc -o sdl_joystick_reader sdl-js-test.c -lSDL2
+	LD_PRELOAD=$(PWD)/selkies_joystick_interposer.so ./sdl_joystick_reader
+
+winetest: build build32 fake-devices
+	LD_PRELOAD=$(PWD)/selkies_joystick_interposer.so wine control

addons/js-interposer/README.md

@@ -23,22 +23,21 @@ If using Wine with `x86_64`, both `/usr/lib/x86_64-linux-gnu/selkies_joystick_in
 ```bash
 sudo mkdir -pm1777 /dev/input
 sudo touch /dev/input/js0 /dev/input/js1 /dev/input/js2 /dev/input/js3
-sudo chmod 777 /dev/input/js*
+sudo touch /dev/input/event1000 /dev/input/event1001 /dev/input/event1002 /dev/input/event1003
+sudo chmod 777 /dev/input/js* /dev/input/event*
 ```
 
 3. Use the below command before running your target application as well as Selkies-GStreamer for the interposer library to intercept joystick/gamepad events (the single quotes are required in the first line).
 
 ```bash
 export SELKIES_INTERPOSER='/usr/$LIB/selkies_joystick_interposer.so'
 export LD_PRELOAD="${SELKIES_INTERPOSER}${LD_PRELOAD:+:${LD_PRELOAD}}"
-export SDL_JOYSTICK_DEVICE=/dev/input/js0
 ```
 
 Otherwise, if you only need one architecture, the below is an equivalent command.
 
 ```bash
 export LD_PRELOAD="/usr/lib/x86_64-linux-gnu/selkies_joystick_interposer.so${LD_PRELOAD:+:${LD_PRELOAD}}"
-export SDL_JOYSTICK_DEVICE=/dev/input/js0
 ```
 
 You can replace `/usr/$LIB/selkies_joystick_interposer.so` with any non-root path of your choice if using the `.tar.gz` tarball. Make sure the correct `selkies_joystick_interposer.so` is installed in that path.