feature: Implement display rotation

We don't really need to run at twice the speed of the display's refresh
rate as Raylib manages the target time between frames well.

HACKING.md

@@ -0,0 +1,23 @@
+# UnrealXR Development Documentation
+
+## Dummies and You
+
+The dummy/development build generally isn't recommended for use if you're developing headset or OS drivers. It's intended for development on the 3D environment itself only (ie. virtual display positioning, widgets, etc.)
+
+To use it, all you need to do is run the Makefile with the `dev` target:
+
+```bash
+make dev
+```
+
+In the code, this mode is typically referred to as "dummy mode" (`dummy_ar.go`) or "fake mode" (ie. `patching_tools_fake_patching.go`).
+
+To control the X11 window, you can use the arrow keys to move the camera around. You **cannot** use the mouse due to the nature of this application. If you use the mouse for this, it would make development really difficult as you're using virtual displays and you need your mouse to interact with the desktop.
+
+If you're adding new headset drivers, but you still want to test in a window, you still can. It's not the dummy mode, but you can compile UnrealXR without the DRM flags (`drm drm_leasing drm_disable_input`) manually. This may differ in the future, but for now, the command is:
+
+```bash
+cd app; go build -v -tags "headset_driver_goes_here noaudio" -o ../uxr .; cd ..
+```
+
+Replace `headset_driver_goes_here` with the name of your headset driver. For example, `xreal` is the Xreal driver.

Makefile

@@ -9,5 +9,8 @@ all: build
 build:
 	cd $(APP_DIR) && go build -v -tags '$(TAGS)' -o ../$(OUTPUT) .
 
+dev:
+	cd $(APP_DIR) && go build -v -tags 'noaudio dummy_ar fake_edid_patching' -o ../$(OUTPUT) .
+
 clean:
 	rm -f $(OUTPUT)

README.md

@@ -1,4 +1,8 @@
 # UnrealXR
+[![Build Status](https://git.terah.dev/UnrealXR/unrealxr/actions/workflows/build.yml/badge.svg)](https://git.terah.dev/UnrealXR/unrealxr/actions)
+[![GoDoc](https://godoc.org/git.terah.dev/UnrealXR/unrealxr?status.svg)](https://godoc.org/git.terah.dev/UnrealXR/unrealxr)
+[![Go Report Card](https://goreportcard.com/badge/git.terah.dev/UnrealXR/unrealxr/app)](https://goreportcard.com/report/git.terah.dev/UnrealXR/unrealxr/app)
+[![License](https://img.shields.io/badge/license-BSD--3--Clause-green)](https://git.terah.dev/imterah/goevdi/src/branch/main/app/LICENSE)
 
 UnrealXR is a spatial multi-display renderer for the Xreal line of devices, enabling immersive, simultaneous viewing of multiple desktops and applications in 3D space.
 
@@ -29,3 +33,7 @@ If you're using Nix/NixOS, all you need to do is use `nix-shell` to enter the de
 ## Building
 
 Just run `make` in the root directory.
+
+## Development Guide
+
+See [HACKING.md](https://git.terah.dev/UnrealXR/unrealxr/src/branch/main/HACKING.md).

app/config/config.go

@@ -6,10 +6,12 @@ import _ "embed"
 var InitialConfig []byte
 
 type DisplayConfig struct {
-	Angle   *int     `yaml:"angle"`
+	Angle              *int     `yaml:"angle"`
-	FOV     *int     `yaml:"fov"`
+	FOV                *int     `yaml:"fov"`
-	Spacing *float32 `yaml:"spacing"`
+	Spacing            *float32 `yaml:"spacing"`
-	Count   *int     `yaml:"count"`
+	RadiusMultiplier   *float32 `yaml:"circle_radius_multiplier"`
+	UseCircularSpacing *bool    `yaml:"use_circular_spacing"`
+	Count              *int     `yaml:"count"`
 }
 
 type AppOverrides struct {
@@ -38,10 +40,12 @@ func getPtrToBool(bool bool) *bool {
 
 var DefaultConfig = &Config{
 	DisplayConfig: DisplayConfig{
-		Angle:   getPtrToInt(45),
+		Angle:              getPtrToInt(45),
-		FOV:     getPtrToInt(45),
+		FOV:                getPtrToInt(45),
-		Spacing: getPtrToFloat32(0.5),
+		Spacing:            getPtrToFloat32(0.5),
-		Count:   getPtrToInt(3),
+		RadiusMultiplier:   getPtrToFloat32(2),
+		UseCircularSpacing: getPtrToBool(true),
+		Count:              getPtrToInt(3),
 	},
 	Overrides: AppOverrides{
 		AllowUnsupportedDevices: getPtrToBool(false),

app/config/default_config.yml

@@ -9,7 +9,9 @@
 display:
   angle: 45 # Angle of the virtual displays
   fov: 45 # FOV of the 3D camera
-  spacing: 0.5 # Spacing between virtual displays
+  spacing: 0.5 # Raw spacing between virtual displays. Does not use circles in the layout. Purely flat plane.
+  circle_radius_multiplier: 2 # Multiplier for the radius of the circle used to calculate the spacing between virtual displays. "Rounded" plane of sorts.
+  use_circular_spacing: true # If true, uses a circular layout for the virtual displays.
   count: 3 # Count of virtual displays
 overrides:
   allow_unsupported_devices: false # If true, allows unsupported devices to be used as long as they're a compatible vendor (Xreal)

app/edidtools/patching_tools_fake_patching.go

@@ -0,0 +1,42 @@
+//go:build fake_edid_patching
+// +build fake_edid_patching
+
+package edidtools
+
+import (
+	_ "embed"
+	"fmt"
+
+	"github.com/charmbracelet/log"
+)
+
+//go:embed bin/xreal-air-edid.bin
+var edidFirmware []byte
+
+// Attempts to fetch the EDID firmware for any supported XR glasses device
+func FetchXRGlassEDID(allowUnsupportedDevices bool) (*DisplayMetadata, error) {
+	log.Warn("Not actually fetching EDID firmware in fake patching build -- using embedded firmware")
+	parsedEDID, err := ParseEDID(edidFirmware, allowUnsupportedDevices)
+
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse embedded EDID firmware: %w", err)
+	}
+
+	parsedEDID.DeviceQuirks.ZVectorDisabled = false
+	parsedEDID.DeviceQuirks.SensorInitDelay = 0
+	parsedEDID.DeviceQuirks.UsesMouseMovement = true
+
+	return parsedEDID, nil
+}
+
+// Loads custom firmware for a supported XR glass device
+func LoadCustomEDIDFirmware(displayMetadata *DisplayMetadata, edidFirmware []byte) error {
+	log.Warn("Not actually patching EDID firmware in fake patching build -- ignoring")
+	return nil
+}
+
+// Unloads custom firmware for a supported XR glass device
+func UnloadCustomEDIDFirmware(displayMetadata *DisplayMetadata) error {
+	log.Warn("Not actually unloading EDID firmware in fake patching build -- ignoring")
+	return nil
+}

app/edidtools/patching_tools_linux.go

@@ -1,5 +1,5 @@
-//go:build linux
+//go:build linux && !fake_edid_patching
-// +build linux
+// +build linux,!fake_edid_patching
 
 package edidtools
 

app/edidtools/patching_tools_macos.go

@@ -1,5 +1,5 @@
-//go:build darwin
+//go:build darwin && !fake_edid_patching
-// +build darwin
+// +build darwin,!fake_edid_patching
 
 package edidtools
 

app/edidtools/patching_tools_win.go

@@ -1,5 +1,5 @@
-//go:build windows
+//go:build windows && !fake_edid_patching
-// +build windows
+// +build windows,!fake_edid_patching
 
 package edidtools
 

app/edidtools/struct.go

@@ -1,11 +1,12 @@
 package edidtools
 
 type DisplayQuirks struct {
-	MaxWidth        int
+	MaxWidth          int
-	MaxHeight       int
+	MaxHeight         int
-	MaxRefreshRate  int
+	MaxRefreshRate    int
-	SensorInitDelay int
+	SensorInitDelay   int
-	ZVectorDisabled bool
+	ZVectorDisabled   bool
+	UsesMouseMovement bool
 }
 
 type DisplayMetadata struct {

app/main.go

@@ -118,7 +118,7 @@ func mainEntrypoint(context.Context, *cli.Command) error {
 	bufio.NewReader(os.Stdin).ReadBytes('\n') // Wait for Enter key press before continuing
 
 	log.Info("Initializing XR headset")
-	rl.SetTargetFPS(int32(displayMetadata.MaxRefreshRate * 2))
+	rl.SetTargetFPS(int32(displayMetadata.MaxRefreshRate))
 	rl.InitWindow(int32(displayMetadata.MaxWidth), int32(displayMetadata.MaxHeight), "UnrealXR")
 
 	atexit.Register(func() {

app/renderer/renderer.go

@@ -35,6 +35,15 @@ func findOptimalHorizontalRes(verticalDisplayRes float32, horizontalDisplayRes f
 	return horizontalSize
 }
 
+func findHfovFromVfov(vfovDeg, w, h float64) float64 {
+	vfovRad := vfovDeg * math.Pi / 180
+
+	ar := w / h
+	hfovRad := 2 * math.Atan(math.Tan(vfovRad/2)*ar)
+
+	return hfovRad * 180 / math.Pi
+}
+
 func EnterRenderLoop(config *libconfig.Config, displayMetadata *edidtools.DisplayMetadata, evdiCards []*EvdiDisplayMetadata) {
 	log.Info("Initializing AR driver")
 	headset, err := ardriver.GetDevice()
@@ -99,7 +108,9 @@ func EnterRenderLoop(config *libconfig.Config, displayMetadata *edidtools.Displa
 
 	headset.RegisterEventListeners(arEventListner)
 
-	fovY := float32(45.0)
+	fovY := float32(*config.DisplayConfig.FOV)
+	fovX := findHfovFromVfov(float64(fovY), float64(displayMetadata.MaxWidth), float64(displayMetadata.MaxHeight))
+
 	verticalSize := findMaxVerticalSize(fovY, 5.0)
 
 	camera := rl.NewCamera3D(
@@ -125,6 +136,21 @@ func EnterRenderLoop(config *libconfig.Config, displayMetadata *edidtools.Displa
 	horizontalSize := findOptimalHorizontalRes(float32(displayMetadata.MaxHeight), float32(displayMetadata.MaxWidth), verticalSize)
 	coreMesh := rl.GenMeshPlane(horizontalSize, verticalSize, 1, 1)
 
+	var radius float32
+
+	if *config.DisplayConfig.UseCircularSpacing == true {
+		radiusX := (horizontalSize / 2) / float32(math.Tan((float64(fovX)*math.Pi/180.0)/2))
+		radiusY := (verticalSize / 2) / float32(math.Tan((float64(fovY)*math.Pi/180.0)/2))
+
+		if radiusY > radiusX {
+			radius = radiusY
+		} else {
+			radius = radiusX
+		}
+
+		radius *= *config.DisplayConfig.RadiusMultiplier
+	}
+
 	movementVector := rl.Vector3{
 		X: 0.0,
 		Y: 0.0,
@@ -171,6 +197,17 @@ func EnterRenderLoop(config *libconfig.Config, displayMetadata *edidtools.Displa
 		texture := rl.LoadTextureFromImage(image)
 		model := rl.LoadModelFromMesh(coreMesh)
 
+		// spin up/down
+		pitchRad := float32(-90 * rl.Deg2rad)
+		// spin left/right
+		yawRad := currentAngle * rl.Deg2rad
+
+		rotX := rl.MatrixRotateX(pitchRad)
+		rotY := rl.MatrixRotateY(yawRad)
+
+		transform := rl.MatrixMultiply(rotX, rotY)
+		model.Transform = transform
+
 		rl.SetMaterialTexture(model.Materials, rl.MapAlbedo, texture)
 
 		rects[i] = &TextureModelPair{
@@ -184,20 +221,24 @@ func EnterRenderLoop(config *libconfig.Config, displayMetadata *edidtools.Displa
 	eventTimeoutDuration := 0 * time.Millisecond
 
 	for !rl.WindowShouldClose() {
-		if hasSensorInitDelayQuirk {
+		if !displayMetadata.DeviceQuirks.UsesMouseMovement {
-			if time.Now().Sub(sensorInitStartTime) > time.Duration(displayMetadata.DeviceQuirks.SensorInitDelay)*time.Second {
+			if hasSensorInitDelayQuirk {
-				log.Info("Movement is now enabled.")
+				if time.Now().Sub(sensorInitStartTime) > time.Duration(displayMetadata.DeviceQuirks.SensorInitDelay)*time.Second {
-				hasSensorInitDelayQuirk = false
+					log.Info("Movement is now enabled.")
+					hasSensorInitDelayQuirk = false
+				}
+			} else {
+				lookVector.X = (currentYaw - previousYaw) * 6.5
+				lookVector.Y = -(currentPitch - previousPitch) * 6.5
+
+				if !hasZVectorDisabledQuirk {
+					lookVector.Z = (currentRoll - previousRoll) * 6.5
+				}
+
+				rl.UpdateCameraPro(&camera, movementVector, lookVector, 0)
 			}
 		} else {
-			lookVector.X = (currentYaw - previousYaw) * 6.5
+			rl.UpdateCamera(&camera, rl.CameraFirstPerson)
-			lookVector.Y = -(currentPitch - previousPitch) * 6.5
-
-			if !hasZVectorDisabledQuirk {
-				lookVector.Z = (currentRoll - previousRoll) * 6.5
-			}
-
-			rl.UpdateCameraPro(&camera, movementVector, lookVector, 0)
 		}
 
 		rl.BeginDrawing()
@@ -231,20 +272,35 @@ func EnterRenderLoop(config *libconfig.Config, displayMetadata *edidtools.Displa
 				card.EvdiNode.RequestUpdate(card.Buffer)
 			}
 
+			worldPos := rl.Vector3{
+				X: 0,
+				Y: verticalSize / 2,
+				Z: 0,
+			}
+
+			if *config.DisplayConfig.UseCircularSpacing == true {
+				yawRad := float32(rl.Deg2rad * rect.CurrentAngle)
+
+				// WTF?
+				posX := float32(math.Sin(float64(yawRad))) * radius
+				posZ := -float32(math.Cos(float64(yawRad))) * radius
+
+				worldPos.X = posX
+				worldPos.Z = posZ + radius
+			} else {
+				worldPos.X = rect.CurrentDisplaySpacing
+			}
+
 			rl.DrawModelEx(
 				rect.Model,
-				rl.Vector3{
+				worldPos,
-					X: rect.CurrentDisplaySpacing,
-					Y: verticalSize / 2,
-					Z: 0,
-				},
 				// rotate around X to make it vertical
 				rl.Vector3{
-					X: 1,
+					X: 0,
 					Y: 0,
 					Z: 0,
 				},
-				90,
+				0,
 				rl.Vector3{
 					X: 1,
 					Y: 1,

ardriver/ardriver.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 
 	"git.terah.dev/UnrealXR/unrealxr/ardriver/commons"
+	"git.terah.dev/UnrealXR/unrealxr/ardriver/dummy"
 	"git.terah.dev/UnrealXR/unrealxr/ardriver/xreal"
 )
 
@@ -19,5 +20,16 @@ func GetDevice() (commons.ARDevice, error) {
 		return device, nil
 	}
 
+	if dummy.IsDummyDeviceEnabled {
+		device, err := dummy.New()
+
+		if err != nil {
+			fmt.Printf("failed to initialize dummy device: %w\n", err)
+			return nil, err
+		}
+
+		return device, nil
+	}
+
 	return nil, fmt.Errorf("failed to initialize any device")
 }

ardriver/dummy/dummy_ar.go

@@ -0,0 +1,40 @@
+//go:build dummy_ar
+// +build dummy_ar
+
+package dummy
+
+import (
+	"git.terah.dev/UnrealXR/unrealxr/ardriver/commons"
+)
+
+var IsDummyDeviceEnabled = true
+
+// Implements commons.ARDevice
+type DummyDevice struct {
+}
+
+func (device *DummyDevice) Initialize() error {
+	return nil
+}
+
+func (device *DummyDevice) End() error {
+	return nil
+}
+
+func (device *DummyDevice) IsPollingLibrary() bool {
+	return false
+}
+
+func (device *DummyDevice) IsEventBasedLibrary() bool {
+	return false
+}
+
+func (device *DummyDevice) Poll() error {
+	return nil
+}
+
+func (device *DummyDevice) RegisterEventListeners(*commons.AREventListener) {}
+
+func New() (*DummyDevice, error) {
+	return &DummyDevice{}, nil
+}

ardriver/dummy/dummy_ar_disabled.go

@@ -0,0 +1,42 @@
+//go:build !dummy_ar
+// +build !dummy_ar
+
+package dummy
+
+import (
+	"fmt"
+
+	"git.terah.dev/UnrealXR/unrealxr/ardriver/commons"
+)
+
+var IsDummyDeviceEnabled = false
+
+// Implements commons.ARDevice
+type DummyDevice struct {
+}
+
+func (device *DummyDevice) Initialize() error {
+	return fmt.Errorf("dummy device is not enabled")
+}
+
+func (device *DummyDevice) End() error {
+	return fmt.Errorf("dummy device is not enabled")
+}
+
+func (device *DummyDevice) IsPollingLibrary() bool {
+	return false
+}
+
+func (device *DummyDevice) IsEventBasedLibrary() bool {
+	return false
+}
+
+func (device *DummyDevice) Poll() error {
+	return fmt.Errorf("dummy device is not enabled")
+}
+
+func (device *DummyDevice) RegisterEventListeners(*commons.AREventListener) {}
+
+func New() (*DummyDevice, error) {
+	return nil, fmt.Errorf("dummy device is not enabled")
+}

ardriver/xreal/xreal.go

@@ -3,127 +3,21 @@
 
 package xreal
 
-// #cgo CFLAGS: -w -I./Fusion/
-// #cgo pkg-config: json-c libusb-1.0 hidapi-libusb
-// #include "go_ffi.h"
-// #include "device.h"
-// #include "device_imu.h"
-// #include "device_mcu.h"
-import "C"
 import (
-	"fmt"
+	xreal "git.terah.dev/UnrealXR/unrealxr/ardriver/xreal/xrealsrc"
-	"sync"
-	"time"
-
-	"git.terah.dev/UnrealXR/unrealxr/ardriver/commons"
 )
 
-var (
+var IsXrealEnabled = true
-	IsXrealEnabled          = true
-	deviceEventHandlerMutex = sync.Mutex{}
-	deviceEventListener     *commons.AREventListener
-)
 
-//export goIMUEventHandler
-func goIMUEventHandler(_ C.uint64_t, event_type C.device_imu_event_type, ahrs *C.struct_device_imu_ahrs_t) {
-	if deviceEventListener == nil {
-		return
-	}
-
-	if event_type != C.DEVICE_IMU_EVENT_UPDATE {
-		return
-	}
-
-	orientation := C.device_imu_get_orientation(ahrs)
-	euler := C.device_imu_get_euler(orientation)
-
-	deviceEventListener.PitchCallback(float32(euler.pitch))
-	deviceEventListener.RollCallback(float32(euler.roll))
-	deviceEventListener.YawCallback(float32(euler.yaw))
-}
-
-// Implements commons.ARDevice
 type XrealDevice struct {
-	eventListener *commons.AREventListener
+	*xreal.XrealDevice
-	imuDevice     *C.struct_device_imu_t
-	deviceIsOpen  bool
-}
-
-func (device *XrealDevice) Initialize() error {
-	if device.deviceIsOpen {
-		return fmt.Errorf("device is already open")
-	}
-
-	device.imuDevice = &C.struct_device_imu_t{}
-
-	// (*[0]byte) is a FUBAR way to cast a pointer to a function, but unsafe.Pointer doesn't work:
-	// cannot use unsafe.Pointer(_Cgo_ptr(_Cfpvar_fp_imuEventHandler)) (value of type unsafe.Pointer) as *[0]byte value in variable declaration
-	if C.DEVICE_IMU_ERROR_NO_ERROR != C.device_imu_open(device.imuDevice, (*[0]byte)(C.imuEventHandler)) {
-		return fmt.Errorf("failed to open IMU device")
-	}
-
-	C.device_imu_clear(device.imuDevice)
-	C.device_imu_calibrate(device.imuDevice, 1000, true, true, false)
-
-	device.deviceIsOpen = true
-
-	// let's hope this doesn't cause race conditions
-	go func() {
-		for device.eventListener == nil {
-			time.Sleep(time.Millisecond * 10)
-		}
-
-		for {
-			if !device.deviceIsOpen {
-				break
-			}
-
-			// I'm sorry.
-			deviceEventHandlerMutex.Lock()
-			deviceEventListener = device.eventListener
-			status := C.device_imu_read(device.imuDevice, -1)
-			deviceEventHandlerMutex.Unlock()
-
-			if status != C.DEVICE_IMU_ERROR_NO_ERROR {
-				break
-			}
-		}
-
-		device.deviceIsOpen = false
-		C.device_imu_close(device.imuDevice)
-	}()
-
-	return nil
-}
-
-func (device *XrealDevice) End() error {
-	if !device.deviceIsOpen {
-		return fmt.Errorf("device is not open")
-	}
-
-	C.device_imu_close(device.imuDevice)
-	device.deviceIsOpen = false
-	return nil
-}
-
-func (device *XrealDevice) IsPollingLibrary() bool {
-	return false
-}
-
-func (device *XrealDevice) IsEventBasedLibrary() bool {
-	return true
-}
-
-func (device *XrealDevice) Poll() error {
-	return fmt.Errorf("not supported")
-}
-
-func (device *XrealDevice) RegisterEventListeners(listener *commons.AREventListener) {
-	device.eventListener = listener
 }
 
 func New() (*XrealDevice, error) {
-	device := &XrealDevice{}
+	device := &XrealDevice{
+		XrealDevice: &xreal.XrealDevice{},
+	}
+
 	err := device.Initialize()
 
 	if err != nil {

ardriver/xreal/xreal_disabled.go

@@ -35,9 +35,7 @@ func (device *XrealDevice) Poll() error {
 	return fmt.Errorf("xreal is not enabled")
 }
 
-func (device *XrealDevice) RegisterEventListeners(*commons.AREventListener) error {
+func (device *XrealDevice) RegisterEventListeners(*commons.AREventListener) {}
-	return fmt.Errorf("xreal is not enabled")
-}
 
 func New() (*XrealDevice, error) {
 	return nil, fmt.Errorf("xreal is not enabled")

ardriver/xreal/xrealsrc/xreal_bindings.go

@@ -0,0 +1,122 @@
+//go:build xreal
+// +build xreal
+
+package xreal
+
+// #cgo CFLAGS: -w
+// #cgo pkg-config: json-c libusb-1.0 hidapi-libusb
+// #include "go_ffi.h"
+// #include "device.h"
+// #include "device_imu.h"
+// #include "device_mcu.h"
+import "C"
+import (
+	"fmt"
+	"sync"
+	"time"
+
+	"git.terah.dev/UnrealXR/unrealxr/ardriver/commons"
+)
+
+var (
+	deviceEventHandlerMutex = sync.Mutex{}
+	deviceEventListener     *commons.AREventListener
+)
+
+//export goIMUEventHandler
+func goIMUEventHandler(_ C.uint64_t, event_type C.device_imu_event_type, ahrs *C.struct_device_imu_ahrs_t) {
+	if deviceEventListener == nil {
+		return
+	}
+
+	if event_type != C.DEVICE_IMU_EVENT_UPDATE {
+		return
+	}
+
+	orientation := C.device_imu_get_orientation(ahrs)
+	euler := C.device_imu_get_euler(orientation)
+
+	deviceEventListener.PitchCallback(float32(euler.pitch))
+	deviceEventListener.RollCallback(float32(euler.roll))
+	deviceEventListener.YawCallback(float32(euler.yaw))
+}
+
+// Implements commons.ARDevice
+type XrealDevice struct {
+	eventListener *commons.AREventListener
+	imuDevice     *C.struct_device_imu_t
+	deviceIsOpen  bool
+}
+
+func (device *XrealDevice) Initialize() error {
+	if device.deviceIsOpen {
+		return fmt.Errorf("device is already open")
+	}
+
+	device.imuDevice = &C.struct_device_imu_t{}
+
+	// (*[0]byte) is a FUBAR way to cast a pointer to a function, but unsafe.Pointer doesn't work:
+	// cannot use unsafe.Pointer(_Cgo_ptr(_Cfpvar_fp_imuEventHandler)) (value of type unsafe.Pointer) as *[0]byte value in variable declaration
+	if C.DEVICE_IMU_ERROR_NO_ERROR != C.device_imu_open(device.imuDevice, (*[0]byte)(C.imuEventHandler)) {
+		return fmt.Errorf("failed to open IMU device")
+	}
+
+	C.device_imu_clear(device.imuDevice)
+	C.device_imu_calibrate(device.imuDevice, 1000, true, true, false)
+
+	device.deviceIsOpen = true
+
+	// let's hope this doesn't cause race conditions
+	go func() {
+		for device.eventListener == nil {
+			time.Sleep(time.Millisecond * 10)
+		}
+
+		for {
+			if !device.deviceIsOpen {
+				break
+			}
+
+			// I'm sorry.
+			deviceEventHandlerMutex.Lock()
+			deviceEventListener = device.eventListener
+			status := C.device_imu_read(device.imuDevice, -1)
+			deviceEventHandlerMutex.Unlock()
+
+			if status != C.DEVICE_IMU_ERROR_NO_ERROR {
+				break
+			}
+		}
+
+		device.deviceIsOpen = false
+		C.device_imu_close(device.imuDevice)
+	}()
+
+	return nil
+}
+
+func (device *XrealDevice) End() error {
+	if !device.deviceIsOpen {
+		return fmt.Errorf("device is not open")
+	}
+
+	C.device_imu_close(device.imuDevice)
+	device.deviceIsOpen = false
+	return nil
+}
+
+func (device *XrealDevice) IsPollingLibrary() bool {
+	return false
+}
+
+func (device *XrealDevice) IsEventBasedLibrary() bool {
+	return true
+}
+
+func (device *XrealDevice) Poll() error {
+	return fmt.Errorf("not supported")
+}
+
+func (device *XrealDevice) RegisterEventListeners(listener *commons.AREventListener) {
+	device.eventListener = listener
+}

shell.nix

@@ -27,12 +27,13 @@
     xorg.libXinerama
     xorg.libX11
 
+    # raylib X11 build dependencies (for dev-only non-XR builds)
+    libxkbcommon
+
     # nreal driver build dependencies
     hidapi
     json_c
-    udev
     libusb1
-    opencv
   ];
 
   shellHook = ''
@@ -40,5 +41,6 @@
     mkdir -p "$PWD/data/config" "$PWD/data/data"
     export UNREALXR_CONFIG_PATH="$PWD/data/config"
     export UNREALXR_DATA_PATH="$PWD/data/data"
+    export UNREALXR_LOG_LEVEL="debug"
   '';
 }

unrealxr

@@ -1 +1,2 @@
+#!/usr/bin/env bash
 sudo UNREALXR_LOG_LEVEL="$UNREALXR_LOG_LEVEL" LD_LIBRARY_PATH="$LD_LIBRARY_PATH" UNREALXR_CONFIG_PATH="$UNREALXR_CONFIG_PATH" UNREALXR_DATA_PATH="$UNREALXR_DATA_PATH" WAYLAND_DISPLAY="$XDG_RUNTIME_DIR/$WAYLAND_DISPLAY" XDG_RUNTIME_DIR="/user/run/0" ./uxr