feature: Add dummy mode

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
+}