st/prober: Allow autoprobe function to create more than one device.

src/xrt/drivers/android/android_prober.c

@@ -62,11 +62,16 @@ android_prober_destroy(struct xrt_auto_prober *p)
 }
 
 //! @public @memberof android_prober
-static struct xrt_device *
-android_prober_autoprobe(struct xrt_auto_prober *xap, cJSON *attached_data, bool no_hmds, struct xrt_prober *xp)
+static int
+android_prober_autoprobe(struct xrt_auto_prober *xap,
+                         cJSON *attached_data,
+                         bool no_hmds,
+                         struct xrt_prober *xp,
+                         struct xrt_device **out_xdevs)
 {
 	struct android_device *dd = android_device_create();
-	return &dd->base;
+	out_xdevs[0] = &dd->base;
+	return 1;
 }
 
 

src/xrt/drivers/arduino/arduino_prober.c

@@ -66,12 +66,16 @@ arduino_prober_destroy(struct xrt_auto_prober *p)
 }
 
 //! @public @memberof arduino_prober
-static struct xrt_device *
-arduino_prober_autoprobe(struct xrt_auto_prober *xap, cJSON *attached_data, bool no_hmds, struct xrt_prober *xp)
+static int
+arduino_prober_autoprobe(struct xrt_auto_prober *xap,
+                         cJSON *attached_data,
+                         bool no_hmds,
+                         struct xrt_prober *xp,
+                         struct xrt_device **out_xdevs)
 {
 	struct arduino_prober *ap = arduino_prober(xap);
 	if (!ap->enabled) {
-		return NULL;
+		return 0;
 	}
 
 	const char *dev_uuid = "00004242-0000-1000-8000-004242424242";
@@ -80,10 +84,11 @@ arduino_prober_autoprobe(struct xrt_auto_prober *xap, cJSON *attached_data, bool
 	struct os_ble_device *ble = NULL;
 	os_ble_notify_open(dev_uuid, char_uuid, &ble);
 	if (ble == NULL) {
-		return NULL;
+		return 0;
 	}
 
-	return arduino_device_create(ble);
+	out_xdevs[0] = arduino_device_create(ble);
+	return 1;
 }
 
 

src/xrt/drivers/daydream/daydream_prober.c

@@ -66,12 +66,16 @@ daydream_prober_destroy(struct xrt_auto_prober *p)
 }
 
 //! @public @memberof daydream_prober
-static struct xrt_device *
-daydream_prober_autoprobe(struct xrt_auto_prober *xap, cJSON *attached_data, bool no_hmds, struct xrt_prober *xp)
+static int
+daydream_prober_autoprobe(struct xrt_auto_prober *xap,
+                          cJSON *attached_data,
+                          bool no_hmds,
+                          struct xrt_prober *xp,
+                          struct xrt_device **out_xdevs)
 {
 	struct daydream_prober *pdaydream = daydream_prober(xap);
 	if (!pdaydream->enabled) {
-		return NULL;
+		return 0;
 	}
 
 	const char *dev_uuid = "0000fe55-0000-1000-8000-00805f9b34fb";
@@ -80,12 +84,13 @@ daydream_prober_autoprobe(struct xrt_auto_prober *xap, cJSON *attached_data, boo
 	struct os_ble_device *ble = NULL;
 	os_ble_notify_open(dev_uuid, char_uuid, &ble);
 	if (ble == NULL) {
-		return NULL;
+		return 0;
 	}
 
 	struct daydream_device *dd = daydream_device_create(ble);
 
-	return &dd->base;
+	out_xdevs[0] = &dd->base;
+	return 1;
 }
 
 

src/xrt/drivers/dummy/dummy_prober.c

@@ -42,18 +42,23 @@ dummy_prober_destroy(struct xrt_auto_prober *p)
 }
 
 //! @public @memberof dummy_prober
-static struct xrt_device *
-dummy_prober_autoprobe(struct xrt_auto_prober *xap, cJSON *attached_data, bool no_hmds, struct xrt_prober *xp)
+static int
+dummy_prober_autoprobe(struct xrt_auto_prober *xap,
+                       cJSON *attached_data,
+                       bool no_hmds,
+                       struct xrt_prober *xp,
+                       struct xrt_device **out_xdevs)
 {
 	struct dummy_prober *dp = dummy_prober(xap);
 	(void)dp;
 
 	// Do not create a dummy HMD if we are not looking for HMDs.
 	if (no_hmds) {
-		return NULL;
+		return 0;
 	}
 
-	return dummy_hmd_create();
+	out_xdevs[0] = dummy_hmd_create();
+	return 1;
 }
 
 struct xrt_auto_prober *

src/xrt/drivers/ht/ht_prober.c

@@ -40,13 +40,17 @@ ht_prober_destroy(struct xrt_auto_prober *p)
 }
 
 //! @public @memberof ht_prober
-static struct xrt_device *
-ht_prober_autoprobe(struct xrt_auto_prober *xap, cJSON *attached_data, bool no_hmds, struct xrt_prober *xp)
+static int
+ht_prober_autoprobe(struct xrt_auto_prober *xap,
+                    cJSON *attached_data,
+                    bool no_hmds,
+                    struct xrt_prober *xp,
+                    struct xrt_device **out_xdevs)
 {
 	struct xrt_device *xdev = ht_device_create(xap, attached_data, xp);
 
 	if (xdev == NULL) {
-		return NULL;
+		return 0;
 	}
 
 	xdev->orientation_tracking_supported = true;
@@ -54,7 +58,8 @@ ht_prober_autoprobe(struct xrt_auto_prober *xap, cJSON *attached_data, bool no_h
 	xdev->hand_tracking_supported = true;
 	xdev->device_type = XRT_DEVICE_TYPE_HAND_TRACKER;
 
-	return xdev;
+	out_xdevs[0] = xdev;
+	return 1;
 }
 
 struct xrt_auto_prober *

src/xrt/drivers/illixr/illixr_prober.c

@@ -33,24 +33,29 @@ illixr_prober_destroy(struct xrt_auto_prober *p)
 	free(dp);
 }
 
-static struct xrt_device *
-illixr_prober_autoprobe(struct xrt_auto_prober *xap, cJSON *attached_data, bool no_hmds, struct xrt_prober *xp)
+static int
+illixr_prober_autoprobe(struct xrt_auto_prober *xap,
+                        cJSON *attached_data,
+                        bool no_hmds,
+                        struct xrt_prober *xp,
+                        struct xrt_device **out_xdevs)
 {
 	struct illixr_prober *dp = illixr_prober(xap);
 	(void)dp;
 
 	if (no_hmds) {
-		return NULL;
+		return 0;
 	}
 
 	const char *illixr_path, *illixr_comp;
 	illixr_path = getenv("ILLIXR_PATH");
 	illixr_comp = getenv("ILLIXR_COMP");
 	if (!illixr_path || !illixr_comp) {
-		return NULL;
+		return 0;
 	}
 
-	return illixr_hmd_create(illixr_path, illixr_comp);
+	out_xdevs[0] = illixr_hmd_create(illixr_path, illixr_comp);
+	return 1;
 }
 
 struct xrt_auto_prober *

src/xrt/drivers/north_star/ns_prober.c

@@ -48,20 +48,25 @@ ns_prober_destroy(struct xrt_auto_prober *p)
 }
 
 //! @public @memberof ns_prober
-static struct xrt_device *
-ns_prober_autoprobe(struct xrt_auto_prober *xap, cJSON *attached_data, bool no_hmds, struct xrt_prober *xp)
+static int
+ns_prober_autoprobe(struct xrt_auto_prober *xap,
+                    cJSON *attached_data,
+                    bool no_hmds,
+                    struct xrt_prober *xp,
+                    struct xrt_device **out_xdevs)
 {
 	struct ns_prober *nsp = ns_prober(xap);
 
 	if (no_hmds) {
-		return NULL;
+		return 0;
 	}
 
 	if (nsp->config_path == NULL) {
-		return NULL;
+		return 0;
 	}
 
-	return ns_hmd_create(nsp->config_path);
+	out_xdevs[0] = ns_hmd_create(nsp->config_path);
+	return 1;
 }
 
 struct xrt_auto_prober *

src/xrt/drivers/ohmd/oh_prober.c

@@ -53,14 +53,18 @@ oh_prober_destroy(struct xrt_auto_prober *p)
 }
 
 //! @public @memberof oh_prober
-static struct xrt_device *
-oh_prober_autoprobe(struct xrt_auto_prober *xap, cJSON *attached_data, bool no_hmds, struct xrt_prober *xp)
+static int
+oh_prober_autoprobe(struct xrt_auto_prober *xap,
+                    cJSON *attached_data,
+                    bool no_hmds,
+                    struct xrt_prober *xp,
+                    struct xrt_device **out_xdevs)
 {
 	struct oh_prober *ohp = oh_prober(xap);
 
 	// Do not use OpenHMD if we are not looking for HMDs.
 	if (no_hmds) {
-		return NULL;
+		return 0;
 	}
 
 	int device_idx = -1;
@@ -103,13 +107,13 @@ oh_prober_autoprobe(struct xrt_auto_prober *xap, cJSON *attached_data, bool no_h
 	}
 
 	if (device_idx < 0) {
-		return NULL;
+		return 0;
 	}
 
 	const char *prod = ohmd_list_gets(ohp->ctx, device_idx, OHMD_PRODUCT);
 	ohmd_device *dev = ohmd_list_open_device(ohp->ctx, device_idx);
 	if (dev == NULL) {
-		return NULL;
+		return 0;
 	}
 
 	struct xrt_device *xdev = oh_device_create(ohp->ctx, dev, prod);
@@ -118,7 +122,8 @@ oh_prober_autoprobe(struct xrt_auto_prober *xap, cJSON *attached_data, bool no_h
 	xdev->position_tracking_supported = position_tracking_supported;
 	xdev->device_type = XRT_DEVICE_TYPE_HMD;
 
-	return xdev;
+	out_xdevs[0] = xdev;
+	return 1;
 }
 
 struct xrt_auto_prober *

src/xrt/drivers/psvr/psvr_prober.c

@@ -74,8 +74,12 @@ psvr_prober_destroy(struct xrt_auto_prober *p)
 }
 
 //! @public @memberof psvr_prober
-static struct xrt_device *
-psvr_prober_autoprobe(struct xrt_auto_prober *xap, cJSON *attached_data, bool no_hmds, struct xrt_prober *xp)
+static int
+psvr_prober_autoprobe(struct xrt_auto_prober *xap,
+                      cJSON *attached_data,
+                      bool no_hmds,
+                      struct xrt_prober *xp,
+                      struct xrt_device **out_xdevs)
 {
 	struct psvr_prober *ppsvr = psvr_prober(xap);
 	struct hid_device_info *info_control = NULL;
@@ -86,7 +90,7 @@ psvr_prober_autoprobe(struct xrt_auto_prober *xap, cJSON *attached_data, bool no
 
 	// Do not look for the PSVR if we are not looking for HMDs.
 	if (no_hmds) {
-		return NULL;
+		return 0;
 	}
 
 	devs = hid_enumerate(PSVR_VID, PSVR_PID);
@@ -110,7 +114,8 @@ psvr_prober_autoprobe(struct xrt_auto_prober *xap, cJSON *attached_data, bool no
 
 	hid_free_enumeration(devs);
 
-	return dev;
+	out_xdevs[0] = dev;
+	return 1;
 }
 
 

src/xrt/include/xrt/xrt_prober.h

@@ -33,8 +33,10 @@ struct xrt_tracking_factory;
 struct os_hid_device;
 
 /*!
- * The maximum number of devices that a single "found" function called by the
- * prober can create per-call.
+ * The maximum number of devices that a single
+ * @ref xrt_prober_entry::found or
+ * @ref xrt_auto_prober::lelo_dallas_autoprobe
+ * function called by the prober can create per-call.
  *
  * @ingroup xrt_iface
  */
@@ -432,13 +434,19 @@ struct xrt_auto_prober
 	 * devices.
 	 * @param[in] xp Prober: provided for access to the tracking factory,
 	 * among other reasons.
+	 * @param[out] out_xdevs Array of @ref XRT_MAX_DEVICES_PER_PROBE @c NULL
+	 * @ref xrt_device pointers. First elements will be populated with new
+	 * devices.
 	 *
-	 * @return New device implementing the xrt_device interface, or NULL.
+	 * @return The amount of devices written into @p out_xdevs, 0 if none.
+	 *
+	 * @note Leeloo Dallas is a reference to The Fifth Element.
 	 */
-	struct xrt_device *(*lelo_dallas_autoprobe)(struct xrt_auto_prober *xap,
-	                                            cJSON *attached_data,
-	                                            bool no_hmds,
-	                                            struct xrt_prober *xp);
+	int (*lelo_dallas_autoprobe)(struct xrt_auto_prober *xap,
+	                             cJSON *attached_data,
+	                             bool no_hmds,
+	                             struct xrt_prober *xp,
+	                             struct xrt_device **out_xdevs);
 	/*!
 	 * Destroy this auto-prober.
 	 *

src/xrt/state_trackers/prober/p_prober.c

@@ -612,13 +612,25 @@ add_from_auto_probers(struct prober *p, struct xrt_device **xdevs, size_t num_xd
 		 */
 		bool no_hmds = *have_hmd;
 
-		struct xrt_device *xdev =
-		    p->auto_probers[i]->lelo_dallas_autoprobe(p->auto_probers[i], NULL, no_hmds, &p->base);
-		if (xdev == NULL) {
+		struct xrt_device *new_xdevs[XRT_MAX_DEVICES_PER_PROBE] = {NULL};
+		int num_found =
+		    p->auto_probers[i]->lelo_dallas_autoprobe(p->auto_probers[i], NULL, no_hmds, &p->base, new_xdevs);
+
+		if (num_found <= 0) {
 			continue;
 		}
 
-		handle_found_device(p, xdevs, num_xdevs, have_hmd, xdev);
+		for (int created_idx = 0; created_idx < num_found; ++created_idx) {
+			if (new_xdevs[created_idx] == NULL) {
+				P_DEBUG(p,
+				        "Leaving device creation loop "
+				        "early: autoprobe function reported %i "
+				        "created, but only %i non-null",
+				        num_found, created_idx);
+				continue;
+			}
+			handle_found_device(p, xdevs, num_xdevs, have_hmd, new_xdevs[created_idx]);
+		}
 	}
 }