d/qwerty: Add qwerty_system for driver management

src/xrt/drivers/qwerty/qwerty_device.c

@@ -40,13 +40,27 @@
 #define QWERTY_AIM 3
 #define QWERTY_VIBRATION 0
 
+static void
+qwerty_system_remove(struct qwerty_system *qs, struct qwerty_device *qd);
+
+static void
+qwerty_system_destroy(struct qwerty_system *qs);
+
+// Compare any two pointers without verbose casts
+static inline bool
+eq(void *a, void *b)
+{
+	return a == b;
+}
+
 // xrt_device functions
 
 struct qwerty_device *
 qwerty_device(struct xrt_device *xd)
 {
 	struct qwerty_device *qd = (struct qwerty_device *)xd;
-	assert(qd);
+	bool is_qwerty_device = eq(qd, qd->sys->hmd) || eq(qd, qd->sys->lctrl) || eq(qd, qd->sys->rctrl);
+	assert(is_qwerty_device);
 	return qd;
 }
 
@@ -54,7 +68,8 @@ struct qwerty_hmd *
 qwerty_hmd(struct xrt_device *xd)
 {
 	struct qwerty_hmd *qh = (struct qwerty_hmd *)xd;
-	assert(qh);
+	bool is_qwerty_hmd = eq(qh, qh->base.sys->hmd);
+	assert(is_qwerty_hmd);
 	return qh;
 }
 
@@ -62,7 +77,8 @@ struct qwerty_controller *
 qwerty_controller(struct xrt_device *xd)
 {
 	struct qwerty_controller *qc = (struct qwerty_controller *)xd;
-	assert(qc);
+	bool is_qwerty_controller = eq(qc, qc->base.sys->lctrl) || eq(qc, qc->base.sys->rctrl);
+	assert(is_qwerty_controller);
 	return qc;
 }
 
@@ -148,6 +164,8 @@ qwerty_get_view_pose(struct xrt_device *xd,
 static void
 qwerty_destroy(struct xrt_device *xd)
 {
+	struct qwerty_device *qd = qwerty_device(xd);
+	qwerty_system_remove(qd->sys, qd);
 	u_device_free(xd);
 }
 
@@ -243,6 +261,58 @@ qwerty_controller_create(bool is_left, struct qwerty_hmd *qhmd)
 	return qc;
 }
 
+// System methods
+
+struct qwerty_system *
+qwerty_system_create(struct qwerty_hmd *qhmd,
+                     struct qwerty_controller *qleft,
+                     struct qwerty_controller *qright)
+{
+	assert(qleft && "Cannot create a qwerty system when Left controller is NULL");
+	assert(qright && "Cannot create a qwerty system when Right controller is NULL");
+
+	struct qwerty_system *qs = U_TYPED_CALLOC(struct qwerty_system);
+	qs->hmd = qhmd;
+	qs->lctrl = qleft;
+	qs->rctrl = qright;
+	qs->process_keys = true;
+
+	if (qhmd) {
+		qhmd->base.sys = qs;
+	}
+	qleft->base.sys = qs;
+	qright->base.sys = qs;
+
+	return qs;
+}
+
+static void
+qwerty_system_remove(struct qwerty_system *qs, struct qwerty_device *qd)
+{
+	if (eq(qd, qs->hmd)) {
+		qs->hmd = NULL;
+	} else if (eq(qd, qs->lctrl)) {
+		qs->lctrl = NULL;
+	} else if (eq(qd, qs->rctrl)) {
+		qs->rctrl = NULL;
+	} else {
+		assert(false && "Trying to remove a device that is not in the qwerty system");
+	}
+
+	bool all_devices_clean = !qs->hmd && !qs->lctrl && !qs->rctrl;
+	if (all_devices_clean) {
+		qwerty_system_destroy(qs);
+	}
+}
+
+static void
+qwerty_system_destroy(struct qwerty_system *qs)
+{
+	bool all_devices_clean = !qs->hmd && !qs->lctrl && !qs->rctrl;
+	assert(all_devices_clean && "Tried to destroy a qwerty_system without destroying its devices before.");
+	free(qs);
+}
+
 // Device methods
 
 // clang-format off

src/xrt/drivers/qwerty/qwerty_device.h

@@ -26,12 +26,22 @@ extern "C" {
  * @{
  */
 
+//! Container of qwerty devices and driver properties.
+struct qwerty_system
+{
+	struct qwerty_hmd *hmd;          //!< Can be NULL
+	struct qwerty_controller *lctrl; //!< Cannot be NULL
+	struct qwerty_controller *rctrl; //!< Cannot be NULL
+	bool process_keys;  //!< If false disable keyboard and mouse input
+};
+
 //! Fake device that modifies its tracked pose through its methods.
 //! @implements xrt_device
 struct qwerty_device
 {
 	struct xrt_device base;
-	struct xrt_pose pose; //!< Internal pose state
+	struct xrt_pose pose;      //!< Internal pose state
+	struct qwerty_system *sys; //!< Reference to the system this device is in.
 
 	float movement_speed; //!< In meters per frame
 	bool left_pressed;
@@ -48,8 +58,8 @@ struct qwerty_device
 	bool look_down_pressed;
 
 	bool sprint_pressed; //!< Movement speed boost
-	float yaw_delta;   //!< How much extra yaw to add for the next pose. Then reset to 0.
-	float pitch_delta; //!< Similar to `yaw_delta`
+	float yaw_delta;     //!< How much extra yaw to add for the next pose. Then reset to 0.
+	float pitch_delta;   //!< Similar to `yaw_delta`
 };
 
 //! @implements qwerty_device
@@ -64,6 +74,23 @@ struct qwerty_controller
 	struct qwerty_device base;
 };
 
+/*!
+ * @name Qwerty System
+ * @memberof qwerty_system
+ * qwerty_system public methods
+ * @{
+ */
+//! @public @memberof qwerty_system <!-- Trick for doxygen -->
+
+struct qwerty_system *
+qwerty_system_create(struct qwerty_hmd *qhmd,
+                     struct qwerty_controller *qleft,
+                     struct qwerty_controller *qright);
+
+/*!
+ * @}
+ */
+
 /*!
  * @name Qwerty Device
  * @memberof qwerty_device

src/xrt/drivers/qwerty/qwerty_prober.c

@@ -51,6 +51,8 @@ qwerty_prober_autoprobe(struct xrt_auto_prober *xap,
 	struct qwerty_controller *qleft = qwerty_controller_create(true, qhmd);
 	struct qwerty_controller *qright = qwerty_controller_create(false, qhmd);
 
+	qwerty_system_create(qhmd, qleft, qright);
+
 	struct xrt_device *xd_hmd = &qhmd->base.base;
 	struct xrt_device *xd_left = &qleft->base.base;
 	struct xrt_device *xd_right = &qright->base.base;

src/xrt/drivers/qwerty/qwerty_sdl.c

@@ -11,44 +11,45 @@
 #include "util/u_device.h"
 #include "xrt/xrt_device.h"
 #include <SDL2/SDL.h>
+#include <assert.h>
 
 // Amount of look_speed units a mouse delta of 1px in screen space will rotate the device
 #define SENSITIVITY 0.1f
 
-static void
-find_qwerty_devices(struct xrt_device **xdevs,
-                    size_t num_xdevs,
-                    struct xrt_device **xd_hmd,
-                    struct xrt_device **xd_left,
-                    struct xrt_device **xd_right)
+static struct qwerty_system *
+find_qwerty_system(struct xrt_device **xdevs, size_t num_xdevs)
 {
+	struct xrt_device *xdev = NULL;
 	for (size_t i = 0; i < num_xdevs; i++) {
 		if (xdevs[i] == NULL) {
 			continue;
 		}
-
-		if (strcmp(xdevs[i]->str, QWERTY_HMD_STR) == 0) {
-			*xd_hmd = xdevs[i];
-		} else if (strcmp(xdevs[i]->str, QWERTY_LEFT_STR) == 0) {
-			*xd_left = xdevs[i];
-		} else if (strcmp(xdevs[i]->str, QWERTY_RIGHT_STR) == 0) {
-			*xd_right = xdevs[i];
+		if (strcmp(xdevs[i]->str, QWERTY_HMD_STR) == 0 || strcmp(xdevs[i]->str, QWERTY_LEFT_STR) == 0 ||
+		    strcmp(xdevs[i]->str, QWERTY_RIGHT_STR) == 0) {
+			xdev = xdevs[i];
+			break;
 		}
 	}
+
+	assert(xdev != NULL && "There is no device in xdevs with the name of a qwerty device");
+	struct qwerty_device *qdev = qwerty_device(xdev);
+	struct qwerty_system *qsys = qdev->sys;
+	assert(qsys != NULL && "The qwerty_system of a qwerty_device was null");
+	return qsys;
 }
 
 // Determines the default qwerty device based on which devices are in use
-struct qwerty_device *
-default_qwerty_device(struct xrt_device **xdevs,
-                      size_t num_xdevs,
-                      struct xrt_device *xd_hmd,
-                      struct xrt_device *xd_left,
-                      struct xrt_device *xd_right)
+static struct qwerty_device *
+default_qwerty_device(struct xrt_device **xdevs, size_t num_xdevs, struct qwerty_system *qsys)
 {
 	int head, left, right;
 	head = left = right = XRT_DEVICE_ROLE_UNASSIGNED;
 	u_device_assign_xdev_roles(xdevs, num_xdevs, &head, &left, &right);
 
+	struct xrt_device *xd_hmd = qsys->hmd ? &qsys->hmd->base.base : NULL;
+	struct xrt_device *xd_left = &qsys->lctrl->base.base;
+	struct xrt_device *xd_right = &qsys->rctrl->base.base;
+
 	struct qwerty_device *default_qdev = NULL;
 	if (xdevs[head] == xd_hmd) {
 		default_qdev = qwerty_device(xd_hmd);
@@ -66,9 +67,7 @@ default_qwerty_device(struct xrt_device **xdevs,
 void
 qwerty_process_event(struct xrt_device **xdevs, size_t num_xdevs, SDL_Event event)
 {
-	static struct xrt_device *xd_hmd = NULL;
-	static struct xrt_device *xd_left = NULL;
-	static struct xrt_device *xd_right = NULL;
+	static struct qwerty_system *qsys = NULL;
 
 	static bool alt_pressed = false;
 	static bool ctrl_pressed = false;
@@ -79,21 +78,25 @@ qwerty_process_event(struct xrt_device **xdevs, size_t num_xdevs, SDL_Event even
 	// We can cache the devices as they don't get destroyed during runtime
 	static bool cached = false;
 	if (!cached) {
-		find_qwerty_devices(xdevs, num_xdevs, &xd_hmd, &xd_left, &xd_right);
-		default_qdev = default_qwerty_device(xdevs, num_xdevs, xd_hmd, xd_left, xd_right);
+		qsys = find_qwerty_system(xdevs, num_xdevs);
+		default_qdev = default_qwerty_device(xdevs, num_xdevs, qsys);
 		cached = true;
 	}
 
+	if (!qsys->process_keys) {
+		return;
+	}
+
 	// Initialize different views of the same pointers.
 
-	struct qwerty_controller *qleft = qwerty_controller(xd_left);
+	struct qwerty_controller *qleft = qsys->lctrl;
 	struct qwerty_device *qd_left = &qleft->base;
 
-	struct qwerty_controller *qright = qwerty_controller(xd_right);
+	struct qwerty_controller *qright = qsys->rctrl;
 	struct qwerty_device *qd_right = &qright->base;
 
-	bool using_qhmd = xd_hmd != NULL;
-	struct qwerty_hmd *qhmd = using_qhmd ? qwerty_hmd(xd_hmd) : NULL;
+	bool using_qhmd = qsys->hmd != NULL;
+	struct qwerty_hmd *qhmd = using_qhmd ? qsys->hmd : NULL;
 	struct qwerty_device *qd_hmd = using_qhmd ? &qhmd->base : NULL;
 
 	// clang-format off