d/qwerty: Implement still HMD creation

src/xrt/drivers/qwerty/qwerty_device.c

@@ -7,6 +7,117 @@
  * @ingroup drv_qwerty
  */
 
-typedef int _silence_compiler_about_empty_translation_unit;
+#include "qwerty_device.h"
 
-// @todo
+#include "util/u_device.h"
+
+#include "util/u_distortion_mesh.h"
+
+#include "math/m_api.h"
+#include "math/m_mathinclude.h"
+
+#include "xrt/xrt_device.h"
+
+#include <stdio.h>
+#include <assert.h>
+
+struct qwerty_device *
+qwerty_device(struct xrt_device *xd)
+{
+	struct qwerty_device *qd = (struct qwerty_device *)xd;
+	assert(qd);
+	return qd;
+}
+
+static void
+qwerty_update_inputs(struct xrt_device *xd)
+{
+	return;
+}
+
+static void
+qwerty_get_tracked_pose(struct xrt_device *xd,
+                        enum xrt_input_name name,
+                        uint64_t at_timestamp_ns,
+                        struct xrt_space_relation *out_relation)
+{
+	if (name != XRT_INPUT_GENERIC_HEAD_POSE) {
+		printf("Unexpected input name = 0x%04X\n", name >> 8); // @todo: use u_logging.h
+		return;
+	}
+
+	struct xrt_pose identity = {{0.0f, 0.0f, 0.0f, 1.0f}, {0.0f, 0.0f, 0.0f}};
+	out_relation->pose = identity;
+	out_relation->relation_flags =
+	    XRT_SPACE_RELATION_ORIENTATION_VALID_BIT | XRT_SPACE_RELATION_POSITION_VALID_BIT |
+	    XRT_SPACE_RELATION_ORIENTATION_TRACKED_BIT | XRT_SPACE_RELATION_POSITION_TRACKED_BIT;
+}
+
+static void
+qwerty_get_view_pose(struct xrt_device *xd,
+                     struct xrt_vec3 *eye_relation,
+                     uint32_t view_index,
+                     struct xrt_pose *out_pose)
+{
+	// Adapted from dummy_hmd_get_view_pose()
+	struct xrt_pose pose = {{0.0f, 0.0f, 0.0f, 1.0f}, {0.0f, 0.0f, 0.0f}};
+	bool is_left = view_index == 0;
+	float adjust = is_left ? -0.5f : 0.5f;
+	struct xrt_vec3 eye_offset = *eye_relation;
+	math_vec3_scalar_mul(adjust, &eye_offset);
+	math_vec3_accum(&eye_offset, &pose.position);
+	*out_pose = pose;
+}
+
+static void
+qwerty_destroy(struct xrt_device *xd)
+{
+	u_device_free(xd);
+}
+
+struct qwerty_device *
+qwerty_hmd_create(void)
+{
+	enum u_device_alloc_flags flags = U_DEVICE_ALLOC_HMD | U_DEVICE_ALLOC_TRACKING_NONE;
+	size_t num_inputs = 1, num_outputs = 0;
+	struct qwerty_device *qd = U_DEVICE_ALLOCATE(struct qwerty_device, flags, num_inputs, num_outputs);
+	assert(qd);
+
+	struct xrt_device *xd = &qd->base;
+	xd->name = XRT_DEVICE_GENERIC_HMD;
+	xd->device_type = XRT_DEVICE_TYPE_HMD;
+
+	snprintf(xd->str, XRT_DEVICE_NAME_LEN, QWERTY_HMD_STR);
+	snprintf(xd->serial, XRT_DEVICE_NAME_LEN, QWERTY_HMD_STR);
+
+	// Fill in xd->hmd
+	struct u_device_simple_info info;
+	info.display.w_pixels = 1280;
+	info.display.h_pixels = 720;
+	info.display.w_meters = 0.13f;
+	info.display.h_meters = 0.07f;
+	info.lens_horizontal_separation_meters = 0.13f / 2.0f;
+	info.lens_vertical_position_meters = 0.07f / 2.0f;
+	info.views[0].fov = 85.0f * (M_PI / 180.0f);
+	info.views[1].fov = 85.0f * (M_PI / 180.0f);
+
+	if (!u_device_setup_split_side_by_side(xd, &info)) {
+		printf("Failed to setup HMD properties\n"); // @todo: Use u_logging.h
+		qwerty_destroy(xd);
+		assert(false);
+		return NULL;
+	}
+
+	xd->tracking_origin->type = XRT_TRACKING_TYPE_OTHER;
+	snprintf(xd->tracking_origin->name, XRT_TRACKING_NAME_LEN, QWERTY_HMD_TRACKER_STR);
+
+	xd->inputs[0].name = XRT_INPUT_GENERIC_HEAD_POSE;
+
+	xd->update_inputs = qwerty_update_inputs;
+	xd->get_tracked_pose = qwerty_get_tracked_pose;
+	xd->get_view_pose = qwerty_get_view_pose;
+	xd->destroy = qwerty_destroy;
+	u_distortion_mesh_set_none(xd); // Fill in xd->compute_distortion()
+
+	return qd;
+}

src/xrt/drivers/qwerty/qwerty_device.h

@@ -8,6 +8,11 @@
  */
 #pragma once
 
+#include "xrt/xrt_device.h"
+
+#define QWERTY_HMD_STR "Qwerty HMD"
+#define QWERTY_HMD_TRACKER_STR QWERTY_HMD_STR " Tracker"
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -17,7 +22,19 @@ extern "C" {
  * @{
  */
 
-// @todo
+//! @implements xrt_device
+struct qwerty_device
+{
+	struct xrt_device base;
+};
+
+//! Cast to qwerty_device. Ensures returning a valid device or crashing.
+struct qwerty_device *
+qwerty_device(struct xrt_device *xd);
+
+//! Create qwerty_hmd. Crash on failure.
+struct qwerty_device *
+qwerty_hmd_create(void);
 
 /*!
  * @}

src/xrt/drivers/qwerty/qwerty_prober.c

@@ -7,6 +7,7 @@
  * @ingroup drv_qwerty
  */
 
+#include "qwerty_device.h"
 #include "util/u_misc.h"
 #include "xrt/xrt_prober.h"
 
@@ -35,8 +36,16 @@ qwerty_prober_autoprobe(struct xrt_auto_prober *xap,
                         struct xrt_prober *xp,
                         struct xrt_device **out_xdevs)
 {
-	// @todo
-	return 0;
+	bool hmd_wanted = !no_hmds; // Hopefully easier to reason about
+
+	struct qwerty_device *qhmd = qwerty_hmd_create();
+
+	if (hmd_wanted) {
+		out_xdevs[0] = &qhmd->base;
+	}
+
+	int num_qwerty_devices = hmd_wanted;
+	return num_qwerty_devices;
 }
 
 struct xrt_auto_prober *

src/xrt/include/xrt/xrt_tracking.h

@@ -57,6 +57,17 @@ enum xrt_tracking_type
 
 	// The device(s) are tracked by external SLAM
 	XRT_TRACKING_TYPE_EXTERNAL_SLAM,
+
+	/* @remove: on next commit
+	Is it a good idea to add a new tracking type instead of using _NONE? Two reasons:
+	1. _NONE makes u_device_setup_tracking_origins modify tracking origins in
+	  the app but this is not yet synced with the service
+	2. _NONE is not quite exact, for what I understand qwerty devices *are*
+	  being tracked. Though I might be missunderstanding what tracking is.
+	*/
+
+	// The device(s) are tracked by other methods.
+	XRT_TRACKING_TYPE_OTHER,
 };
 
 /*!