/**************************************************************************/ /* mobile_vr_interface.cpp */ /**************************************************************************/ /* This file is part of: */ /* GODOT ENGINE */ /* https://godotengine.org */ /**************************************************************************/ /* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */ /* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */ /* */ /* Permission is hereby granted, free of charge, to any person obtaining */ /* a copy of this software and associated documentation files (the */ /* "Software"), to deal in the Software without restriction, including */ /* without limitation the rights to use, copy, modify, merge, publish, */ /* distribute, sublicense, and/or sell copies of the Software, and to */ /* permit persons to whom the Software is furnished to do so, subject to */ /* the following conditions: */ /* */ /* The above copyright notice and this permission notice shall be */ /* included in all copies or substantial portions of the Software. */ /* */ /* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */ /* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */ /* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */ /* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */ /* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */ /* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */ /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ /**************************************************************************/ #include "mobile_vr_interface.h" #include "core/input/input.h" #include "core/os/os.h" #include "servers/display_server.h" #include "servers/rendering/rendering_server_globals.h" StringName MobileVRInterface::get_name() const { return "Native mobile"; }; uint32_t MobileVRInterface::get_capabilities() const { return XRInterface::XR_STEREO; }; Vector3 MobileVRInterface::scale_magneto(const Vector3 &p_magnetometer) { // Our magnetometer doesn't give us nice clean data. // Well it may on macOS because we're getting a calibrated value in the current implementation but Android we're getting raw data. // This is a fairly simple adjustment we can do to correct for the magnetometer data being elliptical Vector3 mag_raw = p_magnetometer; Vector3 mag_scaled = p_magnetometer; // update our variables every x frames if (mag_count > 20) { mag_current_min = mag_next_min; mag_current_max = mag_next_max; mag_count = 0; } else { mag_count++; }; // adjust our min and max if (mag_raw.x > mag_next_max.x) { mag_next_max.x = mag_raw.x; } if (mag_raw.y > mag_next_max.y) { mag_next_max.y = mag_raw.y; } if (mag_raw.z > mag_next_max.z) { mag_next_max.z = mag_raw.z; } if (mag_raw.x < mag_next_min.x) { mag_next_min.x = mag_raw.x; } if (mag_raw.y < mag_next_min.y) { mag_next_min.y = mag_raw.y; } if (mag_raw.z < mag_next_min.z) { mag_next_min.z = mag_raw.z; } // scale our x, y and z if (!(mag_current_max.x - mag_current_min.x)) { mag_raw.x -= (mag_current_min.x + mag_current_max.x) / 2.0; mag_scaled.x = (mag_raw.x - mag_current_min.x) / ((mag_current_max.x - mag_current_min.x) * 2.0 - 1.0); }; if (!(mag_current_max.y - mag_current_min.y)) { mag_raw.y -= (mag_current_min.y + mag_current_max.y) / 2.0; mag_scaled.y = (mag_raw.y - mag_current_min.y) / ((mag_current_max.y - mag_current_min.y) * 2.0 - 1.0); }; if (!(mag_current_max.z - mag_current_min.z)) { mag_raw.z -= (mag_current_min.z + mag_current_max.z) / 2.0; mag_scaled.z = (mag_raw.z - mag_current_min.z) / ((mag_current_max.z - mag_current_min.z) * 2.0 - 1.0); }; return mag_scaled; }; Basis MobileVRInterface::combine_acc_mag(const Vector3 &p_grav, const Vector3 &p_magneto) { // yup, stock standard cross product solution... Vector3 up = -p_grav.normalized(); Vector3 magneto_east = up.cross(p_magneto.normalized()); // or is this west?, but should be horizon aligned now magneto_east.normalize(); Vector3 magneto = up.cross(magneto_east); // and now we have a horizon aligned north magneto.normalize(); // We use our gravity and magnetometer vectors to construct our matrix Basis acc_mag_m3; acc_mag_m3.rows[0] = -magneto_east; acc_mag_m3.rows[1] = up; acc_mag_m3.rows[2] = magneto; return acc_mag_m3; }; void MobileVRInterface::set_position_from_sensors() { _THREAD_SAFE_METHOD_ // this is a helper function that attempts to adjust our transform using our 9dof sensors // 9dof is a misleading marketing term coming from 3 accelerometer axis + 3 gyro axis + 3 magnetometer axis = 9 axis // but in reality this only offers 3 dof (yaw, pitch, roll) orientation Basis orientation; uint64_t ticks = OS::get_singleton()->get_ticks_usec(); uint64_t ticks_elapsed = ticks - last_ticks; float delta_time = (double)ticks_elapsed / 1000000.0; // few things we need Input *input = Input::get_singleton(); Vector3 down(0.0, -1.0, 0.0); // Down is Y negative Vector3 north(0.0, 0.0, 1.0); // North is Z positive // make copies of our inputs bool has_grav = false; Vector3 acc = input->get_accelerometer(); Vector3 gyro = input->get_gyroscope(); Vector3 grav = input->get_gravity(); Vector3 magneto = scale_magneto(input->get_magnetometer()); // this may be overkill on iOS because we're already getting a calibrated magnetometer reading if (sensor_first) { sensor_first = false; } else { acc = scrub(acc, last_accerometer_data, 2, 0.2); magneto = scrub(magneto, last_magnetometer_data, 3, 0.3); }; last_accerometer_data = acc; last_magnetometer_data = magneto; if (grav.length() < 0.1) { // not ideal but use our accelerometer, this will contain shaky user behavior // maybe look into some math but I'm guessing that if this isn't available, it's because we lack the gyro sensor to actually work out // what a stable gravity vector is grav = acc; if (grav.length() > 0.1) { has_grav = true; }; } else { has_grav = true; }; bool has_magneto = magneto.length() > 0.1; if (gyro.length() > 0.1) { /* this can return to 0.0 if the user doesn't move the phone, so once on, it's on */ has_gyro = true; }; if (has_gyro) { // start with applying our gyro (do NOT smooth our gyro!) Basis rotate; rotate.rotate(orientation.get_column(0), gyro.x * delta_time); rotate.rotate(orientation.get_column(1), gyro.y * delta_time); rotate.rotate(orientation.get_column(2), gyro.z * delta_time); orientation = rotate * orientation; tracking_state = XRInterface::XR_NORMAL_TRACKING; tracking_confidence = XRPose::XR_TRACKING_CONFIDENCE_HIGH; }; ///@TODO improve this, the magnetometer is very fidgety sometimes flipping the axis for no apparent reason (probably a bug on my part) // if you have a gyro + accelerometer that combo tends to be better than combining all three but without a gyro you need the magnetometer.. if (has_magneto && has_grav && !has_gyro) { // convert to quaternions, easier to smooth those out Quaternion transform_quat(orientation); Quaternion acc_mag_quat(combine_acc_mag(grav, magneto)); transform_quat = transform_quat.slerp(acc_mag_quat, 0.1); orientation = Basis(transform_quat); tracking_state = XRInterface::XR_NORMAL_TRACKING; tracking_confidence = XRPose::XR_TRACKING_CONFIDENCE_HIGH; } else if (has_grav) { // use gravity vector to make sure down is down... // transform gravity into our world space grav.normalize(); Vector3 grav_adj = orientation.xform(grav); float dot = grav_adj.dot(down); if ((dot > -1.0) && (dot < 1.0)) { // axis around which we have this rotation Vector3 axis = grav_adj.cross(down); axis.normalize(); Basis drift_compensation(axis, acos(dot) * delta_time * 10); orientation = drift_compensation * orientation; }; }; // and copy to our head transform head_transform.basis = orientation.orthonormalized(); last_ticks = ticks; }; void MobileVRInterface::_bind_methods() { ClassDB::bind_method(D_METHOD("set_eye_height", "eye_height"), &MobileVRInterface::set_eye_height); ClassDB::bind_method(D_METHOD("get_eye_height"), &MobileVRInterface::get_eye_height); ClassDB::bind_method(D_METHOD("set_iod", "iod"), &MobileVRInterface::set_iod); ClassDB::bind_method(D_METHOD("get_iod"), &MobileVRInterface::get_iod); ClassDB::bind_method(D_METHOD("set_display_width", "display_width"), &MobileVRInterface::set_display_width); ClassDB::bind_method(D_METHOD("get_display_width"), &MobileVRInterface::get_display_width); ClassDB::bind_method(D_METHOD("set_display_to_lens", "display_to_lens"), &MobileVRInterface::set_display_to_lens); ClassDB::bind_method(D_METHOD("get_display_to_lens"), &MobileVRInterface::get_display_to_lens); ClassDB::bind_method(D_METHOD("set_oversample", "oversample"), &MobileVRInterface::set_oversample); ClassDB::bind_method(D_METHOD("get_oversample"), &MobileVRInterface::get_oversample); ClassDB::bind_method(D_METHOD("set_k1", "k"), &MobileVRInterface::set_k1); ClassDB::bind_method(D_METHOD("get_k1"), &MobileVRInterface::get_k1); ClassDB::bind_method(D_METHOD("set_k2", "k"), &MobileVRInterface::set_k2); ClassDB::bind_method(D_METHOD("get_k2"), &MobileVRInterface::get_k2); ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "eye_height", PROPERTY_HINT_RANGE, "0.0,3.0,0.1"), "set_eye_height", "get_eye_height"); ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "iod", PROPERTY_HINT_RANGE, "4.0,10.0,0.1"), "set_iod", "get_iod"); ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "display_width", PROPERTY_HINT_RANGE, "5.0,25.0,0.1"), "set_display_width", "get_display_width"); ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "display_to_lens", PROPERTY_HINT_RANGE, "5.0,25.0,0.1"), "set_display_to_lens", "get_display_to_lens"); ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "oversample", PROPERTY_HINT_RANGE, "1.0,2.0,0.1"), "set_oversample", "get_oversample"); ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "k1", PROPERTY_HINT_RANGE, "0.1,10.0,0.0001"), "set_k1", "get_k1"); ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "k2", PROPERTY_HINT_RANGE, "0.1,10.0,0.0001"), "set_k2", "get_k2"); } void MobileVRInterface::set_eye_height(const double p_eye_height) { eye_height = p_eye_height; } double MobileVRInterface::get_eye_height() const { return eye_height; } void MobileVRInterface::set_iod(const double p_iod) { intraocular_dist = p_iod; }; double MobileVRInterface::get_iod() const { return intraocular_dist; }; void MobileVRInterface::set_display_width(const double p_display_width) { display_width = p_display_width; }; double MobileVRInterface::get_display_width() const { return display_width; }; void MobileVRInterface::set_display_to_lens(const double p_display_to_lens) { display_to_lens = p_display_to_lens; }; double MobileVRInterface::get_display_to_lens() const { return display_to_lens; }; void MobileVRInterface::set_oversample(const double p_oversample) { oversample = p_oversample; }; double MobileVRInterface::get_oversample() const { return oversample; }; void MobileVRInterface::set_k1(const double p_k1) { k1 = p_k1; }; double MobileVRInterface::get_k1() const { return k1; }; void MobileVRInterface::set_k2(const double p_k2) { k2 = p_k2; }; double MobileVRInterface::get_k2() const { return k2; }; uint32_t MobileVRInterface::get_view_count() { // needs stereo... return 2; }; XRInterface::TrackingStatus MobileVRInterface::get_tracking_status() const { return tracking_state; } bool MobileVRInterface::is_initialized() const { return (initialized); }; bool MobileVRInterface::initialize() { XRServer *xr_server = XRServer::get_singleton(); ERR_FAIL_NULL_V(xr_server, false); if (!initialized) { // reset our sensor data mag_count = 0; has_gyro = false; sensor_first = true; mag_next_min = Vector3(10000, 10000, 10000); mag_next_max = Vector3(-10000, -10000, -10000); mag_current_min = Vector3(0, 0, 0); mag_current_max = Vector3(0, 0, 0); head_transform.basis = Basis(); head_transform.origin = Vector3(0.0, eye_height, 0.0); // we must create a tracker for our head head.instantiate(); head->set_tracker_type(XRServer::TRACKER_HEAD); head->set_tracker_name("head"); head->set_tracker_desc("Players head"); xr_server->add_tracker(head); // make this our primary interface xr_server->set_primary_interface(this); last_ticks = OS::get_singleton()->get_ticks_usec(); initialized = true; }; return true; }; void MobileVRInterface::uninitialize() { if (initialized) { // do any cleanup here... XRServer *xr_server = XRServer::get_singleton(); if (xr_server != nullptr) { if (head.is_valid()) { xr_server->remove_tracker(head); head.unref(); } if (xr_server->get_primary_interface() == this) { // no longer our primary interface xr_server->set_primary_interface(nullptr); } } initialized = false; }; }; Dictionary MobileVRInterface::get_system_info() { Dictionary dict; dict[SNAME("XRRuntimeName")] = String("Godot mobile VR interface"); dict[SNAME("XRRuntimeVersion")] = String(""); return dict; } bool MobileVRInterface::supports_play_area_mode(XRInterface::PlayAreaMode p_mode) { // This interface has no positional tracking so fix this to 3DOF return p_mode == XR_PLAY_AREA_3DOF; } XRInterface::PlayAreaMode MobileVRInterface::get_play_area_mode() const { return XR_PLAY_AREA_3DOF; } bool MobileVRInterface::set_play_area_mode(XRInterface::PlayAreaMode p_mode) { return p_mode == XR_PLAY_AREA_3DOF; } Size2 MobileVRInterface::get_render_target_size() { _THREAD_SAFE_METHOD_ // we use half our window size Size2 target_size = DisplayServer::get_singleton()->window_get_size(); target_size.x *= 0.5 * oversample; target_size.y *= oversample; return target_size; }; Transform3D MobileVRInterface::get_camera_transform() { _THREAD_SAFE_METHOD_ Transform3D transform_for_eye; XRServer *xr_server = XRServer::get_singleton(); ERR_FAIL_NULL_V(xr_server, transform_for_eye); if (initialized) { float world_scale = xr_server->get_world_scale(); // just scale our origin point of our transform Transform3D _head_transform = head_transform; _head_transform.origin *= world_scale; transform_for_eye = (xr_server->get_reference_frame()) * _head_transform; } return transform_for_eye; }; Transform3D MobileVRInterface::get_transform_for_view(uint32_t p_view, const Transform3D &p_cam_transform) { _THREAD_SAFE_METHOD_ Transform3D transform_for_eye; XRServer *xr_server = XRServer::get_singleton(); ERR_FAIL_NULL_V(xr_server, transform_for_eye); if (initialized) { float world_scale = xr_server->get_world_scale(); // we don't need to check for the existence of our HMD, doesn't affect our values... // note * 0.01 to convert cm to m and * 0.5 as we're moving half in each direction... if (p_view == 0) { transform_for_eye.origin.x = -(intraocular_dist * 0.01 * 0.5 * world_scale); } else if (p_view == 1) { transform_for_eye.origin.x = intraocular_dist * 0.01 * 0.5 * world_scale; } else { // should not have any other values.. }; // just scale our origin point of our transform Transform3D _head_transform = head_transform; _head_transform.origin *= world_scale; transform_for_eye = p_cam_transform * (xr_server->get_reference_frame()) * _head_transform * transform_for_eye; } else { // huh? well just return what we got.... transform_for_eye = p_cam_transform; }; return transform_for_eye; }; Projection MobileVRInterface::get_projection_for_view(uint32_t p_view, double p_aspect, double p_z_near, double p_z_far) { _THREAD_SAFE_METHOD_ Projection eye; aspect = p_aspect; eye.set_for_hmd(p_view + 1, p_aspect, intraocular_dist, display_width, display_to_lens, oversample, p_z_near, p_z_far); return eye; }; Vector<BlitToScreen> MobileVRInterface::post_draw_viewport(RID p_render_target, const Rect2 &p_screen_rect) { _THREAD_SAFE_METHOD_ Vector<BlitToScreen> blit_to_screen; // We must have a valid render target ERR_FAIL_COND_V(!p_render_target.is_valid(), blit_to_screen); // Because we are rendering to our device we must use our main viewport! ERR_FAIL_COND_V(p_screen_rect == Rect2(), blit_to_screen); // and add our blits BlitToScreen blit; blit.render_target = p_render_target; blit.multi_view.use_layer = true; blit.lens_distortion.apply = true; blit.lens_distortion.k1 = k1; blit.lens_distortion.k2 = k2; blit.lens_distortion.upscale = oversample; blit.lens_distortion.aspect_ratio = aspect; // left eye blit.dst_rect = p_screen_rect; blit.dst_rect.size.width *= 0.5; blit.multi_view.layer = 0; blit.lens_distortion.eye_center.x = ((-intraocular_dist / 2.0) + (display_width / 4.0)) / (display_width / 2.0); blit_to_screen.push_back(blit); // right eye blit.dst_rect = p_screen_rect; blit.dst_rect.size.width *= 0.5; blit.dst_rect.position.x = blit.dst_rect.size.width; blit.multi_view.layer = 1; blit.lens_distortion.eye_center.x = ((intraocular_dist / 2.0) - (display_width / 4.0)) / (display_width / 2.0); blit_to_screen.push_back(blit); return blit_to_screen; } void MobileVRInterface::process() { _THREAD_SAFE_METHOD_ if (initialized) { // update our head transform orientation set_position_from_sensors(); // update our head transform position (should be constant) head_transform.origin = Vector3(0.0, eye_height, 0.0); if (head.is_valid()) { // Set our head position, note in real space, reference frame and world scale is applied later head->set_pose("default", head_transform, Vector3(), Vector3(), tracking_confidence); } }; }; MobileVRInterface::MobileVRInterface() {} MobileVRInterface::~MobileVRInterface() { // and make sure we cleanup if we haven't already if (is_initialized()) { uninitialize(); }; };