feat(openxr): Monado playspace mover

Co-authored-by: RinLovesYou <xxklintan123xx@gmail.com>

src/backend/openxr/helpers.rs

@@ -1,6 +1,9 @@
+use std::path::PathBuf;
+
 use anyhow::{bail, ensure};
 use glam::{Affine3A, Quat, Vec3, Vec3A};
 use openxr as xr;
+use sysinfo::Process;
 use xr::OverlaySessionCreateFlagsEXTX;
 
 pub(super) fn init_xr() -> Result<(xr::Instance, xr::SystemId), anyhow::Error> {
@@ -169,3 +172,44 @@ pub(super) fn transform_to_posef(transform: &Affine3A) -> xr::Posef {
     let rotation = transform_to_norm_quat(transform);
     translation_rotation_to_posef(translation, rotation)
 }
+
+pub(super) fn find_libmonado() -> anyhow::Result<libloading::Library> {
+    //check env var first
+    if let Ok(path) = std::env::var("LIBMONADO_PATH") {
+        let path = PathBuf::from(path);
+        if path.exists() {
+            return Ok(unsafe { libloading::Library::new(path)? });
+        } else {
+            bail!("LIBMONADO_PATH points to a non-existing file.");
+        }
+    }
+
+    const PROC_NAMES: [&str; 1] = ["monado-service"];
+    let mut system = sysinfo::System::new();
+    system.refresh_processes();
+    for p in system.processes().values() {
+        for proc_name in PROC_NAMES.iter() {
+            if p.name().contains(proc_name) {
+                if let Some(lib) = proc_load_libmonado(p) {
+                    return Ok(lib);
+                }
+            }
+        }
+    }
+    bail!("Could not find libmonado.");
+}
+
+fn proc_load_libmonado(proc: &Process) -> Option<libloading::Library> {
+    let path = proc
+        .exe()?
+        .parent()?
+        .parent()?
+        .join("lib")
+        .join("libmonado.so");
+
+    if path.exists() {
+        Some(unsafe { libloading::Library::new(path).ok()? })
+    } else {
+        None
+    }
+}

src/backend/openxr/input.rs

@@ -51,6 +51,7 @@ pub(super) struct OpenXrHandSource {
     action_scroll: xr::Action<f32>,
     action_alt_click: xr::Action<f32>,
     action_show_hide: xr::Action<bool>,
+    action_space_drag: xr::Action<bool>,
     action_click_modifier_right: xr::Action<bool>,
     action_click_modifier_middle: xr::Action<bool>,
     action_move_mouse: xr::Action<bool>,
@@ -201,6 +202,12 @@ impl OpenXrHand {
             .state(&xr.session, xr::Path::NULL)?
             .current_state;
 
+        pointer.now.space_drag = self
+            .source
+            .action_space_drag
+            .state(&xr.session, xr::Path::NULL)?
+            .current_state;
+
         Ok(())
     }
 }
@@ -259,6 +266,11 @@ impl OpenXrHandSource {
             &format!("{} hand haptics", side),
             &[],
         )?;
+        let action_space_drag = action_set.create_action::<bool>(
+            &format!("{}_space_drag", side),
+            &format!("{} hand space drag", side),
+            &[],
+        )?;
 
         Ok(Self {
             action_pose,
@@ -271,6 +283,7 @@ impl OpenXrHandSource {
             action_click_modifier_middle,
             action_move_mouse,
             action_haptics,
+            action_space_drag,
         })
     }
 }
@@ -380,6 +393,10 @@ fn suggest_bindings(
                 &hands[1].action_move_mouse,
                 instance.string_to_path("/user/hand/right/input/trigger/touch")?,
             ),
+            xr::Binding::new(
+                &hands[0].action_space_drag,
+                instance.string_to_path("/user/hand/left/input/menu/click")?,
+            ),
             xr::Binding::new(
                 &hands[0].action_haptics,
                 instance.string_to_path("/user/hand/left/output/haptic")?,
@@ -439,6 +456,10 @@ fn suggest_bindings(
                 &hands[0].action_show_hide,
                 instance.string_to_path("/user/hand/left/input/b/click")?,
             ),
+            xr::Binding::new(
+                &hands[1].action_space_drag,
+                instance.string_to_path("/user/hand/right/input/b/click")?,
+            ),
             xr::Binding::new(
                 &hands[0].action_click_modifier_right,
                 instance.string_to_path("/user/hand/left/input/b/touch")?,

src/backend/openxr/mod.rs

@@ -32,6 +32,7 @@ mod helpers;
 mod input;
 mod lines;
 mod overlay;
+mod playspace;
 mod swapchain;
 
 const VIEW_TYPE: xr::ViewConfigurationType = xr::ViewConfigurationType::PRIMARY_STEREO;
@@ -72,6 +73,9 @@ pub fn openxr_run(running: Arc<AtomicBool>) -> Result<(), BackendError> {
     notifications.run_udp();
 
     let mut delete_queue = vec![];
+    let mut space_mover = playspace::PlayspaceMover::try_new()
+        .map_err(|e| log::warn!("Failed to initialize Monado playspace mover: {}", e))
+        .ok();
 
     #[cfg(feature = "osc")]
     let mut osc_sender =
@@ -204,6 +208,9 @@ pub fn openxr_run(running: Arc<AtomicBool>) -> Result<(), BackendError> {
         }
 
         watch_fade(&mut app_state, overlays.mut_by_id(watch_id).unwrap()); // want panic
+        if let Some(ref mut space_mover) = space_mover {
+            space_mover.update(&mut overlays, &app_state);
+        }
 
         for o in overlays.iter_mut() {
             o.after_input(&mut app_state)?;

src/backend/openxr/playspace.rs

@@ -0,0 +1,98 @@
+use std::ffi::c_void;
+
+use glam::Vec3A;
+use libloading::{Library, Symbol};
+
+use crate::{backend::common::OverlayContainer, state::AppState};
+
+use super::{helpers, input::DoubleClickCounter, overlay::OpenXrOverlayData};
+
+pub(super) struct PlayspaceMover {
+    drag_hand: Option<usize>,
+    offset: Vec3A,
+    start_position: Vec3A,
+
+    double_click_counter: DoubleClickCounter,
+
+    libmonado: Library,
+    mnd_root: *mut c_void,
+    playspace_move: extern "C" fn(*mut c_void, f32, f32, f32) -> i32,
+}
+
+impl PlayspaceMover {
+    pub fn try_new() -> anyhow::Result<Self> {
+        unsafe {
+            let libmonado = helpers::find_libmonado()?;
+
+            let root_create: Symbol<extern "C" fn(*mut *mut c_void) -> i32> =
+                libmonado.get(b"mnd_root_create\0")?;
+            let playspace_move: Symbol<extern "C" fn(*mut c_void, f32, f32, f32) -> i32> =
+                libmonado.get(b"mnd_root_playspace_move\0")?;
+            let playspace_move_raw = *playspace_move;
+
+            let mut root: *mut c_void = std::ptr::null_mut();
+
+            let ret = root_create(&mut root);
+
+            if ret != 0 {
+                anyhow::bail!("Failed to create root, code: {}", ret);
+            }
+
+            Ok(Self {
+                drag_hand: None,
+                offset: Vec3A::ZERO,
+                start_position: Vec3A::ZERO,
+
+                double_click_counter: DoubleClickCounter::new(),
+
+                libmonado,
+                mnd_root: root,
+                playspace_move: playspace_move_raw,
+            })
+        }
+    }
+
+    pub fn update(&mut self, overlays: &mut OverlayContainer<OpenXrOverlayData>, state: &AppState) {
+        if let Some(hand) = self.drag_hand {
+            let pointer = &state.input_state.pointers[hand];
+            if !pointer.now.space_drag {
+                self.drag_hand = None;
+                log::info!("End space drag");
+                return;
+            }
+
+            let hand_pos = state.input_state.pointers[hand].pose.translation;
+            let relative_pos = hand_pos - self.start_position;
+
+            overlays.iter_mut().for_each(|overlay| {
+                if overlay.state.grabbable {
+                    overlay.state.dirty = true;
+                    overlay.state.transform.translation += relative_pos * -1.0;
+                }
+            });
+
+            self.offset += relative_pos;
+            self.apply_offset();
+        } else {
+            for (i, pointer) in state.input_state.pointers.iter().enumerate() {
+                if pointer.now.space_drag
+                    && !pointer.before.space_drag
+                    && self.double_click_counter.click()
+                {
+                    self.drag_hand = Some(i);
+                    self.start_position = pointer.pose.translation;
+                    break;
+                }
+            }
+        }
+    }
+
+    pub fn reset(&mut self) {
+        self.offset = Vec3A::ZERO;
+        self.start_position = Vec3A::ZERO;
+    }
+
+    fn apply_offset(&mut self) {
+        (self.playspace_move)(self.mnd_root, self.offset.x, self.offset.y, self.offset.z);
+    }
+}