Render model components

src/compositor/mod.rs

@@ -21,28 +21,14 @@ use super::*;
 
 impl<'a> Compositor<'a> {
     pub fn vulkan_instance_extensions_required(&self) -> Vec<CString> {
-        let temp = unsafe {
+        let temp = unsafe { get_string(|ptr, n| self.0.GetVulkanInstanceExtensionsRequired.unwrap()(ptr, n)) }.unwrap();
-            let n = self.0.GetVulkanInstanceExtensionsRequired.unwrap()(ptr::null_mut(), 0);
+        temp.as_bytes().split(|&x| x == b' ').map(|x| CString::new(x.to_vec()).expect("extension name contained null byte")).collect()
-            let mut buffer: Vec<u8> = Vec::new();
-            buffer.resize(n as usize, mem::uninitialized());
-            (self.0.GetVulkanInstanceExtensionsRequired.unwrap())(buffer.as_mut_ptr() as *mut i8, n);
-            buffer.truncate((n-1) as usize); // Strip trailing null
-            buffer
-        };
-        temp.split(|&x| x == b' ').map(|x| CString::new(x.to_vec()).expect("extension name contained null byte")).collect()
     }
 
     /// Safety: physical_device must be a valid VkPhysicalDevice
     pub unsafe fn vulkan_device_extensions_required(&self, physical_device: *mut VkPhysicalDevice_T) -> Vec<CString> {
-        let temp = {
+        let temp = get_string(|ptr, n| self.0.GetVulkanDeviceExtensionsRequired.unwrap()(physical_device, ptr, n)).unwrap();
-            let n = self.0.GetVulkanDeviceExtensionsRequired.unwrap()(physical_device, ptr::null_mut(), 0);
+        temp.as_bytes().split(|&x| x == b' ').map(|x| CString::new(x.to_vec()).expect("extension name contained null byte")).collect()
-            let mut buffer: Vec<u8> = Vec::new();
-            buffer.resize(n as usize, mem::uninitialized());
-            (self.0.GetVulkanDeviceExtensionsRequired.unwrap())(physical_device as *mut _, buffer.as_mut_ptr() as *mut i8, n);
-            buffer.truncate((n-1) as usize); // Strip trailing null
-            buffer
-        };
-        temp.split(|&x| x == b' ').map(|x| CString::new(x.to_vec()).expect("extension name contained null byte")).collect()
     }
 
     /// Sets tracking space returned by WaitGetPoses

src/lib.rs

@@ -1,8 +1,8 @@
 extern crate openvr_sys;
 
 use std::sync::atomic::{Ordering, AtomicBool, ATOMIC_BOOL_INIT};
-use std::{fmt, error};
+use std::{fmt, error, ptr, mem};
-use std::ffi::CStr;
+use std::ffi::{CStr, CString};
 
 use openvr_sys as sys;
 
@@ -130,3 +130,32 @@ pub enum Eye {
     Left = sys::EVREye_Eye_Left as isize,
     Right = sys::EVREye_Eye_Right as isize,
 }
+
+/// Helper to call OpenVR functions that return strings
+unsafe fn get_string<F: FnMut(*mut std::os::raw::c_char, u32) -> u32>(mut f: F) -> Option<CString> {
+    let n = f(ptr::null_mut(), 0);
+    if n == 0 { return None }
+    let mut storage = Vec::new();
+    storage.reserve_exact(n as usize);
+    storage.resize(n as usize, mem::uninitialized());
+    let n_ = f(storage.as_mut_ptr() as *mut _, n);
+    assert!(n == n_);
+    storage.truncate((n-1) as usize); // Strip trailing null
+    Some(CString::from_vec_unchecked(storage))
+}
+
+#[repr(C)]
+#[derive(Debug, Copy, Clone)]
+pub struct ControllerAxis {
+    pub x: f32,
+    pub y: f32,
+}
+
+#[repr(C)]
+#[derive(Debug, Copy, Clone)]
+pub struct ControllerState {
+    pub packet_num: u32,
+    pub button_pressed: u64,
+    pub button_touched: u64,
+    pub axis: [ControllerAxis; 5],
+}

src/render_models.rs

@@ -1,9 +1,9 @@
-use std::{fmt, ptr, slice};
+use std::{fmt, ptr, slice, mem};
-use std::ffi::CStr;
+use std::ffi::{CStr, CString};
 
 use openvr_sys as sys;
 
-use {RenderModels};
+use {RenderModels, ControllerState, get_string};
 
 impl<'a> RenderModels<'a> {
     /// Loads and returns a render model for use in the application. `name` should be a render model name from the
@@ -14,7 +14,7 @@ impl<'a> RenderModels<'a> {
     pub fn load_render_model(&self, name: &CStr) -> Result<Option<Model>> {
         let mut ptr = ptr::null_mut();
         let r = unsafe {
-            self.0.LoadRenderModel_Async.unwrap()(name as *const _ as *mut _, &mut ptr)
+            self.0.LoadRenderModel_Async.unwrap()(name.as_ptr() as *mut _, &mut ptr)
         };
         match Error(r) {
             error::NONE => Ok(Some(Model { ptr: ptr, sys: self.0 })),
@@ -23,6 +23,64 @@ impl<'a> RenderModels<'a> {
         }
     }
 
+    /// Returns the number of components of the specified render model.
+    ///
+    /// Components are useful when client application wish to draw, label, or otherwise interact with components of tracked objects.
+    /// Examples controller components:
+    ///  renderable things such as triggers, buttons
+    ///  non-renderable things which include coordinate systems such as 'tip', 'base', a neutral controller agnostic hand-pose
+    ///  If all controller components are enumerated and rendered, it will be equivalent to drawing the traditional render model
+    ///  Returns 0 if components not supported, >0 otherwise
+    pub fn component_count(&self, model: &CStr) -> u32 {
+        unsafe { self.0.GetComponentCount.unwrap()(model.as_ptr() as *mut _) }
+    }
+
+    /// Get the names of available components.
+    ///
+    /// `component` does not correlate to a tracked device index, but is only used for iterating over all available
+    /// components.  If it's out of range, this function will return None.  Otherwise, it will return the size of the
+    /// buffer required for the name.
+    pub fn component_name(&self, model: &CStr, component: u32) -> Option<CString> {
+        unsafe { get_string(|ptr, n| self.0.GetComponentName.unwrap()(model.as_ptr() as *mut _, component, ptr, n)) }
+    }
+
+    /// Gets all component names of a given model
+    pub fn component_names(&self, model: &CStr) -> ::std::vec::IntoIter<CString> { // FIXME: impl Iterator rather than allocating
+        let n = self.component_count(model);
+        (0..n).map(|i| self.component_name(model, i).expect("inconsistent component presence reported by OpenVR")).collect::<Vec<_>>().into_iter()
+    }
+
+    /// Use this to get the render model name for the specified rendermode/component combination, to be passed to
+    /// `load_render_model`.
+    ///
+    /// If the component name is out of range, this function will return None.
+    /// Otherwise, it will return the size of the buffer required for the name.
+    pub fn component_render_model_name(&self, model: &CStr, component: &CStr) -> Option<CString> {
+        unsafe {
+            get_string(|ptr, n| self.0.GetComponentRenderModelName.unwrap()(
+                model.as_ptr() as *mut _, component.as_ptr() as *mut _, ptr, n))
+        }
+    }
+
+    /// Use this to query information about the component, as a function of the controller state.
+    ///
+    /// Returns None if the component is invalid or should not be rendered in the current state.
+    ///
+    /// For dynamic controller components (ex: trigger) values will reflect component motions
+    /// For static components this will return a consistent value independent of the VRControllerState_t
+    pub fn component_state(&self, model: &CStr, component: &CStr, state: &ControllerState, mode: &ControllerMode) -> Option<ComponentState> {
+        unsafe {
+            let mut out = mem::uninitialized();
+            if self.0.GetComponentState.unwrap()(model.as_ptr() as *mut _, component.as_ptr() as *mut _,
+                                                 state as *const _ as *mut _, mode as *const _ as *mut _,
+                                                 &mut out as *mut _ as *mut _) {
+                Some(out)
+            } else {
+                None
+            }
+        }
+    }
+
     /// Loads and returns a texture for use in the application. Texture IDs can be obtained from
     /// `Model::diffuse_texture_id()`.
     ///
@@ -162,3 +220,33 @@ pub struct Vertex {
     pub normal: [f32; 3],
     pub texture_coord: [f32; 2],
 }
+
+#[repr(C)]
+#[derive(Debug, Copy, Clone)]
+pub struct ControllerMode {
+    pub scroll_wheel_visible: bool,
+}
+
+impl Default for ControllerMode {
+    fn default() -> Self { ControllerMode { scroll_wheel_visible: false } }
+}
+
+#[repr(C)]
+#[derive(Debug, Copy, Clone)]
+pub struct ComponentState {
+    pub tracking_to_component_render_model: [[f32; 4]; 3],
+    pub tracking_to_component_local: [[f32; 4]; 3],
+    pub properties: ComponentProperties,
+}
+
+type ComponentProperties = sys::VRComponentProperties;
+
+pub mod component_properties {
+    use super::{sys, ComponentProperties};
+
+    pub const IS_STATIC: ComponentProperties = sys::EVRComponentProperty_VRComponentProperty_IsStatic;
+    pub const IS_VISIBLE: ComponentProperties = sys::EVRComponentProperty_VRComponentProperty_IsVisible;
+    pub const IS_TOUCHED: ComponentProperties = sys::EVRComponentProperty_VRComponentProperty_IsTouched;
+    pub const IS_PRESSED: ComponentProperties = sys::EVRComponentProperty_VRComponentProperty_IsPressed;
+    pub const IS_SCROLLED: ComponentProperties = sys::EVRComponentProperty_VRComponentProperty_IsScrolled;
+}

src/system/mod.rs

@@ -1,7 +1,7 @@
 //! The `System` interface provides access to display configuration information, tracking data, controller state,
 //! events, and device properties. It is the main interface of OpenVR.
 
-use std::{mem, ptr};
+use std::mem;
 use std::ffi::CString;
 
 use openvr_sys as sys;
@@ -205,13 +205,25 @@ impl<'a> System<'a> {
     pub fn string_tracked_device_property(&self, device: TrackedDeviceIndex, property: TrackedDeviceProperty) -> Result<CString, TrackedPropertyError> {
         unsafe {
             let mut error = mem::uninitialized();
-            let n = self.0.GetStringTrackedDeviceProperty.unwrap()(device, property, ptr::null_mut(), 0, &mut error);
+            let res = get_string(|ptr, n| self.0.GetStringTrackedDeviceProperty.unwrap()(device, property, ptr, n, &mut error));
-            if n == 0 { return Err(TrackedPropertyError(error)); }
+            res.map_or(Err(TrackedPropertyError(error)), Ok)
-            let mut storage = Vec::new();
+        }
-            storage.reserve_exact(n as usize);
+    }
-            storage.resize(n as usize, mem::uninitialized());
+
-            self.0.GetStringTrackedDeviceProperty.unwrap()(device, property, storage.as_mut_ptr() as *mut i8, n, ptr::null_mut());
+    /// Looks up the current input state of a controller.
-            Ok(CString::from_vec_unchecked(storage))
+    ///
+    /// Returns None if the device is not a controller, or if the user is currently in the system menu.
+    ///
+    /// Needed for rendering controller components (e.g. trigger) accurately wrt. user input using the `render_models`
+    /// API.
+    pub fn controller_state(&self, device: TrackedDeviceIndex) -> Option<ControllerState> {
+        unsafe {
+            let mut state = mem::uninitialized();
+            if self.0.GetControllerState.unwrap()(device, &mut state as *mut _ as *mut _, mem::size_of_val(&state) as u32) {
+                Some(state)
+            } else {
+                None
+            }
         }
     }
 }