implemented error wrapper

Cargo.lock

@@ -1,6 +1,6 @@
 [root]
 name = "openvr"
-version = "0.2.0"
+version = "0.3.0"
 dependencies = [
  "glium 0.14.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "nalgebra 0.8.2 (registry+https://github.com/rust-lang/crates.io-index)",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "openvr"
-version = "0.2.0"
+version = "0.3.0"
 authors = [
     "Colin Sherratt",
     "Erick Tryzelaar",

src/error.rs

@@ -0,0 +1,123 @@
+use openvr_sys;
+use subsystems::*;
+
+pub trait RawError {
+    fn is_err(&self) -> bool;
+    fn message(&self) -> String;
+}
+
+#[derive(Debug)]
+pub struct Error<Err: RawError + Copy> {
+    raw: Err
+}
+
+impl<Err: RawError + Copy> Error<Err> {
+    /// Creates a new error object using the raw openvr_sys error
+    pub fn from_raw(raw: Err) -> Self {
+        Error {
+            raw: raw
+        }
+    }
+
+    /// Turns managed error into raw enum from binding
+    pub fn to_raw(&self) -> Err {
+        self.raw
+    }
+
+    /// Gets an human-readable error message (if available)
+    pub fn message(&self) -> String {
+        self.raw.message()
+    }
+
+    /// Returns true when current object is not an error
+    pub fn is_ok(&self) -> bool {
+        !self.raw.is_err()
+    }
+
+    /// Return true when current object is an error
+    pub fn is_err(&self) -> bool {
+        self.raw.is_err()
+    }
+}
+
+// OpenVR implement per error type a new function to get a error string
+//  for easier use, this macro will generate easily the RawError trait
+macro_rules! impl_raw_error {
+    ($subsystem:ident, $fntable: ident, $get:ident, $raw_name:ident, $none_name:ident) => {
+        impl RawError for $raw_name {
+            fn is_err(&self) -> bool {
+                match *self {
+                    $none_name => {
+                        true
+                    },
+                    _ => {
+                        false
+                    }
+                }
+            }
+
+            fn message(&self) -> String {
+                let sstr = unsafe {
+                    let sub = * { $subsystem().unwrap().0 as *mut openvr_sys::$fntable};
+                    CStr::from_ptr(sub.$get.unwrap()(*self)).to_str().unwrap()
+                };
+
+                String::from(sstr)
+            }
+        }
+    }
+}
+
+use std::ffi::CStr;
+use openvr_sys::*;
+use openvr_sys::Enum_ETrackedPropertyError::*;
+use openvr_sys::Enum_EVRInitError::*;
+use openvr_sys::Enum_EVRRenderModelError::*;
+
+impl_raw_error!(
+    system,
+    Struct_VR_IVRSystem_FnTable,
+    GetPropErrorNameFromEnum,
+    ETrackedPropertyError,
+    ETrackedPropertyError_TrackedProp_Success);
+
+
+// The init error has some special function to retrieve string
+impl RawError for Enum_EVRInitError {
+    fn is_err(&self) -> bool {
+        match *self {
+            EVRInitError_VRInitError_None => {
+                true
+            },
+            _ => {
+                false
+            }
+        }
+    }
+
+    fn message(&self) -> String {
+        let sstr = unsafe {
+            CStr::from_ptr(openvr_sys::VR_GetVRInitErrorAsEnglishDescription(*self)).to_str().unwrap()
+        };
+
+        String::from(sstr)
+    }
+}
+
+// RenderModelError has no implementation in 0.1.19 unfortunately
+impl RawError for Enum_EVRRenderModelError {
+    fn is_err(&self) -> bool {
+        match *self {
+            EVRRenderModelError_VRRenderModelError_None => {
+                true
+            },
+            _ => {
+                false
+            }
+        }
+    }
+
+    fn message(&self) -> String {
+        String::from(format!("{:?}", *self))
+    }
+}

src/lib.rs

@@ -5,6 +5,7 @@ pub use openvr_sys::Enum_ETrackedDeviceProperty::*;
 pub use openvr_sys::Enum_ETrackedDeviceClass::*;
 
 pub mod common;
+pub mod error;
 pub mod tracking;
 pub mod system;
 pub mod extended_display;
@@ -18,11 +19,12 @@ pub use compositor::IVRCompositor;
 pub use render_models::IVRRenderModels;
 
 pub use subsystems::*;
+pub use error::*;
 
 pub use common::Eye;
 
 /// Inits the open vr interface and returns the system
-pub fn init() ->  Result<system::IVRSystem, openvr_sys::HmdError> {
+pub fn init() ->  Result<system::IVRSystem, Error<openvr_sys::Enum_EVRInitError>> {
     let mut err = EVRInitError_VRInitError_None;
     let app_type = EVRApplicationType_VRApplication_Scene;
 
@@ -46,7 +48,7 @@ pub fn init() ->  Result<system::IVRSystem, openvr_sys::HmdError> {
             }
         },
         _ => {
-            return Err(err);
+            return Err(Error::from_raw(err));
         }
     };
 }

src/render_models.rs

@@ -5,12 +5,31 @@ use std::string::String;
 use std::ptr::null_mut;
 use std::slice;
 use subsystems::render_models;
+use error::*;
 
 pub struct IVRRenderModels(*const ());
 
 pub struct RenderModel(*mut openvr_sys::RenderModel_t);
 pub struct RenderModelTexture(*mut openvr_sys::RenderModel_TextureMap_t);
 
+trait AsyncError {
+    /// checks if result is currently loading
+    fn is_loading(&self) -> bool;
+}
+
+impl AsyncError for Error<openvr_sys::Enum_EVRRenderModelError> {
+    fn is_loading(&self) -> bool {
+        match self.to_raw() {
+            EVRRenderModelError_VRRenderModelError_Loading => {
+                true
+            },
+            _ => {
+                false
+            }
+        }
+    }
+}
+
 impl Drop for RenderModel {
     /// will inform openvr that the memory for the render model is no longer required
     fn drop (&mut self) {
@@ -54,7 +73,7 @@ impl RenderModel {
 
     /// asynchronosly loads the texture for the current render model
     /// see IVRRenderModels::load_async for info how openvr async work
-    pub fn load_texture_async(&self) -> Result<RenderModelTexture, openvr_sys::Enum_EVRRenderModelError> {
+    pub fn load_texture_async(&self) -> Result<RenderModelTexture, Error<openvr_sys::Enum_EVRRenderModelError>> {
         unsafe {
             let models = * { render_models().unwrap().0 as *mut openvr_sys::Struct_VR_IVRRenderModels_FnTable};
             let mut resp: *mut openvr_sys::RenderModel_TextureMap_t = null_mut();
@@ -69,7 +88,7 @@ impl RenderModel {
                     Ok(RenderModelTexture (resp))
                 },
                 _ => {
-                    Err(err)
+                    Err(Error::from_raw(err))
                 }
             }
 
@@ -77,7 +96,7 @@ impl RenderModel {
     }
 
     /// loads the texture for current model
-    pub fn load_texture(&self) -> Result<RenderModelTexture, openvr_sys::Enum_EVRRenderModelError> {
+    pub fn load_texture(&self) -> Result<RenderModelTexture, Error<openvr_sys::Enum_EVRRenderModelError>> {
         use std;
 
         loop {
@@ -87,13 +106,8 @@ impl RenderModel {
                     return Ok(texture);
                 },
                 Err(err) => {
-                    match err {
+                    if !err.is_loading() {
-                        EVRRenderModelError_VRRenderModelError_Loading => {
+                        return Err(err);
-                            // ask again later
-                        },
-                        _ => {
-                            return Err(err);
-                        }
                     }
                 }
             }
@@ -158,7 +172,7 @@ impl IVRRenderModels {
 
     /// Loads an render model into local memory
     ///  blocks the thread and waits until driver responds with model
-    pub fn load(&self, name: String) -> Result<RenderModel, openvr_sys::EVRRenderModelError> {
+    pub fn load(&self, name: String) -> Result<RenderModel, Error<openvr_sys::EVRRenderModelError>> {
         use std;
 
         loop {
@@ -168,13 +182,8 @@ impl IVRRenderModels {
                     return Ok(model);
                 },
                 Err(err) => {
-                    match err {
+                    if !err.is_loading() {
-                        EVRRenderModelError_VRRenderModelError_Loading => {
+                        return Err(err);
-                            // ask again later
-                        },
-                        _ => {
-                            return Err(err);
-                        }
                     }
                 }
             }
@@ -186,7 +195,7 @@ impl IVRRenderModels {
     ///  When called for the first time openvr will start to load the model into memory
     ///  In the mean time this call will respond with EVRRenderModelError_VRRenderModelError_Loading
     ///  It is designed to be used wihtin the render loop as it won't block the user, for sync usage use load()
-    pub fn load_async(&self, name: String) -> Result<RenderModel, openvr_sys::EVRRenderModelError> {
+    pub fn load_async(&self, name: String) -> Result<RenderModel, Error<openvr_sys::EVRRenderModelError>> {
         use std;
 
         unsafe {
@@ -207,7 +216,7 @@ impl IVRRenderModels {
                     Ok(RenderModel ( resp ))
                 },
                 _ => {
-                    Err(err)
+                    Err(Error::from_raw(err))
                 }
             }
 

src/subsystems.rs

@@ -1,6 +1,7 @@
 extern crate openvr_sys;
 use openvr_sys::Enum_EVRInitError::*;
 
+use error::*;
 use system::IVRSystem;
 use extended_display::IVRExtendedDisplay;
 use compositor::IVRCompositor;
@@ -9,7 +10,7 @@ use render_models::IVRRenderModels;
 use std;
 
 /// gets the current vr system interface (initialization is required beforehand)
-pub fn system() -> Result<IVRSystem, openvr_sys::HmdError> {
+pub fn system() -> Result<IVRSystem, Error<openvr_sys::Enum_EVRInitError>> {
     let mut err = EVRInitError_VRInitError_None;
     let name = std::ffi::CString::new("FnTable:IVRSystem_012").unwrap();
     let ptr = unsafe {
@@ -23,13 +24,13 @@ pub fn system() -> Result<IVRSystem, openvr_sys::HmdError> {
             }
         },
         _ => {
-            return Err(err);
+            return Err(Error::from_raw(err));
         }
     }
 }
 
 /// gets the current vr extended display interface (initialization is required beforehand)
-pub fn extended_display() -> Result<IVRExtendedDisplay, openvr_sys::HmdError> {
+pub fn extended_display() -> Result<IVRExtendedDisplay, Error<openvr_sys::Enum_EVRInitError>> {
     let mut err = EVRInitError_VRInitError_None;
     let name = std::ffi::CString::new("FnTable:IVRExtendedDisplay_001").unwrap();
     let ptr = unsafe {
@@ -43,13 +44,13 @@ pub fn extended_display() -> Result<IVRExtendedDisplay, openvr_sys::HmdError> {
             }
         },
         _ => {
-            return Err(err);
+            return Err(Error::from_raw(err));
         }
     }
 }
 
 /// gets the current vr extended display interface (initialization is required beforehand)
-pub fn compositor() -> Result<IVRCompositor, openvr_sys::HmdError> {
+pub fn compositor() -> Result<IVRCompositor, Error<openvr_sys::Enum_EVRInitError>> {
     let mut err = EVRInitError_VRInitError_None;
     let name = std::ffi::CString::new("FnTable:IVRCompositor_013").unwrap();
     let ptr = unsafe {
@@ -63,13 +64,13 @@ pub fn compositor() -> Result<IVRCompositor, openvr_sys::HmdError> {
             }
         },
         _ => {
-            return Err(err);
+            return Err(Error::from_raw(err));
         }
     }
 }
 
 /// gets the current vr extended display interface (initialization is required beforehand)
-pub fn render_models() -> Result<IVRRenderModels, openvr_sys::HmdError> {
+pub fn render_models() -> Result<IVRRenderModels, Error<openvr_sys::Enum_EVRInitError>> {
     let mut err = EVRInitError_VRInitError_None;
     let name = std::ffi::CString::new("FnTable:IVRRenderModels_005").unwrap();
     let ptr = unsafe {
@@ -83,7 +84,7 @@ pub fn render_models() -> Result<IVRRenderModels, openvr_sys::HmdError> {
             }
         },
         _ => {
-            return Err(err);
+            return Err(Error::from_raw(err));
         }
     }
 }

src/tracking.rs

@@ -1,6 +1,8 @@
 use openvr_sys;
 use openvr_sys::Enum_ETrackedPropertyError::*;
+
 use subsystems::*;
+use error::*;
 
 #[derive(Debug, Copy, Clone)]
 pub struct TrackedDevicePose {
@@ -22,7 +24,7 @@ impl TrackedDevicePose {
     }
 
     /// gets a propery as a string
-    pub fn get_property_string(&self, property: openvr_sys::Enum_ETrackedDeviceProperty) -> Result<String, openvr_sys::Enum_ETrackedPropertyError> {
+    pub fn get_property_string(&self, property: openvr_sys::Enum_ETrackedDeviceProperty) -> Result<String, Error<openvr_sys::Enum_ETrackedPropertyError>> {
         unsafe {
             let system = * { system().unwrap().0 as *mut openvr_sys::Struct_VR_IVRSystem_FnTable};
 
@@ -40,7 +42,7 @@ impl TrackedDevicePose {
             if size > 0 {
                 return Ok(String::from_raw_parts(val_out.as_ptr() as *mut _, (size - 1) as usize, (size - 1) as usize));
             } else {
-                return Err(err);
+                return Err(Error::from_raw(err));
             }
         }
     }