From cad1e5fcda8b24c2364419bead27fa66e8a0d603 Mon Sep 17 00:00:00 2001
From: Colin Sherratt <colin.sherratt@gmail.com>
Date: Sun, 5 Jul 2015 00:06:45 -0400
Subject: [PATCH] Added groundwork for the compositor

---
 examples/test.rs | 14 ++++++++++++++
 scripts/gen.py   |  1 +
 src/lib.rs       | 42 +++++++++++++++++++++++++++++++++++++++++-
 src/sys/lib.rs   |  1 +
 4 files changed, 57 insertions(+), 1 deletion(-)

diff --git a/examples/test.rs b/examples/test.rs
index 98039ed..4f759da 100644
--- a/examples/test.rs
+++ b/examples/test.rs
@@ -23,5 +23,19 @@ fn main() {
     println!("eye_to_head: {:?}", ivr.eye_to_head_transform(vr::Eye::Left));
     println!("vsync: {:?}", ivr.time_since_last_vsync());
     println!("poses {:?}", ivr.tracked_devices(0.).as_slice());
+
+    println!("Trying to create a compositor");
+    match ivr.compositor() {
+        Err(err) => println!("Could not create compositor {:?}", err),
+        Ok(comp) => {
+            println!("\tCreated one!");
+            println!("\tis fullscreen    ={}", comp.is_fullscreen());
+            println!("\tis vsync         ={}", comp.get_vsync());
+            println!("\tcan render scene ={}", comp.can_render_scene());
+        }
+    }
+
     println!("Done! \\o/");
+
+
 }
\ No newline at end of file
diff --git a/scripts/gen.py b/scripts/gen.py
index 8066918..7a59a7d 100644
--- a/scripts/gen.py
+++ b/scripts/gen.py
@@ -90,6 +90,7 @@ extern "C" {
 	pub fn VR_Shutdown();
 	pub fn VR_IsHmdPresent() -> bool;
 	pub fn VR_GetStringForHmdError(err: HmdError) -> *const u8;
+	pub fn VR_GetGenericInterface(name: *const u8, err: *mut HmdError) -> *const ();
 }
 """
 
diff --git a/src/lib.rs b/src/lib.rs
index 4345b25..9f66a57 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -195,6 +195,7 @@ impl IVRSystem {
         }  
     }
 
+    /// Fetch the tracked results from the HMD
     pub fn tracked_devices(&self, time: f32) -> TrackedDevicePoses {
         unsafe {
             let mut data: [openvr_sys::TrackedDevicePose_t; 16] = std::mem::zeroed();
@@ -221,6 +222,19 @@ impl IVRSystem {
             out
         }
     }
+
+    /// If the device supports a compositor return a instance
+    pub fn compositor(&self) -> Result<Compositor, openvr_sys::HmdError> {
+        unsafe {
+            let mut err = openvr_sys::HmdError::None;
+            let name = std::ffi::CString::new("IVRCompositor_006").unwrap();
+            let ptr = openvr_sys::VR_GetGenericInterface(name.as_ptr(), &mut err as *mut openvr_sys::HmdError);
+            match err {
+                openvr_sys::HmdError::None => Ok(Compositor(ptr)),
+                err => Err(err)
+            }
+        }
+    }
 }
 
 impl Drop for IVRSystem {
@@ -231,4 +245,30 @@ impl Drop for IVRSystem {
             println!("Should be done now.");
         }
     }
-}
\ No newline at end of file
+}
+
+/// A VR compositor
+pub struct Compositor(*const ());
+
+impl Compositor {
+    /// Check to see if the compositor is fullscreen
+    pub fn is_fullscreen(&self) -> bool {
+        unsafe {
+            openvr_sys::VR_IVRCompositor_IsFullscreen(self.0)
+        }
+    }
+
+    /// Check if vsync in enabled
+    pub fn get_vsync(&self) -> bool {
+        unsafe {
+            openvr_sys::VR_IVRCompositor_GetVSync(self.0)
+        }
+    }
+
+    /// Check if vsync in enabled
+    pub fn can_render_scene(&self) -> bool {
+        unsafe {
+            openvr_sys::VR_IVRCompositor_CanRenderScene(self.0)
+        }
+    }
+}
diff --git a/src/sys/lib.rs b/src/sys/lib.rs
index d844d5c..02b4db7 100755
--- a/src/sys/lib.rs
+++ b/src/sys/lib.rs
@@ -11,6 +11,7 @@ extern "C" {
 	pub fn VR_Shutdown();
 	pub fn VR_IsHmdPresent() -> bool;
 	pub fn VR_GetStringForHmdError(err: HmdError) -> *const u8;
+	pub fn VR_GetGenericInterface(name: *const i8, err: *mut HmdError) -> *const ();
 }
 
 pub type TrackedDeviceIndex_t = u32;