Add is_current function

src/android/mod.rs

@@ -61,6 +61,11 @@ impl HeadlessContext {
         unimplemented!()
     }
 
+    /// See the docs in the crate root file.
+    pub fn is_current(&self) -> bool {
+        unimplemented!()
+    }
+
     /// See the docs in the crate root file.
     pub fn get_proc_address(&self, _addr: &str) -> *const () {
         unimplemented!()
@@ -312,6 +317,10 @@ impl Window {
         }
     }
 
+    pub fn is_current(&self) -> bool {
+        unsafe { ffi::egl::GetCurrentContext() == self.context }
+    }
+
     pub fn get_proc_address(&self, addr: &str) -> *const () {
         let addr = CString::from_slice(addr.as_bytes());
         let addr = addr.as_ptr();

src/cocoa/headless.rs

@@ -76,6 +76,10 @@ impl HeadlessContext {
         }
     }
 
+    pub fn is_current(&self) -> bool {
+        unimplemented!()
+    }
+
     pub fn get_proc_address(&self, _addr: &str) -> *const () {
         let symbol_name: CFString = _addr.parse().unwrap();
         let framework_name: CFString = "com.apple.opengl".parse().unwrap();

src/cocoa/mod.rs

@@ -587,6 +587,10 @@ impl Window {
         self.context.makeCurrentContext();
     }
 
+    pub fn is_current(&self) -> bool {
+        unimplemented!()
+    }
+
     pub fn get_proc_address(&self, _addr: &str) -> *const () {
         let symbol_name: CFString = FromStr::from_str(_addr).unwrap();
         let framework_name: CFString = FromStr::from_str("com.apple.opengl").unwrap();

src/headless.rs

@@ -78,6 +78,12 @@ impl HeadlessContext {
         self.context.make_current()
     }
     
+    /// Returns true if this context is the current one in this thread.
+    #[inline]
+    pub fn is_current(&self) -> bool {
+        self.context.is_current()
+    }
+
     /// Returns the address of an OpenGL function.
     ///
     /// Contrary to `wglGetProcAddress`, all available OpenGL functions return an address.

src/win32/headless.rs

@@ -20,6 +20,11 @@ impl HeadlessContext {
         self.0.make_current()
     }
 
+    /// See the docs in the crate root file.
+    pub fn is_current(&self) -> bool {
+        self.0.is_current()
+    }
+
     /// See the docs in the crate root file.
     pub fn get_proc_address(&self, addr: &str) -> *const () {
         self.0.get_proc_address(addr)

src/win32/mod.rs

@@ -208,6 +208,11 @@ impl Window {
                              self.context.0 as *const libc::c_void);
     }
 
+    /// See the docs in the crate root file.
+    pub fn is_current(&self) -> bool {
+        unsafe { gl::wgl::GetCurrentContext() == self.context.0 as *const libc::c_void }
+    }
+
     /// See the docs in the crate root file.
     pub fn get_proc_address(&self, addr: &str) -> *const () {
         let addr = CString::new(addr.as_bytes()).unwrap();

src/window.rs

@@ -329,6 +329,12 @@ impl Window {
         self.window.make_current()
     }
 
+    /// Returns true if this context is the current one in this thread.
+    #[inline]
+    pub fn is_current(&self) -> bool {
+        self.window.is_current()
+    }
+
     /// Returns the address of an OpenGL function.
     ///
     /// Contrary to `wglGetProcAddress`, all available OpenGL functions return an address.

src/x11/headless.rs

@@ -47,6 +47,10 @@ impl HeadlessContext {
         }
     }
 
+    pub fn is_current(&self) -> bool {
+        unsafe { ffi::OSMesaGetCurrentContext() == self.context }
+    }
+
     pub fn get_proc_address(&self, addr: &str) -> *const () {
         unsafe {
             with_c_str(addr, |s| {

src/x11/window/mod.rs

@@ -701,6 +701,10 @@ impl Window {
         }
     }
 
+    pub fn is_current(&self) -> bool {
+        unsafe { ffi::glx::GetCurrentContext() == self.x.context }
+    }
+
     pub fn get_proc_address(&self, addr: &str) -> *const () {
         use std::mem;