feat(opengl-bindings): add fn to make context current without surface

1 files changed, 37 insertions, 1 deletions

diff --git a/opengl-bindings/src/lib.rs b/opengl-bindings/src/lib.rs
index e4ae27d..3dcd61d 100644
--- a/opengl-bindings/src/lib.rs
+++ b/opengl-bindings/src/lib.rs
@@ -51,7 +51,7 @@ impl MaybeCurrentContextWithFns
         Ok(Self { context, fns: Box::new(gl) })
     }
 
-    /// Attempts to make this context & the specified surface current in the current
+    /// Attempts to make this context & the specified surface current in the calling
     /// thread.
     ///
     /// # Errors
@@ -70,6 +70,20 @@ impl MaybeCurrentContextWithFns
         Ok(())
     }
 
+    /// Attempts to make this context current on the calling thread.
+    ///
+    /// # Errors
+    /// Returns `Err` if making this context current fails.
+    pub fn make_current_surfaceless(&self) -> Result<(), MakeContextCurrentError>
+    {
+        if !self.context.is_current() {
+            make_glutin_context_current_surfaceless(&self.context)
+                .map_err(MakeContextCurrentError)?;
+        }
+
+        Ok(())
+    }
+
     #[must_use]
     pub fn context(&self) -> &PossiblyCurrentContext
     {
@@ -89,6 +103,28 @@ impl MaybeCurrentContextWithFns
 #[error("Failed to make context current")]
 pub struct MakeContextCurrentError(#[source] glutin::error::Error);
 
+fn make_glutin_context_current_surfaceless(
+    context: &PossiblyCurrentContext,
+) -> Result<(), glutin::error::Error>
+{
+    #[cfg(not(any(target_os = "linux", target_os = "windows", target_os = "macos")))]
+    compile_error!("Unsupported target OS");
+
+    match context {
+        #[cfg(any(target_os = "windows", target_os = "linux"))]
+        PossiblyCurrentContext::Egl(context) => context.make_current_surfaceless(),
+
+        #[cfg(target_os = "linux")]
+        PossiblyCurrentContext::Glx(context) => context.make_current_surfaceless(),
+
+        #[cfg(target_os = "windows")]
+        PossiblyCurrentContext::Wgl(context) => context.make_current_surfaceless(),
+
+        #[cfg(target_os = "macos")]
+        PossiblyCurrentContext::Cgl(context) => context.make_current_surfaceless(),
+    }
+}
+
 mod sys
 {
     #![allow(