feat: add OpenGL bindings crate

1 files changed, 119 insertions, 0 deletions

diff --git a/opengl-bindings/src/lib.rs b/opengl-bindings/src/lib.rs
new file mode 100644
index 0000000..7fd9933
--- /dev/null
+++ b/opengl-bindings/src/lib.rs
@@ -0,0 +1,119 @@
+#![deny(clippy::all, clippy::pedantic)]
+use std::ffi::CString;
+use std::process::abort;
+
+use glutin::context::{NotCurrentContext, PossiblyCurrentContext};
+use glutin::display::GetGlDisplay;
+use glutin::prelude::{GlDisplay, NotCurrentGlContext, PossiblyCurrentGlContext};
+use glutin::surface::{Surface, SurfaceTypeTrait};
+
+pub mod buffer;
+pub mod data_types;
+pub mod debug;
+pub mod misc;
+pub mod shader;
+pub mod texture;
+pub mod vertex_array;
+
+pub struct ContextWithFns
+{
+    context: PossiblyCurrentContext,
+    fns: Box<sys::Gl>,
+}
+
+impl ContextWithFns
+{
+    /// Returns a new `ContextWithFns`.
+    ///
+    /// # Errors
+    /// Returns `Err` if making this context current fails.
+    pub fn new<SurfaceType: SurfaceTypeTrait>(
+        context: NotCurrentContext,
+        surface: &Surface<SurfaceType>,
+    ) -> Result<Self, Error>
+    {
+        let context = context
+            .make_current(surface)
+            .map_err(Error::MakeContextCurrentFailed)?;
+
+        let display = context.display();
+
+        let gl = sys::Gl::load_with(|symbol| {
+            let Ok(symbol) = CString::new(symbol) else {
+                eprintln!("GL symbol contains nul byte");
+                abort();
+            };
+
+            display.get_proc_address(&symbol)
+        });
+
+        Ok(Self { context, fns: Box::new(gl) })
+    }
+
+    /// Attempts to make this context current.
+    ///
+    /// # Errors
+    /// Returns `Err` if making this context current fails.
+    pub fn make_current<SurfaceType: SurfaceTypeTrait>(
+        &self,
+        surface: &Surface<SurfaceType>,
+    ) -> Result<CurrentContextWithFns<'_>, Error>
+    {
+        if !self.context.is_current() {
+            self.context
+                .make_current(surface)
+                .map_err(Error::MakeContextCurrentFailed)?;
+        }
+
+        Ok(CurrentContextWithFns { ctx: self })
+    }
+
+    #[must_use]
+    pub fn context(&self) -> &PossiblyCurrentContext
+    {
+        &self.context
+    }
+
+    #[must_use]
+    pub fn context_mut(&mut self) -> &mut PossiblyCurrentContext
+    {
+        &mut self.context
+    }
+}
+
+pub struct CurrentContextWithFns<'ctx>
+{
+    ctx: &'ctx ContextWithFns,
+}
+
+impl CurrentContextWithFns<'_>
+{
+    #[inline]
+    pub(crate) fn fns(&self) -> &sys::Gl
+    {
+        &self.ctx.fns
+    }
+}
+
+#[derive(Debug, thiserror::Error)]
+pub enum Error
+{
+    #[error("Failed to make context current")]
+    MakeContextCurrentFailed(#[source] glutin::error::Error),
+}
+
+mod sys
+{
+    #![allow(
+        clippy::missing_safety_doc,
+        clippy::missing_transmute_annotations,
+        clippy::too_many_arguments,
+        clippy::unused_unit,
+        clippy::upper_case_acronyms,
+        clippy::doc_markdown,
+        clippy::unreadable_literal,
+        unsafe_op_in_unsafe_fn
+    )]
+
+    include!(concat!(env!("OUT_DIR"), "/bindings.rs"));
+}