Macro to call an OpenGL function, check errors and optionally return a value.

glcall.rs

#[macro_export]
macro_rules! GL {
	($fun:ident ( $($arg:expr),*)) => {{
		unsafe {
			let result = ::gl::$fun( $($arg),* );
			let err = ::gl::GetError();
			if err != ::gl::NO_ERROR {
				let err_str = match err {
					::gl::INVALID_OPERATION => "Invalid Operation",
					::gl::INVALID_ENUM => "Invalid Enum",
					::gl::INVALID_VALUE => "Invalid Value",
					::gl::OUT_OF_MEMORY => "Out Of Memory",
					::gl::INVALID_FRAMEBUFFER_OPERATION => "Invalid Framebuffer Operation",
					_ => "Unknown Error"
				};
				panic!("OpenGL Error ({}): {}\n\tFile:{}",
					err, err_str, line!()
				);
			}
			result
		}
	}};
}