diff options
| -rw-r--r-- | src/win32/init.rs | 23 | ||||
| -rw-r--r-- | src/win32/make_current_guard.rs | 53 | ||||
| -rw-r--r-- | src/win32/mod.rs | 1 |
3 files changed, 61 insertions, 16 deletions
diff --git a/src/win32/init.rs b/src/win32/init.rs index f842028..09d5878 100644 --- a/src/win32/init.rs +++ b/src/win32/init.rs @@ -9,6 +9,7 @@ use super::Window; use super::MonitorID; use super::ContextWrapper; use super::WindowWrapper; +use super::make_current_guard::CurrentContextGuard; use Api; use BuilderAttribs; @@ -143,24 +144,18 @@ unsafe fn init(title: Vec<u16>, builder: BuilderAttribs<'static>, let dummy_context = try!(create_context(None, &dummy_window, None)); // making context current - gl::wgl::MakeCurrent(dummy_window.1 as *const libc::c_void, - dummy_context.0 as *const libc::c_void); + let current_context = try!(CurrentContextGuard::make_current(&dummy_window, + &dummy_context)); // loading the extra WGL functions - let extra_functions = gl::wgl_extra::Wgl::load_with(|addr| { + gl::wgl_extra::Wgl::load_with(|addr| { use libc; let addr = CString::new(addr.as_bytes()).unwrap(); let addr = addr.as_ptr(); gl::wgl::GetProcAddress(addr) as *const libc::c_void - }); - - // removing current context - gl::wgl::MakeCurrent(ptr::null(), ptr::null()); - - // returning the address - extra_functions + }) }; // creating the real window this time @@ -237,15 +232,11 @@ unsafe fn init(title: Vec<u16>, builder: BuilderAttribs<'static>, // handling vsync if builder.vsync { if extra_functions.SwapIntervalEXT.is_loaded() { - gl::wgl::MakeCurrent(real_window.1 as *const libc::c_void, - context.0 as *const libc::c_void); + let guard = try!(CurrentContextGuard::make_current(&real_window, &context)); + if extra_functions.SwapIntervalEXT(1) == 0 { return Err(OsError(format!("wglSwapIntervalEXT failed"))); } - - // it is important to remove the current context, otherwise you get very weird - // errors - gl::wgl::MakeCurrent(ptr::null(), ptr::null()); } } diff --git a/src/win32/make_current_guard.rs b/src/win32/make_current_guard.rs new file mode 100644 index 0000000..d6bcc8e --- /dev/null +++ b/src/win32/make_current_guard.rs @@ -0,0 +1,53 @@ +use std::marker::PhantomData; +use std::os; + +use libc; +use winapi; +use CreationError; + +use super::gl; +use super::ContextWrapper; +use super::WindowWrapper; + +/// A guard for when you want to make the context current. Destroying the guard restores the +/// previously-current context. +pub struct CurrentContextGuard<'a, 'b> { + previous_hdc: winapi::HDC, + previous_hglrc: winapi::HGLRC, + marker1: PhantomData<&'a ()>, + marker2: PhantomData<&'b ()>, +} + +impl<'a, 'b> CurrentContextGuard<'a, 'b> { + pub unsafe fn make_current(window: &'a WindowWrapper, context: &'b ContextWrapper) + -> Result<CurrentContextGuard<'a, 'b>, CreationError> + { + let previous_hdc = gl::wgl::GetCurrentDC() as winapi::HDC; + let previous_hglrc = gl::wgl::GetCurrentContext() as winapi::HGLRC; + + let result = gl::wgl::MakeCurrent(window.1 as *const libc::c_void, + context.0 as *const libc::c_void); + + if result == 0 { + return Err(CreationError::OsError(format!("wglMakeCurrent function failed: {}", + os::error_string(os::errno())))); + } + + Ok(CurrentContextGuard { + previous_hdc: previous_hdc, + previous_hglrc: previous_hglrc, + marker1: PhantomData, + marker2: PhantomData, + }) + } +} + +#[unsafe_destructor] +impl<'a, 'b> Drop for CurrentContextGuard<'a, 'b> { + fn drop(&mut self) { + unsafe { + gl::wgl::MakeCurrent(self.previous_hdc as *const libc::c_void, + self.previous_hglrc as *const libc::c_void); + } + } +} diff --git a/src/win32/mod.rs b/src/win32/mod.rs index 4e6a803..327b71d 100644 --- a/src/win32/mod.rs +++ b/src/win32/mod.rs @@ -21,6 +21,7 @@ mod event; mod gl; mod headless; mod init; +mod make_current_guard; mod monitor; /// The Win32 implementation of the main `Window` object. |