Start splitting win32::init into multiple functions

1 files changed, 338 insertions, 327 deletions

diff --git a/src/win32/init.rs b/src/win32/init.rs
index c3352b6..c0d193a 100644
--- a/src/win32/init.rs
+++ b/src/win32/init.rs
@@ -1,7 +1,10 @@
 use std::sync::atomic::AtomicBool;
 use std::ptr;
+use std::mem;
+use std::os;
 use super::callback;
 use super::Window;
+use super::MonitorID;
 use BuilderAttribs;
 use CreationError;
 use CreationError::OsError;
@@ -23,9 +26,6 @@ unsafe impl Send for ContextHack {}
 pub fn new_window(builder: BuilderAttribs<'static>, builder_sharelists: Option<ContextHack>)
                   -> Result<Window, CreationError>
 {
-    use std::mem;
-    use std::os;
-
     // initializing variables to be sent to the task
     let title = builder.title.as_slice().utf16_units()
         .chain(Some(0).into_iter()).collect::<Vec<u16>>();    // title to utf16
@@ -36,382 +36,393 @@ pub fn new_window(builder: BuilderAttribs<'static>, builder_sharelists: Option<C
     //  so we create a new thread dedicated to this window.
     // This is the only safe method. Using `nosend` wouldn't work for non-native runtime.
     ::std::thread::Thread::spawn(move || {
-        let builder_sharelists = builder_sharelists.map(|s| s.0);
-
-        // registering the window class
-        let class_name = {
-            let class_name: Vec<u16> = "Window Class".utf16_units().chain(Some(0).into_iter())
-                .collect::<Vec<u16>>();
-            
-            let class = winapi::WNDCLASSEXW {
-                cbSize: mem::size_of::<winapi::WNDCLASSEXW>() as winapi::UINT,
-                style: winapi::CS_HREDRAW | winapi::CS_VREDRAW | winapi::CS_OWNDC,
-                lpfnWndProc: callback::callback,
-                cbClsExtra: 0,
-                cbWndExtra: 0,
-                hInstance: unsafe { kernel32::GetModuleHandleW(ptr::null()) },
-                hIcon: ptr::null_mut(),
-                hCursor: ptr::null_mut(),
-                hbrBackground: ptr::null_mut(),
-                lpszMenuName: ptr::null(),
-                lpszClassName: class_name.as_ptr(),
-                hIconSm: ptr::null_mut(),
-            };
-
-            // We ignore errors because registering the same window class twice would trigger
-            //  an error, and because errors here are detected during CreateWindowEx anyway.
-            // Also since there is no weird element in the struct, there is no reason for this
-            //  call to fail.
-            unsafe { user32::RegisterClassExW(&class) };
-
-            class_name
-        };
-
-        // building a RECT object with coordinates
-        let mut rect = winapi::RECT {
-            left: 0, right: builder.dimensions.unwrap_or((1024, 768)).0 as winapi::LONG,
-            top: 0, bottom: builder.dimensions.unwrap_or((1024, 768)).1 as winapi::LONG,
-        };
-
-        // switching to fullscreen if necessary
-        // this means adjusting the window's position so that it overlaps the right monitor,
-        //  and change the monitor's resolution if necessary
-        if builder.monitor.is_some() {
-            let monitor = builder.monitor.as_ref().unwrap();
-
-            // adjusting the rect
-            {
-                let pos = monitor.get_position();
-                rect.left += pos.0 as winapi::LONG;
-                rect.right += pos.0 as winapi::LONG;
-                rect.top += pos.1 as winapi::LONG;
-                rect.bottom += pos.1 as winapi::LONG;
-            }
-
-            // changing device settings
-            let mut screen_settings: winapi::DEVMODEW = unsafe { mem::zeroed() };
-            screen_settings.dmSize = mem::size_of::<winapi::DEVMODEW>() as winapi::WORD;
-            screen_settings.dmPelsWidth = (rect.right - rect.left) as winapi::DWORD;
-            screen_settings.dmPelsHeight = (rect.bottom - rect.top) as winapi::DWORD;
-            screen_settings.dmBitsPerPel = 32;      // TODO: ?
-            screen_settings.dmFields = winapi::DM_BITSPERPEL | winapi::DM_PELSWIDTH | winapi::DM_PELSHEIGHT;
-
-            let result = unsafe { user32::ChangeDisplaySettingsExW(monitor.get_system_name().as_ptr(),
-                &mut screen_settings, ptr::null_mut(), winapi::CDS_FULLSCREEN, ptr::null_mut()) };
-            
-            if result != winapi::DISP_CHANGE_SUCCESSFUL {
-                tx.send(Err(OsError(format!("ChangeDisplaySettings failed: {}", result))));
+        // sending
+        match init(title, builder, builder_sharelists) {
+            Ok(w) => tx.send(Ok(w)).ok(),
+            Err(e) => {
+                tx.send(Err(e)).ok();
                 return;
             }
-        }
-
-        // computing the style and extended style of the window
-        let (ex_style, style) = if builder.monitor.is_some() {
-            (winapi::WS_EX_APPWINDOW, winapi::WS_POPUP | winapi::WS_CLIPSIBLINGS | winapi::WS_CLIPCHILDREN)
-        } else {
-            (winapi::WS_EX_APPWINDOW | winapi::WS_EX_WINDOWEDGE,
-                winapi::WS_OVERLAPPEDWINDOW | winapi::WS_CLIPSIBLINGS | winapi::WS_CLIPCHILDREN)
         };
 
-        // adjusting the window coordinates using the style
-        unsafe { user32::AdjustWindowRectEx(&mut rect, style, 0, ex_style) };
-
-        // getting the address of wglCreateContextAttribsARB and the pixel format
-        //  that we will use
-        let (extra_functions, pixel_format) = {
-            // creating a dummy invisible window for GL initialization
-            let dummy_window = unsafe {
-                let handle = user32::CreateWindowExW(ex_style, class_name.as_ptr(),
-                    title.as_ptr() as winapi::LPCWSTR,
-                    style | winapi::WS_CLIPSIBLINGS | winapi::WS_CLIPCHILDREN,
-                    winapi::CW_USEDEFAULT, winapi::CW_USEDEFAULT,
-                    rect.right - rect.left, rect.bottom - rect.top,
-                    ptr::null_mut(), ptr::null_mut(), kernel32::GetModuleHandleW(ptr::null()),
-                    ptr::null_mut());
-
-                if handle.is_null() {
-                    use std::os;
-                    tx.send(Err(OsError(format!("CreateWindowEx function failed: {}",
-                        os::error_string(os::errno() as usize)))));
-                    return;
-                }
-
-                handle
-            };
-
-            // getting the HDC of the dummy window
-            let dummy_hdc = {
-                let hdc = unsafe { user32::GetDC(dummy_window) };
-                if hdc.is_null() {
-                    tx.send(Err(OsError(format!("GetDC function failed: {}",
-                        os::error_string(os::errno() as usize)))));
-                    unsafe { user32::DestroyWindow(dummy_window); }
-                    return;
-                }
-                hdc
-            };
-
-            // getting the pixel format that we will use
-            let pixel_format = {
-                // initializing a PIXELFORMATDESCRIPTOR that indicates what we want
-                let mut output: winapi::PIXELFORMATDESCRIPTOR = unsafe { mem::zeroed() };
-                output.nSize = mem::size_of::<winapi::PIXELFORMATDESCRIPTOR>() as winapi::WORD;
-                output.nVersion = 1;
-                output.dwFlags = winapi::PFD_DRAW_TO_WINDOW | winapi::PFD_DOUBLEBUFFER |
-                    winapi::PFD_SUPPORT_OPENGL | winapi::PFD_GENERIC_ACCELERATED;
-                output.iPixelType = winapi::PFD_TYPE_RGBA;
-                output.cColorBits = 24;
-                output.cAlphaBits = 8;
-                output.cAccumBits = 0;
-                output.cDepthBits = 24;
-                output.cStencilBits = 8;
-                output.cAuxBuffers = 0;
-                output.iLayerType = winapi::PFD_MAIN_PLANE;
-
-                let pf_index = unsafe { gdi32::ChoosePixelFormat(dummy_hdc, &output) };
-
-                if pf_index == 0 {
-                    tx.send(Err(OsError(format!("ChoosePixelFormat function failed: {}",
-                        os::error_string(os::errno() as usize)))));
-                    unsafe { user32::DestroyWindow(dummy_window); }
-                    return;
-                }
-
-                if unsafe { gdi32::DescribePixelFormat(dummy_hdc, pf_index,
-                    mem::size_of::<winapi::PIXELFORMATDESCRIPTOR>() as winapi::UINT, &mut output) } == 0
-                {
-                    tx.send(Err(OsError(format!("DescribePixelFormat function failed: {}",
-                        os::error_string(os::errno() as usize)))));
-                    unsafe { user32::DestroyWindow(dummy_window); }
-                    return;
-                }
-
-                output
-            };
-
-            // calling SetPixelFormat
-            unsafe {
-                if gdi32::SetPixelFormat(dummy_hdc, 1, &pixel_format) == 0 {
-                    tx.send(Err(OsError(format!("SetPixelFormat function failed: {}",
-                        os::error_string(os::errno() as usize)))));
-                    user32::DestroyWindow(dummy_window);
-                    return;
-                }
-            }
-
-            // creating the dummy OpenGL context
-            let dummy_context = {
-                let ctxt = unsafe { gl::wgl::CreateContext(dummy_hdc as *const libc::c_void) };
-                if ctxt.is_null() {
-                    tx.send(Err(OsError(format!("wglCreateContext function failed: {}",
-                        os::error_string(os::errno() as usize)))));
-                    unsafe { user32::DestroyWindow(dummy_window); }
-                    return;
-                }
-                ctxt
-            };
-
-            // making context current
-            unsafe { gl::wgl::MakeCurrent(dummy_hdc as *const libc::c_void, dummy_context); }
-
-            // loading the extra WGL functions
-            let extra_functions = gl::wgl_extra::Wgl::load_with(|addr| {
-                use libc;
-
-                let addr = CString::from_slice(addr.as_bytes());
-                let addr = addr.as_slice_with_nul().as_ptr();
-
-                unsafe {
-                    gl::wgl::GetProcAddress(addr) as *const libc::c_void
-                }
-            });
-
-            // removing current context
-            unsafe { gl::wgl::MakeCurrent(ptr::null(), ptr::null()); }
-
-            // destroying the context and the window
-            unsafe { gl::wgl::DeleteContext(dummy_context); }
-            unsafe { user32::DestroyWindow(dummy_window); }
+        // now that the `Window` struct is initialized, the main `Window::new()` function will
+        //  return and this events loop will run in parallel
+        loop {
+            let mut msg = unsafe { mem::uninitialized() };
 
-            // returning the address
-            (extra_functions, pixel_format)
-        };
+            if unsafe { user32::GetMessageW(&mut msg, ptr::null_mut(), 0, 0) } == 0 {
+                break;
+            }
 
-        // creating the real window this time
-        let real_window = unsafe {
-            let (width, height) = if builder.monitor.is_some() || builder.dimensions.is_some() {
-                (Some(rect.right - rect.left), Some(rect.bottom - rect.top))
-            } else {
-                (None, None)
-            };
+            unsafe { user32::TranslateMessage(&msg) };
+            unsafe { user32::DispatchMessageW(&msg) };     // calls `callback` (see below)
+        }
+    });
 
-            let style = if !builder.visible || builder.headless {
-                style
-            } else {
-                style | winapi::WS_VISIBLE
-            };
+    rx.recv().unwrap()
+}
 
+fn init(title: Vec<u16>, builder: BuilderAttribs<'static>, builder_sharelists: Option<ContextHack>)
+        -> Result<Window, CreationError>
+{
+    let builder_sharelists = builder_sharelists.map(|s| s.0);
+
+    // registering the window class
+    let class_name = register_window_class();
+
+    // building a RECT object with coordinates
+    let mut rect = winapi::RECT {
+        left: 0, right: builder.dimensions.unwrap_or((1024, 768)).0 as winapi::LONG,
+        top: 0, bottom: builder.dimensions.unwrap_or((1024, 768)).1 as winapi::LONG,
+    };
+
+    // switching to fullscreen if necessary
+    // this means adjusting the window's position so that it overlaps the right monitor,
+    //  and change the monitor's resolution if necessary
+    if builder.monitor.is_some() {
+        let monitor = builder.monitor.as_ref().unwrap();
+        switch_to_fullscreen(&mut rect, monitor);
+    }
+
+    // computing the style and extended style of the window
+    let (ex_style, style) = if builder.monitor.is_some() {
+        (winapi::WS_EX_APPWINDOW, winapi::WS_POPUP | winapi::WS_CLIPSIBLINGS | winapi::WS_CLIPCHILDREN)
+    } else {
+        (winapi::WS_EX_APPWINDOW | winapi::WS_EX_WINDOWEDGE,
+            winapi::WS_OVERLAPPEDWINDOW | winapi::WS_CLIPSIBLINGS | winapi::WS_CLIPCHILDREN)
+    };
+
+    // adjusting the window coordinates using the style
+    unsafe { user32::AdjustWindowRectEx(&mut rect, style, 0, ex_style) };
+
+    // getting the address of wglCreateContextAttribsARB and the pixel format
+    //  that we will use
+    let (extra_functions, pixel_format) = {
+        // creating a dummy invisible window for GL initialization
+        let dummy_window = unsafe {
             let handle = user32::CreateWindowExW(ex_style, class_name.as_ptr(),
                 title.as_ptr() as winapi::LPCWSTR,
                 style | winapi::WS_CLIPSIBLINGS | winapi::WS_CLIPCHILDREN,
-                if builder.monitor.is_some() { 0 } else { winapi::CW_USEDEFAULT },
-                if builder.monitor.is_some() { 0 } else { winapi::CW_USEDEFAULT },
-                width.unwrap_or(winapi::CW_USEDEFAULT), height.unwrap_or(winapi::CW_USEDEFAULT),
+                winapi::CW_USEDEFAULT, winapi::CW_USEDEFAULT,
+                rect.right - rect.left, rect.bottom - rect.top,
                 ptr::null_mut(), ptr::null_mut(), kernel32::GetModuleHandleW(ptr::null()),
                 ptr::null_mut());
 
             if handle.is_null() {
-                use std::os;
-                tx.send(Err(OsError(format!("CreateWindowEx function failed: {}",
-                    os::error_string(os::errno() as usize)))));
-                return;
+                return Err(OsError(format!("CreateWindowEx function failed: {}",
+                    os::error_string(os::errno() as usize))));
             }
 
             handle
         };
 
-        // getting the HDC of the window
-        let hdc = {
-            let hdc = unsafe { user32::GetDC(real_window) };
+        // getting the HDC of the dummy window
+        let dummy_hdc = {
+            let hdc = unsafe { user32::GetDC(dummy_window) };
             if hdc.is_null() {
-                tx.send(Err(OsError(format!("GetDC function failed: {}",
-                    os::error_string(os::errno() as usize)))));
-                unsafe { user32::DestroyWindow(real_window); }
-                return;
+                let err = Err(OsError(format!("GetDC function failed: {}",
+                    os::error_string(os::errno() as usize))));
+                unsafe { user32::DestroyWindow(dummy_window); }
+                return err;
             }
             hdc
         };
 
+        // getting the pixel format that we will use
+        let pixel_format = {
+            // initializing a PIXELFORMATDESCRIPTOR that indicates what we want
+            let mut output: winapi::PIXELFORMATDESCRIPTOR = unsafe { mem::zeroed() };
+            output.nSize = mem::size_of::<winapi::PIXELFORMATDESCRIPTOR>() as winapi::WORD;
+            output.nVersion = 1;
+            output.dwFlags = winapi::PFD_DRAW_TO_WINDOW | winapi::PFD_DOUBLEBUFFER |
+                winapi::PFD_SUPPORT_OPENGL | winapi::PFD_GENERIC_ACCELERATED;
+            output.iPixelType = winapi::PFD_TYPE_RGBA;
+            output.cColorBits = 24;
+            output.cAlphaBits = 8;
+            output.cAccumBits = 0;
+            output.cDepthBits = 24;
+            output.cStencilBits = 8;
+            output.cAuxBuffers = 0;
+            output.iLayerType = winapi::PFD_MAIN_PLANE;
+
+            let pf_index = unsafe { gdi32::ChoosePixelFormat(dummy_hdc, &output) };
+
+            if pf_index == 0 {
+                let err = Err(OsError(format!("ChoosePixelFormat function failed: {}",
+                    os::error_string(os::errno() as usize))));
+                unsafe { user32::DestroyWindow(dummy_window); }
+                return err;
+            }
+
+            if unsafe { gdi32::DescribePixelFormat(dummy_hdc, pf_index,
+                mem::size_of::<winapi::PIXELFORMATDESCRIPTOR>() as winapi::UINT, &mut output) } == 0
+            {
+                let err = Err(OsError(format!("DescribePixelFormat function failed: {}",
+                    os::error_string(os::errno() as usize))));
+                unsafe { user32::DestroyWindow(dummy_window); }
+                return err;
+            }
+
+            output
+        };
+
         // calling SetPixelFormat
         unsafe {
-            if gdi32::SetPixelFormat(hdc, 1, &pixel_format) == 0 {
-                tx.send(Err(OsError(format!("SetPixelFormat function failed: {}",
-                    os::error_string(os::errno() as usize)))));
-                user32::DestroyWindow(real_window);
-                return;
+            if gdi32::SetPixelFormat(dummy_hdc, 1, &pixel_format) == 0 {
+                let err = Err(OsError(format!("SetPixelFormat function failed: {}",
+                    os::error_string(os::errno() as usize))));
+                user32::DestroyWindow(dummy_window);
+                return err;
             }
         }
 
-        // creating the OpenGL context
-        let context = {
-            use libc;
+        // creating the dummy OpenGL context
+        let dummy_context = {
+            let ctxt = unsafe { gl::wgl::CreateContext(dummy_hdc as *const libc::c_void) };
+            if ctxt.is_null() {
+                let err = Err(OsError(format!("wglCreateContext function failed: {}",
+                    os::error_string(os::errno() as usize))));
+                unsafe { user32::DestroyWindow(dummy_window); }
+                return err;
+            }
+            ctxt
+        };
 
-            let mut attributes = Vec::new();
+        // making context current
+        unsafe { gl::wgl::MakeCurrent(dummy_hdc as *const libc::c_void, dummy_context); }
 
-            if builder.gl_version.is_some() {
-                let version = builder.gl_version.as_ref().unwrap();
-                attributes.push(gl::wgl_extra::CONTEXT_MAJOR_VERSION_ARB as libc::c_int);
-                attributes.push(version.0 as libc::c_int);
-                attributes.push(gl::wgl_extra::CONTEXT_MINOR_VERSION_ARB as libc::c_int);
-                attributes.push(version.1 as libc::c_int);
-            }
+        // loading the extra WGL functions
+        let extra_functions = gl::wgl_extra::Wgl::load_with(|addr| {
+            use libc;
+
+            let addr = CString::from_slice(addr.as_bytes());
+            let addr = addr.as_slice_with_nul().as_ptr();
 
-            if builder.gl_debug {
-                attributes.push(gl::wgl_extra::CONTEXT_FLAGS_ARB as libc::c_int);
-                attributes.push(gl::wgl_extra::CONTEXT_DEBUG_BIT_ARB as libc::c_int);
+            unsafe {
+                gl::wgl::GetProcAddress(addr) as *const libc::c_void
             }
+        });
 
-            attributes.push(0);
+        // removing current context
+        unsafe { gl::wgl::MakeCurrent(ptr::null(), ptr::null()); }
 
-            let ctxt = unsafe {
-                if extra_functions.CreateContextAttribsARB.is_loaded() {
-                    let share = if let Some(c) = builder_sharelists { c } else { ptr::null_mut() };
-                    extra_functions.CreateContextAttribsARB(hdc as *const libc::c_void,
-                                                            share as *const libc::c_void,
-                                                            attributes.as_slice().as_ptr())
+        // destroying the context and the window
+        unsafe { gl::wgl::DeleteContext(dummy_context); }
+        unsafe { user32::DestroyWindow(dummy_window); }
 
-                } else {
-                    let ctxt = gl::wgl::CreateContext(hdc as *const libc::c_void);
-                    if let Some(c) = builder_sharelists {
-                        gl::wgl::ShareLists(c as *const libc::c_void, ctxt);
-                    };
-                    ctxt
-                }
-            };
+        // returning the address
+        (extra_functions, pixel_format)
+    };
 
-            if ctxt.is_null() {
-                tx.send(Err(OsError(format!("OpenGL context creation failed: {}",
-                    os::error_string(os::errno() as usize)))));
-                unsafe { user32::DestroyWindow(real_window); }
-                return;
-            }
+    // creating the real window this time
+    let real_window = unsafe {
+        let (width, height) = if builder.monitor.is_some() || builder.dimensions.is_some() {
+            (Some(rect.right - rect.left), Some(rect.bottom - rect.top))
+        } else {
+            (None, None)
+        };
 
-            ctxt
+        let style = if !builder.visible || builder.headless {
+            style
+        } else {
+            style | winapi::WS_VISIBLE
         };
 
-        // calling SetForegroundWindow if fullscreen
-        if builder.monitor.is_some() {
-            unsafe { user32::SetForegroundWindow(real_window) };
+        let handle = user32::CreateWindowExW(ex_style, class_name.as_ptr(),
+            title.as_ptr() as winapi::LPCWSTR,
+            style | winapi::WS_CLIPSIBLINGS | winapi::WS_CLIPCHILDREN,
+            if builder.monitor.is_some() { 0 } else { winapi::CW_USEDEFAULT },
+            if builder.monitor.is_some() { 0 } else { winapi::CW_USEDEFAULT },
+            width.unwrap_or(winapi::CW_USEDEFAULT), height.unwrap_or(winapi::CW_USEDEFAULT),
+            ptr::null_mut(), ptr::null_mut(), kernel32::GetModuleHandleW(ptr::null()),
+            ptr::null_mut());
+
+        if handle.is_null() {
+            return Err(OsError(format!("CreateWindowEx function failed: {}",
+                os::error_string(os::errno() as usize))));
         }
 
-        // filling the WINDOW task-local storage
-        let events_receiver = {
-            let (tx, rx) = channel();
-            let mut tx = Some(tx);
-            callback::WINDOW.with(|window| {
-                (*window.borrow_mut()) = Some((real_window, tx.take().unwrap()));
-            });
-            rx
-        };
+        handle
+    };
+
+    // getting the HDC of the window
+    let hdc = {
+        let hdc = unsafe { user32::GetDC(real_window) };
+        if hdc.is_null() {
+            let err = Err(OsError(format!("GetDC function failed: {}",
+                os::error_string(os::errno() as usize))));
+            unsafe { user32::DestroyWindow(real_window); }
+            return err;
+        }
+        hdc
+    };
+
+    // calling SetPixelFormat
+    unsafe {
+        if gdi32::SetPixelFormat(hdc, 1, &pixel_format) == 0 {
+            let err = Err(OsError(format!("SetPixelFormat function failed: {}",
+                os::error_string(os::errno() as usize))));
+            user32::DestroyWindow(real_window);
+            return err;
+        }
+    }
 
-        // loading the opengl32 module
-        let gl_library = {
-            let name = "opengl32.dll".utf16_units().chain(Some(0).into_iter())
-                .collect::<Vec<u16>>().as_ptr();
-            let lib = unsafe { kernel32::LoadLibraryW(name) };
-            if lib.is_null() {
-                tx.send(Err(OsError(format!("LoadLibrary function failed: {}",
-                    os::error_string(os::errno() as usize)))));
-                unsafe { gl::wgl::DeleteContext(context); }
-                unsafe { user32::DestroyWindow(real_window); }
-                return;
-            }
-            lib
-        };
+    // creating the OpenGL context
+    let context = {
+        use libc;
 
-        // handling vsync
-        if builder.vsync {
-            if extra_functions.SwapIntervalEXT.is_loaded() {
-                unsafe { gl::wgl::MakeCurrent(hdc as *const libc::c_void, context) };
-                if unsafe { extra_functions.SwapIntervalEXT(1) } == 0 {
-                    tx.send(Err(OsError(format!("wglSwapIntervalEXT failed"))));
-                    unsafe { gl::wgl::DeleteContext(context); }
-                    unsafe { user32::DestroyWindow(real_window); }
-                    return;
-                }
-
-                // it is important to remove the current context, otherwise you get very weird
-                // errors
-                unsafe { gl::wgl::MakeCurrent(ptr::null(), ptr::null()); }
-            }
+        let mut attributes = Vec::new();
+
+        if builder.gl_version.is_some() {
+            let version = builder.gl_version.as_ref().unwrap();
+            attributes.push(gl::wgl_extra::CONTEXT_MAJOR_VERSION_ARB as libc::c_int);
+            attributes.push(version.0 as libc::c_int);
+            attributes.push(gl::wgl_extra::CONTEXT_MINOR_VERSION_ARB as libc::c_int);
+            attributes.push(version.1 as libc::c_int);
         }
 
-        // building the struct
-        let window = Window{
-            window: real_window,
-            hdc: hdc as winapi::HDC,
-            context: context as winapi::HGLRC,
-            gl_library: gl_library,
-            events_receiver: events_receiver,
-            is_closed: AtomicBool::new(false),
-        };
+        if builder.gl_debug {
+            attributes.push(gl::wgl_extra::CONTEXT_FLAGS_ARB as libc::c_int);
+            attributes.push(gl::wgl_extra::CONTEXT_DEBUG_BIT_ARB as libc::c_int);
+        }
 
-        // sending
-        tx.send(Ok(window));
+        attributes.push(0);
 
-        // now that the `Window` struct is initialized, the main `Window::new()` function will
-        //  return and this events loop will run in parallel
-        loop {
-            let mut msg = unsafe { mem::uninitialized() };
+        let ctxt = unsafe {
+            if extra_functions.CreateContextAttribsARB.is_loaded() {
+                let share = if let Some(c) = builder_sharelists { c } else { ptr::null_mut() };
+                extra_functions.CreateContextAttribsARB(hdc as *const libc::c_void,
+                                                        share as *const libc::c_void,
+                                                        attributes.as_slice().as_ptr())
 
-            if unsafe { user32::GetMessageW(&mut msg, ptr::null_mut(), 0, 0) } == 0 {
-                break;
+            } else {
+                let ctxt = gl::wgl::CreateContext(hdc as *const libc::c_void);
+                if let Some(c) = builder_sharelists {
+                    gl::wgl::ShareLists(c as *const libc::c_void, ctxt);
+                };
+                ctxt
             }
+        };
 
-            unsafe { user32::TranslateMessage(&msg) };
-            unsafe { user32::DispatchMessageW(&msg) };     // calls `callback` (see below)
+        if ctxt.is_null() {
+            let err = Err(OsError(format!("OpenGL context creation failed: {}",
+                os::error_string(os::errno() as usize))));
+            unsafe { user32::DestroyWindow(real_window); }
+            return err;
         }
-    });
 
-    rx.recv().unwrap()
+        ctxt
+    };
+
+    // calling SetForegroundWindow if fullscreen
+    if builder.monitor.is_some() {
+        unsafe { user32::SetForegroundWindow(real_window) };
+    }
+
+    // filling the WINDOW task-local storage
+    let events_receiver = {
+        let (tx, rx) = channel();
+        let mut tx = Some(tx);
+        callback::WINDOW.with(|window| {
+            (*window.borrow_mut()) = Some((real_window, tx.take().unwrap()));
+        });
+        rx
+    };
+
+    // loading the opengl32 module
+    let gl_library = {
+        let name = "opengl32.dll".utf16_units().chain(Some(0).into_iter())
+            .collect::<Vec<u16>>().as_ptr();
+        let lib = unsafe { kernel32::LoadLibraryW(name) };
+        if lib.is_null() {
+            let err = Err(OsError(format!("LoadLibrary function failed: {}",
+                                          os::error_string(os::errno() as usize))));
+            unsafe { gl::wgl::DeleteContext(context); }
+            unsafe { user32::DestroyWindow(real_window); }
+            return err;
+        }
+        lib
+    };
+
+    // handling vsync
+    if builder.vsync {
+        if extra_functions.SwapIntervalEXT.is_loaded() {
+            unsafe { gl::wgl::MakeCurrent(hdc as *const libc::c_void, context) };
+            if unsafe { extra_functions.SwapIntervalEXT(1) } == 0 {
+                unsafe { gl::wgl::DeleteContext(context); }
+                unsafe { user32::DestroyWindow(real_window); }
+                return Err(OsError(format!("wglSwapIntervalEXT failed")));
+            }
+
+            // it is important to remove the current context, otherwise you get very weird
+            // errors
+            unsafe { gl::wgl::MakeCurrent(ptr::null(), ptr::null()); }
+        }
+    }
+
+    // building the struct
+    Ok(Window {
+        window: real_window,
+        hdc: hdc as winapi::HDC,
+        context: context as winapi::HGLRC,
+        gl_library: gl_library,
+        events_receiver: events_receiver,
+        is_closed: AtomicBool::new(false),
+    })
+}
+
+fn register_window_class() -> Vec<u16> {
+    let class_name: Vec<u16> = "Window Class".utf16_units().chain(Some(0).into_iter())
+                                             .collect::<Vec<u16>>();
+    
+    let class = winapi::WNDCLASSEXW {
+        cbSize: mem::size_of::<winapi::WNDCLASSEXW>() as winapi::UINT,
+        style: winapi::CS_HREDRAW | winapi::CS_VREDRAW | winapi::CS_OWNDC,
+        lpfnWndProc: callback::callback,
+        cbClsExtra: 0,
+        cbWndExtra: 0,
+        hInstance: unsafe { kernel32::GetModuleHandleW(ptr::null()) },
+        hIcon: ptr::null_mut(),
+        hCursor: ptr::null_mut(),
+        hbrBackground: ptr::null_mut(),
+        lpszMenuName: ptr::null(),
+        lpszClassName: class_name.as_ptr(),
+        hIconSm: ptr::null_mut(),
+    };
+
+    // We ignore errors because registering the same window class twice would trigger
+    //  an error, and because errors here are detected during CreateWindowEx anyway.
+    // Also since there is no weird element in the struct, there is no reason for this
+    //  call to fail.
+    unsafe { user32::RegisterClassExW(&class) };
+
+    class_name
+}
+
+fn switch_to_fullscreen(rect: &mut winapi::RECT, monitor: &MonitorID) -> Result<(), CreationError> {
+    // adjusting the rect
+    {
+        let pos = monitor.get_position();
+        rect.left += pos.0 as winapi::LONG;
+        rect.right += pos.0 as winapi::LONG;
+        rect.top += pos.1 as winapi::LONG;
+        rect.bottom += pos.1 as winapi::LONG;
+    }
+
+    // changing device settings
+    let mut screen_settings: winapi::DEVMODEW = unsafe { mem::zeroed() };
+    screen_settings.dmSize = mem::size_of::<winapi::DEVMODEW>() as winapi::WORD;
+    screen_settings.dmPelsWidth = (rect.right - rect.left) as winapi::DWORD;
+    screen_settings.dmPelsHeight = (rect.bottom - rect.top) as winapi::DWORD;
+    screen_settings.dmBitsPerPel = 32;      // TODO: ?
+    screen_settings.dmFields = winapi::DM_BITSPERPEL | winapi::DM_PELSWIDTH | winapi::DM_PELSHEIGHT;
+
+    let result = unsafe { user32::ChangeDisplaySettingsExW(monitor.get_system_name().as_ptr(),
+        &mut screen_settings, ptr::null_mut(), winapi::CDS_FULLSCREEN, ptr::null_mut()) };
+    
+    if result != winapi::DISP_CHANGE_SUCCESSFUL {
+        return Err(OsError(format!("ChangeDisplaySettings failed: {}", result)));
+    }
+
+    Ok(())
 }