diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/api/wgl/mod.rs | 308 | ||||
| -rw-r--r-- | src/lib.rs | 2 |
2 files changed, 170 insertions, 140 deletions
diff --git a/src/api/wgl/mod.rs b/src/api/wgl/mod.rs index 1da20aa..d1f42d2 100644 --- a/src/api/wgl/mod.rs +++ b/src/api/wgl/mod.rs @@ -24,6 +24,9 @@ use gdi32; mod make_current_guard; mod gl; +/// A WGL context. +/// +/// Note: should be destroyed before its window. pub struct Context { context: ContextWrapper, @@ -50,6 +53,7 @@ impl Drop for WindowWrapper { } } +/// Wraps around a context so that it is destroyed when necessary. struct ContextWrapper(winapi::HGLRC); impl Drop for ContextWrapper { @@ -64,127 +68,85 @@ impl Context { /// Attempt to build a new WGL context on a window. /// /// The window must **not** have had `SetPixelFormat` called on it. - pub fn new(builder: &BuilderAttribs<'static>, window: winapi::HWND, - builder_sharelists: Option<winapi::HGLRC>) - -> Result<Context, CreationError> + /// + /// # Unsafety + /// + /// The `window` must continue to exist as long as the resulting `Context` exists. + pub unsafe fn new(builder: &BuilderAttribs<'static>, window: winapi::HWND, + builder_sharelists: Option<winapi::HGLRC>) + -> Result<Context, CreationError> { - unsafe { - let hdc = user32::GetDC(window); - if hdc.is_null() { - let err = Err(CreationError::OsError(format!("GetDC function failed: {}", - format!("{}", io::Error::last_os_error())))); - return err; - } - - // the first step is to create a dummy window and a dummy context which we will use - // to load the pointers to some functions in the OpenGL driver in `extra_functions` - let extra_functions = { - let (ex_style, style) = (winapi::WS_EX_APPWINDOW, winapi::WS_POPUP | - winapi::WS_CLIPSIBLINGS | winapi::WS_CLIPCHILDREN); - - // creating a dummy invisible window - let dummy_window = { - let rect = { - let mut placement: winapi::WINDOWPLACEMENT = unsafe { mem::zeroed() }; - placement.length = mem::size_of::<winapi::WINDOWPLACEMENT>() as winapi::UINT; - if unsafe { user32::GetWindowPlacement(window, &mut placement) } == 0 { - panic!(); - } - placement.rcNormalPosition - }; - - let mut class_name = [0u16; 128]; - if user32::GetClassNameW(window, class_name.as_mut_ptr(), 128) == 0 { - return Err(CreationError::OsError(format!("GetClassNameW function failed: {}", - format!("{}", io::Error::last_os_error())))); - } + let hdc = user32::GetDC(window); + if hdc.is_null() { + let err = Err(CreationError::OsError(format!("GetDC function failed: {}", + format!("{}", io::Error::last_os_error())))); + return err; + } - let handle = user32::CreateWindowExW(ex_style, class_name.as_ptr(), - b"dummy window\0".as_ptr() as *const _, style, - 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() { - return Err(CreationError::OsError(format!("CreateWindowEx function failed: {}", - format!("{}", io::Error::last_os_error())))); - } + // loading the functions that are not guaranteed to be supported + let extra_functions = try!(load_extra_functions(window)); - let hdc = user32::GetDC(handle); - if hdc.is_null() { - let err = Err(CreationError::OsError(format!("GetDC function failed: {}", - format!("{}", io::Error::last_os_error())))); - return err; - } + // getting the list of the supported extensions + let extensions = if extra_functions.GetExtensionsStringARB.is_loaded() { + let data = extra_functions.GetExtensionsStringARB(hdc as *const _); + let data = CStr::from_ptr(data).to_bytes().to_vec(); + String::from_utf8(data).unwrap() - WindowWrapper(handle, hdc) - }; + } else if extra_functions.GetExtensionsStringEXT.is_loaded() { + let data = extra_functions.GetExtensionsStringEXT(); + let data = CStr::from_ptr(data).to_bytes().to_vec(); + String::from_utf8(data).unwrap() - // getting the pixel format that we will use and setting it - { - let formats = enumerate_native_pixel_formats(dummy_window.1); - let id = try!(choose_dummy_pixel_format(formats.into_iter())); - try!(set_pixel_format(dummy_window.1, id)); + } else { + format!("") + }; + + // calling SetPixelFormat + let pixel_format = { + let formats = if extensions.split(' ').find(|&i| i == "WGL_ARB_pixel_format") + .is_some() + { + let f = enumerate_arb_pixel_formats(&extra_functions, &extensions, hdc); + if f.is_empty() { + enumerate_native_pixel_formats(hdc) + } else { + f } - - // creating the dummy OpenGL context and making it current - let dummy_context = try!(create_context(None, dummy_window.0, dummy_window.1, None)); - let _current_context = try!(CurrentContextGuard::make_current(dummy_window.1, - dummy_context.0)); - - // loading the extra WGL functions - gl::wgl_extra::Wgl::load_with(|addr| { - let addr = CString::new(addr.as_bytes()).unwrap(); - let addr = addr.as_ptr(); - gl::wgl::GetProcAddress(addr) as *const libc::c_void - }) + } else { + enumerate_native_pixel_formats(hdc) }; - // calling SetPixelFormat - let pixel_format = { - let formats = if extra_functions.GetPixelFormatAttribivARB.is_loaded() { - let f = enumerate_arb_pixel_formats(&extra_functions, hdc); - if f.is_empty() { - enumerate_native_pixel_formats(hdc) - } else { - f - } - } else { - enumerate_native_pixel_formats(hdc) - }; - - let (id, f) = try!(builder.choose_pixel_format(formats.into_iter().map(|(a, b)| (b, a)))); - try!(set_pixel_format(hdc, id)); - f - }; + let (id, f) = try!(builder.choose_pixel_format(formats)); + try!(set_pixel_format(hdc, id)); + f + }; - // creating the OpenGL context - let context = try!(create_context(Some((&extra_functions, builder)), window, hdc, - builder_sharelists)); + // creating the OpenGL context + let context = try!(create_context(Some((&extra_functions, builder, &extensions)), + window, hdc, builder_sharelists)); - // loading the opengl32 module - let gl_library = try!(load_opengl32_dll()); + // loading the opengl32 module + let gl_library = try!(load_opengl32_dll()); - // handling vsync - if builder.vsync { - if extra_functions.SwapIntervalEXT.is_loaded() { - let _guard = try!(CurrentContextGuard::make_current(hdc, context.0)); + // handling vsync + if builder.vsync { + // contrary to most extensions, it is permitted to discover the presence of + // `WGL_EXT_swap_control` by seeing if the function pointer is available + if extra_functions.SwapIntervalEXT.is_loaded() { + let _guard = try!(CurrentContextGuard::make_current(hdc, context.0)); - if extra_functions.SwapIntervalEXT(1) == 0 { - return Err(CreationError::OsError(format!("wglSwapIntervalEXT failed"))); - } + if extra_functions.SwapIntervalEXT(1) == 0 { + return Err(CreationError::OsError(format!("wglSwapIntervalEXT failed"))); } } - - Ok(Context { - context: context, - hdc: hdc, - gl_library: gl_library, - pixel_format: pixel_format, - }) } + + Ok(Context { + context: context, + hdc: hdc, + gl_library: gl_library, + pixel_format: pixel_format, + }) } /// Returns the raw HGLRC. @@ -233,14 +195,21 @@ impl GlContext for Context { unsafe impl Send for Context {} unsafe impl Sync for Context {} -unsafe fn create_context(extra: Option<(&gl::wgl_extra::Wgl, &BuilderAttribs<'static>)>, +/// Creates an OpenGL context. +/// +/// If `extra` is `Some`, this function will attempt to use the latest WGL functions to create the +/// context. +/// +/// Otherwise, only the basic API will be used and the chances of `CreationError::NotSupported` +/// being returned increase. +unsafe fn create_context(extra: Option<(&gl::wgl_extra::Wgl, &BuilderAttribs<'static>, &str)>, _: winapi::HWND, hdc: winapi::HDC, share: Option<winapi::HGLRC>) -> Result<ContextWrapper, CreationError> { let share = share.unwrap_or(ptr::null_mut()); - let ctxt = if let Some((extra_functions, builder)) = extra { - if extra_functions.CreateContextAttribsARB.is_loaded() { + let ctxt = if let Some((extra_functions, builder, extensions)) = extra { + if extensions.split(' ').find(|&i| i == "WGL_ARB_create_context").is_some() { let mut attributes = Vec::new(); match builder.gl_version { @@ -252,8 +221,8 @@ unsafe fn create_context(extra: Option<(&gl::wgl_extra::Wgl, &BuilderAttribs<'st attributes.push(minor as libc::c_int); }, GlRequest::Specific(Api::OpenGlEs, (major, minor)) => { - if is_extension_supported(extra_functions, hdc, - "WGL_EXT_create_context_es2_profile") + if extensions.split(' ').find(|&i| i == "WGL_EXT_create_context_es2_profile") + .is_some() { attributes.push(gl::wgl_extra::CONTEXT_PROFILE_MASK_ARB as libc::c_int); attributes.push(gl::wgl_extra::CONTEXT_ES2_PROFILE_BIT_EXT as libc::c_int); @@ -276,8 +245,7 @@ unsafe fn create_context(extra: Option<(&gl::wgl_extra::Wgl, &BuilderAttribs<'st } if let Some(profile) = builder.gl_profile { - if is_extension_supported(extra_functions, hdc, - "WGL_ARB_create_context_profile") + if extensions.split(' ').find(|&i| i == "WGL_ARB_create_context_profile").is_some() { let flag = match profile { GlProfile::Compatibility => @@ -329,7 +297,10 @@ unsafe fn create_context(extra: Option<(&gl::wgl_extra::Wgl, &BuilderAttribs<'st Ok(ContextWrapper(ctxt as winapi::HGLRC)) } -unsafe fn enumerate_native_pixel_formats(hdc: winapi::HDC) -> Vec<(PixelFormat, libc::c_int)> { +/// Enumerates the list of pixel formats without using WGL. +/// +/// Gives less precise results than `enumerate_arb_pixel_formats`. +unsafe fn enumerate_native_pixel_formats(hdc: winapi::HDC) -> Vec<(libc::c_int, PixelFormat)> { let size_of_pxfmtdescr = mem::size_of::<winapi::PIXELFORMATDESCRIPTOR>() as u32; let num = gdi32::DescribePixelFormat(hdc, 1, size_of_pxfmtdescr, ptr::null_mut()); @@ -354,7 +325,7 @@ unsafe fn enumerate_native_pixel_formats(hdc: winapi::HDC) -> Vec<(PixelFormat, continue; } - result.push((PixelFormat { + result.push((index, PixelFormat { hardware_accelerated: (output.dwFlags & winapi::PFD_GENERIC_FORMAT) == 0, color_bits: output.cRedBits + output.cGreenBits + output.cBlueBits, alpha_bits: output.cAlphaBits, @@ -364,14 +335,17 @@ unsafe fn enumerate_native_pixel_formats(hdc: winapi::HDC) -> Vec<(PixelFormat, double_buffer: (output.dwFlags & winapi::PFD_DOUBLEBUFFER) != 0, multisampling: None, srgb: false, - }, index)); + })); } result } -unsafe fn enumerate_arb_pixel_formats(extra: &gl::wgl_extra::Wgl, hdc: winapi::HDC) - -> Vec<(PixelFormat, libc::c_int)> +/// Enumerates the list of pixel formats by using extra WGL functions. +/// +/// Gives more precise results than `enumerate_native_pixel_formats`. +unsafe fn enumerate_arb_pixel_formats(extra: &gl::wgl_extra::Wgl, extensions: &str, + hdc: winapi::HDC) -> Vec<(libc::c_int, PixelFormat)> { let get_info = |index: u32, attrib: u32| { let mut value = mem::uninitialized(); @@ -403,7 +377,7 @@ unsafe fn enumerate_arb_pixel_formats(extra: &gl::wgl_extra::Wgl, hdc: winapi::H continue; } - result.push((PixelFormat { + result.push((index as libc::c_int, PixelFormat { hardware_accelerated: true, color_bits: get_info(index, gl::wgl_extra::RED_BITS_ARB) as u8 + get_info(index, gl::wgl_extra::GREEN_BITS_ARB) as u8 + @@ -414,7 +388,7 @@ unsafe fn enumerate_arb_pixel_formats(extra: &gl::wgl_extra::Wgl, hdc: winapi::H stereoscopy: get_info(index, gl::wgl_extra::STEREO_ARB) != 0, double_buffer: get_info(index, gl::wgl_extra::DOUBLE_BUFFER_ARB) != 0, multisampling: { - if is_extension_supported(extra, hdc, "WGL_ARB_multisample") { + if extensions.split(' ').find(|&i| i == "WGL_ARB_multisample").is_some() { match get_info(index, gl::wgl_extra::SAMPLES_ARB) { 0 => None, a => Some(a as u16), @@ -423,19 +397,20 @@ unsafe fn enumerate_arb_pixel_formats(extra: &gl::wgl_extra::Wgl, hdc: winapi::H None } }, - srgb: if is_extension_supported(extra, hdc, "WGL_ARB_framebuffer_sRGB") { + srgb: if extensions.split(' ').find(|&i| i == "WGL_ARB_framebuffer_sRGB").is_some() { get_info(index, gl::wgl_extra::FRAMEBUFFER_SRGB_CAPABLE_ARB) != 0 - } else if is_extension_supported(extra, hdc, "WGL_EXT_framebuffer_sRGB") { + } else if extensions.split(' ').find(|&i| i == "WGL_EXT_framebuffer_sRGB").is_some() { get_info(index, gl::wgl_extra::FRAMEBUFFER_SRGB_CAPABLE_EXT) != 0 } else { false }, - }, index as libc::c_int)); + })); } result } +/// Calls `SetPixelFormat` on a window. unsafe fn set_pixel_format(hdc: winapi::HDC, id: libc::c_int) -> Result<(), CreationError> { let mut output: winapi::PIXELFORMATDESCRIPTOR = mem::zeroed(); @@ -454,6 +429,7 @@ unsafe fn set_pixel_format(hdc: winapi::HDC, id: libc::c_int) -> Result<(), Crea Ok(()) } +/// Loads the `opengl32.dll` library. unsafe fn load_opengl32_dll() -> Result<winapi::HMODULE, CreationError> { let name = OsStr::new("opengl32.dll").encode_wide().chain(Some(0).into_iter()) .collect::<Vec<_>>(); @@ -468,32 +444,86 @@ unsafe fn load_opengl32_dll() -> Result<winapi::HMODULE, CreationError> { Ok(lib) } -unsafe fn is_extension_supported(extra: &gl::wgl_extra::Wgl, hdc: winapi::HDC, - extension: &str) -> bool -{ - let extensions = if extra.GetExtensionsStringARB.is_loaded() { - let data = extra.GetExtensionsStringARB(hdc as *const _); - let data = CStr::from_ptr(data).to_bytes().to_vec(); - String::from_utf8(data).unwrap() +/// Loads the WGL functions that are not guaranteed to be supported. +/// +/// The `window` must be passed because the driver can vary depending on the window's +/// characteristics. +unsafe fn load_extra_functions(window: winapi::HWND) -> Result<gl::wgl_extra::Wgl, CreationError> { + let (ex_style, style) = (winapi::WS_EX_APPWINDOW, winapi::WS_POPUP | + winapi::WS_CLIPSIBLINGS | winapi::WS_CLIPCHILDREN); + + // creating a dummy invisible window + let dummy_window = { + // getting the rect of the real window + let rect = { + let mut placement: winapi::WINDOWPLACEMENT = mem::zeroed(); + placement.length = mem::size_of::<winapi::WINDOWPLACEMENT>() as winapi::UINT; + if user32::GetWindowPlacement(window, &mut placement) == 0 { + panic!(); + } + placement.rcNormalPosition + }; + + // getting the class name of the real window + let mut class_name = [0u16; 128]; + if user32::GetClassNameW(window, class_name.as_mut_ptr(), 128) == 0 { + return Err(CreationError::OsError(format!("GetClassNameW function failed: {}", + format!("{}", io::Error::last_os_error())))); + } - } else if extra.GetExtensionsStringEXT.is_loaded() { - let data = extra.GetExtensionsStringEXT(); - let data = CStr::from_ptr(data).to_bytes().to_vec(); - String::from_utf8(data).unwrap() + // this dummy window should match the real one enough to get the same OpenGL driver + let win = user32::CreateWindowExW(ex_style, class_name.as_ptr(), + b"dummy window\0".as_ptr() as *const _, style, + 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 win.is_null() { + return Err(CreationError::OsError(format!("CreateWindowEx function failed: {}", + format!("{}", io::Error::last_os_error())))); + } - } else { - return false; + let hdc = user32::GetDC(win); + if hdc.is_null() { + let err = Err(CreationError::OsError(format!("GetDC function failed: {}", + format!("{}", io::Error::last_os_error())))); + return err; + } + + WindowWrapper(win, hdc) }; - extensions.split(" ").find(|&e| e == extension).is_some() + // getting the pixel format that we will use and setting it + { + let formats = enumerate_native_pixel_formats(dummy_window.1); + let id = try!(choose_dummy_pixel_format(formats.into_iter())); + try!(set_pixel_format(dummy_window.1, id)); + } + + // creating the dummy OpenGL context and making it current + let dummy_context = try!(create_context(None, dummy_window.0, dummy_window.1, None)); + let _current_context = try!(CurrentContextGuard::make_current(dummy_window.1, + dummy_context.0)); + + // loading the extra WGL functions + Ok(gl::wgl_extra::Wgl::load_with(|addr| { + let addr = CString::new(addr.as_bytes()).unwrap(); + let addr = addr.as_ptr(); + gl::wgl::GetProcAddress(addr) as *const libc::c_void + })) } +/// Given a list of pixel formats, this function chooses one that is likely to be provided by +/// the main video driver of the system. fn choose_dummy_pixel_format<I>(iter: I) -> Result<libc::c_int, CreationError> - where I: Iterator<Item=(PixelFormat, libc::c_int)> + where I: Iterator<Item=(libc::c_int, PixelFormat)> { let mut backup_id = None; - for (format, id) in iter { + for (id, format) in iter { if backup_id.is_none() { backup_id = Some(id); } @@ -352,7 +352,7 @@ impl<'a> BuilderAttribs<'a> { } fn choose_pixel_format<T, I>(&self, iter: I) -> Result<(T, PixelFormat), CreationError> - where I: Iterator<Item=(T, PixelFormat)>, T: Clone + where I: IntoIterator<Item=(T, PixelFormat)>, T: Clone { let mut current_result = None; let mut current_software_result = None; |