Several WGL cleanups

This commit is contained in:
Pierre Krieger 2015-05-22 11:54:28 +02:00
parent e5f888e19a
commit ead31e3ef8
2 changed files with 183 additions and 153 deletions

View file

@ -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 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()))));
}
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;
}
WindowWrapper(handle, hdc)
};
// 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
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
})
};
// 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
};
// creating the OpenGL context
let context = try!(create_context(Some((&extra_functions, builder)), window, hdc,
builder_sharelists));
// 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));
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,
})
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;
}
// loading the functions that are not guaranteed to be supported
let extra_functions = try!(load_extra_functions(window));
// 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()
} 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()
} 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
}
} else {
enumerate_native_pixel_formats(hdc)
};
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, &extensions)),
window, hdc, builder_sharelists));
// loading the opengl32 module
let gl_library = try!(load_opengl32_dll());
// 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")));
}
}
}
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);
} 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()
// 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
};
} else {
return false;
// 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()))));
}
// 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()))));
}
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);
}

View file

@ -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;