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-rw-r--r--src/api/wgl/mod.rs308
1 files changed, 169 insertions, 139 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);
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-24 12:44:13 +0000