aboutsummaryrefslogtreecommitdiffstats
path: root/src/api/wgl/mod.rs
diff options
context:
space:
mode:
Diffstat (limited to 'src/api/wgl/mod.rs')
-rw-r--r--src/api/wgl/mod.rs537
1 files changed, 537 insertions, 0 deletions
diff --git a/src/api/wgl/mod.rs b/src/api/wgl/mod.rs
new file mode 100644
index 0000000..d1f42d2
--- /dev/null
+++ b/src/api/wgl/mod.rs
@@ -0,0 +1,537 @@
+#![cfg(any(target_os = "windows"))]
+
+use BuilderAttribs;
+use CreationError;
+use GlContext;
+use GlRequest;
+use GlProfile;
+use PixelFormat;
+use Api;
+
+use self::make_current_guard::CurrentContextGuard;
+
+use libc;
+use std::ffi::{CStr, CString, OsStr};
+use std::os::windows::ffi::OsStrExt;
+use std::{mem, ptr};
+use std::io;
+
+use winapi;
+use kernel32;
+use user32;
+use gdi32;
+
+mod make_current_guard;
+mod gl;
+
+/// A WGL context.
+///
+/// Note: should be destroyed before its window.
+pub struct Context {
+ context: ContextWrapper,
+
+ hdc: winapi::HDC,
+
+ /// Binded to `opengl32.dll`.
+ ///
+ /// `wglGetProcAddress` returns null for GL 1.1 functions because they are
+ /// already defined by the system. This module contains them.
+ gl_library: winapi::HMODULE,
+
+ /// The pixel format that has been used to create this context.
+ pixel_format: PixelFormat,
+}
+
+/// A simple wrapper that destroys the window when it is destroyed.
+struct WindowWrapper(winapi::HWND, winapi::HDC);
+
+impl Drop for WindowWrapper {
+ fn drop(&mut self) {
+ unsafe {
+ user32::DestroyWindow(self.0);
+ }
+ }
+}
+
+/// Wraps around a context so that it is destroyed when necessary.
+struct ContextWrapper(winapi::HGLRC);
+
+impl Drop for ContextWrapper {
+ fn drop(&mut self) {
+ unsafe {
+ gl::wgl::DeleteContext(self.0 as *const _);
+ }
+ }
+}
+
+impl Context {
+ /// Attempt to build a new WGL context on a window.
+ ///
+ /// The window must **not** have had `SetPixelFormat` called on it.
+ ///
+ /// # 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>
+ {
+ 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.
+ pub fn get_hglrc(&self) -> winapi::HGLRC {
+ self.context.0
+ }
+}
+
+impl GlContext for Context {
+ unsafe fn make_current(&self) {
+ // TODO: check return value
+ gl::wgl::MakeCurrent(self.hdc as *const _, self.context.0 as *const _);
+ }
+
+ fn is_current(&self) -> bool {
+ unsafe { gl::wgl::GetCurrentContext() == self.context.0 as *const libc::c_void }
+ }
+
+ fn get_proc_address(&self, addr: &str) -> *const libc::c_void {
+ let addr = CString::new(addr.as_bytes()).unwrap();
+ let addr = addr.as_ptr();
+
+ unsafe {
+ let p = gl::wgl::GetProcAddress(addr) as *const _;
+ if !p.is_null() { return p; }
+ kernel32::GetProcAddress(self.gl_library, addr) as *const _
+ }
+ }
+
+ fn swap_buffers(&self) {
+ unsafe {
+ gdi32::SwapBuffers(self.hdc);
+ }
+ }
+
+ fn get_api(&self) -> Api {
+ // FIXME: can be opengl es
+ Api::OpenGl
+ }
+
+ fn get_pixel_format(&self) -> PixelFormat {
+ self.pixel_format.clone()
+ }
+}
+
+unsafe impl Send for Context {}
+unsafe impl Sync for Context {}
+
+/// 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, extensions)) = extra {
+ if extensions.split(' ').find(|&i| i == "WGL_ARB_create_context").is_some() {
+ let mut attributes = Vec::new();
+
+ match builder.gl_version {
+ GlRequest::Latest => {},
+ GlRequest::Specific(Api::OpenGl, (major, minor)) => {
+ attributes.push(gl::wgl_extra::CONTEXT_MAJOR_VERSION_ARB as libc::c_int);
+ attributes.push(major as libc::c_int);
+ attributes.push(gl::wgl_extra::CONTEXT_MINOR_VERSION_ARB as libc::c_int);
+ attributes.push(minor as libc::c_int);
+ },
+ GlRequest::Specific(Api::OpenGlEs, (major, minor)) => {
+ 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);
+ } else {
+ return Err(CreationError::NotSupported);
+ }
+
+ attributes.push(gl::wgl_extra::CONTEXT_MAJOR_VERSION_ARB as libc::c_int);
+ attributes.push(major as libc::c_int);
+ attributes.push(gl::wgl_extra::CONTEXT_MINOR_VERSION_ARB as libc::c_int);
+ attributes.push(minor as libc::c_int);
+ },
+ GlRequest::Specific(_, _) => return Err(CreationError::NotSupported),
+ GlRequest::GlThenGles { opengl_version: (major, minor), .. } => {
+ attributes.push(gl::wgl_extra::CONTEXT_MAJOR_VERSION_ARB as libc::c_int);
+ attributes.push(major as libc::c_int);
+ attributes.push(gl::wgl_extra::CONTEXT_MINOR_VERSION_ARB as libc::c_int);
+ attributes.push(minor as libc::c_int);
+ },
+ }
+
+ if let Some(profile) = builder.gl_profile {
+ if extensions.split(' ').find(|&i| i == "WGL_ARB_create_context_profile").is_some()
+ {
+ let flag = match profile {
+ GlProfile::Compatibility =>
+ gl::wgl_extra::CONTEXT_COMPATIBILITY_PROFILE_BIT_ARB,
+ GlProfile::Core =>
+ gl::wgl_extra::CONTEXT_CORE_PROFILE_BIT_ARB,
+ };
+ attributes.push(gl::wgl_extra::CONTEXT_PROFILE_MASK_ARB as libc::c_int);
+ attributes.push(flag as libc::c_int);
+ } else {
+ return Err(CreationError::NotSupported);
+ }
+ }
+
+ 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);
+ }
+
+ attributes.push(0);
+
+ Some(extra_functions.CreateContextAttribsARB(hdc as *const libc::c_void,
+ share as *const libc::c_void,
+ attributes.as_ptr()))
+
+ } else {
+ None
+ }
+ } else {
+ None
+ };
+
+ let ctxt = match ctxt {
+ Some(ctxt) => ctxt,
+ None => {
+ let ctxt = gl::wgl::CreateContext(hdc as *const libc::c_void);
+ if !ctxt.is_null() && !share.is_null() {
+ gl::wgl::ShareLists(share as *const libc::c_void, ctxt);
+ };
+ ctxt
+ }
+ };
+
+ if ctxt.is_null() {
+ return Err(CreationError::OsError(format!("OpenGL context creation failed: {}",
+ format!("{}", io::Error::last_os_error()))));
+ }
+
+ Ok(ContextWrapper(ctxt as winapi::HGLRC))
+}
+
+/// 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());
+
+ let mut result = Vec::new();
+
+ for index in (0 .. num) {
+ let mut output: winapi::PIXELFORMATDESCRIPTOR = mem::zeroed();
+
+ if gdi32::DescribePixelFormat(hdc, index, size_of_pxfmtdescr, &mut output) == 0 {
+ continue;
+ }
+
+ if (output.dwFlags & winapi::PFD_DRAW_TO_WINDOW) == 0 {
+ continue;
+ }
+
+ if (output.dwFlags & winapi::PFD_SUPPORT_OPENGL) == 0 {
+ continue;
+ }
+
+ if output.iPixelType != winapi::PFD_TYPE_RGBA {
+ continue;
+ }
+
+ 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,
+ depth_bits: output.cDepthBits,
+ stencil_bits: output.cStencilBits,
+ stereoscopy: (output.dwFlags & winapi::PFD_STEREO) != 0,
+ double_buffer: (output.dwFlags & winapi::PFD_DOUBLEBUFFER) != 0,
+ multisampling: None,
+ srgb: false,
+ }));
+ }
+
+ result
+}
+
+/// 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();
+ extra.GetPixelFormatAttribivARB(hdc as *const _, index as libc::c_int,
+ 0, 1, [attrib as libc::c_int].as_ptr(),
+ &mut value);
+ value as u32
+ };
+
+ // getting the number of formats
+ // the `1` is ignored
+ let num = get_info(1, gl::wgl_extra::NUMBER_PIXEL_FORMATS_ARB);
+
+ let mut result = Vec::new();
+
+ for index in (0 .. num) {
+ if get_info(index, gl::wgl_extra::DRAW_TO_WINDOW_ARB) == 0 {
+ continue;
+ }
+ if get_info(index, gl::wgl_extra::SUPPORT_OPENGL_ARB) == 0 {
+ continue;
+ }
+
+ if get_info(index, gl::wgl_extra::ACCELERATION_ARB) == gl::wgl_extra::NO_ACCELERATION_ARB {
+ continue;
+ }
+
+ if get_info(index, gl::wgl_extra::PIXEL_TYPE_ARB) != gl::wgl_extra::TYPE_RGBA_ARB {
+ continue;
+ }
+
+ 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 +
+ get_info(index, gl::wgl_extra::BLUE_BITS_ARB) as u8,
+ alpha_bits: get_info(index, gl::wgl_extra::ALPHA_BITS_ARB) as u8,
+ depth_bits: get_info(index, gl::wgl_extra::DEPTH_BITS_ARB) as u8,
+ stencil_bits: get_info(index, gl::wgl_extra::STENCIL_BITS_ARB) as u8,
+ stereoscopy: get_info(index, gl::wgl_extra::STEREO_ARB) != 0,
+ double_buffer: get_info(index, gl::wgl_extra::DOUBLE_BUFFER_ARB) != 0,
+ multisampling: {
+ 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),
+ }
+ } else {
+ None
+ }
+ },
+ 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 extensions.split(' ').find(|&i| i == "WGL_EXT_framebuffer_sRGB").is_some() {
+ get_info(index, gl::wgl_extra::FRAMEBUFFER_SRGB_CAPABLE_EXT) != 0
+ } else {
+ false
+ },
+ }));
+ }
+
+ 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();
+
+ if gdi32::DescribePixelFormat(hdc, id, mem::size_of::<winapi::PIXELFORMATDESCRIPTOR>()
+ as winapi::UINT, &mut output) == 0
+ {
+ return Err(CreationError::OsError(format!("DescribePixelFormat function failed: {}",
+ format!("{}", io::Error::last_os_error()))));
+ }
+
+ if gdi32::SetPixelFormat(hdc, id, &output) == 0 {
+ return Err(CreationError::OsError(format!("SetPixelFormat function failed: {}",
+ format!("{}", io::Error::last_os_error()))));
+ }
+
+ 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<_>>();
+
+ let lib = kernel32::LoadLibraryW(name.as_ptr());
+
+ if lib.is_null() {
+ return Err(CreationError::OsError(format!("LoadLibrary function failed: {}",
+ format!("{}", io::Error::last_os_error()))));
+ }
+
+ Ok(lib)
+}
+
+/// 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()))));
+ }
+
+ // 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)
+ };
+
+ // 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=(libc::c_int, PixelFormat)>
+{
+ let mut backup_id = None;
+
+ for (id, format) in iter {
+ if backup_id.is_none() {
+ backup_id = Some(id);
+ }
+
+ if format.hardware_accelerated {
+ return Ok(id);
+ }
+ }
+
+ backup_id.ok_or(CreationError::NotSupported)
+}
generated by cgit v1.2.3 (git 2.39.1) at 2025-03-04 02:18:33 +0000