Function create_window

native/linux/src/lib.rs:143–183

Returns (physical_w, physical_h). Caller's `width`/`height` are *logical*; on a HiDPI X11 display we multiply by the monitor's scale factor so the window appears the right size while its surface is at the screen's physical resolution. `headless = true` keeps the X11 window + Vulkan surface alive (wgpu needs a surface) but never maps the window — so it never appears on screen and never steals focu

(width: f64, height: f64, title: &str, headless: bool)

    /// appears on screen and never steals focus. Mirrors the macOS
    /// BLOOM_HEADLESS path for batch / CI rendering harnesses.
    pub fn create_window(width: f64, height: f64, title: &str, headless: bool) -> (u32, u32) {
        unsafe {
            HEADLESS = headless;
            DISPLAY = x11::xlib::XOpenDisplay(std::ptr::null());
            if DISPLAY.is_null() {
                panic!("Failed to open X11 display");
            }

            let screen = x11::xlib::XDefaultScreen(DISPLAY);
            let root = x11::xlib::XRootWindow(DISPLAY, screen);

            let scale = display_scale(DISPLAY, screen);
            let phys_w = (width * scale).round() as u32;
            let phys_h = (height * scale).round() as u32;

            // Off-screen origin is belt-and-braces: even if some WM
            // chooses to map the window despite us never calling
            // XMapWindow, it'll appear far off the visible desktop.
            let origin_x: i32 = if headless { -20000 } else { 0 };
            X11_WINDOW = x11::xlib::XCreateSimpleWindow(
                DISPLAY, root,
                origin_x, 0, phys_w, phys_h, 0,
                x11::xlib::XBlackPixel(DISPLAY, screen),
                x11::xlib::XWhitePixel(DISPLAY, screen),
            );

            let title_cstr = std::ffi::CString::new(title).unwrap();
            x11::xlib::XStoreName(DISPLAY, X11_WINDOW, title_cstr.as_ptr());

            x11::xlib::XSelectInput(DISPLAY, X11_WINDOW,
                x11::xlib::ExposureMask | x11::xlib::KeyPressMask | x11::xlib::KeyReleaseMask |
                x11::xlib::ButtonPressMask | x11::xlib::ButtonReleaseMask |
                x11::xlib::PointerMotionMask | x11::xlib::StructureNotifyMask);

            if !headless {
                x11::xlib::XMapWindow(DISPLAY, X11_WINDOW);
            }
            x11::xlib::XFlush(DISPLAY);
            (phys_w, phys_h)
        }
    }

    pub fn set_no_fullscreen(no_fs: bool) { unsafe { NO_FULLSCREEN = no_fs; } }
    pub fn is_headless() -> bool { unsafe { HEADLESS } }