As the popularity of the library minifb shows, it is useful to put a 2D buffer/image on a window in a platform-independent way. Minifb's approach to doing window management itself, however, is problematic code duplication. We already have very high quality libraries for this in the Rust ecosystem (such as winit), and minifb's implementation of window management is not ideal. For example, it occasionally segfaults on some platforms and is missing key features such as the ability to set a window icon. While it would be possible to add these features to minifb, it makes more sense to instead use the standard window handling systems.

Softbuffer integrates with the raw-window-handle crate to allow writing to a window in a cross-platform way while using the very high quality dedicated window management libraries that are available in the Rust ecosystem.

What about pixels? Pixels accomplishes a very similar goal to softbuffer, however there are two key differences. Pixels provides some capacity for GPU-accelerated post-processing of what is displayed, while Softbuffer does not. Due to not having this post-processing, Softbuffer does not rely on the GPU or hardware accelerated graphics stack in any way, and is thus more portable to installations that do not have access to hardware acceleration (e.g. VMs, older computers, computers with misconfigured drivers). Softbuffer should be used over pixels when its GPU-accelerated post-processing effects are not needed.

This library is dual-licensed under MIT or Apache-2.0, just like minifb and rust. Significant portions of code were taken from the minifb library to do platform-specific work.

Some, but not all, platforms supported in raw-window-handle are supported by Softbuffer. Pull requests are welcome to add new platforms! Nonetheless, all major desktop platforms that winit uses on desktop are supported.

For now, the priority for new platforms is:

1. to have at least one platform on each OS working (e.g. one of Win32 or WinRT, or one of Xlib, Xcb, and Wayland) and
2. for that one platform on each OS to be the one that winit uses.

(PRs will be accepted for any platform, even if it does not follow the above priority.)

✅: Present | ❌: Absent

• AndroidNdk ❌
• AppKit ✅ (Thanks to Seo Sanghyeon and lunixbochs!)
• Orbital ❌
• UiKit ❌
• Wayland ✅ (Wayland support in winit is immature at the moment, so it might be wise to force X11 if you're using winit)
• Web ✅ (Thanks to Liamolucko!)
• Win32 ✅
• WinRt ❌
• Xcb ❌
• Xlib ✅

use softbuffer::GraphicsContext;
use winit::event::{Event, WindowEvent};
use winit::event_loop::{ControlFlow, EventLoop};
use winit::window::WindowBuilder;

fn main() {
    let event_loop = EventLoop::new();
    let window = WindowBuilder::new().build(&event_loop).unwrap();
    let mut graphics_context = unsafe { GraphicsContext::new(window) }.unwrap();

    event_loop.run(move |event, _, control_flow| {
        *control_flow = ControlFlow::Wait;

        match event {
            Event::RedrawRequested(window_id) if window_id == graphics_context.window().id() => {
                let (width, height) = {
                    let size = graphics_context.window().inner_size();
                    (size.width, size.height)
                };
                let buffer = (0..((width * height) as usize))
                    .map(|index| {
                        let y = index / (width as usize);
                        let x = index % (width as usize);
                        let red = x % 255;
                        let green = y % 255;
                        let blue = (x * y) % 255;

                        let color = blue | (green << 8) | (red << 16);

                        color as u32
                    })
                    .collect::<Vec<_>>();

                graphics_context.set_buffer(&buffer, width as u16, height as u16);
            }
            Event::WindowEvent {
                event: WindowEvent::CloseRequested,
                window_id,
            } if window_id == graphics_context.window().id() => {
                *control_flow = ControlFlow::Exit;
            }
            _ => {}
        }
    });
}

See git tags for associated commits.

• Added WASM support (Thanks to Liamolucko!)
• CALayer is now used for Mac OS backend, which is more flexible about what happens in the windowing library (Thanks to lunixbochs!)

Initial published version with support for Linux (X11 and Wayland), Mac OS (but buggy), and WIndows.