Android backend

.github/CODEOWNERS

@@ -1,3 +1,6 @@
+# Android
+/src/android.rs     @MarijnS95
+
 # Apple platforms
 /src/cg.rs          @madsmtm
 

CHANGELOG.md

@@ -73,38 +73,38 @@
 
 # 0.3.0
 
-* On MacOS, the contents scale is updated when set_buffer() is called, to adapt when the window is on a new screen (#68).
-* **Breaking:** Split the `GraphicsContext` type into `Context` and `Surface` (#64).
-* On Web, cache the document in the `Context` type (#66).
-* **Breaking:** Introduce a new "owned buffer" for no-copy presentation (#65).
-* Enable support for multi-threaded WASM (#77).
-* Fix buffer resizing on X11 (#69).
-* Add a set of functions for handling buffer damage (#99).
-* Add a `fetch()` function for getting the window contents (#104).
-* Bump MSRV to 1.64 (#81).
+- On MacOS, the contents scale is updated when set_buffer() is called, to adapt when the window is on a new screen (#68).
+- **Breaking:** Split the `GraphicsContext` type into `Context` and `Surface` (#64).
+- On Web, cache the document in the `Context` type (#66).
+- **Breaking:** Introduce a new "owned buffer" for no-copy presentation (#65).
+- Enable support for multi-threaded WASM (#77).
+- Fix buffer resizing on X11 (#69).
+- Add a set of functions for handling buffer damage (#99).
+- Add a `fetch()` function for getting the window contents (#104).
+- Bump MSRV to 1.64 (#81).
 
 # 0.2.1
 
-* Bump `windows-sys` to 0.48
+- Bump `windows-sys` to 0.48
 
 # 0.2.0
 
-* Add support for Redox/Orbital.
-* Add support for BSD distributions.
-* Ported Windows backend from `winapi` to `windows-sys`.
-* **Breaking:** Take a reference to a window instead of owning the window.
-* Add a `from_raw` function for directly using raw handles.
-* Improvements for Wayland support.
-* Support for HiDPI on macOS.
-* **Breaking:** Add feature flags for `x11` and `wayland` backends.
-* Use static dispatch instead of dynamic dispatch for the backends.
-* Add `libxcb` support to the X11 backend.
-* Use X11 MIT-SHM extension, if available.
+- Add support for Redox/Orbital.
+- Add support for BSD distributions.
+- Ported Windows backend from `winapi` to `windows-sys`.
+- **Breaking:** Take a reference to a window instead of owning the window.
+- Add a `from_raw` function for directly using raw handles.
+- Improvements for Wayland support.
+- Support for HiDPI on macOS.
+- **Breaking:** Add feature flags for `x11` and `wayland` backends.
+- Use static dispatch instead of dynamic dispatch for the backends.
+- Add `libxcb` support to the X11 backend.
+- Use X11 MIT-SHM extension, if available.
 
 # 0.1.1
 
-* Added WASM support (Thanks to [Liamolucko](https://github.com/Liamolucko)!)
-* CALayer is now used for Mac OS backend, which is more flexible about what happens in the windowing library (Thanks to [lunixbochs](https://github.com/lunixbochs)!)
+- Added WASM support (Thanks to [Liamolucko](https://github.com/Liamolucko)!)
+- CALayer is now used for Mac OS backend, which is more flexible about what happens in the windowing library (Thanks to [lunixbochs](https://github.com/lunixbochs)!)
 
 # 0.1.0
 

Cargo.toml

@@ -28,6 +28,10 @@ x11-dlopen = ["tiny-xlib/dlopen", "x11rb/dl-libxcb"]
 log = "0.4.17"
 raw_window_handle = { package = "raw-window-handle", version = "0.6", features = ["std"] }
 
+[target.'cfg(target_os = "android")'.dependencies]
+bytemuck = "1.12.3"
+ndk = "0.9.0"
+
 [target.'cfg(all(unix, not(any(target_vendor = "apple", target_os = "android", target_os = "redox"))))'.dependencies]
 as-raw-xcb-connection = { version = "1.0.0", optional = true }
 bytemuck = { version = "1.12.3", optional = true }
@@ -89,6 +93,10 @@ criterion = { version = "0.4.0", default-features = false, features = ["cargo_be
 web-time = "1.0.0"
 winit = "0.30.0"
 
+[target.'cfg(target_os = "android")'.dev-dependencies]
+winit = { version = "0.30.0", features = ["android-native-activity"] }
+android-activity = "0.6"
+
 [dev-dependencies.image]
 version = "0.25.0"
 # Disable rayon on web
@@ -110,6 +118,16 @@ members = [
     "run-wasm",
 ]
 
+[[example]]
+# Run with `cargo apk r --example winit_android`
+name = "winit_android"
+crate-type = ["cdylib"]
+
+[[example]]
+# Run with `cargo apk r --example winit_multithread_android`
+name = "winit_multithread_android"
+crate-type = ["cdylib"]
+
 [package.metadata.docs.rs]
 all-features = true
 rustdoc-args = ["--cfg", "docsrs"]

README.md

@@ -1,14 +1,12 @@
-Overview
-==
+# Softbuffer
 
 Enables software rendering via drawing an image straight to a window.
 
 Softbuffer integrates with the [`raw-window-handle`](https://crates.io/crates/raw-window-handle) crate
 to allow writing pixels 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.
 
-Alternatives
-==
+## Alternatives
 
 [minifb](https://crates.io/crates/minifb) also allows putting 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
@@ -24,27 +22,27 @@
 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.
 
-License & Credits
-==
+## License & Credits
 
 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.
 
-Platform support:
-==
+## Platform support:
+
 Some, but not all, platforms supported in [raw-window-handle](https://crates.io/crates/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.
+
+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.)
 
 |  Platform ||
 |-----------|--|
-|Android NDK|❌|
+|Android NDK|✅|
 |   AppKit  |✅|
 |  Orbital  |✅|
 |    UIKit  |✅|
@@ -59,13 +57,16 @@
 ❔: Immature\
 ❌: Absent
 
-WebAssembly
------------
+## WebAssembly
 
 To run an example with the web backend: `cargo run-wasm --example winit`
 
-Example
-==
+## Android
+
+To run the Android-specific example on an Android phone: `cargo apk r --example winit_android` or `cargo apk r --example winit_multithread_android`.
+
+## Example
+
 ```rust,no_run
 use std::num::NonZeroU32;
 use std::rc::Rc;
@@ -75,25 +76,31 @@
 
 #[path = "../examples/utils/winit_app.rs"]
 mod winit_app;
 
 fn main() {
     let event_loop = EventLoop::new().unwrap();
 
-    let mut app = winit_app::WinitAppBuilder::with_init(|elwt| {
-        let window = {
-            let window = elwt.create_window(Window::default_attributes());
-            Rc::new(window.unwrap())
-        };
-        let context = softbuffer::Context::new(window.clone()).unwrap();
-        let surface = softbuffer::Surface::new(&context, window.clone()).unwrap();
-
-        (window, surface)
-    }).with_event_handler(|state, event, elwt| {
-        let (window, surface) = state;
+    let mut app = winit_app::WinitAppBuilder::with_init(
+        |elwt| {
+            let window = {
+                let window = elwt.create_window(Window::default_attributes());
+                Rc::new(window.unwrap())
+            };
+            let context = softbuffer::Context::new(window.clone()).unwrap();
+
+            (window, context)
+        },
+        |_elwt, (window, context)| softbuffer::Surface::new(context, window.clone()).unwrap(),
+    )
+    .with_event_handler(|(window, _context), surface, event, elwt| {
         elwt.set_control_flow(ControlFlow::Wait);
 
         match event {
             Event::WindowEvent { window_id, event: WindowEvent::RedrawRequested } if window_id == window.id() => {
+                let Some(surface) = surface else {
+                    eprintln!("RedrawRequested fired before Resumed or after Suspended");
+                    return;
+                };
                 let (width, height) = {
                     let size = window.inner_size();
                     (size.width, size.height)
@@ -132,8 +139,8 @@
 }
 ```
 
-MSRV Policy
-==
+## MSRV Policy
+
 This crate's Minimum Supported Rust Version (MSRV) is **1.70**. Changes to
 the MSRV will be accompanied by a minor version bump.
 
@@ -157,7 +164,6 @@
 
 [`rust-windowing`]: https://github.com/rust-windowing
 
-Changelog
----------
+## Changelog
 
 See the [changelog](CHANGELOG.md) for a list of this package's versions and the changes made in each version.

examples/animation.rs

@@ -14,19 +14,23 @@ fn main() {
     let event_loop = EventLoop::new().unwrap();
     let start = Instant::now();
 
-    let app = winit_app::WinitAppBuilder::with_init(|event_loop| {
-        let window = winit_app::make_window(event_loop, |w| w);
+    let app = winit_app::WinitAppBuilder::with_init(
+        |event_loop| {
+            let window = winit_app::make_window(event_loop, |w| w);
 
-        let context = softbuffer::Context::new(window.clone()).unwrap();
-        let surface = softbuffer::Surface::new(&context, window.clone()).unwrap();
+            let context = softbuffer::Context::new(window.clone()).unwrap();
 
-        let old_size = (0, 0);
-        let frames = pre_render_frames(0, 0);
+            let old_size = (0, 0);
+            let frames = pre_render_frames(0, 0);
 
-        (window, surface, old_size, frames)
-    })
-    .with_event_handler(move |state, event, elwt| {
-        let (window, surface, old_size, frames) = state;
+            (window, context, old_size, frames)
+        },
+        |_elwft, (window, context, _old_size, _frames)| {
+            softbuffer::Surface::new(context, window.clone()).unwrap()
+        },
+    )
+    .with_event_handler(move |state, surface, event, elwt| {
+        let (window, _context, old_size, frames) = state;
 
         elwt.set_control_flow(ControlFlow::Poll);
 
@@ -35,6 +39,11 @@ fn main() {
                 window_id,
                 event: WindowEvent::Resized(size),
             } if window_id == window.id() => {
+                let Some(surface) = surface else {
+                    eprintln!("Resized fired before Resumed or after Suspended");
+                    return;
+                };
+
                 if let (Some(width), Some(height)) =
                     (NonZeroU32::new(size.width), NonZeroU32::new(size.height))
                 {
@@ -45,6 +54,11 @@ fn main() {
                 window_id,
                 event: WindowEvent::RedrawRequested,
             } if window_id == window.id() => {
+                let Some(surface) = surface else {
+                    eprintln!("RedrawRequested fired before Resumed or after Suspended");
+                    return;
+                };
+
                 let size = window.inner_size();
                 if let (Some(width), Some(height)) =
                     (NonZeroU32::new(size.width), NonZeroU32::new(size.height))

examples/fruit.rs

@@ -14,35 +14,44 @@ fn main() {
 
     let event_loop = EventLoop::new().unwrap();
 
-    let app = winit_app::WinitAppBuilder::with_init(move |elwt| {
-        let window = winit_app::make_window(elwt, |w| {
-            w.with_inner_size(winit::dpi::PhysicalSize::new(width, height))
-        });
+    let app = winit_app::WinitAppBuilder::with_init(
+        move |elwt| {
+            let window = winit_app::make_window(elwt, |w| {
+                w.with_inner_size(winit::dpi::PhysicalSize::new(width, height))
+            });
 
-        let context = softbuffer::Context::new(window.clone()).unwrap();
-        let mut surface = softbuffer::Surface::new(&context, window.clone()).unwrap();
+            let context = softbuffer::Context::new(window.clone()).unwrap();
 
-        // Intentionally only set the size of the surface once, at creation.
-        // This is needed if the window chooses to ignore the size we passed in above, and for the
-        // platforms softbuffer supports that don't yet extract the size from the window.
-        surface
-            .resize(
-                NonZeroU32::new(width).unwrap(),
-                NonZeroU32::new(height).unwrap(),
-            )
-            .unwrap();
-
-        (window, surface)
-    })
-    .with_event_handler(move |state, event, elwt| {
-        let (window, surface) = state;
+            (window, context)
+        },
+        move |_elwt, (window, context)| {
+            let mut surface = softbuffer::Surface::new(context, window.clone()).unwrap();
+            // Intentionally only set the size of the surface once, at creation.
+            // This is needed if the window chooses to ignore the size we passed in above, and for the
+            // platforms softbuffer supports that don't yet extract the size from the window.
+            surface
+                .resize(
+                    NonZeroU32::new(width).unwrap(),
+                    NonZeroU32::new(height).unwrap(),
+                )
+                .unwrap();
+            surface
+        },
+    )
+    .with_event_handler(move |state, surface, event, elwt| {
+        let (window, _context) = state;
         elwt.set_control_flow(ControlFlow::Wait);
 
         match event {
             Event::WindowEvent {
                 window_id,
                 event: WindowEvent::RedrawRequested,
             } if window_id == window.id() => {
+                let Some(surface) = surface else {
+                    eprintln!("RedrawRequested fired before Resumed or after Suspended");
+                    return;
+                };
+
                 let mut buffer = surface.buffer_mut().unwrap();
                 let width = fruit.width() as usize;
                 for (x, y, pixel) in fruit.pixels() {