Merge pull request Rust-SDL2#962 from lmcgrath/raw-window-handle

Support for raw-window-handle

Cargo.toml

@@ -30,6 +30,15 @@ optional = true
 
 [dev-dependencies]
 rand = "^0.7"
+wgpu = "^0.4.0"
+glsl-to-spirv = "^0.1.7"
+
+[target.'cfg(target_os = "macos")'.dev-dependencies.objc]
+version = "^0.2.7"
+
+[dependencies.raw-window-handle]
+version = "0.3.3"
+optional = true
 
 [features]
 
@@ -136,3 +145,7 @@ name = "ttf-demo"
 
 [[example]]
 name = "window-properties"
+
+[[example]]
+required-features = ["raw-window-handle"]
+name = "raw-window-handle-with-wgpu"

README.md

@@ -543,6 +543,28 @@ fn main() {
 
 ```
 
+# Support for raw-window-handle
+
+`raw-window-handle` can be enabled using the feature name:
+
+```toml
+[dependencies.sdl2]
+version = "0.32"
+features = ["raw-window-handle"]
+```
+
+An example working with [`wgpu`](https://crates.io/crates/wgpu) is also available:
+
+```bash
+cargo run --example raw-window-handle-with-wgpu --features raw-window-handle
+```
+
+### sdl2 with raw-window-handle on macOS:
+
+On macOS the `RawWindowHandle.ns_view` field is returned null. Libraries consuming the `RawWindowHandle` (such as 
+`wgpu`) should determine a sane default for `ns_view`. If they do not, please file an issue with the associated 
+project.
+
 # When things go wrong
 Rust, and Rust-SDL2, are both still heavily in development, and you may run
 into teething issues when using this. Before panicking, check that you're using

changelog.md

@@ -27,6 +27,9 @@ Ignore unknown bits in `SDL_Keysym`'s `mod` field (key modifiers) when construct
 [PR #898](https://github.com/Rust-SDL2/rust-sdl2/pull/898):
 Implements `TryFrom<PixelFormatEnum>` for `PixelFormat`
 
+[PR #962](https://github.com/Rust-SDL2/rust-sdl2/pull/962):
+Added `raw-window-handle` support for Windows, Linux (X11 and Wayland) and macOS.
+
 ### v0.32.2
 
 [PR #868](https://github.com/Rust-SDL2/rust-sdl2/pull/868):

examples/raw-window-handle-with-wgpu/main.rs

@@ -0,0 +1,191 @@
+/// Minimal example for getting sdl2 and wgpu working together with raw-window-handle.
+///
+/// TODO: update wgpu and this example after https://github.com/gfx-rs/wgpu/pull/462 ships
+
+extern crate glsl_to_spirv;
+extern crate libc;
+#[cfg(target_os = "macos")]
+extern crate objc;
+extern crate raw_window_handle;
+extern crate sdl2;
+extern crate wgpu;
+
+use raw_window_handle::{HasRawWindowHandle, RawWindowHandle};
+
+use sdl2::event::{Event, WindowEvent};
+use sdl2::keyboard::Keycode;
+use sdl2::video::Window;
+
+/// sdl2 implements raw-window-handle correctly, but wgpu does not for macOS
+/// wgpu wrongly expects an NSView to be provided by raw-window-handle, so we have to do a little more work
+struct WindowWrapper<'a>(pub &'a Window);
+
+unsafe impl<'a> HasRawWindowHandle for WindowWrapper<'a> {
+    #[cfg(not(target_os = "macos"))]
+    /// all non-mac platforms work correctly, so return the handle directly
+    fn raw_window_handle(&self) -> RawWindowHandle {
+        self.0.raw_window_handle()
+    }
+
+    #[cfg(target_os = "macos")]
+    /// do some work on macOS to get the root NSView for the NSWindow returned by sdl2
+    fn raw_window_handle(&self) -> RawWindowHandle {
+        use objc::{msg_send, sel, sel_impl};
+        use objc::runtime::Object;
+        use raw_window_handle::macos::MacOSHandle;
+        let handle = self.0.raw_window_handle();
+        match handle {
+            RawWindowHandle::MacOS(macos_handle) => {
+                RawWindowHandle::MacOS(MacOSHandle {
+                    ns_window: macos_handle.ns_window,
+                    ns_view: unsafe { msg_send![macos_handle.ns_window as *mut Object, contentView] },
+                    ..MacOSHandle::empty()
+                })
+            }
+            _ => unreachable!()
+        }
+    }
+}
+
+fn load_glsl(code: &str, ty: glsl_to_spirv::ShaderType) -> Result<Vec<u32>, String> {
+    let spirv = glsl_to_spirv::compile(&code, ty)?;
+    let result = wgpu::read_spirv(spirv).map_err(|e| e.to_string())?;
+    Ok(result)
+}
+
+fn main() -> Result<(), String> {
+    let sdl_context = sdl2::init()?;
+    let video_subsystem = sdl_context.video()?;
+    let window = video_subsystem
+        .window("Raw Window Handle Example", 800, 600)
+        .position_centered()
+        .resizable()
+        .build()
+        .map_err(|e| e.to_string())?;
+    let (width, height) = window.size();
+
+    let adapter_opt = wgpu::Adapter::request(&wgpu::RequestAdapterOptions {
+        power_preference: wgpu::PowerPreference::Default,
+        backends: wgpu::BackendBit::PRIMARY,
+    });
+    let adapter = match adapter_opt {
+        Some(a) => a,
+        None => return Err(String::from("No adapter found")),
+    };
+
+    let (device, mut queue) = adapter.request_device(&wgpu::DeviceDescriptor {
+        extensions: wgpu::Extensions {
+            anisotropic_filtering: false,
+        },
+        limits: wgpu::Limits::default(),
+    });
+
+    let vs = include_str!("shader.vert");
+    let vs_spirv = &load_glsl(vs, glsl_to_spirv::ShaderType::Vertex)?;
+    let vs_module = device.create_shader_module(vs_spirv);
+
+    let fs = include_str!("shader.frag");
+    let fs_spirv = &load_glsl(fs, glsl_to_spirv::ShaderType::Fragment)?;
+    let fs_module = device.create_shader_module(fs_spirv);
+
+    let bind_group_layout = device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor { bindings: &[] });
+    let bind_group = device.create_bind_group(&wgpu::BindGroupDescriptor {
+        layout: &bind_group_layout,
+        bindings: &[],
+    });
+    let pipeline_layout = device.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor {
+        bind_group_layouts: &[&bind_group_layout],
+    });
+
+    let render_pipeline = device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
+        layout: &pipeline_layout,
+        vertex_stage: wgpu::ProgrammableStageDescriptor {
+            module: &vs_module,
+            entry_point: "main",
+        },
+        fragment_stage: Some(wgpu::ProgrammableStageDescriptor {
+            module: &fs_module,
+            entry_point: "main",
+        }),
+        rasterization_state: Some(wgpu::RasterizationStateDescriptor {
+            front_face: wgpu::FrontFace::Ccw,
+            cull_mode: wgpu::CullMode::None,
+            depth_bias: 0,
+            depth_bias_slope_scale: 0.0,
+            depth_bias_clamp: 0.0,
+        }),
+        primitive_topology: wgpu::PrimitiveTopology::TriangleList,
+        color_states: &[wgpu::ColorStateDescriptor {
+            format: wgpu::TextureFormat::Bgra8UnormSrgb,
+            color_blend: wgpu::BlendDescriptor::REPLACE,
+            alpha_blend: wgpu::BlendDescriptor::REPLACE,
+            write_mask: wgpu::ColorWrite::ALL,
+        }],
+        depth_stencil_state: None,
+        index_format: wgpu::IndexFormat::Uint16,
+        vertex_buffers: &[],
+        sample_count: 1,
+        sample_mask: !0,
+        alpha_to_coverage_enabled: false,
+    });
+
+    // use the WindowWrapper to make sure wgpu will work on macOS
+    let surface = wgpu::Surface::create(&WindowWrapper(&window));
+
+    let mut sc_desc = wgpu::SwapChainDescriptor {
+        usage: wgpu::TextureUsage::OUTPUT_ATTACHMENT,
+        format: wgpu::TextureFormat::Bgra8UnormSrgb,
+        width,
+        height,
+        present_mode: wgpu::PresentMode::Vsync,
+    };
+
+    let mut swap_chain = device.create_swap_chain(&surface, &sc_desc);
+
+    let mut event_pump = sdl_context.event_pump()?;
+    'running: loop {
+        for event in event_pump.poll_iter() {
+            match event {
+                Event::Window {
+                    win_event: WindowEvent::Resized(width, height),
+                    ..
+                } => {
+                    sc_desc.width = width as u32;
+                    sc_desc.height = height as u32;
+                    swap_chain = device.create_swap_chain(&surface, &sc_desc);
+                }
+                Event::Quit { .. }
+                | Event::KeyDown {
+                    keycode: Some(Keycode::Escape),
+                    ..
+                } => {
+                    break 'running;
+                }
+                _ => {}
+            }
+        }
+
+        let frame = swap_chain.get_next_texture();
+        let mut encoder =
+            device.create_command_encoder(&wgpu::CommandEncoderDescriptor { todo: 0 });
+        {
+            let mut rpass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
+                color_attachments: &[wgpu::RenderPassColorAttachmentDescriptor {
+                    attachment: &frame.view,
+                    resolve_target: None,
+                    load_op: wgpu::LoadOp::Clear,
+                    store_op: wgpu::StoreOp::Store,
+                    clear_color: wgpu::Color::GREEN,
+                }],
+                depth_stencil_attachment: None,
+            });
+            rpass.set_pipeline(&render_pipeline);
+            rpass.set_bind_group(0, &bind_group, &[]);
+            rpass.draw(0 .. 3, 0 .. 1);
+        }
+
+        queue.submit(&[encoder.finish()]);
+    }
+
+    Ok(())
+}

examples/raw-window-handle-with-wgpu/shader.frag

@@ -0,0 +1,7 @@
+#version 450
+
+layout(location = 0) out vec4 outColor;
+
+void main() {
+    outColor = vec4(1.0, 0.0, 0.0, 1.0);
+}

examples/raw-window-handle-with-wgpu/shader.vert

@@ -0,0 +1,15 @@
+#version 450
+
+out gl_PerVertex {
+    vec4 gl_Position;
+};
+
+const vec2 positions[3] = vec2[3](
+    vec2(0.0, -0.5),
+    vec2(0.5, 0.5),
+    vec2(-0.5, 0.5)
+);
+
+void main() {
+    gl_Position = vec4(positions[gl_VertexIndex], 0.0, 1.0);
+}

src/sdl2/lib.rs

@@ -103,3 +103,6 @@ pub mod gfx;
 mod common;
 // Export return types and such from the common module.
 pub use crate::common::IntegerOrSdlError;
+
+#[cfg(feature = "raw-window-handle")]
+pub mod raw_window_handle;