Add ContextDesc::device_id to force adapter selection

blade-graphics/src/lib.rs

@@ -104,6 +104,8 @@ pub struct ContextDesc {
     pub capture: bool,
     /// Enable GAPI overlay.
     pub overlay: bool,
+    /// Force selection of a specific Device ID, unless 0.
+    pub device_id: u32,
 }
 
 #[derive(Debug)]

blade-graphics/src/metal/mod.rs

@@ -418,6 +418,9 @@ impl Context {
         if desc.overlay {
             std::env::set_var("MTL_HUD_ENABLED", "1");
         }
+        if desc.device_id != 0 {
+            log::warn!("Unable to filter devices by ID");
+        }
 
         let device = metal::Device::system_default()
             .ok_or(super::NotSupportedError::NoSupportedDeviceFound)?;

blade-graphics/src/vulkan/init.rs

@@ -89,6 +89,11 @@ unsafe fn inspect_adapter(
     let name = ffi::CStr::from_ptr(properties.device_name.as_ptr());
     log::info!("Adapter: {:?}", name);
 
+    if desc.device_id != 0 && desc.device_id != properties.device_id {
+        log::info!("Rejected device ID 0x{:X}", properties.device_id);
+        return None;
+    }
+
     let api_version = properties.api_version.min(driver_api_version);
     if api_version < vk::API_VERSION_1_1 {
         log::warn!("\tRejected for API version {}", api_version);

docs/CHANGELOG.md

@@ -10,6 +10,7 @@ Changelog for Blade
   - every pass now takes a label
   - automatic GPU pass markers
   - ability to capture pass GPU timings
+  - ability to force the use of a specific GPU
   - Metal:
     - support for workgroup memory
     - concurrent compute dispatches

examples/bunnymark/main.rs

@@ -83,6 +83,7 @@
                 timing: false,
                 capture: false,
                 overlay: true,
+                device_id: 0,
             })
             .unwrap()
         };
@@ -365,7 +366,7 @@
     let window_attributes =
         winit::window::Window::default_attributes().with_title("blade-bunnymark");
 
     let window = event_loop.create_window(window_attributes).unwrap();
 
     #[cfg(target_arch = "wasm32")]
     {
@@ -394,7 +395,7 @@
     let mut frame_count = 0;
 
     event_loop
         .run(|event, target| {
             target.set_control_flow(winit::event_loop::ControlFlow::Poll);
             match event {
                 winit::event::Event::AboutToWait => {

examples/particle/main.rs

@@ -22,7 +22,7 @@
                 validation: cfg!(debug_assertions),
                 timing: true,
                 capture: true,
-                overlay: false,
+                ..Default::default()
             })
             .unwrap()
         };
@@ -141,7 +141,7 @@
     let window_attributes =
         winit::window::Window::default_attributes().with_title("blade-particle");
 
     let window = event_loop.create_window(window_attributes).unwrap();
 
     let egui_ctx = egui::Context::default();
     let viewport_id = egui_ctx.viewport_id();
@@ -150,7 +150,7 @@
     let mut example = Example::new(&window);
 
     event_loop
         .run(|event, target| {
             target.set_control_flow(winit::event_loop::ControlFlow::Poll);
             match event {
                 winit::event::Event::AboutToWait => {

src/lib.rs

@@ -418,6 +418,7 @@ impl Engine {
                 timing: true,
                 capture: false,
                 overlay: false,
+                device_id: 0,
             })
             .unwrap()
         });