layers/extensions passed to Vulkan::new honored now

also permit extensions to fail being used while still creating a device

crates/renderer/Cargo.toml

@@ -27,3 +27,4 @@ egui = { workspace = true , features = ["bytemuck"]}
 egui_winit_platform = { workspace = true }
 bytemuck = { version = "1.21.0", features = ["derive"] }
 indexmap = "2.7.0"
+itertools = "0.14.0"

crates/renderer/src/lib.rs

@@ -1163,18 +1163,35 @@ impl Vulkan {
         let mut validation_info =
             vk::LayerSettingsCreateInfoEXT::default().settings(&validation_settings);
 
-        let layers = Self::get_layers(&entry, &[Self::VALIDATION_LAYER_NAME]).unwrap();
-
-        // optional display handle
-        let extensions = Self::get_extensions(
+        let layers = Self::get_layers(
             &entry,
-            &layers,
-            // &[ash::ext::debug_utils::NAME, ash::ext::layer_settings::NAME],
-            &[ash::ext::debug_utils::NAME],
-            display_handle,
+            instance_layers
+                .into_iter()
+                .chain(&[
+                    #[cfg(debug_assertions)]
+                    Self::VALIDATION_LAYER_NAME,
+                ])
+                .cloned(),
         )
         .unwrap();
 
+        let (extensions, unsupported_extensions) = Self::get_extensions(
+            &entry,
+            &layers,
+            instance_extensions
+                .into_iter()
+                .chain([ash::ext::debug_utils::NAME, ash::ext::layer_settings::NAME].iter())
+                .cloned(),
+            display_handle,
+        )?;
+
+        if !unsupported_extensions.is_empty() {
+            tracing::error!(
+                "extensions were requested but not supported by instance: {:?}",
+                unsupported_extensions
+            );
+        }
+
         let layers = VkNameList::from_strs(&layers);
         let extensions = VkNameList::from_strs(&extensions);
 
@@ -1580,38 +1597,35 @@ impl Vulkan {
         }
     }
 
+    /// returns a tuple of supported/enabled extensions and unsupported/requested extensions
     fn get_extensions<'a>(
         entry: &ash::Entry,
         layers: &[&'a CStr],
-        extensions: &[&'a CStr],
+        extensions: impl Iterator<Item = &'a CStr> + 'a,
         display_handle: Option<RawDisplayHandle>,
-    ) -> core::result::Result<Vec<&'a CStr>, (Vec<&'a CStr>, Vec<&'a CStr>)> {
+    ) -> Result<(Vec<&'a CStr>, Vec<&'a CStr>)> {
         unsafe {
-            let available_extensions = Self::get_available_extensions(entry, layers)
-                .map_err(|_| (Vec::<&'a CStr>::new(), extensions.to_vec()))?;
+            let available_extensions = Self::get_available_extensions(entry, layers)?;
 
             let available_extension_names = available_extensions
                 .iter()
-                .map(|layer| layer.extension_name_as_c_str())
-                .collect::<core::result::Result<BTreeSet<_>, _>>()
-                .map_err(|_| (Vec::<&'a CStr>::new(), extensions.to_vec()))?;
+                .filter_map(|layer| layer.extension_name_as_c_str().ok())
+                .collect::<BTreeSet<_>>();
 
-            let mut out_extensions = Vec::with_capacity(extensions.len());
-            let mut unsupported_extensions = Vec::with_capacity(extensions.len());
-            for &extension in extensions {
-                if available_extension_names.contains(&extension) {
+            let mut out_extensions = Vec::new();
+            let mut unsupported_extensions = Vec::new();
+
+            for extension in extensions {
+                if available_extension_names.contains(extension) {
                     out_extensions.push(extension);
                 } else {
                     unsupported_extensions.push(extension);
                 }
             }
 
-            let Ok(required_extension_names) = display_handle
+            let required_extension_names = display_handle
                 .map(|display_handle| ash_window::enumerate_required_extensions(display_handle))
-                .unwrap_or(Ok(&[]))
-            else {
-                return Err((out_extensions, unsupported_extensions));
-            };
+                .unwrap_or(Ok(&[]))?;
 
             for &extension in required_extension_names {
                 let extension = core::ffi::CStr::from_ptr(extension);
@@ -1622,31 +1636,30 @@ impl Vulkan {
                 }
             }
 
-            if !unsupported_extensions.is_empty() {
-                Err((out_extensions, unsupported_extensions))
-            } else {
-                Ok(out_extensions)
-            }
+            Ok((out_extensions, unsupported_extensions))
         }
     }
 
     fn get_layers<'a>(
         entry: &ash::Entry,
-        wants_layers: &[&'a CStr],
+        wants_layers: impl Iterator<Item = &'a CStr> + 'a,
     ) -> core::result::Result<Vec<&'a CStr>, (Vec<&'a CStr>, Vec<&'a CStr>)> {
         unsafe {
+            let wants_layers = wants_layers.collect::<Vec<_>>();
+
             let available_layers = entry
                 .enumerate_instance_layer_properties()
-                .map_err(|_| (Vec::<&'a CStr>::new(), wants_layers.to_vec()))?;
+                .map_err(|_| (Vec::<&'a CStr>::new(), wants_layers.clone()))?;
             let available_layer_names = available_layers
                 .iter()
                 .map(|layer| layer.layer_name_as_c_str())
                 .collect::<core::result::Result<BTreeSet<_>, _>>()
-                .map_err(|_| (Vec::<&'a CStr>::new(), wants_layers.to_vec()))?;
+                .map_err(|_| (Vec::<&'a CStr>::new(), wants_layers.clone()))?;
 
-            let mut out_layers = Vec::with_capacity(wants_layers.len());
-            let mut unsupported_layers = Vec::with_capacity(wants_layers.len());
-            for &layer in wants_layers {
+            let mut out_layers = Vec::new();
+            let mut unsupported_layers = Vec::new();
+
+            for layer in wants_layers {
                 if available_layer_names.contains(&layer) {
                     out_layers.push(layer);
                 } else {