1 files changed, 135 insertions, 0 deletions
diff --git a/stockton-render/src/queue_negotiator.rs b/stockton-render/src/queue_negotiator.rs
new file mode 100644
index 0000000..65c7aa4
--- /dev/null
+++ b/stockton-render/src/queue_negotiator.rs
@@ -0,0 +1,135 @@
+use crate::{error::EnvironmentError, types::*};
+
+use anyhow::{Error, Result};
+use hal::queue::family::QueueFamilyId;
+use std::{
+    any::TypeId,
+    collections::HashMap,
+    sync::{Arc, RwLock},
+};
+
+/// Used to find appropriate queue families and share queues from them as needed.
+pub struct QueueNegotiator {
+    family_ids: HashMap<TypeId, QueueFamilyId>,
+    already_allocated: HashMap<TypeId, (Vec<Arc<RwLock<QueueT>>>, usize)>,
+    all: Vec<QueueGroup>,
+}
+
+/// Can be used to select a specific queue family
+pub trait QueueFamilySelector: 'static {
+    /// Check if the given family is suitable
+    fn is_suitable(&self, family: &QueueFamilyT) -> bool;
+}
+
+impl QueueNegotiator {
+    pub fn new() -> Self {
+        QueueNegotiator {
+            family_ids: HashMap::new(),
+            already_allocated: HashMap::new(),
+            all: vec![],
+        }
+    }
+
+    pub fn find<T: QueueFamilySelector>(&mut self, adapter: &Adapter, filter: &T) -> Result<()> {
+        if self.family_ids.contains_key(&TypeId::of::<T>()) {
+            return Ok(());
+        }
+
+        let candidates: Vec<&QueueFamilyT> = adapter
+            .queue_families
+            .iter()
+            .filter(|x| filter.is_suitable(*x))
+            .collect();
+
+        if candidates.is_empty() {
+            return Err(Error::new(EnvironmentError::NoSuitableFamilies));
+        }
+
+        // Prefer using unique families
+        let family = match candidates
+            .iter()
+            .find(|x| !self.family_ids.values().any(|y| *y == x.id()))
+        {
+            Some(x) => *x,
+            None => candidates[0],
+        };
+
+        self.family_ids.insert(TypeId::of::<T>(), family.id());
+
+        Ok(())
+    }
+
+    pub fn set_queue_groups(&mut self, queue_groups: Vec<QueueGroup>) {
+        self.all = queue_groups
+    }
+
+    pub fn get_queue<T: QueueFamilySelector>(&mut self) -> Option<Arc<RwLock<QueueT>>> {
+        let tid = TypeId::of::<T>();
+        let family_id = self.family_ids.get(&tid)?;
+        log::debug!("{:?}", self.all);
+        log::debug!("{:?}", self.already_allocated);
+        match self
+            .all
+            .iter()
+            .position(|x| !x.queues.is_empty() && x.family == *family_id)
+        {
+            Some(idx) => {
+                // At least one remaining queue
+                let queue = self.all[idx].queues.pop().unwrap();
+                let queue = Arc::new(RwLock::new(queue));
+
+                self.add_to_allocated::<T>(queue.clone());
+
+                Some(queue)
+            }
+            None => match self.already_allocated.get_mut(&tid) {
+                Some((queues, next_share)) => {
+                    let queue = (&queues[*next_share]).clone();
+
+                    *next_share += 1;
+
+                    Some(queue)
+                }
+                None => None,
+            },
+        }
+    }
+
+    pub fn family<T: QueueFamilySelector>(&self) -> Option<QueueFamilyId> {
+        self.family_ids.get(&TypeId::of::<T>()).cloned()
+    }
+
+    fn add_to_allocated<T: QueueFamilySelector>(&mut self, queue: Arc<RwLock<QueueT>>) {
+        let tid = TypeId::of::<T>();
+        match self.already_allocated.get_mut(&tid) {
+            None => {
+                self.already_allocated.insert(tid, (vec![queue], 0));
+            }
+            Some(x) => {
+                x.0.push(queue);
+            }
+        }
+    }
+
+    pub fn family_spec<'a, T: QueueFamilySelector>(
+        &self,
+        queue_families: &'a Vec<QueueFamilyT>,
+        count: usize,
+    ) -> Option<(&'a QueueFamilyT, Vec<f32>)> {
+        let qf_id = self.family::<T>()?;
+
+        let qf = queue_families.iter().find(|x| x.id() == qf_id)?;
+        let v = vec![1.0; count];
+
+        Some((qf, v))
+    }
+}
+
+pub struct DrawQueue {
+    pub surface: SurfaceT,
+}
+impl QueueFamilySelector for DrawQueue {
+    fn is_suitable(&self, family: &QueueFamilyT) -> bool {
+        self.surface.supports_queue_family(family) && family.queue_type().supports_graphics()
+    }
+}