1 files changed, 66 insertions, 0 deletions
diff --git a/stockton-render/src/draw_passes/cons.rs b/stockton-render/src/draw_passes/cons.rs
new file mode 100644
index 0000000..ad94b1c
--- /dev/null
+++ b/stockton-render/src/draw_passes/cons.rs
@@ -0,0 +1,66 @@
+//! Code for using multiple draw passes in place of just one
+//! Note that this can be extended to an arbitrary amount of draw passes.
+
+use super::{DrawPass, IntoDrawPass};
+use crate::{context::RenderingContext, queue_negotiator::QueueNegotiator, types::*};
+use stockton_types::Session;
+
+use anyhow::Result;
+
+/// One draw pass, then another.
+pub struct ConsDrawPass<A: DrawPass, B: DrawPass> {
+    pub a: A,
+    pub b: B,
+}
+
+impl<A: DrawPass, B: DrawPass> DrawPass for ConsDrawPass<A, B> {
+    fn queue_draw(
+        &mut self,
+        session: &Session,
+        img_view: &ImageViewT,
+        cmd_buffer: &mut CommandBufferT,
+    ) -> Result<()> {
+        self.a.queue_draw(session, img_view, cmd_buffer)?;
+        self.b.queue_draw(session, img_view, cmd_buffer)?;
+
+        Ok(())
+    }
+
+    fn deactivate(self, context: &mut RenderingContext) -> Result<()> {
+        self.a.deactivate(context)?;
+        self.b.deactivate(context)
+    }
+
+    fn handle_surface_change(
+        &mut self,
+        session: &Session,
+        context: &mut RenderingContext,
+    ) -> Result<()> {
+        self.a.handle_surface_change(session, context)?;
+        self.b.handle_surface_change(session, context)
+    }
+}
+
+impl<A: DrawPass, B: DrawPass, IA: IntoDrawPass<A>, IB: IntoDrawPass<B>>
+    IntoDrawPass<ConsDrawPass<A, B>> for (IA, IB)
+{
+    fn init(
+        self,
+        session: &mut Session,
+        context: &mut RenderingContext,
+    ) -> Result<ConsDrawPass<A, B>> {
+        Ok(ConsDrawPass {
+            a: self.0.init(session, context)?,
+            b: self.1.init(session, context)?,
+        })
+    }
+
+    fn find_aux_queues<'a>(
+        adapter: &'a Adapter,
+        queue_negotiator: &mut QueueNegotiator,
+    ) -> Result<Vec<(&'a QueueFamilyT, Vec<f32>)>> {
+        let mut v = IA::find_aux_queues(adapter, queue_negotiator)?;
+        v.extend(IB::find_aux_queues(adapter, queue_negotiator)?);
+        Ok(v)
+    }
+}