diff --git a/crates/game/src/main.rs b/crates/game/src/main.rs
index 03c7395..355dfae 100644
--- a/crates/game/src/main.rs
+++ b/crates/game/src/main.rs
@@ -148,10 +148,7 @@ impl ApplicationHandler for WinitState {
         for (&window, &resize) in self.last_resize_events.clone().iter() {
             self.handle_final_resize(window, resize);
         }
-        // let window_ids = self.windows2.keys().cloned().collect::<Vec<_>>();
-        // for window in window_ids {
-        //     self.handle_draw_request(window);
-        // }
+
         self.last_resize_events.clear();
 
         if self.windows2.is_empty() {
diff --git a/crates/renderer/src/render_graph.rs b/crates/renderer/src/render_graph.rs
index 925b5ae..75efc76 100644
--- a/crates/renderer/src/render_graph.rs
+++ b/crates/renderer/src/render_graph.rs
@@ -1,42 +1,44 @@
 #![allow(dead_code)]
 
-use crate::util::hash_f32;
+use std::{collections::BTreeMap, fmt::Debug, sync::Arc};
+
+use crate::{
+    buffers::{Buffer, BufferDesc},
+    commands, def_monotonic_id,
+    device::{self, Device},
+    images::{Image, ImageDesc},
+    util::Rgba,
+    SwapchainFrame,
+};
 use ash::vk;
+use petgraph::visit::NodeRef;
+
+def_monotonic_id!(pub RenderGraphResourceId);
+
+#[derive(Debug)]
+pub enum RenderGraphResourceDesc {
+    Image(ImageDesc),
+    Buffer(BufferDesc),
+}
+
+#[derive(Debug)]
+pub enum RenderGraphResource {
+    Framebuffer(Arc<SwapchainFrame>),
+    ImportedImage(Arc<Image>),
+    ImportedBuffer(Arc<Buffer>),
+    Image(Image),
+    Buffer(Buffer),
+}
 
 #[derive(Debug, Clone, Copy)]
-pub struct Rgba(pub [f32; 4]);
-
-impl std::hash::Hash for Rgba {
-    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
-        self.0.map(|f| hash_f32(state, f));
-    }
-}
-
-impl Rgba {
-    pub fn new(r: f32, g: f32, b: f32, a: f32) -> Self {
-        Self([r, g, b, a])
-    }
-    pub fn into_u32(&self) -> [u32; 4] {
-        self.0.map(|f| (f.clamp(0.0, 1.0) * 255.0) as u32)
-    }
-    pub fn into_f32(&self) -> [f32; 4] {
-        self.0
-    }
-    pub fn into_snorm(&self) -> [f32; 4] {
-        self.0.map(|f| (f - 0.5) * 2.0)
-    }
-    pub fn into_i32(&self) -> [i32; 4] {
-        self.0.map(|f| (f.clamp(0.0, 1.0) * 255.0) as i32 - 128)
-    }
-}
-
-enum LoadOp {
+pub enum LoadOp {
     Clear(Rgba),
     Load,
     DontCare,
 }
 
-enum StoreOp {
+#[derive(Debug, Clone, Copy)]
+pub enum StoreOp {
     DontCare,
     Store,
 }
@@ -48,8 +50,279 @@ struct AttachmentInfo {
     store: StoreOp,
 }
 
-struct Texture {
-    texture: vk::Image,
+pub struct RenderContext<'a> {
+    device: device::Device,
+    cmd: &'a commands::SingleUseCommand,
 }
 
-pub struct RenderGraph {}
+pub trait Pass: Debug {
+    /// returns the layout the pass requires an image dependency to be in prior
+    /// to the pass.
+    fn get_layout_of_in_image_dependency(&self, id: RenderGraphResourceId) -> vk::ImageLayout;
+    /// returns the layout the pass will leave an image dependency in after the
+    /// pass.
+    fn get_layout_of_out_image_dependency(&self, id: RenderGraphResourceId) -> vk::ImageLayout;
+    /// mask of the queue capability requirements of this pass.
+    fn get_queue_capability_requirements(&self) -> device::QueueFlags;
+    /// returns an iterator over all (in) dependencies.
+    fn get_in_dependencies<'a>(&'a self) -> Box<dyn Iterator<Item = RenderGraphResourceId> + 'a>;
+    fn get_out_dependencies<'a>(&'a self) -> Box<dyn Iterator<Item = RenderGraphResourceId> + 'a>;
+
+    fn record(self, ctx: &RenderContext) -> crate::Result<()>;
+}
+
+def_monotonic_id!(pub RenderGraphPassId);
+
+// Non-imported resources remain `RenderGraphResourceDesc`s because they may be
+// able to be aliased.
+// This should be dual to liveness/register allocation in a compiler.
+// Dummy-impl is just allocating every resource_desc itself. 5head-impl is trying
+// to find resource_descs which are eq, but whose liveness doesn't overlap.
+#[derive(Debug)]
+pub struct RenderGraph {
+    resource_descs: BTreeMap<RenderGraphResourceId, RenderGraphResourceDesc>,
+    resources: BTreeMap<RenderGraphResourceId, RenderGraphResource>,
+    passes: Vec<Box<dyn Pass>>,
+    /// the rendergraph produces these resources. Any passes on which these
+    /// outputs do not depend are pruned.
+    outputs: Vec<RenderGraphResourceId>,
+}
+
+impl RenderGraph {
+    pub fn new() -> Self {
+        Self {
+            resource_descs: BTreeMap::new(),
+            resources: BTreeMap::new(),
+            passes: Vec::new(),
+            outputs: Vec::new(),
+        }
+    }
+
+    pub fn add_resource(&mut self, desc: RenderGraphResourceDesc) -> RenderGraphResourceId {
+        let id = RenderGraphResourceId::new();
+        self.resource_descs.insert(id, desc);
+        id
+    }
+    pub fn mark_as_output(&mut self, id: RenderGraphResourceId) {
+        // TODO: dedup
+        self.outputs.push(id);
+    }
+    pub fn import_image(&mut self, image: Arc<Image>) -> RenderGraphResourceId {
+        let id = RenderGraphResourceId::new();
+        self.resources
+            .insert(id, RenderGraphResource::ImportedImage(image));
+        id
+    }
+    pub fn import_buffer(&mut self, buffer: Arc<Buffer>) -> RenderGraphResourceId {
+        let id = RenderGraphResourceId::new();
+        self.resources
+            .insert(id, RenderGraphResource::ImportedBuffer(buffer));
+        id
+    }
+    pub fn import_framebuffer(&mut self, frame: Arc<SwapchainFrame>) -> RenderGraphResourceId {
+        let id = RenderGraphResourceId::new();
+        self.resources
+            .insert(id, RenderGraphResource::Framebuffer(frame));
+        id
+    }
+    pub fn add_pass<P: Pass + 'static>(&mut self, pass: P) {
+        self.passes.push(Box::new(pass));
+    }
+
+    // https://blog.traverseresearch.nl/render-graph-101-f42646255636
+    // https://github.com/EmbarkStudios/kajiya/blob/main/crates/lib/kajiya-rg/src/graph.rs
+    // https://themaister.net/blog/2017/08/15/render-graphs-and-vulkan-a-deep-dive/
+    pub fn resolve(mut self) {
+        eprintln!("{:#?}", &self);
+        let mut last_write = BTreeMap::new();
+
+        let mut dag = petgraph::stable_graph::StableDiGraph::new();
+
+        // insert edges between write->read edges of 2 passes
+        for (i, pass) in self.passes.iter().enumerate() {
+            let node = dag.add_node(i);
+            for dep in pass.get_in_dependencies() {
+                if let Some(&other) = last_write.get(&dep) {
+                    dag.add_edge(other, node, dep);
+                }
+            }
+
+            for dep in pass.get_out_dependencies() {
+                // keep track of which pass last wrote to a resource
+                // this is the node to build an edge from next time this resource is read
+                last_write.insert(dep, node);
+            }
+        }
+
+        // pseudo pass for trackingoutputs
+        let output = dag.add_node(!0);
+        for (id, node) in self
+            .outputs
+            .into_iter()
+            .filter_map(|id| last_write.get(&id).cloned().map(|node| (id, node)))
+        {
+            dag.add_edge(node, output, id);
+        }
+
+        // prune dead nodes
+        loop {
+            let sinks = dag
+                .externals(petgraph::Direction::Outgoing)
+                .filter(|idx| idx != &output)
+                .collect::<Vec<_>>();
+            if sinks.is_empty() {
+                break;
+            }
+            for sink in sinks {
+                dag.remove_node(sink);
+            }
+        }
+
+        #[cfg(any(debug_assertions, test))]
+        std::fs::write(
+            "render_graph.dot",
+            &format!(
+                "{:?}",
+                petgraph::dot::Dot::with_attr_getters(
+                    &dag,
+                    &[],
+                    &|_graph, edgeref| { format!("label = \"{:?}\"", edgeref.weight()) },
+                    &|_graph, noderef| { format!("label = \"Pass({:?})\"", noderef.weight()) }
+                )
+            ),
+        )
+        .expect("writing render_graph repr");
+
+        let mut topological_map = Vec::new();
+        loop {
+            let (sources, indices): (Vec<_>, Vec<_>) = dag
+                .externals(petgraph::Direction::Incoming)
+                .filter(|&id| id != output)
+                .filter_map(|id| dag.node_weight(id).cloned().map(|idx| (id, idx)))
+                .unzip();
+
+            if sources.is_empty() {
+                break;
+            }
+
+            for &source in &sources {
+                dag.remove_node(source);
+            }
+
+            topological_map.push(indices);
+        }
+
+        // I don't think this can currently happen with the way passes are added.
+        dag.remove_node(output);
+        if dag.node_count() > 0 {
+            panic!("dag is cyclic!");
+        }
+
+        eprintln!("topology: {:?}", topological_map);
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    macro_rules! def_dummy_pass {
+        ($name:ident: {$queue:path, $layout_in:path, $layout_out:path}) => {
+            #[derive(Debug, Clone)]
+            struct $name(Vec<RenderGraphResourceId>, Vec<RenderGraphResourceId>);
+            impl Pass for $name {
+                fn get_layout_of_in_image_dependency(
+                    &self,
+                    _id: RenderGraphResourceId,
+                ) -> vk::ImageLayout {
+                    $layout_in
+                }
+
+                fn get_layout_of_out_image_dependency(
+                    &self,
+                    _id: RenderGraphResourceId,
+                ) -> vk::ImageLayout {
+                    $layout_out
+                }
+
+                fn get_queue_capability_requirements(&self) -> device::QueueFlags {
+                    $queue
+                }
+
+                fn get_in_dependencies<'a>(
+                    &'a self,
+                ) -> Box<dyn Iterator<Item = RenderGraphResourceId> + 'a> {
+                    Box::new(self.0.iter().cloned())
+                }
+
+                fn get_out_dependencies<'a>(
+                    &'a self,
+                ) -> Box<dyn Iterator<Item = RenderGraphResourceId> + 'a> {
+                    Box::new(self.1.iter().cloned())
+                }
+
+                fn record(self, _ctx: &RenderContext) -> crate::Result<()> {
+                    Ok(())
+                }
+            }
+        };
+    }
+
+    def_dummy_pass!(DepthPass: {
+        device::QueueFlags::GRAPHICS,
+        vk::ImageLayout::DEPTH_ATTACHMENT_OPTIMAL,
+        vk::ImageLayout::DEPTH_ATTACHMENT_OPTIMAL});
+    def_dummy_pass!(RenderPass: {
+        device::QueueFlags::GRAPHICS,
+        vk::ImageLayout::COLOR_ATTACHMENT_OPTIMAL,
+        vk::ImageLayout::COLOR_ATTACHMENT_OPTIMAL});
+    def_dummy_pass!(AsyncPass: {
+        device::QueueFlags::ASYNC_COMPUTE,
+        vk::ImageLayout::UNDEFINED,
+        vk::ImageLayout::GENERAL});
+    def_dummy_pass!(PostProcessPass: {
+        device::QueueFlags::ASYNC_COMPUTE,
+        vk::ImageLayout::GENERAL,
+        vk::ImageLayout::GENERAL});
+    def_dummy_pass!(PresentPass: {
+        device::QueueFlags::PRESENT,
+        vk::ImageLayout::PRESENT_SRC_KHR,
+        vk::ImageLayout::UNDEFINED});
+    def_dummy_pass!(DepthVisualisationPass: {
+        device::QueueFlags::ASYNC_COMPUTE,
+        vk::ImageLayout::GENERAL,
+        vk::ImageLayout::UNDEFINED});
+
+    #[test]
+    fn resolve_graph() {
+        let mut graph = RenderGraph::new();
+        let gbuffer = graph.add_resource(RenderGraphResourceDesc::Image(ImageDesc {
+            ..Default::default()
+        }));
+        let depth_image = graph.add_resource(RenderGraphResourceDesc::Image(ImageDesc {
+            ..Default::default()
+        }));
+        let depth_visualisation = graph.add_resource(RenderGraphResourceDesc::Image(ImageDesc {
+            ..Default::default()
+        }));
+        let compute_buffer = graph.add_resource(RenderGraphResourceDesc::Buffer(BufferDesc {
+            ..Default::default()
+        }));
+
+        graph.add_pass(DepthPass(vec![depth_image], vec![depth_image]));
+        graph.add_pass(DepthVisualisationPass(
+            vec![depth_image, depth_visualisation],
+            vec![depth_visualisation],
+        ));
+        graph.add_pass(AsyncPass(vec![compute_buffer], vec![compute_buffer]));
+        graph.add_pass(RenderPass(
+            vec![depth_image, compute_buffer, gbuffer],
+            vec![gbuffer],
+        ));
+        graph.add_pass(PostProcessPass(vec![gbuffer], vec![gbuffer]));
+        graph.mark_as_output(gbuffer);
+        graph.mark_as_output(depth_image);
+
+        graph.resolve();
+    }
+}