diff --git a/src/buffers.rs b/src/buffers.rs
index f1a315d..a3b5f1b 100644
--- a/src/buffers.rs
+++ b/src/buffers.rs
@@ -1,15 +1,12 @@
-use crate::events::EventBus;
 use crate::geometry::*;
 use crate::lib8::interpolate::Fract8Ops;
 use crate::power::AsMilliwatts;
 use crate::render::{PixelView, Sample, Shader, Surface, Surfaces, HardwarePixel};
-use crate::task::Task;
 
-use std::fmt::Debug;
+use std::cell::RefCell;
 use std::ops::IndexMut;
 
 use std::sync::atomic::AtomicBool;
-use std::sync::RwLock;
 use std::sync::{Arc, Mutex};
 
 struct ShaderBinding {
@@ -80,9 +77,9 @@ impl Surface for BufferedSurface {
         });
     }
 
-    fn set_shader(&mut self, shader: Box<dyn Shader>) {
+    fn set_shader<T: Shader + 'static>(&mut self, shader: T) {
         self.updater.push(SurfaceUpdate {
-            shader: Some(Some(shader)),
+            shader: Some(Some(Box::new(shader))),
             slot: self.slot,
             ..Default::default()
         });
@@ -143,31 +140,28 @@ impl ShaderChain {
     }
 
     pub fn commit(&mut self) {
-        let mut queue: Vec<SurfaceUpdate> = {
-            let mut updates = self.updates.pending.lock().unwrap();
-            std::mem::take(updates.as_mut())
-        };
-        for update in queue.iter_mut() {
-            let target_slot = &mut self.bindings[update.slot];
-            if let Some(shader) = update.shader.take() {
-                target_slot.shader = shader;
-            }
-            if let Some(opacity) = update.opacity.take() {
-                target_slot.opacity = opacity;
-            }
-            if let Some(rect) = update.rect.take() {
-                target_slot.rect = rect;
+        if self.is_dirty() {
+            let mut queue: Vec<SurfaceUpdate> = {
+                let mut updates = self.updates.pending.lock().unwrap();
+                std::mem::take(updates.as_mut())
+            };
+            for update in queue.iter_mut() {
+                let target_slot = &mut self.bindings[update.slot];
+                if let Some(shader) = update.shader.take() {
+                    target_slot.shader = shader;
+                }
+                if let Some(opacity) = update.opacity.take() {
+                    target_slot.opacity = opacity;
+                }
+                if let Some(rect) = update.rect.take() {
+                    target_slot.rect = rect;
+                }
             }
+            self.updates.damaged.store(false, std::sync::atomic::Ordering::Relaxed);
         }
-        self.updates.damaged.store(false, std::sync::atomic::Ordering::Relaxed);
     }
-}
 
-impl Surfaces for ShaderChain {
-    type Error = ();
-    type Surface = BufferedSurface;
-
-    fn new_surface(&mut self, area: Rectangle<Virtual>) -> Result<Self::Surface, Self::Error> {
+    fn new_surface(&mut self, area: Rectangle<Virtual>) -> Result<BufferedSurface, ()> {
         let next_slot = self.bindings.len();
         self.bindings.push(ShaderBinding {
             opacity: 255,
@@ -182,12 +176,12 @@ impl Surfaces for ShaderChain {
     }
 
     fn render_to<S: Sample>(&self, output: &mut S, frame: usize) {
-        for surface in self.bindings.iter() {
+        for surface in &self.bindings {
             let opacity = surface.opacity;
             if opacity > 0 {
-                let rect = surface.rect;
-                let mut sample = output.sample(&rect);
                 if let Some(ref shader) = surface.shader {
+                    let rect = surface.rect;
+                    let mut sample = output.sample(&rect);
                     while let Some((virt_coords, pixel)) = sample.next() {
                         *pixel = pixel.blend8(shader.draw(&virt_coords, frame).into(), opacity);
                     }
@@ -197,37 +191,29 @@ impl Surfaces for ShaderChain {
     }
 }
 
-#[derive(Clone)]
 pub struct BufferedSurfacePool {
-    pool: Arc<RwLock<ShaderChain>>
+    pool: RefCell<ShaderChain>
 }
 
 impl BufferedSurfacePool {
     pub fn new() -> Self {
         BufferedSurfacePool {
-            pool: Arc::new(RwLock::new(ShaderChain::new()))
+            pool: RefCell::new(ShaderChain::new())
         }
     }
 }
 
 impl Surfaces for BufferedSurfacePool {
     type Error = ();
-    type Surface = <ShaderChain as Surfaces>::Surface;
+    type Surface = BufferedSurface;
     fn new_surface(&mut self, area: crate::geometry::Rectangle<crate::geometry::Virtual>) -> Result<Self::Surface, Self::Error> {
-        self.pool.write().unwrap().new_surface(area)
+        self.pool.borrow_mut().new_surface(area)
     }
 
     fn render_to<S: crate::render::Sample>(&self, output: &mut S, frame: usize) {
-        self.pool.read().unwrap().render_to(output, frame);
-    }
-}
-
-
-impl Task for BufferedSurfacePool {
-    fn on_tick(&mut self, _bus: &mut EventBus) {
-        if self.pool.read().unwrap().is_dirty() {
-            self.pool.write().unwrap().commit();
-        }
+        let mut b = self.pool.borrow_mut();
+        b.commit();
+        b.render_to(output, frame);
     }
 }