diff --git a/piet-gpu-types/src/scene.rs b/piet-gpu-types/src/scene.rs
index 5e4899f..0d72650 100644
--- a/piet-gpu-types/src/scene.rs
+++ b/piet-gpu-types/src/scene.rs
@@ -1,60 +1,10 @@
 use piet_gpu_derive::piet_gpu;
 
-pub use self::scene::{
-    Bbox, PietCircle, PietFill, PietItem, PietStrokeLine, PietStrokePolyLine, Point, SimpleGroup,
-};
-
 pub use self::scene::{CubicSeg, Element, Fill, LineSeg, QuadSeg, SetLineWidth, Stroke, Transform};
 
 piet_gpu! {
     #[rust_encode]
     mod scene {
-        struct Bbox {
-            bbox: [i16; 4],
-        }
-        struct Point {
-            xy: [f32; 2],
-        }
-        struct SimpleGroup {
-            n_items: u32,
-            // Note: both of the following items are actually arrays
-            items: Ref<PietItem>,
-            bboxes: Ref<Bbox>,
-            offset: Point,
-        }
-        struct PietCircle {
-            rgba_color: u32,
-            center: Point,
-            radius: f32,
-        }
-        struct PietStrokeLine {
-            flags: u32,
-            rgba_color: u32,
-            width: f32,
-            start: Point,
-            end: Point,
-        }
-        struct PietFill {
-            flags: u32,
-            rgba_color: u32,
-            n_points: u32,
-            points: Ref<Point>,
-        }
-        struct PietStrokePolyLine {
-            rgba_color: u32,
-            width: f32,
-            n_points: u32,
-            points: Ref<Point>,
-        }
-        enum PietItem {
-            Group(SimpleGroup),
-            Circle(PietCircle),
-            Line(PietStrokeLine),
-            Fill(PietFill),
-            Poly(PietStrokePolyLine),
-        }
-
-        // New approach follows (above to be deleted)
         struct LineSeg {
             p0: [f32; 2],
             p1: [f32; 2],
diff --git a/piet-gpu/shader/build.ninja b/piet-gpu/shader/build.ninja
index 13fb1b2..cce8615 100644
--- a/piet-gpu/shader/build.ninja
+++ b/piet-gpu/shader/build.ninja
@@ -7,8 +7,6 @@ glslang_validator = glslangValidator
 rule glsl
   command = $glslang_validator -V -o $out $in
 
-build image.spv: glsl image.comp | scene.h
-
 
 build elements.spv: glsl elements.comp | scene.h state.h annotated.h
 
diff --git a/piet-gpu/shader/image.comp b/piet-gpu/shader/image.comp
deleted file mode 100644
index 6d84eb5..0000000
--- a/piet-gpu/shader/image.comp
+++ /dev/null
@@ -1,54 +0,0 @@
-// A simple kernel to create an image.
-
-// Right now, this kernel stores the image in a buffer, but a better
-// plan is to use a texture. This is because of limited support.
-
-#version 450
-#extension GL_GOOGLE_include_directive : enable
-
-layout(local_size_x = 16, local_size_y = 16) in;
-
-layout(set = 0, binding = 0) readonly buffer SceneBuf {
-    uint[] scene;
-};
-
-layout(set = 0, binding = 1) buffer ImageBuf {
-    uint[] image;
-};
-
-#include "scene.h"
-
-// TODO: make the image size dynamic.
-#define IMAGE_WIDTH 2048
-#define IMAGE_HEIGHT 1535
-
-void main() {
-    uvec2 xy_uint = gl_GlobalInvocationID.xy;
-    vec2 xy = vec2(xy_uint);
-    vec2 uv = xy * vec2(1.0 / IMAGE_WIDTH, 1.0 / IMAGE_HEIGHT);
-    vec3 rgb = uv.xyy;
-
-    // Render the scene. Right now, every pixel traverses the scene graph,
-    // which is horribly wasteful, but the goal is to get *some* output and
-    // then optimize.
-
-    SimpleGroup group = PietItem_Group_read(PietItemRef(0));
-    for (uint i = 0; i < group.n_items; i++) {
-        PietItemRef item_ref = PietItem_index(group.items, i);
-        uint tag = PietItem_tag(item_ref);
-        tag = PietItem_Circle;
-        if (tag == PietItem_Circle) {
-            PietCircle circle = PietItem_Circle_read(item_ref);
-            float r = length(xy + vec2(0.5, 0.5) - circle.center.xy);
-            float alpha = clamp(0.5 + circle.radius - r, 0.0, 1.0);
-            vec4 fg_rgba = unpackUnorm4x8(circle.rgba_color);
-            // TODO: sRGB
-            rgb = mix(rgb, fg_rgba.rgb, alpha * fg_rgba.a);
-        }
-    }
-
-    // TODO: sRGB
-    uvec4 s = uvec4(round(vec4(rgb, 1.0) * 255.0));
-    uint rgba_packed = s.r | (s.g << 8) | (s.b << 16) | (s.a << 24);
-    image[xy_uint.y * IMAGE_WIDTH + xy_uint.x] = rgba_packed;
-}
diff --git a/piet-gpu/shader/image.spv b/piet-gpu/shader/image.spv
deleted file mode 100644
index 097add1..0000000
Binary files a/piet-gpu/shader/image.spv and /dev/null differ
diff --git a/piet-gpu/shader/scene.h b/piet-gpu/shader/scene.h
index 3e57303..eee8075 100644
--- a/piet-gpu/shader/scene.h
+++ b/piet-gpu/shader/scene.h
@@ -1,37 +1,5 @@
 // Code auto-generated by piet-gpu-derive
 
-struct BboxRef {
-    uint offset;
-};
-
-struct PointRef {
-    uint offset;
-};
-
-struct SimpleGroupRef {
-    uint offset;
-};
-
-struct PietCircleRef {
-    uint offset;
-};
-
-struct PietStrokeLineRef {
-    uint offset;
-};
-
-struct PietFillRef {
-    uint offset;
-};
-
-struct PietStrokePolyLineRef {
-    uint offset;
-};
-
-struct PietItemRef {
-    uint offset;
-};
-
 struct LineSegRef {
     uint offset;
 };
@@ -64,102 +32,6 @@ struct ElementRef {
     uint offset;
 };
 
-struct Bbox {
-    ivec4 bbox;
-};
-
-#define Bbox_size 8
-
-BboxRef Bbox_index(BboxRef ref, uint index) {
-    return BboxRef(ref.offset + index * Bbox_size);
-}
-
-struct Point {
-    vec2 xy;
-};
-
-#define Point_size 8
-
-PointRef Point_index(PointRef ref, uint index) {
-    return PointRef(ref.offset + index * Point_size);
-}
-
-struct SimpleGroup {
-    uint n_items;
-    PietItemRef items;
-    BboxRef bboxes;
-    Point offset;
-};
-
-#define SimpleGroup_size 20
-
-SimpleGroupRef SimpleGroup_index(SimpleGroupRef ref, uint index) {
-    return SimpleGroupRef(ref.offset + index * SimpleGroup_size);
-}
-
-struct PietCircle {
-    uint rgba_color;
-    Point center;
-    float radius;
-};
-
-#define PietCircle_size 16
-
-PietCircleRef PietCircle_index(PietCircleRef ref, uint index) {
-    return PietCircleRef(ref.offset + index * PietCircle_size);
-}
-
-struct PietStrokeLine {
-    uint flags;
-    uint rgba_color;
-    float width;
-    Point start;
-    Point end;
-};
-
-#define PietStrokeLine_size 28
-
-PietStrokeLineRef PietStrokeLine_index(PietStrokeLineRef ref, uint index) {
-    return PietStrokeLineRef(ref.offset + index * PietStrokeLine_size);
-}
-
-struct PietFill {
-    uint flags;
-    uint rgba_color;
-    uint n_points;
-    PointRef points;
-};
-
-#define PietFill_size 16
-
-PietFillRef PietFill_index(PietFillRef ref, uint index) {
-    return PietFillRef(ref.offset + index * PietFill_size);
-}
-
-struct PietStrokePolyLine {
-    uint rgba_color;
-    float width;
-    uint n_points;
-    PointRef points;
-};
-
-#define PietStrokePolyLine_size 16
-
-PietStrokePolyLineRef PietStrokePolyLine_index(PietStrokePolyLineRef ref, uint index) {
-    return PietStrokePolyLineRef(ref.offset + index * PietStrokePolyLine_size);
-}
-
-#define PietItem_Group 0
-#define PietItem_Circle 1
-#define PietItem_Line 2
-#define PietItem_Fill 3
-#define PietItem_Poly 4
-#define PietItem_size 32
-
-PietItemRef PietItem_index(PietItemRef ref, uint index) {
-    return PietItemRef(ref.offset + index * PietItem_size);
-}
-
 struct LineSeg {
     vec2 p0;
     vec2 p1;
@@ -254,114 +126,6 @@ ElementRef Element_index(ElementRef ref, uint index) {
     return ElementRef(ref.offset + index * Element_size);
 }
 
-Bbox Bbox_read(BboxRef ref) {
-    uint ix = ref.offset >> 2;
-    uint raw0 = scene[ix + 0];
-    uint raw1 = scene[ix + 1];
-    Bbox s;
-    s.bbox = ivec4(int(raw0 << 16) >> 16, int(raw0) >> 16, int(raw1 << 16) >> 16, int(raw1) >> 16);
-    return s;
-}
-
-Point Point_read(PointRef ref) {
-    uint ix = ref.offset >> 2;
-    uint raw0 = scene[ix + 0];
-    uint raw1 = scene[ix + 1];
-    Point s;
-    s.xy = vec2(uintBitsToFloat(raw0), uintBitsToFloat(raw1));
-    return s;
-}
-
-SimpleGroup SimpleGroup_read(SimpleGroupRef ref) {
-    uint ix = ref.offset >> 2;
-    uint raw0 = scene[ix + 0];
-    uint raw1 = scene[ix + 1];
-    uint raw2 = scene[ix + 2];
-    SimpleGroup s;
-    s.n_items = raw0;
-    s.items = PietItemRef(raw1);
-    s.bboxes = BboxRef(raw2);
-    s.offset = Point_read(PointRef(ref.offset + 12));
-    return s;
-}
-
-PietCircle PietCircle_read(PietCircleRef ref) {
-    uint ix = ref.offset >> 2;
-    uint raw0 = scene[ix + 0];
-    uint raw3 = scene[ix + 3];
-    PietCircle s;
-    s.rgba_color = raw0;
-    s.center = Point_read(PointRef(ref.offset + 4));
-    s.radius = uintBitsToFloat(raw3);
-    return s;
-}
-
-PietStrokeLine PietStrokeLine_read(PietStrokeLineRef ref) {
-    uint ix = ref.offset >> 2;
-    uint raw0 = scene[ix + 0];
-    uint raw1 = scene[ix + 1];
-    uint raw2 = scene[ix + 2];
-    PietStrokeLine s;
-    s.flags = raw0;
-    s.rgba_color = raw1;
-    s.width = uintBitsToFloat(raw2);
-    s.start = Point_read(PointRef(ref.offset + 12));
-    s.end = Point_read(PointRef(ref.offset + 20));
-    return s;
-}
-
-PietFill PietFill_read(PietFillRef ref) {
-    uint ix = ref.offset >> 2;
-    uint raw0 = scene[ix + 0];
-    uint raw1 = scene[ix + 1];
-    uint raw2 = scene[ix + 2];
-    uint raw3 = scene[ix + 3];
-    PietFill s;
-    s.flags = raw0;
-    s.rgba_color = raw1;
-    s.n_points = raw2;
-    s.points = PointRef(raw3);
-    return s;
-}
-
-PietStrokePolyLine PietStrokePolyLine_read(PietStrokePolyLineRef ref) {
-    uint ix = ref.offset >> 2;
-    uint raw0 = scene[ix + 0];
-    uint raw1 = scene[ix + 1];
-    uint raw2 = scene[ix + 2];
-    uint raw3 = scene[ix + 3];
-    PietStrokePolyLine s;
-    s.rgba_color = raw0;
-    s.width = uintBitsToFloat(raw1);
-    s.n_points = raw2;
-    s.points = PointRef(raw3);
-    return s;
-}
-
-uint PietItem_tag(PietItemRef ref) {
-    return scene[ref.offset >> 2];
-}
-
-SimpleGroup PietItem_Group_read(PietItemRef ref) {
-    return SimpleGroup_read(SimpleGroupRef(ref.offset + 4));
-}
-
-PietCircle PietItem_Circle_read(PietItemRef ref) {
-    return PietCircle_read(PietCircleRef(ref.offset + 4));
-}
-
-PietStrokeLine PietItem_Line_read(PietItemRef ref) {
-    return PietStrokeLine_read(PietStrokeLineRef(ref.offset + 4));
-}
-
-PietFill PietItem_Fill_read(PietItemRef ref) {
-    return PietFill_read(PietFillRef(ref.offset + 4));
-}
-
-PietStrokePolyLine PietItem_Poly_read(PietItemRef ref) {
-    return PietStrokePolyLine_read(PietStrokePolyLineRef(ref.offset + 4));
-}
-
 LineSeg LineSeg_read(LineSegRef ref) {
     uint ix = ref.offset >> 2;
     uint raw0 = scene[ix + 0];