diff --git a/piet-gpu-types/src/annotated.rs b/piet-gpu-types/src/annotated.rs
index cedbd3f..304726c 100644
--- a/piet-gpu-types/src/annotated.rs
+++ b/piet-gpu-types/src/annotated.rs
@@ -9,10 +9,6 @@ piet_gpu! {
             bbox: [f32; 4],
             rgba_color: u32,
         }
-        struct AnnoFillMask {
-            bbox: [f32; 4],
-            mask: f32,
-        }
         struct AnnoStroke {
             bbox: [f32; 4],
             rgba_color: u32,
@@ -27,8 +23,6 @@ piet_gpu! {
             Nop,
             Stroke(AnnoStroke),
             Fill(AnnoFill),
-            FillMask(AnnoFillMask),
-            FillMaskInv(AnnoFillMask),
             BeginClip(AnnoClip),
             EndClip(AnnoClip),
         }
diff --git a/piet-gpu-types/src/ptcl.rs b/piet-gpu-types/src/ptcl.rs
index 86e4572..7e7d10c 100644
--- a/piet-gpu-types/src/ptcl.rs
+++ b/piet-gpu-types/src/ptcl.rs
@@ -25,11 +25,6 @@ piet_gpu! {
             backdrop: i32,
             rgba_color: u32,
         }
-        struct CmdFillMask {
-            tile_ref: u32,
-            backdrop: i32,
-            mask: f32,
-        }
         struct CmdBeginClip {
             tile_ref: u32,
             backdrop: i32,
@@ -57,8 +52,6 @@ piet_gpu! {
             Circle(CmdCircle),
             Line(CmdLine),
             Fill(CmdFill),
-            FillMask(CmdFillMask),
-            FillMaskInv(CmdFillMask),
             BeginClip(CmdBeginClip),
             BeginSolidClip(CmdBeginSolidClip),
             EndClip(CmdEndClip),
@@ -67,24 +60,5 @@ piet_gpu! {
             SolidMask(CmdSolidMask),
             Jump(CmdJump),
         }
-
-        // TODO: strongly consider using f16. If so, these would be
-        // relative to the tile. We're doing f32 for now to minimize
-        // divergence from piet-metal originals.
-        struct Segment {
-            start: [f32; 2],
-            end: [f32; 2],
-
-            // This is used for fills only, but we're including it in
-            // the general structure for simplicity.
-            y_edge: f32,
-        }
-
-        struct SegChunk {
-            n: u32,
-            next: Ref<SegChunk>,
-            // Actually a reference to a variable-sized slice.
-            segs: Ref<Segment>,
-        }
     }
 }
diff --git a/piet-gpu-types/src/scene.rs b/piet-gpu-types/src/scene.rs
index 855b500..e0adf4e 100644
--- a/piet-gpu-types/src/scene.rs
+++ b/piet-gpu-types/src/scene.rs
@@ -25,9 +25,6 @@ piet_gpu! {
         struct Fill {
             rgba_color: u32,
         }
-        struct FillMask {
-            mask: f32,
-        }
         struct Stroke {
             rgba_color: u32,
         }
@@ -59,8 +56,6 @@ piet_gpu! {
             Fill(Fill),
             SetLineWidth(SetLineWidth),
             Transform(Transform),
-            FillMask(FillMask),
-            FillMaskInv(FillMask),
             BeginClip(Clip),
             EndClip(Clip),
         }
diff --git a/piet-gpu/shader/annotated.h b/piet-gpu/shader/annotated.h
index 677e473..2adacb1 100644
--- a/piet-gpu/shader/annotated.h
+++ b/piet-gpu/shader/annotated.h
@@ -4,10 +4,6 @@ struct AnnoFillRef {
     uint offset;
 };
 
-struct AnnoFillMaskRef {
-    uint offset;
-};
-
 struct AnnoStrokeRef {
     uint offset;
 };
@@ -31,17 +27,6 @@ AnnoFillRef AnnoFill_index(AnnoFillRef ref, uint index) {
     return AnnoFillRef(ref.offset + index * AnnoFill_size);
 }
 
-struct AnnoFillMask {
-    vec4 bbox;
-    float mask;
-};
-
-#define AnnoFillMask_size 20
-
-AnnoFillMaskRef AnnoFillMask_index(AnnoFillMaskRef ref, uint index) {
-    return AnnoFillMaskRef(ref.offset + index * AnnoFillMask_size);
-}
-
 struct AnnoStroke {
     vec4 bbox;
     uint rgba_color;
@@ -67,10 +52,8 @@ AnnoClipRef AnnoClip_index(AnnoClipRef ref, uint index) {
 #define Annotated_Nop 0
 #define Annotated_Stroke 1
 #define Annotated_Fill 2
-#define Annotated_FillMask 3
-#define Annotated_FillMaskInv 4
-#define Annotated_BeginClip 5
-#define Annotated_EndClip 6
+#define Annotated_BeginClip 3
+#define Annotated_EndClip 4
 #define Annotated_size 28
 
 AnnotatedRef Annotated_index(AnnotatedRef ref, uint index) {
@@ -99,28 +82,6 @@ void AnnoFill_write(AnnoFillRef ref, AnnoFill s) {
     annotated[ix + 4] = s.rgba_color;
 }
 
-AnnoFillMask AnnoFillMask_read(AnnoFillMaskRef ref) {
-    uint ix = ref.offset >> 2;
-    uint raw0 = annotated[ix + 0];
-    uint raw1 = annotated[ix + 1];
-    uint raw2 = annotated[ix + 2];
-    uint raw3 = annotated[ix + 3];
-    uint raw4 = annotated[ix + 4];
-    AnnoFillMask s;
-    s.bbox = vec4(uintBitsToFloat(raw0), uintBitsToFloat(raw1), uintBitsToFloat(raw2), uintBitsToFloat(raw3));
-    s.mask = uintBitsToFloat(raw4);
-    return s;
-}
-
-void AnnoFillMask_write(AnnoFillMaskRef ref, AnnoFillMask s) {
-    uint ix = ref.offset >> 2;
-    annotated[ix + 0] = floatBitsToUint(s.bbox.x);
-    annotated[ix + 1] = floatBitsToUint(s.bbox.y);
-    annotated[ix + 2] = floatBitsToUint(s.bbox.z);
-    annotated[ix + 3] = floatBitsToUint(s.bbox.w);
-    annotated[ix + 4] = floatBitsToUint(s.mask);
-}
-
 AnnoStroke AnnoStroke_read(AnnoStrokeRef ref) {
     uint ix = ref.offset >> 2;
     uint raw0 = annotated[ix + 0];
@@ -177,14 +138,6 @@ AnnoFill Annotated_Fill_read(AnnotatedRef ref) {
     return AnnoFill_read(AnnoFillRef(ref.offset + 4));
 }
 
-AnnoFillMask Annotated_FillMask_read(AnnotatedRef ref) {
-    return AnnoFillMask_read(AnnoFillMaskRef(ref.offset + 4));
-}
-
-AnnoFillMask Annotated_FillMaskInv_read(AnnotatedRef ref) {
-    return AnnoFillMask_read(AnnoFillMaskRef(ref.offset + 4));
-}
-
 AnnoClip Annotated_BeginClip_read(AnnotatedRef ref) {
     return AnnoClip_read(AnnoClipRef(ref.offset + 4));
 }
@@ -207,16 +160,6 @@ void Annotated_Fill_write(AnnotatedRef ref, AnnoFill s) {
     AnnoFill_write(AnnoFillRef(ref.offset + 4), s);
 }
 
-void Annotated_FillMask_write(AnnotatedRef ref, AnnoFillMask s) {
-    annotated[ref.offset >> 2] = Annotated_FillMask;
-    AnnoFillMask_write(AnnoFillMaskRef(ref.offset + 4), s);
-}
-
-void Annotated_FillMaskInv_write(AnnotatedRef ref, AnnoFillMask s) {
-    annotated[ref.offset >> 2] = Annotated_FillMaskInv;
-    AnnoFillMask_write(AnnoFillMaskRef(ref.offset + 4), s);
-}
-
 void Annotated_BeginClip_write(AnnotatedRef ref, AnnoClip s) {
     annotated[ref.offset >> 2] = Annotated_BeginClip;
     AnnoClip_write(AnnoClipRef(ref.offset + 4), s);
diff --git a/piet-gpu/shader/backdrop.comp b/piet-gpu/shader/backdrop.comp
index 6fa9f9f..9e235c9 100644
--- a/piet-gpu/shader/backdrop.comp
+++ b/piet-gpu/shader/backdrop.comp
@@ -55,8 +55,6 @@ void main() {
         uint tag = Annotated_tag(ref);
         switch (tag) {
         case Annotated_Fill:
-        case Annotated_FillMask:
-        case Annotated_FillMaskInv:
         case Annotated_BeginClip:
             PathRef path_ref = PathRef(element_ix * Path_size);
             Path path = Path_read(path_ref);
diff --git a/piet-gpu/shader/backdrop.spv b/piet-gpu/shader/backdrop.spv
index ee4dda8..54bf736 100644
Binary files a/piet-gpu/shader/backdrop.spv and b/piet-gpu/shader/backdrop.spv differ
diff --git a/piet-gpu/shader/binning.comp b/piet-gpu/shader/binning.comp
index 5dce813..53edadf 100644
--- a/piet-gpu/shader/binning.comp
+++ b/piet-gpu/shader/binning.comp
@@ -59,8 +59,6 @@ void main() {
     int x0 = 0, y0 = 0, x1 = 0, y1 = 0;
     switch (tag) {
     case Annotated_Fill:
-    case Annotated_FillMask:
-    case Annotated_FillMaskInv:
     case Annotated_Stroke:
     case Annotated_BeginClip:
     case Annotated_EndClip:
diff --git a/piet-gpu/shader/binning.spv b/piet-gpu/shader/binning.spv
index 2c923c4..abe17d4 100644
Binary files a/piet-gpu/shader/binning.spv and b/piet-gpu/shader/binning.spv differ
diff --git a/piet-gpu/shader/coarse.comp b/piet-gpu/shader/coarse.comp
index 12ebb98..3e230d9 100644
--- a/piet-gpu/shader/coarse.comp
+++ b/piet-gpu/shader/coarse.comp
@@ -169,8 +169,6 @@ void main() {
         uint tile_count;
         switch (tag) {
         case Annotated_Fill:
-        case Annotated_FillMask:
-        case Annotated_FillMaskInv:
         case Annotated_Stroke:
         case Annotated_BeginClip:
         case Annotated_EndClip:
@@ -234,9 +232,7 @@ void main() {
                 // Include the path in the tile if
                 // - the tile contains at least a segment (tile offset non-zero)
                 // - the tile is completely covered (backdrop non-zero)
-                bool inside = tile.backdrop != 0;
-                bool fill = tag != Annotated_FillMaskInv;
-                include_tile =  tile.tile.offset != 0 || inside == fill;
+                include_tile = tile.tile.offset != 0 || tile.backdrop != 0;
             }
             if (include_tile) {
                 uint el_slice = el_ix / 32;
@@ -312,27 +308,6 @@ void main() {
                 Cmd_EndClip_write(cmd_ref, CmdEndClip(1.0));
                 cmd_ref.offset += Cmd_size;
                 break;
-            case Annotated_FillMask:
-            case Annotated_FillMaskInv:
-                tile = Tile_read(TileRef(sh_tile_base[element_ref_ix]
-                    + (sh_tile_stride[element_ref_ix] * tile_y + tile_x) * Tile_size));
-                AnnoFillMask fill_mask = Annotated_FillMask_read(ref);
-                alloc_cmd(cmd_ref, cmd_limit);
-                if (tile.tile.offset != 0) {
-                    CmdFillMask cmd_fill;
-                    cmd_fill.tile_ref = tile.tile.offset;
-                    cmd_fill.backdrop = tile.backdrop;
-                    cmd_fill.mask = fill_mask.mask;
-                    if (tag == Annotated_FillMask) {
-                        Cmd_FillMask_write(cmd_ref, cmd_fill);
-                    } else {
-                        Cmd_FillMaskInv_write(cmd_ref, cmd_fill);
-                    }
-                } else {
-                    Cmd_SolidMask_write(cmd_ref, CmdSolidMask(fill_mask.mask));
-                }
-                cmd_ref.offset += Cmd_size;
-                break;
             case Annotated_Stroke:
                 tile = Tile_read(TileRef(sh_tile_base[element_ref_ix]
                     + (sh_tile_stride[element_ref_ix] * tile_y + tile_x) * Tile_size));
diff --git a/piet-gpu/shader/coarse.spv b/piet-gpu/shader/coarse.spv
index 98dde1b..bd014c2 100644
Binary files a/piet-gpu/shader/coarse.spv and b/piet-gpu/shader/coarse.spv differ
diff --git a/piet-gpu/shader/elements.comp b/piet-gpu/shader/elements.comp
index 7606554..568445b 100644
--- a/piet-gpu/shader/elements.comp
+++ b/piet-gpu/shader/elements.comp
@@ -129,8 +129,6 @@ State map_element(ElementRef ref) {
         c.pathseg_count = 1;
         break;
     case Element_Fill:
-    case Element_FillMask:
-    case Element_FillMaskInv:
     case Element_Stroke:
     case Element_BeginClip:
         c.flags = FLAG_RESET_BBOX;
@@ -408,23 +406,6 @@ void main() {
             out_ref = AnnotatedRef((st.path_count - 1) * Annotated_size);
             Annotated_Fill_write(out_ref, anno_fill);
             break;
-        case Element_FillMask:
-            FillMask fill_mask = Element_FillMask_read(this_ref);
-            AnnoFillMask anno_fill_mask;
-            anno_fill_mask.mask = fill_mask.mask;
-            anno_fill_mask.bbox = st.bbox;
-            out_ref = AnnotatedRef((st.path_count - 1) * Annotated_size);
-            Annotated_FillMask_write(out_ref, anno_fill_mask);
-            break;
-        case Element_FillMaskInv:
-            fill_mask = Element_FillMaskInv_read(this_ref);
-            anno_fill_mask.mask = fill_mask.mask;
-            // The inverse fill conceptually takes up the entire screen.
-            // TODO: Tighten bounds to contain only affected paths.
-            anno_fill_mask.bbox = vec4(0, 0, 1e9, 1e9);
-            out_ref = AnnotatedRef((st.path_count - 1) * Annotated_size);
-            Annotated_FillMaskInv_write(out_ref, anno_fill_mask);
-            break;
         case Element_BeginClip:
             Clip begin_clip = Element_BeginClip_read(this_ref);
             AnnoClip anno_begin_clip = AnnoClip(begin_clip.bbox);
diff --git a/piet-gpu/shader/elements.spv b/piet-gpu/shader/elements.spv
index 73ff3f4..28e3c30 100644
Binary files a/piet-gpu/shader/elements.spv and b/piet-gpu/shader/elements.spv differ
diff --git a/piet-gpu/shader/kernel4.comp b/piet-gpu/shader/kernel4.comp
index 9fc9657..02c7f6f 100644
--- a/piet-gpu/shader/kernel4.comp
+++ b/piet-gpu/shader/kernel4.comp
@@ -161,20 +161,6 @@ void main() {
                 rgb[k] = mix(rgb[k], fg_rgba.rgb, mask[k] * area[k] * fg_rgba.a);
             }
             break;
-        case Cmd_FillMask:
-            CmdFillMask fill_mask = Cmd_FillMask_read(cmd_ref);
-            area = computeArea(xy, fill_mask.backdrop, fill_mask.tile_ref);
-            for (uint k = 0; k < CHUNK; k++) {
-                mask[k] = mix(mask[k], fill_mask.mask, area[k]);
-            }
-            break;
-        case Cmd_FillMaskInv:
-            fill_mask = Cmd_FillMask_read(cmd_ref);
-            area = computeArea(xy, fill_mask.backdrop, fill_mask.tile_ref);
-            for (uint k = 0; k < CHUNK; k++) {
-                mask[k] = mix(mask[k], fill_mask.mask, 1.0 - area[k]);
-            }
-            break;
         case Cmd_BeginClip:
         case Cmd_BeginSolidClip:
             uint blend_slot = blend_sp % BLEND_STACK_SIZE;
diff --git a/piet-gpu/shader/kernel4.spv b/piet-gpu/shader/kernel4.spv
index cf325fd..6f3c33f 100644
Binary files a/piet-gpu/shader/kernel4.spv and b/piet-gpu/shader/kernel4.spv differ
diff --git a/piet-gpu/shader/ptcl.h b/piet-gpu/shader/ptcl.h
index db8d47b..0236183 100644
--- a/piet-gpu/shader/ptcl.h
+++ b/piet-gpu/shader/ptcl.h
@@ -16,10 +16,6 @@ struct CmdFillRef {
     uint offset;
 };
 
-struct CmdFillMaskRef {
-    uint offset;
-};
-
 struct CmdBeginClipRef {
     uint offset;
 };
@@ -48,14 +44,6 @@ struct CmdRef {
     uint offset;
 };
 
-struct SegmentRef {
-    uint offset;
-};
-
-struct SegChunkRef {
-    uint offset;
-};
-
 struct CmdCircle {
     vec2 center;
     float radius;
@@ -103,18 +91,6 @@ CmdFillRef CmdFill_index(CmdFillRef ref, uint index) {
     return CmdFillRef(ref.offset + index * CmdFill_size);
 }
 
-struct CmdFillMask {
-    uint tile_ref;
-    int backdrop;
-    float mask;
-};
-
-#define CmdFillMask_size 12
-
-CmdFillMaskRef CmdFillMask_index(CmdFillMaskRef ref, uint index) {
-    return CmdFillMaskRef(ref.offset + index * CmdFillMask_size);
-}
-
 struct CmdBeginClip {
     uint tile_ref;
     int backdrop;
@@ -180,45 +156,19 @@ CmdJumpRef CmdJump_index(CmdJumpRef ref, uint index) {
 #define Cmd_Circle 1
 #define Cmd_Line 2
 #define Cmd_Fill 3
-#define Cmd_FillMask 4
-#define Cmd_FillMaskInv 5
-#define Cmd_BeginClip 6
-#define Cmd_BeginSolidClip 7
-#define Cmd_EndClip 8
-#define Cmd_Stroke 9
-#define Cmd_Solid 10
-#define Cmd_SolidMask 11
-#define Cmd_Jump 12
+#define Cmd_BeginClip 4
+#define Cmd_BeginSolidClip 5
+#define Cmd_EndClip 6
+#define Cmd_Stroke 7
+#define Cmd_Solid 8
+#define Cmd_SolidMask 9
+#define Cmd_Jump 10
 #define Cmd_size 20
 
 CmdRef Cmd_index(CmdRef ref, uint index) {
     return CmdRef(ref.offset + index * Cmd_size);
 }
 
-struct Segment {
-    vec2 start;
-    vec2 end;
-    float y_edge;
-};
-
-#define Segment_size 20
-
-SegmentRef Segment_index(SegmentRef ref, uint index) {
-    return SegmentRef(ref.offset + index * Segment_size);
-}
-
-struct SegChunk {
-    uint n;
-    SegChunkRef next;
-    SegmentRef segs;
-};
-
-#define SegChunk_size 12
-
-SegChunkRef SegChunk_index(SegChunkRef ref, uint index) {
-    return SegChunkRef(ref.offset + index * SegChunk_size);
-}
-
 CmdCircle CmdCircle_read(CmdCircleRef ref) {
     uint ix = ref.offset >> 2;
     uint raw0 = ptcl[ix + 0];
@@ -298,25 +248,6 @@ void CmdFill_write(CmdFillRef ref, CmdFill s) {
     ptcl[ix + 2] = s.rgba_color;
 }
 
-CmdFillMask CmdFillMask_read(CmdFillMaskRef ref) {
-    uint ix = ref.offset >> 2;
-    uint raw0 = ptcl[ix + 0];
-    uint raw1 = ptcl[ix + 1];
-    uint raw2 = ptcl[ix + 2];
-    CmdFillMask s;
-    s.tile_ref = raw0;
-    s.backdrop = int(raw1);
-    s.mask = uintBitsToFloat(raw2);
-    return s;
-}
-
-void CmdFillMask_write(CmdFillMaskRef ref, CmdFillMask s) {
-    uint ix = ref.offset >> 2;
-    ptcl[ix + 0] = s.tile_ref;
-    ptcl[ix + 1] = uint(s.backdrop);
-    ptcl[ix + 2] = floatBitsToUint(s.mask);
-}
-
 CmdBeginClip CmdBeginClip_read(CmdBeginClipRef ref) {
     uint ix = ref.offset >> 2;
     uint raw0 = ptcl[ix + 0];
@@ -414,14 +345,6 @@ CmdFill Cmd_Fill_read(CmdRef ref) {
     return CmdFill_read(CmdFillRef(ref.offset + 4));
 }
 
-CmdFillMask Cmd_FillMask_read(CmdRef ref) {
-    return CmdFillMask_read(CmdFillMaskRef(ref.offset + 4));
-}
-
-CmdFillMask Cmd_FillMaskInv_read(CmdRef ref) {
-    return CmdFillMask_read(CmdFillMaskRef(ref.offset + 4));
-}
-
 CmdBeginClip Cmd_BeginClip_read(CmdRef ref) {
     return CmdBeginClip_read(CmdBeginClipRef(ref.offset + 4));
 }
@@ -469,16 +392,6 @@ void Cmd_Fill_write(CmdRef ref, CmdFill s) {
     CmdFill_write(CmdFillRef(ref.offset + 4), s);
 }
 
-void Cmd_FillMask_write(CmdRef ref, CmdFillMask s) {
-    ptcl[ref.offset >> 2] = Cmd_FillMask;
-    CmdFillMask_write(CmdFillMaskRef(ref.offset + 4), s);
-}
-
-void Cmd_FillMaskInv_write(CmdRef ref, CmdFillMask s) {
-    ptcl[ref.offset >> 2] = Cmd_FillMaskInv;
-    CmdFillMask_write(CmdFillMaskRef(ref.offset + 4), s);
-}
-
 void Cmd_BeginClip_write(CmdRef ref, CmdBeginClip s) {
     ptcl[ref.offset >> 2] = Cmd_BeginClip;
     CmdBeginClip_write(CmdBeginClipRef(ref.offset + 4), s);
@@ -514,45 +427,3 @@ void Cmd_Jump_write(CmdRef ref, CmdJump s) {
     CmdJump_write(CmdJumpRef(ref.offset + 4), s);
 }
 
-Segment Segment_read(SegmentRef ref) {
-    uint ix = ref.offset >> 2;
-    uint raw0 = ptcl[ix + 0];
-    uint raw1 = ptcl[ix + 1];
-    uint raw2 = ptcl[ix + 2];
-    uint raw3 = ptcl[ix + 3];
-    uint raw4 = ptcl[ix + 4];
-    Segment s;
-    s.start = vec2(uintBitsToFloat(raw0), uintBitsToFloat(raw1));
-    s.end = vec2(uintBitsToFloat(raw2), uintBitsToFloat(raw3));
-    s.y_edge = uintBitsToFloat(raw4);
-    return s;
-}
-
-void Segment_write(SegmentRef ref, Segment s) {
-    uint ix = ref.offset >> 2;
-    ptcl[ix + 0] = floatBitsToUint(s.start.x);
-    ptcl[ix + 1] = floatBitsToUint(s.start.y);
-    ptcl[ix + 2] = floatBitsToUint(s.end.x);
-    ptcl[ix + 3] = floatBitsToUint(s.end.y);
-    ptcl[ix + 4] = floatBitsToUint(s.y_edge);
-}
-
-SegChunk SegChunk_read(SegChunkRef ref) {
-    uint ix = ref.offset >> 2;
-    uint raw0 = ptcl[ix + 0];
-    uint raw1 = ptcl[ix + 1];
-    uint raw2 = ptcl[ix + 2];
-    SegChunk s;
-    s.n = raw0;
-    s.next = SegChunkRef(raw1);
-    s.segs = SegmentRef(raw2);
-    return s;
-}
-
-void SegChunk_write(SegChunkRef ref, SegChunk s) {
-    uint ix = ref.offset >> 2;
-    ptcl[ix + 0] = s.n;
-    ptcl[ix + 1] = s.next.offset;
-    ptcl[ix + 2] = s.segs.offset;
-}
-
diff --git a/piet-gpu/shader/scene.h b/piet-gpu/shader/scene.h
index 6558ad3..03a4884 100644
--- a/piet-gpu/shader/scene.h
+++ b/piet-gpu/shader/scene.h
@@ -16,10 +16,6 @@ struct FillRef {
     uint offset;
 };
 
-struct FillMaskRef {
-    uint offset;
-};
-
 struct StrokeRef {
     uint offset;
 };
@@ -86,16 +82,6 @@ FillRef Fill_index(FillRef ref, uint index) {
     return FillRef(ref.offset + index * Fill_size);
 }
 
-struct FillMask {
-    float mask;
-};
-
-#define FillMask_size 4
-
-FillMaskRef FillMask_index(FillMaskRef ref, uint index) {
-    return FillMaskRef(ref.offset + index * FillMask_size);
-}
-
 struct Stroke {
     uint rgba_color;
 };
@@ -148,10 +134,8 @@ ClipRef Clip_index(ClipRef ref, uint index) {
 #define Element_Fill 8
 #define Element_SetLineWidth 9
 #define Element_Transform 10
-#define Element_FillMask 11
-#define Element_FillMaskInv 12
-#define Element_BeginClip 13
-#define Element_EndClip 14
+#define Element_BeginClip 11
+#define Element_EndClip 12
 #define Element_size 36
 
 ElementRef Element_index(ElementRef ref, uint index) {
@@ -211,14 +195,6 @@ Fill Fill_read(FillRef ref) {
     return s;
 }
 
-FillMask FillMask_read(FillMaskRef ref) {
-    uint ix = ref.offset >> 2;
-    uint raw0 = scene[ix + 0];
-    FillMask s;
-    s.mask = uintBitsToFloat(raw0);
-    return s;
-}
-
 Stroke Stroke_read(StrokeRef ref) {
     uint ix = ref.offset >> 2;
     uint raw0 = scene[ix + 0];
@@ -304,14 +280,6 @@ Transform Element_Transform_read(ElementRef ref) {
     return Transform_read(TransformRef(ref.offset + 4));
 }
 
-FillMask Element_FillMask_read(ElementRef ref) {
-    return FillMask_read(FillMaskRef(ref.offset + 4));
-}
-
-FillMask Element_FillMaskInv_read(ElementRef ref) {
-    return FillMask_read(FillMaskRef(ref.offset + 4));
-}
-
 Clip Element_BeginClip_read(ElementRef ref) {
     return Clip_read(ClipRef(ref.offset + 4));
 }
diff --git a/piet-gpu/shader/tile_alloc.comp b/piet-gpu/shader/tile_alloc.comp
index de6e827..f8bbc0d 100644
--- a/piet-gpu/shader/tile_alloc.comp
+++ b/piet-gpu/shader/tile_alloc.comp
@@ -47,8 +47,6 @@ void main() {
     int x0 = 0, y0 = 0, x1 = 0, y1 = 0;
     switch (tag) {
     case Annotated_Fill:
-    case Annotated_FillMask:
-    case Annotated_FillMaskInv:
     case Annotated_Stroke:
     case Annotated_BeginClip:
     case Annotated_EndClip:
diff --git a/piet-gpu/shader/tile_alloc.spv b/piet-gpu/shader/tile_alloc.spv
index 93cdea6..e901bad 100644
Binary files a/piet-gpu/shader/tile_alloc.spv and b/piet-gpu/shader/tile_alloc.spv differ