Clarify licensing for WGSL shaders (#205)

As stated by the README, the intention is for the shaders to be provided under the terms of the Unlicense in addition to the MIT and Apache-2.0 licenses. While here, add a self-contained UNLICENSE file to replace the external reference to unlicense.org.
2025-01-09 20:31:29 +11:00 · 2022-11-19 10:45:42 -06:00 · 2022-11-19 10:45:42 -06:00 · 18c0da02e5
parent de998220db
commit 18c0da02e5
29 changed files with 54 additions and 364 deletions
--- a/README.md
+++ b/README.md
@ -38,7 +38,7 @@ In short, the goal is to facilitate the research now, collect the data, and then

 The piet-gpu project is dual-licensed under both [Apache 2.0](LICENSE-APACHE) and [MIT](LICENSE_MIT) licenses.

-In addition, the shaders are provided under the terms of the [Unlicense]. The intent is for this research to be used in as broad a context as possible.
+In addition, the shaders are provided under the terms of the [Unlicense](UNLICENSE). The intent is for this research to be used in as broad a context as possible.

 The dx12 backend was adapted from piet-dx12 by Brian Merchant.

@ -51,6 +51,5 @@ Contributions are welcome by pull request. The [Rust code of conduct] applies. P
 [Shader Model 6]: https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/hlsl-shader-model-6-0-features-for-direct3d-12
 [DXC]: https://github.com/microsoft/DirectXShaderCompiler
 [Druid]: https://github.com/linebender/druid
-[Unlicense]: https://unlicense.org/
 [Rust code of conduct]: https://www.rust-lang.org/policies/code-of-conduct
 [shader_compilation.md]: ./doc/shader_compilation.md
--- a/24
+++ b/24
@ -0,0 +1,24 @@
+This is free and unencumbered software released into the public domain.
+
+Anyone is free to copy, modify, publish, use, compile, sell, or
+distribute this software, either in source code form or as a compiled
+binary, for any purpose, commercial or non-commercial, and by any
+means.
+
+In jurisdictions that recognize copyright laws, the author or authors
+of this software dedicate any and all copyright interest in the
+software to the public domain. We make this dedication for the benefit
+of the public at large and to the detriment of our heirs and
+successors. We intend this dedication to be an overt act of
+relinquishment in perpetuity of all present and future rights to this
+software under copyright law.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
+
+For more information, please refer to <http://unlicense.org/>
--- a/piet-wgsl/shader/backdrop.wgsl
+++ b/piet-wgsl/shader/backdrop.wgsl
@ -1,18 +1,4 @@
-// Copyright 2022 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// Also licensed under MIT license, at your choice.
+// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense

 // Note: this is the non-atomic version
 struct Tile {
--- a/piet-wgsl/shader/backdrop_dyn.wgsl
+++ b/piet-wgsl/shader/backdrop_dyn.wgsl
@ -1,18 +1,4 @@
-// Copyright 2022 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// Also licensed under MIT license, at your choice.
+// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense

 // Prefix sum for dynamically allocated backdrops

--- a/piet-wgsl/shader/bbox_clear.wgsl
+++ b/piet-wgsl/shader/bbox_clear.wgsl
@ -1,18 +1,4 @@
-// Copyright 2022 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// Also licensed under MIT license, at your choice.
+// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense

 #import config

--- a/piet-wgsl/shader/binning.wgsl
+++ b/piet-wgsl/shader/binning.wgsl
@ -1,18 +1,4 @@
-// Copyright 2022 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// Also licensed under MIT license, at your choice.
+// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense

 // The binning stage

--- a/piet-wgsl/shader/clip_leaf.wgsl
+++ b/piet-wgsl/shader/clip_leaf.wgsl
@ -1,3 +1,4 @@
+// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense

 #import config
 #import bbox
--- a/piet-wgsl/shader/clip_reduce.wgsl
+++ b/piet-wgsl/shader/clip_reduce.wgsl
@ -1,3 +1,4 @@
+// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense

 #import config
 #import bbox
--- a/piet-wgsl/shader/coarse.wgsl
+++ b/piet-wgsl/shader/coarse.wgsl
@ -1,18 +1,4 @@
-// Copyright 2022 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// Also licensed under MIT license, at your choice.
+// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense

 // The coarse rasterization stage.

--- a/piet-wgsl/shader/draw_leaf.wgsl
+++ b/piet-wgsl/shader/draw_leaf.wgsl
@ -1,18 +1,4 @@
-// Copyright 2022 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// Also licensed under MIT license, at your choice.
+// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense

 // Finish prefix sum of drawtags, decode draw objects.

--- a/piet-wgsl/shader/draw_reduce.wgsl
+++ b/piet-wgsl/shader/draw_reduce.wgsl
@ -1,18 +1,4 @@
-// Copyright 2022 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// Also licensed under MIT license, at your choice.
+// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense

 #import config
 #import drawtag
--- a/piet-wgsl/shader/fine.wgsl
+++ b/piet-wgsl/shader/fine.wgsl
@ -1,18 +1,4 @@
-// Copyright 2022 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// Also licensed under MIT license, at your choice.
+// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense

 // Fine rasterizer. This can run in simple (just path rendering) and full
 // modes, controllable by #define.
--- a/piet-wgsl/shader/path_coarse.wgsl
+++ b/piet-wgsl/shader/path_coarse.wgsl
@ -1,18 +1,4 @@
-// Copyright 2022 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// Also licensed under MIT license, at your choice.
+// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense

 #import config
 #import pathtag
--- a/piet-wgsl/shader/path_coarse_full.wgsl
+++ b/piet-wgsl/shader/path_coarse_full.wgsl
@ -1,18 +1,4 @@
-// Copyright 2022 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// Also licensed under MIT license, at your choice.
+// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense

 // Path coarse rasterization for the full implementation.

--- a/piet-wgsl/shader/pathseg.wgsl
+++ b/piet-wgsl/shader/pathseg.wgsl
@ -1,18 +1,4 @@
-// Copyright 2022 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// Also licensed under MIT license, at your choice.
+// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense

 // Path segment decoding for the full case.

--- a/piet-wgsl/shader/pathtag_reduce.wgsl
+++ b/piet-wgsl/shader/pathtag_reduce.wgsl
@ -1,18 +1,4 @@
-// Copyright 2022 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// Also licensed under MIT license, at your choice.
+// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense

 #import config
 #import pathtag
--- a/piet-wgsl/shader/pathtag_scan.wgsl
+++ b/piet-wgsl/shader/pathtag_scan.wgsl
@ -1,18 +1,4 @@
-// Copyright 2022 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// Also licensed under MIT license, at your choice.
+// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense

 #import config
 #import pathtag
--- a/piet-wgsl/shader/shared/bbox.wgsl
+++ b/piet-wgsl/shader/shared/bbox.wgsl
@ -1,18 +1,4 @@
-// Copyright 2022 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// Also licensed under MIT license, at your choice.
+// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense

 // The annotated bounding box for a path. It has been transformed,
 // but contains a link to the active transform, mostly for gradients.
--- a/piet-wgsl/shader/shared/blend.wgsl
+++ b/piet-wgsl/shader/shared/blend.wgsl
@ -1,19 +1,4 @@
-// Copyright 2022 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// Also licensed under MIT license, at your choice.
-
+// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense

 // Color mixing modes

--- a/piet-wgsl/shader/shared/bump.wgsl
+++ b/piet-wgsl/shader/shared/bump.wgsl
@ -1,18 +1,4 @@
-// Copyright 2022 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// Also licensed under MIT license, at your choice.
+// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense

 // TODO: robust memory (failure flags)
 struct BumpAllocators {
--- a/piet-wgsl/shader/shared/clip.wgsl
+++ b/piet-wgsl/shader/shared/clip.wgsl
@ -1,3 +1,5 @@
+// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense
+ 
 struct Bic {
    a: u32,
    b: u32,
--- a/piet-wgsl/shader/shared/config.wgsl
+++ b/piet-wgsl/shader/shared/config.wgsl
@ -1,18 +1,4 @@
-// Copyright 2022 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// Also licensed under MIT license, at your choice.
+// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense

 struct Config {
    width_in_tiles: u32,
--- a/piet-wgsl/shader/shared/cubic.wgsl
+++ b/piet-wgsl/shader/shared/cubic.wgsl
@ -1,18 +1,4 @@
-// Copyright 2022 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// Also licensed under MIT license, at your choice.
+// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense

 struct Cubic {
    p0: vec2<f32>,
--- a/piet-wgsl/shader/shared/drawtag.wgsl
+++ b/piet-wgsl/shader/shared/drawtag.wgsl
@ -1,18 +1,4 @@
-// Copyright 2022 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// Also licensed under MIT license, at your choice.
+// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense

 // The DrawMonoid is computed as a prefix sum to aid in decoding
 // the variable-length encoding of draw objects.
--- a/piet-wgsl/shader/shared/pathtag.wgsl
+++ b/piet-wgsl/shader/shared/pathtag.wgsl
@ -1,18 +1,4 @@
-// Copyright 2022 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// Also licensed under MIT license, at your choice.
+// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense

 struct TagMonoid {
    trans_ix: u32,
--- a/piet-wgsl/shader/shared/ptcl.wgsl
+++ b/piet-wgsl/shader/shared/ptcl.wgsl
@ -1,18 +1,4 @@
-// Copyright 2022 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// Also licensed under MIT license, at your choice.
+// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense

 // Layout of per-tile command list
 // Initial allocation, in u32's.
--- a/piet-wgsl/shader/shared/segment.wgsl
+++ b/piet-wgsl/shader/shared/segment.wgsl
@ -1,18 +1,4 @@
-// Copyright 2022 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// Also licensed under MIT license, at your choice.
+// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense

 struct Segment {
    origin: vec2<f32>,
--- a/piet-wgsl/shader/shared/tile.wgsl
+++ b/piet-wgsl/shader/shared/tile.wgsl
@ -1,18 +1,4 @@
-// Copyright 2022 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// Also licensed under MIT license, at your choice.
+// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense

 // Common datatypes for path and tile intermediate info.

@ -26,4 +12,4 @@ struct Path {
 struct Tile {
    backdrop: i32,
    segments: u32,
-}
+}
--- a/piet-wgsl/shader/tile_alloc.wgsl
+++ b/piet-wgsl/shader/tile_alloc.wgsl
@ -1,18 +1,4 @@
-// Copyright 2022 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-// Also licensed under MIT license, at your choice.
+// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense

 // Tile allocation (and zeroing of tiles)