mirror of
https://github.com/italicsjenga/vello.git
synced 2024-10-17 23:11:30 +11:00
afa706bd7e
This lets us use https://github.com/wgsl-analyzer/wgsl-analyzer for writing the wgsl files. The imports (for wgsl-analyzer) have to be machine specific at the moment - to use this you need to configure .vscode/settings.json yourself. The alternative is to point them at static files on GitHub, which is tempting to make things easier, but would potentially go out of sync with what is actually used.
62 lines
1.8 KiB
GLSL
62 lines
1.8 KiB
GLSL
// Copyright 2022 Google LLC
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// https://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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//
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// Also licensed under MIT license, at your choice.
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// Note: this is the non-atomic version
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struct Tile {
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backdrop: i32,
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segments: u32,
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}
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#import config
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@group(0) @binding(0)
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var<storage> config: Config;
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@group(0) @binding(1)
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var<storage, read_write> tiles: array<Tile>;
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let WG_SIZE = 64u;
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var<workgroup> sh_backdrop: array<i32, WG_SIZE>;
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// Each workgroup computes the inclusive prefix sum of the backdrops
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// in one row of tiles.
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@compute @workgroup_size(64)
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fn main(
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@builtin(local_invocation_id) local_id: vec3<u32>,
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@builtin(workgroup_id) wg_id: vec3<u32>,
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) {
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let width_in_tiles = config.width_in_tiles;
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let ix = wg_id.x * width_in_tiles + local_id.x;
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var backdrop = 0;
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if (local_id.x < width_in_tiles) {
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backdrop = tiles[ix].backdrop;
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}
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sh_backdrop[local_id.x] = backdrop;
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// iterate log2(WG_SIZE) times
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for (var i = 0u; i < firstTrailingBit(WG_SIZE); i += 1u) {
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workgroupBarrier();
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if (local_id.x >= (1u << i)) {
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backdrop += sh_backdrop[local_id.x - (1u << i)];
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}
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workgroupBarrier();
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sh_backdrop[local_id.x] = backdrop;
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}
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if (local_id.x < width_in_tiles) {
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tiles[ix].backdrop = backdrop;
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}
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}
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