SamandClaude Fable 5
2ad0043523
A from-scratch World of Warcraft 1.12.1 client in Rust + Bevy. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
45 lines
1.9 KiB
WebGPU Shading Language
45 lines
1.9 KiB
WebGPU Shading Language
// The visible CLOUD LAYER — the reference's sky-dome cloud strip (wow-re
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// `cloud-coverage-pipeline.md` §3 + Addendum A).
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//
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// All color math already happened CPU-side, exactly like the reference: the kernel's `0x6cfb00`
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// port builds the RGBA image per regen (gradient + sun-aligned glow in gamma bytes, alpha = the
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// curve-mapped coverage byte) and uploads it — the reference binds that color buffer zero-copy to
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// its gx texture (`0x58ac70`). The fragment therefore only samples the texel and applies the dome
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// mesh's vertex-colour rim fade (ring alphas 0xff×9, 0x80, 0, 0 — `0x6d0530`).
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//
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// GAMMA: the texels are gamma bytes in a NON-sRGB texture (sampling returns them raw), and the
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// output is a premultiplied-gamma blend over the (gamma) sky, like the celestial discs
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// (decision 0161).
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//
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// SKY-PASS DEPTH (see `sky_order.rs`, "The depth law"): the dome's radius does not decide occlusion —
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// the reference draws the whole sky first, in a squashed back depth slice, and the opaque world paints
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// over it. Forcing the far depth reproduces that: clouds survive only where no world geometry drew.
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#import bevy_pbr::forward_io::VertexOutput
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@group(#{MATERIAL_BIND_GROUP}) @binding(100) var cloud_tex: texture_2d<f32>;
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@group(#{MATERIAL_BIND_GROUP}) @binding(101) var cloud_samp: sampler;
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/// Reverse-Z "infinitely far" — the sky pass's forced depth (`sky_order.rs`).
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const SKY_FAR_DEPTH: f32 = 0.0;
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struct CloudOutput {
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@location(0) color: vec4<f32>,
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@builtin(frag_depth) depth: f32,
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}
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@fragment
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fn fragment(in: VertexOutput) -> CloudOutput {
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let texel = textureSample(cloud_tex, cloud_samp, in.uv);
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var a = texel.a;
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#ifdef VERTEX_COLORS
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a *= in.color.a; // the dome's rim fade (ring alphas)
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#endif
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var out: CloudOutput;
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// Premultiplied gamma blend; the RGB is already the reference's byte math.
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out.color = vec4<f32>(texel.rgb * a, a);
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out.depth = SKY_FAR_DEPTH;
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return out;
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}
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