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>
38 lines
1.9 KiB
WebGPU Shading Language
38 lines
1.9 KiB
WebGPU Shading Language
// Night-sky stars (the `Stars.m2` patches) — premultiplied white dots over the sky dome.
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//
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// GAMMA-SPACE BLEND — the gamma composite lane (decision 0161): the reference's framebuffer holds
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// gamma bytes and all its hardware blending happens in gamma space, so the stars' faithful blend is
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// a GAMMA-space alpha blend of white-on-transparent dots (`Stars.blp`, ~98% transparent, mostly low
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// alpha). Under that lane our framebuffer likewise holds gamma bytes and ALL blending is gamma, so the
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// faithful output is simply premultiplied white at the dot's alpha: `(a, a, a, a)` with
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// `a` = texture alpha × the star-curve global alpha (`StandardMaterial::base_color` alpha, set
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// per-frame). Over the near-black night sky that lands on screen at gamma value `a` — the
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// reference's byte — with zero conversion math.
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// SKY-PASS DEPTH (see `sky_order.rs`, "The depth law"): the star dome's own geometry depth is not
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// what decides occlusion — the reference draws its whole sky FIRST, in a squashed back depth slice,
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// and the opaque world paints over it. Forcing the far depth reproduces that from the transparent
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// pass: stars survive only on pixels no world geometry claimed.
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#import bevy_pbr::{
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pbr_fragment::pbr_input_from_standard_material,
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forward_io::VertexOutput,
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}
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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 StarOutput {
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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, @builtin(front_facing) is_front: bool) -> StarOutput {
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let pbr_input = pbr_input_from_standard_material(in, is_front);
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let a = pbr_input.material.base_color.a; // dot texture alpha × the star-curve global alpha
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var out: StarOutput;
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out.color = vec4<f32>(vec3<f32>(a), a); // premultiplied white — raw (GAMMA LANE, 0161)
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out.depth = SKY_FAR_DEPTH;
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return out;
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}
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