Shader files compile again on save; an attached GUI runs the session's post chain

shader_build.zig takes the Shadertoy compile out of the GUI's Post: the
process that holds the core compiles each chain file behind the prefix on a
thread, watches its directory (file_watch's new shader slots), and on a
change reads and hashes each file, compiling only one whose bytes moved. A
failed compile keeps the last good SPIR-V and is said once; the same bytes
are never compiled or reported twice. A file is read with std, not fs.zig's
readFile, whose turn hand-off a worker thread does not hold.

A detached session compiles for its frontends and sends them the chain
(wire post: each pass's scene and level or the file's SPIR-V, and
ShaderAnimation) on attach and on every change, so an attached GUI runs the
same passes, levels and animation as a local one while still reading no disk
and running no program. The attached GUI describes its frames to the chain
from the session's chrome and redraws an animating chain on its own.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/config.zig b/src/config.zig
index 1b432415..86f3e7eb 100644
--- a/src/config.zig
+++ b/src/config.zig
@@ -1017,7 +1017,7 @@ pub const Runtime = struct {
         .{ .word = "Bloom", .action = .{ .scene = .bloom }, .availability = .scene_shaders, .doc = "The brightest ink glows a little: a level, 0 (off) through 3." },
         .{ .word = "Vignette", .action = .{ .scene = .vignette }, .availability = .scene_shaders, .doc = "The window's corners fall into shade: a level, 0 (off) through 3." },
         .{ .word = "Grain", .action = .{ .scene = .grain }, .availability = .scene_shaders, .doc = "The page takes a fine, still grain, like paper: a level, 0 (off) through 3." },
-        .{ .word = "Shader", .action = .shader, .availability = .scene_shaders, .doc = "A Shadertoy file into the post chain, or out of it; off empties the chain." },
+        .{ .word = "Shader", .action = .shader, .availability = .scene_shaders, .doc = "A Shadertoy file into the post chain, or out of it, compiled again when saved; off empties the chain." },
         .{ .word = "ShaderAnimation", .action = .shader_animation, .availability = .scene_shaders, .doc = "When the post chain animates on its own: off, on (while focused) or always." },
         .{ .word = "Placement", .action = .{ .choice = .placement }, .doc = "Where a new pane goes: acme, as makenewwindow does, or pardes, the older rules." },
         .{ .word = "BootShell", .action = .{ .choice = .boot_shell }, .doc = "A document dropped where a lone untouched shell stands: keep the shell, or replace it." },