62 lines
2.9 KiB
Markdown
62 lines
2.9 KiB
Markdown
# Proposal
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## Why
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Commit `tpypxmkn` changed the vendor PPD default `*DefaultBRColorMode:
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Normal → None` on the theory that the printer's own CIE conversion washes out
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colours, and the spec recorded the result as `Requirement: Colour output is
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saturated by default`. A controlled before/after comparison now shows the
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change had **no visible effect**: prints made after it look the same as prints
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made before it, and both are clearly less saturated than the same document
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printed through the Mac's local driver. The commit itself had already noted
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that a second candidate (`VividNoCIE`) produced no difference from `None`; the
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new comparison extends that to `None` vs. the vendor default `Normal`. The
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washout originates in the server-side PostScript path, not in the printer's
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`UseCIEColor` switch — so the README and the spec currently promise a fix that
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does not exist, and the PPD carries a "modified by this repo" deviation for no
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measurable benefit.
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## What Changes
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- **PPD** (`assets/Brother HL-4150CDN/ppd/BR4150_2.PPD`): restore the vendor
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default `*DefaultBRColorMode: Normal` and remove the comment block that
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justified the `None` deviation. The six `APPrinterPreset` entries stay —
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they are a separate feature and unaffected by this finding.
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- **README**: correct all three places that repeat the claim — the options
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table (`Normal` is the default again), *Changes to the vendor PPD* (only the
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presets remain a deviation), and the troubleshooting section *Colours are
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printed pale / washed out*, rewritten from "fixed via `UseCIEColor` off" to
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a documented, tested limitation: `BRColorMode`/`UseCIEColor` settings do not
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measurably change saturation; for colour-critical output use the local
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driver.
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- **Spec** (`printserver/cups`): remove `Requirement: Colour output is
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saturated by default` (its claim is disproven) and add a requirement that
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the queue preserves the vendor PPD colour-mode default unless explicitly
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overridden — encoding the revert and preventing another untested deviation.
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## Capabilities
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### New Capabilities
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(none)
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### Modified Capabilities
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- `printserver/cups`: the requirement *Colour output is saturated by default*
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is removed and replaced by a requirement that the vendor PPD colour-mode
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default is preserved.
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## Impact
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- `assets/Brother HL-4150CDN/ppd/BR4150_2.PPD` — one value line plus its
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comment restored to the vendor original.
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- `README.md` — three sections (options table, vendor-PPD section,
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colours troubleshooting).
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- `openspec/specs/printserver/cups/spec.md` — one requirement removed, one
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added (applied at archive time).
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- Runtime behaviour: only the queue's `BRColorMode` default changes back
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(`None` → `Normal`); per-job/per-queue overrides via `PRINTER_OPTIONS` or
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`-o` are untouched, as are the presets and `PRINTER_OPTIONS` itself. No
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container, entrypoint or discovery changes. Since the two defaults print
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identically, no user-visible difference is expected from the revert either.
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