makeover-tui

The terminal renderer for makeover-layout, on ratatui.

Named for the target and not for the library, the same way makeover-immediate is named for the mode and not for egui.

What a terminal actually costs you

Not colour, on any terminal built this decade. Measured across the 31 shipped themes (makeover’s well_fidelity example):

The threshold is 256, not 24-bit. The two failures surviving at truecolor are not terminal failures: they are the themes whose raised surface is already white, so the lightening clamps and the well lands on its face. Those render identically in a browser, and makeover already asserts them.

What a terminal costs is geometry. An edge occupies a whole cell per side, and a cell is roughly 8x17 pixels, so a one-pixel bevel becomes an order of magnitude heavier. frame returns a shrunk Rect rather than pretending the region survived. There is nowhere to put a corner radius, so radius_control and radius_container mean the same thing here. A fill begins and ends on a cell boundary.

That is the constraint worth designing against. It does not improve, it is not detectable, and it applies equally to the best terminal ever written.

Where fidelity matters

At Fidelity::Ansi16 the depth vocabulary collapses: a well cannot be filled distinctly on most themes and a bevel loses an edge on all of them, so a raised card and a well both read as one single-tone box. Colour cannot carry the distinction, so frame carries it with the glyphs, doubling the frame for a raised surface and leaving a well light. Above sixteen colours that fallback never fires, which is tested, because a doubled frame on every modern terminal would be shouting.

Fidelity::detect() reads COLORTERM then TERM and is deliberately credulous. A terminal that understates itself costs a slightly heavier frame; a terminal that overstates itself was going to render wrongly whatever this crate assumed.

Palette::shows is not a low-colour workaround. It is a correctness check that a fill will be visible against what is behind it, and at truecolor it fires on exactly the two clamping themes, which is when it should.

Substitution is renderer policy

Substituting one intent for another belongs to a renderer, never to the description. Falling back from Fill::Well to Page is an answer for a renderer that can always paint an exact colour; here it is wrong, because the page is usually the surface a well is cut into, so the substitution produces the invisibility it was meant to prevent. makeover-immediate wants that fallback and this renderer does not.

Status

On crates.io. Intended first consumers are alloy_tui and shop, both of which already take makeover and makeover-geometry from the registry.

Design lives in the wiki note makeover-tui; the backlog is in GoingsOn under the project of the same name.

Licence

MIT.