max / makeover

Measure well and bevel fidelity across colour depths The 18-of-31 figure that shaped makeover-tui is an ANSI-16 number and was the only one anyone had. This asks the same questions at 256 and 24 bits. Wells collapse onto their face 18/31 at ANSI-16, 4/31 at 256, 2/31 at truecolor. The residual two are not a terminal problem: they are the themes whose raised surface is already white, so the lightening clamps, and they look the same in a browser. Bevels are worse than recorded and recover better. At least one edge vanishes into its own face on 31/31 themes at ANSI-16, not some of them, which is what the sixteen-colour test was pointing at. At 256 it is 4/31. The two edges never collapse onto each other at any depth.

Author: Max Johnson <me@maxj.phd> · 2026-07-28 22:43 UTC

Signed with PGP, not checked

Commit: f6f5c6773d1dbd8771987cb08b224a31edf19399

Parent: ca7c3f0

1 file changed, +85 insertions, -0 deletions

A examples/well_fidelity.rs +85

		@@ -1,0 +1,85 @@
1	+	//! How often a well survives as a fill, per colour depth.
2	+	//!
3	+	//! `makeover-tui` degrades depth from colour to structure because two surface
4	+	//! intents can quantise onto one palette entry. That is measured at ANSI-16.
5	+	//! This asks the same question at 256 and at 24 bits, which is what a modern
6	+	//! terminal actually offers.
7	+
8	+	fn main() {
9	+	let mut n = 0;
10	+	let (mut c16, mut c256, mut ctrue) = (0, 0, 0);
11	+	let (mut b16, mut b256) = (0, 0);
12	+	let (mut e16, mut e256) = (0, 0);
13	+
14	+	for (id, src) in makeover::embedded_themes() {
15	+	let Ok(table) = src.parse::<toml::Table>() else {
16	+	continue;
17	+	};
18	+	let theme = makeover::ThemeColors {
19	+	meta: makeover::parse_meta(id, &table, false),
20	+	colors: makeover::extract_colors(&table),
21	+	};
22	+	let t = makeover::resolve(&theme);
23	+	let rgb = \|k: &str\| t.rgb(k).map(\|(r, g, b)\| makeover::Rgb { r, g, b });
24	+	let (Some(well), Some(raised)) = (rgb("surface-well"), rgb("surface-raised")) else {
25	+	continue;
26	+	};
27	+	let (Some(light), Some(dark)) = (rgb("bevel-light"), rgb("bevel-dark")) else {
28	+	continue;
29	+	};
30	+	n += 1;
31	+
32	+	// A fill is invisible when it lands on the same entry as its face.
33	+	if makeover::quantize(well, &makeover::ANSI_16)
34	+	== makeover::quantize(raised, &makeover::ANSI_16)
35	+	{
36	+	c16 += 1;
37	+	}
38	+	if makeover::quantize(well, &makeover::ANSI_256)
39	+	== makeover::quantize(raised, &makeover::ANSI_256)
40	+	{
41	+	c256 += 1;
42	+	}
43	+	if well.r == raised.r && well.g == raised.g && well.b == raised.b {
44	+	ctrue += 1;
45	+	}
46	+
47	+	// An edge can also vanish into the face it is drawn on, which is the
48	+	// other half of the degradation and the more common one.
49	+	for (pal, counter) in [
50	+	(&makeover::ANSI_16[..], 0usize),
51	+	(makeover::ANSI_240, 1usize),
52	+	] {
53	+	let face = makeover::quantize(raised, pal);
54	+	let lit = makeover::quantize(light, pal);
55	+	let shadow = makeover::quantize(dark, pal);
56	+	if lit == face \|\| shadow == face {
57	+	if counter == 0 { e16 += 1 } else { e256 += 1 }
58	+	}
59	+	}
60	+
61	+	// A bevel loses its second tone the same way.
62	+	if makeover::quantize(light, &makeover::ANSI_16)
63	+	== makeover::quantize(dark, &makeover::ANSI_16)
64	+	{
65	+	b16 += 1;
66	+	}
67	+	if makeover::quantize(light, &makeover::ANSI_256)
68	+	== makeover::quantize(dark, &makeover::ANSI_256)
69	+	{
70	+	b256 += 1;
71	+	}
72	+	}
73	+
74	+	println!("themes measured: {n}\n");
75	+	println!("well collapses onto its face:");
76	+	println!(" ANSI-16 {c16:>3} / {n}");
77	+	println!(" ANSI-256 {c256:>3} / {n}");
78	+	println!(" truecolor {ctrue:>3} / {n}");
79	+	println!("\nbevel loses its second tone:");
80	+	println!(" ANSI-16 {b16:>3} / {n}");
81	+	println!(" ANSI-256 {b256:>3} / {n}");
82	+	println!("\nat least one bevel edge vanishes into its own face:");
83	+	println!(" ANSI-16 {e16:>3} / {n}");
84	+	println!(" ANSI-256 {e256:>3} / {n}");
85	+	}