3dtours/RecipesCam
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

light: the HIGHLIGHT knob rides half its anchor too, so a lift stops drawing a cloud to paper and a pull stops flattening the quarter under it — the top quarter came back at 0.26x of its own contrast, 0.62x now

Browse Source
This commit is contained in:
3dtours
2026-09-30 17:59:57 +07:00
parent 36fb93658b
commit a56581c757
2 changed files with 68 additions and 37 deletions
Download Patch File Download Diff File Expand all files Collapse all files
docker/frontend/scripts/highlight-knee-check.mjs
+42 -20
View File
@@ -16,15 +16,16 @@
// THE TONE PASS builds the luma a new ramp instead. The four knobs
// (HIGHLIGHT, SHADOW, WHITE, BLACK) are the four zones of the tone-mapping doc —
// one tent each, one per quarter of the ramp — and each knob moves the knot it
// owns by TONE_ANCHOR of the ramp, held inside the knot before it; SHADOW, whose
// knot is the head of the band above it rather than an end of the ramp, moves
// half that. The 0.50 midpoint is the one value all four leave where it was.
// owns by TONE_ANCHOR of the ramp, held inside the knot before it; SHADOW and
// HIGHLIGHT, whose knots are the HEAD of a quarter rather than an end of the
// ramp, move half that. The 0.50 midpoint is the one value all four leave where
// it was.
//
// Both are SkSL, so the SHAPE is pinned on the source; the arithmetic is then
// checked against the source's own constants, and the ramp re-run here as a twin
// so monotonicity, the neutral identity, the partition of the four masks and the
// slope SHADOW leaves the band above it are checked rather than asserted in a
// comment.
// slopes SHADOW and HIGHLIGHT leave the quarters around them are checked rather
// than asserted in a comment.
//
// node scripts/highlight-knee-check.mjs
import assert from 'node:assert/strict';
@@ -84,7 +85,7 @@ assert.match(sksl, /float hlMask = clamp\(smoothstep\(0\.50, 0\.75, t\) - whMask
// pair of masked terms (0.12 at t = 0, 0.18 at t = 1) and half of each at the
// knots next to them.
assert.match(sksl, /float a4 = 1\.0 \+ 0\.25 \* wh - dr \* 0\.18;/);
assert.match(sksl, /float a3 = clamp\(0\.75 \+ 0\.25 \* hl - dr \* 0\.09, 0\.5, a4\);/);
assert.match(sksl, /float a3 = clamp\(0\.75 \+ 0\.25 \* 0\.5 \* hl - dr \* 0\.09, 0\.5, a4\);/);
assert.match(sksl, /float a1 = clamp\(0\.25 \+ 0\.25 \* 0\.5 \* sh \+ dr \* 0\.06, 0\.0, 0\.5\);/);
assert.match(sksl, /float a0 = clamp\(0\.25 \* bl \+ dr \* 0\.12, 0\.0, a1\);/);
assert.doesNotMatch(sksl, /o \+= dr \* 0\.12/, 'DR is an additive term again — it folds the flat stretch at 0.238');
@@ -174,7 +175,7 @@ function ramp(t, k) {
const whMask = smoothstep(0.75, 1, t);
const hlMask = clamp01(smoothstep(0.5, 0.75, t) - whMask);
const a4 = 1 + A * wh - dr * 0.18;
const a3 = Math.min(a4, Math.max(0.5, 0.75 + A * hl - dr * 0.09));
const a3 = Math.min(a4, Math.max(0.5, 0.75 + A * 0.5 * hl - dr * 0.09));
const a1 = Math.min(0.5, Math.max(0, 0.25 + A * 0.5 * sh + dr * 0.06));
const a0 = Math.min(a1, Math.max(0, A * bl + dr * 0.12));
let o = mix(a0, a1, lin(0, 0.25, t));
@@ -237,16 +238,18 @@ for (const k of combos) {
}
assert.ok(worst > -1e-12, `worst step ${worst} — the ramp is folded`);
// A knob moves its own quarter, and only its own: +BLACK takes the toe off the
// floor, -HIGHLIGHT pulls the 0.75 knot onto the midpoint, and WHITE - rolls the
// head under 1.0. That is the reach a tonal-range slider has — a quarter of the
// ramp, so the middle stays a middle. SHADOW is the exception and moves HALF of
// it: its knot is the HEAD of the 0.25..0.50 band, so a whole quarter would draw
// that band flat, which is the wash-out the knob was reported for.
// floor, -HIGHLIGHT rolls the 0.75 knot down a quarter of the way to the
// midpoint, and WHITE - rolls the head under 1.0. That is the reach a
// tonal-range slider has — a quarter of the ramp, so the middle stays a middle.
// SHADOW and HIGHLIGHT are the exceptions and move HALF of it: their knots (a1,
// a3) are the HEAD of the quarter in front of them, so a whole quarter would draw
// that quarter flat, which is the wash-out both knobs were reported for.
close(ramp(0, {}).o, 0, 'a neutral toe moved');
close(ramp(0, { bl: 1 }).o, A, 'BLACK no longer reaches a quarter of the ramp');
close(ramp(0.25, { sh: 1 }).o, 0.375, 'SHADOW no longer stops halfway to the midpoint');
close(ramp(0.25, { sh: -1 }).o, 0.125, 'SHADOW no longer stops halfway to the floor');
close(ramp(0.75, { hl: -1 }).o, 0.5, 'HIGHLIGHT no longer reaches the midpoint');
close(ramp(0.75, { hl: -1 }).o, 0.625, 'HIGHLIGHT no longer stops halfway to the midpoint');
close(ramp(0.75, { hl: 1 }).o, 0.875, 'HIGHLIGHT no longer stops halfway to the white knot');
close(ramp(1, { wh: -1 }).o, 0.75, 'WHITE no longer rolls the head under 1.0');
close(ramp(0.25, {}).o, 0.25, 'a neutral knot moved');
close(ramp(0.75, {}).o, 0.75, 'a neutral knot moved');
@@ -285,26 +288,45 @@ for (let sh = -1; sh <= 1.0001; sh += 1 / 64) {
assert.ok(below >= 0.5 - 1e-12, `SHADOW drew the quarter below it flat at ${sh}: slope ${below}`);
assert.ok(band <= 1.5 + 1e-12, `SHADOW stretched the band above it at ${sh}: slope ${band}`);
}
// The film stocks ride the same knot, so a halved SHADOW would have halved their
// crush with it. They are written at DOUBLE for that reason, and the look they
// were tuned to is the knot, not the unit: these three land where they always
// did (0.18 Classic Chrome/Vivid, 0.22 Acros, 0.17 Acros HC).
// HIGHLIGHT pays the same way and at BOTH ends, which is why its knot is the
// worse of the two: a3 is the head of the top quarter, so lifting it draws
// 0.75..1.00 flat (a cloud to paper) and pulling it draws 0.50..0.75 flat. At the
// whole anchor the sweep in scratchpad/knob-sweep.mjs read the quarter slopes as
// 1.00 1.00 2.00 0.00 at +100 and 1.00 1.00 0.00 2.00 at -100 — a quarter flat
// either way. Half draws neither, over the whole travel.
for (let hl = -1; hl <= 1.0001; hl += 1 / 64) {
const mid = (ramp(0.75, { hl }).o - ramp(0.5, { hl }).o) / 0.25;
const top = (ramp(1, { hl }).o - ramp(0.75, { hl }).o) / 0.25;
assert.ok(mid >= 0.5 - 1e-12, `HIGHLIGHT drew the quarter below it flat at ${hl}: slope ${mid}`);
assert.ok(top >= 0.5 - 1e-12, `HIGHLIGHT drew the top quarter flat at ${hl}: slope ${top}`);
assert.ok(mid <= 1.5 + 1e-12, `HIGHLIGHT stretched the quarter below it at ${hl}: slope ${mid}`);
assert.ok(top <= 1.5 + 1e-12, `HIGHLIGHT stretched the top quarter at ${hl}: slope ${top}`);
}
// The film stocks ride the same knots, so a halved SHADOW or HIGHLIGHT would have
// halved their crush and their shoulder with it. They are written at DOUBLE for
// that reason, and the look they were tuned to is the knot, not the unit: these
// land where they always did (0.18 Classic Chrome/Vivid, 0.22 Acros, 0.17 Acros
// HC; the head 0.7375 on Acros and 0.815 on Acros HC).
const filmTone = tone.match(/const FILM_TONE[\s\S]*?\n};/)?.[0];
assert.ok(filmTone, 'FILM_TONE is gone — the stocks no longer shape the ramp at all');
// The keys are quoted or not depending on whether they are identifiers, so the
// quotes come off before the lookup.
const filmFlat = filmTone.replace(/['"]/g, '');
for (const [name, sh, knot] of [
for (const [name, sh, knot, hlSrc, hl, head] of [
['classic-chrome', -0.56, 0.18],
['classic-vivid', -0.56, 0.18],
['monochrome', -0.24, 0.22],
['mono-high-contrast', -0.64, 0.17],
['monochrome', -0.24, 0.22, '-0.10', -0.1, 0.7375],
['mono-high-contrast', -0.64, 0.17, '0.52', 0.52, 0.815],
]) {
assert.ok(
filmFlat.includes(`${name}: { sh: ${sh}`),
`${name} is not on the doubled ${sh} — the stock's crush moved with the knob's reach`
);
close(ramp(0.25, { sh }).o, knot, `${name}'s shadow knot moved`);
if (hlSrc) {
assert.ok(filmFlat.includes(`hl: ${hlSrc}`), `${name} is not on the doubled ${hlSrc} — its shoulder moved with the knob's reach`);
close(ramp(0.75, { hl }).o, head, `${name}'s highlight knot moved`);
}
}
// The two ends stay ordered even at full deflection against each other: the toe
// can never climb past the head.
docker/frontend/shared/utils/toneShader.ts
+26 -17
View File
@@ -110,9 +110,9 @@ const BAND_BLOCK = hslBandGaps()
// the toe can reach the quarter above it and the head can be rolled onto it —
// and never past, because each knot is clamped inside the one after it.
//
// SHADOW is the one knob that moves HALF of it. The knot it owns is the HEAD of
// the 0.25..0.50 quarter, so a unit of lift is a unit of slope that quarter
// loses, and at a whole quarter the band is drawn flat — see the note on a1.
// SHADOW and HIGHLIGHT move HALF of it. The knots they own (a1, a3) are the HEAD
// of a quarter, so a unit of lift is a unit of slope that quarter loses, and at
// a whole quarter the band is drawn flat — see the notes on a1 and a3.
export const TONE_ANCHOR = 0.25;
// The tone and exposure maths, in ONE copy, because two passes ask it: the
@@ -132,9 +132,9 @@ float lin(float e0, float e1, float x) {
return clamp((x - e0) / (e1 - e0), 0.0, 1.0);
}
// The ramp the pixel is rebuilt through. Knots on 0.00, 0.25, 0.50, 0.75 and
// 1.00; a knob moves the knot it owns by TONE_ANCHOR of the ramp — SHADOW by
// half of that, its knot being the head of a band — and each knot is held inside
// the one after it so the five can never cross. 0.50 is fixed:
// 1.00; a knob moves the knot it owns by TONE_ANCHOR of the ramp — SHADOW and
// HIGHLIGHT by half of that, their knots being the heads of bands — and each knot
// is held inside the one after it so the five can never cross. 0.50 is fixed:
// it is the one point all four sliders leave alone, which is what keeps a
// mid-grey a mid-grey while the ends move around it. Straight between the knots,
// so every knob on zero is exactly the identity (see the note at the head of
@@ -193,7 +193,15 @@ vec3 lightMove(vec3 c, float t, float o) {
}
vec3 toneRamp(vec3 c, float t, float bl, float sh, float hl, float wh, float dr) {
float a4 = 1.0 + ${TONE_ANCHOR} * wh - dr * 0.18;
float a3 = clamp(0.75 + ${TONE_ANCHOR} * hl - dr * 0.09, 0.5, a4);
// HIGHLIGHT rides half the anchor for the reason a1 below does, and this knot
// is the worse of the two: a3 is the HEAD of the 0.75..1.00 quarter, so a unit
// of lift is a unit of slope the top quarter loses — at the whole anchor +100
// lands the knot ON a4 and the quarter is drawn flat (a cloud to paper, the
// quarter slopes 1.00 1.00 2.00 0.00), and the same knob the other way pins it
// on 0.50 and flattens the quarter BELOW it instead (1.00 1.00 0.00 2.00).
// Half draws neither: every quarter keeps between 0.5 and 1.5 of its own slope
// over the whole travel, and the head still rolls from 0.625 to 0.875.
float a3 = clamp(0.75 + ${TONE_ANCHOR} * 0.5 * hl - dr * 0.09, 0.5, a4);
// SHADOW rides HALF the anchor, and that is a measured ceiling rather than a
// taste. a1 is the HEAD of the quarter above it, so the band 0.25..0.50 pays
// in slope for every unit this knot rises — the slope is (0.5 - a1) / 0.25 —
@@ -659,11 +667,12 @@ export interface ToneUniforms {
// here instead of in the 4x5 matrix, which cannot move one end of the curve
// without also moving the other.
//
// The `sh` here is written at DOUBLE what the knob's own arithmetic reads, which
// is not a taste either: SHADOW moves its knot half an anchor per unit (see a1
// in TONE_MATH_SKSL), so a stock that wants the toe on 0.18 has to ask for -0.56
// to land it there. The stock's crush is the knot it puts the ramp on; the unit
// it is written in belongs to the knob, not to the look.
// The `sh` and `hl` here are written at DOUBLE what the knob's own arithmetic
// reads, which is not a taste either: SHADOW and HIGHLIGHT each move their knot
// half an anchor per unit (see a1 and a3 in TONE_MATH_SKSL), so a stock that
// wants the toe on 0.18 has to ask for -0.56 to land it there. The stock's crush
// is the knot it puts the ramp on; the unit it is written in belongs to the
// knob, not to the look.
const FILM_TONE: Partial<Record<BaseFilter, Partial<ToneUniforms>>> = {
'classic-chrome': { sh: -0.56 },
// Classic Vivid is Classic Chrome's sibling — the shadow crush belongs to the
@@ -678,18 +687,18 @@ const FILM_TONE: Partial<Record<BaseFilter, Partial<ToneUniforms>>> = {
// every step the matrix handed over — which is what 'deep black' costs in a
// colour stock and does not have to cost here.
// The values move the two end knots of the ramp: -0.24 puts the toe on 0.22
// and -0.05 rolls the head to 0.7375 (HIGHLIGHT is TONE_ANCHOR per unit, the
// doubled SHADOW half of it).
monochrome: { sh: -0.24, hl: -0.05 },
// and -0.10 rolls the head to 0.7375 (both SHADOW and HIGHLIGHT ride HALF an
// anchor per unit, so a stock written against the knot asks for double).
monochrome: { sh: -0.24, hl: -0.10 },
// B&W HIGH CONTRAST. Acros' ramp with both ends pushed hard: a deeper toe
// (-0.64 against Acros' -0.24, so 0.17 against 0.22) so the darks reach true
// black, and a shoulder that LIFTS instead of rolling (-0.05 → +0.26, the
// black, and a shoulder that LIFTS instead of rolling (-0.10 → +0.52, the
// head going to 0.815), which is the whites step of the brief. The stretch
// between the two inner knots (0.25 and 0.75) is still the identity, so the
// long smooth stretch of the greys survives — that is what keeps a hard push
// off the posterised look, and the strength the stock needs on the greys is
// its matrix slope (SIM_CONTRAST_BIAS in colorUtils), not another move here.
'mono-high-contrast': { sh: -0.64, hl: 0.26 },
'mono-high-contrast': { sh: -0.64, hl: 0.52 },
};
export function getToneUniforms(adj: ColorAdjustments, baseFilter?: BaseFilter): ToneUniforms {