Add the B&W HIGH CONTRAST film sim next to ACRIPES

A second black-and-white stock, so it gets its own baseFilter rather than
borrowing Acros': the PHOTO STYLE chips are keyed by baseFilter and the two
greys have to sit side by side.

The look is the B&W MIX plus a push at both ends. The mix rides the matrix — a
non-BT.709 row set (0.38/0.56/0.06, identical rows, sum 1.00) so a red roof
reads bright, a blue sky deep, and the separation is contrast before any curve.
The push rides FILM_TONE (shadow -0.32, highlight +0.26) so the ends move
without touching the midtones, and the midtone slope is SIM_CONTRAST_BIAS (4
contrast units). Every knob still opens at neutral: a sim is colour and tone
only.

Both B&W stocks being mono is now asked once, through isMonochromeBase, so the
colour-only stages (saturation, white balance, the R/B fine-tune) and the
chrome/hue-mixer gate can never half-apply to one of them.

Mirrors the web app's rail (c403dd0).

src/types/index.ts

@@ -62,7 +62,11 @@ export const MIN_CROP_FRAC = 0.08;
 // cool tint in shade, plus a seasonal atmospheric haze/fog veil.
 export type CinemaSeason = 'spring' | 'summer' | 'autumn' | 'winter';
 
-export type BaseFilter = 'classic-neg' | 'classic-chrome' | 'provia' | 'velvia' | 'astia' | 'eterna' | 'monochrome' | 'leica' | 'leica-vivid' | 'none';
+// `monochrome` is Acros' grey ramp; `mono-high-contrast` is the B&W HIGH
+// CONTRAST stock's own — both are black-and-white, so anything that asks "is
+// this a colour stock?" must ask it through isMonochromeBase (colorUtils.ts)
+// rather than comparing against one of these two strings.
+export type BaseFilter = 'classic-neg' | 'classic-chrome' | 'provia' | 'velvia' | 'astia' | 'eterna' | 'monochrome' | 'mono-high-contrast' | 'leica' | 'leica-vivid' | 'none';
 
 export interface ColorAdjustments {
   exposure: number; // -10 to +10 (mapped to matrix multiplier or offset)

src/utils/colorUtils.ts

@@ -52,6 +52,22 @@ function normalizeGainLuma(gain: number[]): { r: number; g: number; b: number }
   return { r: gain[0] * s, g: gain[1] * s, b: gain[2] * s };
 }
 
+// A brightness a stock owns, in Contrast-slider units. The knob itself stays
+// at 0 (a sim is colour only), so the extra slope is added here, where the
+// knob's own gain/offset mapping already lives.
+const SIM_CONTRAST_BIAS: Partial<Record<BaseFilter, number>> = {
+  'mono-high-contrast': 4,
+};
+
+// Black-and-white stocks. Their grey ramp is the whole look, so every
+// colour-only stage below — saturation, white balance, the R/B fine-tune — is
+// skipped for them. One list, asked through one function, so a second B&W
+// stock cannot end up half excluded (a stray Kelvin gain on a grey ramp shows
+// up as a tint).
+const MONO_BASES: BaseFilter[] = ['monochrome', 'mono-high-contrast'];
+export const isMonochromeBase = (baseFilter: BaseFilter | undefined): boolean =>
+  !!baseFilter && MONO_BASES.includes(baseFilter);
+
 // Generate a 4x5 ColorMatrix (array of 20 floats) based on base style and
 // adjustments. Tone-domain knobs (dynamicRange/highlight/shadow) and the
 // exposure-compensation EV gain are intentionally NOT part of the matrix —
@@ -60,7 +76,7 @@ function normalizeGainLuma(gain: number[]): { r: number; g: number; b: number }
 // applyExposureGain (library), never doubled.
 export function getSkiaColorMatrix(baseFilter: BaseFilter, adj: ColorAdjustments): number[] {
   const exposure = adj.exposure;
-  const contrast = adj.contrast;
+  const contrast = adj.contrast + (SIM_CONTRAST_BIAS[baseFilter] ?? 0);
   const saturation = adj.saturation;
   const temperature = adj.temperature;
   const tint = adj.tint;
@@ -190,10 +206,37 @@ export function getSkiaColorMatrix(baseFilter: BaseFilter, adj: ColorAdjustments
       r, g, b, 0, 0,
       0, 0, 0, 1, 0,
     ];
+  } else if (baseFilter === 'mono-high-contrast') {
+    // B&W HIGH CONTRAST — Acros taken through a warm filter, then pushed at the
+    // ends (the push itself lives in FILM_TONE, and its midtone slope in
+    // SIM_CONTRAST_BIAS above).
+    //
+    // The mix is the B&W MIX step: the channel weights are the matrix's whole
+    // job here, and they are deliberately not BT.709. Red is nearly doubled
+    // against its luminance share — so a red roof reads bright, a blue sky and
+    // foliage read deep, and the separation between them is what gives the ramp
+    // its contrast before any curve is applied.
+    //
+    // ponytail: the weights ride the CHANNELS, while the brief that asked for
+    // this stock names HUE groups (red 1.15, orange 1.20, blue 0.70). A 4x5
+    // matrix cannot be hue-selective; if those exact factors are ever wanted,
+    // that is a per-pixel HSL pass in the tone shader, not a row edit here.
+    //
+    // The three rows are identical and sum to 1.00, so a neutral stays the
+    // neutral the sensor recorded and nothing clips at either end.
+    const r = 0.38;
+    const g = 0.56;
+    const b = 0.06;
+    matrix = [
+      r, g, b, 0, 0,
+      r, g, b, 0, 0,
+      r, g, b, 0, 0,
+      0, 0, 0, 1, 0,
+    ];
   }
 
   // 3. Apply Saturation adjustment (standard color matrix transformation)
-  if (baseFilter !== 'monochrome' && saturation !== 0) {
+  if (!isMonochromeBase(baseFilter) && saturation !== 0) {
     const s = 1 + (saturation / 10) * 0.5; // -10 maps to 0.5x, +10 maps to 1.5x saturation
     const invS = 1 - s;
     const r = 0.213 * invS;
@@ -217,7 +260,7 @@ export function getSkiaColorMatrix(baseFilter: BaseFilter, adj: ColorAdjustments
   // consumed by getToneUniforms instead.
 
   // 5. White Balance (Kelvin Temperature and Tint) — skip for monochrome to prevent color leakage
-  if (baseFilter !== 'monochrome') {
+  if (!isMonochromeBase(baseFilter)) {
     const rgbTemp = kelvinToRGB(temperature);
     // Tint is the green↔magenta axis, and it is symmetric: + pushes magenta
     // (red and blue up, green down), - pushes green (green up, red and blue
@@ -246,7 +289,7 @@ export function getSkiaColorMatrix(baseFilter: BaseFilter, adj: ColorAdjustments
   // perceptible size of one Fuji fine-tune step (-9..+9).
   const wbRed = adj.wbRed ?? 0;
   const wbBlue = adj.wbBlue ?? 0;
-  if (baseFilter !== 'monochrome' && (wbRed !== 0 || wbBlue !== 0)) {
+  if (!isMonochromeBase(baseFilter) && (wbRed !== 0 || wbBlue !== 0)) {
     const shiftMat = [
       1 + (wbRed / 9) * 0.1, 0, 0, 0, 0,
       0, 1, 0, 0, 0,

src/utils/defaultRecipes.ts

@@ -45,6 +45,11 @@ export const FILM_SIMS: FilmSim[] = [
   { id: 'sim-astia', name: 'ASTIPES', baseFilter: 'astia', adjustments: { ...DEFAULT_ADJUSTMENTS } },
   { id: 'sim-eterna', name: 'ETERNIPES', baseFilter: 'eterna', adjustments: { ...DEFAULT_ADJUSTMENTS } },
   { id: 'sim-acros', name: 'ACRIPES', baseFilter: 'monochrome', adjustments: { ...DEFAULT_ADJUSTMENTS, grain: 3 } },
+  // Acros taken through a warm filter, then pushed at both ends: the mix (red
+  // up, blue down) rides the matrix, the end push rides FILM_TONE, and the
+  // midtone slope the stock owns is SIM_CONTRAST_BIAS in colorUtils — never an
+  // `adjustments` value, so every knob still opens at neutral.
+  { id: 'sim-bw-high-contrast', name: 'B&W HIGH CONTRAST', baseFilter: 'mono-high-contrast', adjustments: { ...DEFAULT_ADJUSTMENTS } },
   // The rangefinder digital look (M/Q/SL) is not a film stock, so it ships as its own
   // pair instead of one look that has to compromise:
   //   CLASSIC — the stock character: deep solid darks, natural shadows, rich but

src/utils/toneShader.ts

@@ -1,4 +1,5 @@
 import { BaseFilter, ColorAdjustments } from '../types';
+import { isMonochromeBase } from './colorUtils';
 
 // Tone-domain adjustments (Fuji-style Dynamic Range + Highlight/Shadow).
 // SkSL runtime effect over a child image shader.
@@ -199,6 +200,14 @@ const FILM_TONE: Partial<Record<BaseFilter, Partial<ToneUniforms>>> = {
   // Gains are TONE_SKSL's own (sh * 0.34, hl * 0.22), so -0.12 puts the toe at
   // ~5% and -0.05 trims the top ~1%.
   monochrome: { sh: -0.12, hl: -0.05 },
+  // B&W HIGH CONTRAST. Acros' ramp with both ends pushed hard: a deeper toe
+  // (-0.32 against Acros' -0.12) so the darks reach true black, and a shoulder
+  // that LIFTS instead of rolling (-0.05 → +0.26), which is the whites step of
+  // the brief. Midtones see neither mask, so the long smooth stretch between
+  // the two ends 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 mask here.
+  'mono-high-contrast': { sh: -0.32, hl: 0.26 },
 };
 
 export function getToneUniforms(adj: ColorAdjustments, baseFilter?: BaseFilter): ToneUniforms {
@@ -213,7 +222,7 @@ export function getToneUniforms(adj: ColorAdjustments, baseFilter?: BaseFilter):
   // Color Chrome depth per stop of the UI's none/weak/strong. A chrome set is a
   // monochrome look, so both are forced off there: the effect is colour-only
   // (the preview/export matrix skips them for monochrome for the same reason).
-  const colour = baseFilter !== 'monochrome';
+  const colour = !isMonochromeBase(baseFilter);
   const chromeDepth = (v: ColorAdjustments['colorChrome'] | undefined) =>
     !colour || v === 'none' || v == null ? 0 : v === 'strong' ? 0.9 : 0.45;
   const blueDepth = (v: ColorAdjustments['colorChromeBlue'] | undefined) =>