/**
* Pure helpers + constants for layers and adjustment sub-layers.
*
* Everything in this module is stateless — feed in a layer object and
* get back a value. The legacy gallery editor's module-level helpers
* re-export from here so existing call sites keep working unchanged.
*/
/** True if the layer has at least one FX/adjustment sub-layer. */
export function layerHasAdjustments(layer) {
return !!(layer && layer.adjLayers && layer.adjLayers.length > 0);
}
/**
* True if the layer carries a non-identity Levels OR Color-Balance
* adjustment that needs the per-pixel pass (vs the cheap CSS-filter
* path for plain B/C/H/S).
*/
export function layerNeedsPixelPass(layer) {
if (!layer || !layer.adjustments) return false;
const a = layer.adjustments;
if (a.levels && (a.levels.inBlack !== 0 || a.levels.inWhite !== 255 ||
a.levels.gamma !== 1 ||
a.levels.outBlack !== 0 || a.levels.outWhite !== 255)) return true;
if (a.colorBalance) {
for (const tone of ['shadows', 'midtones', 'highlights']) {
const v = a.colorBalance[tone];
if (v && (v.r || v.g || v.b)) return true;
}
}
return false;
}
/**
* Compact hash of a layer's Levels + Color-Balance values. Used to
* key the per-pixel adjustment cache so we can skip recomputing when
* nothing changed.
*/
export function adjustmentsKey(adj) {
const l = adj.levels || {};
const cb = adj.colorBalance || {};
const s = cb.shadows || {}, m = cb.midtones || {}, h = cb.highlights || {};
return [
l.inBlack|0, l.inWhite|0, l.gamma || 1, l.outBlack|0, l.outWhite|0,
s.r|0, s.g|0, s.b|0, m.r|0, m.g|0, m.b|0, h.r|0, h.g|0, h.b|0,
].join('|');
}
/** Identity params for each adjustment type. */
export function defaultAdjParams(type) {
switch (type) {
case 'brightness-contrast': return { brightness: 1, contrast: 1 };
case 'hue-saturation': return { hue: 0, saturation: 1 };
case 'levels': return { inBlack: 0, inWhite: 255, gamma: 1.0, outBlack: 0, outWhite: 255 };
case 'color-balance': return {
shadows: { r: 0, g: 0, b: 0 },
midtones: { r: 0, g: 0, b: 0 },
highlights: { r: 0, g: 0, b: 0 },
};
}
return {};
}
/** Human-readable name for an adjustment type. */
export function adjLayerLabel(type) {
return {
'brightness-contrast': 'Brightness/Contrast',
'hue-saturation': 'Hue/Saturation',
'levels': 'Levels',
'color-balance': 'Color Balance',
}[type] || type;
}
/**
* Per-type SVG icon strings. Used in popup title bars, the minimised
* FX-dock chips, and the layer-panel sub-row name so the same glyph
* shows up everywhere a given adjustment type appears.
*/
export const ADJ_ICONS = {
'brightness-contrast': '',
'hue-saturation': '',
'levels': '',
'color-balance': '',
};
/** SVG used in the topbar/history button glyphs. */
export const HISTORY_ICON = '';
/** Quick downsampled-alpha check: are there any opaque pixels on this canvas? */
export function isMaskCanvasEmpty(canvas) {
if (!canvas) return true;
try {
const w = canvas.width, h = canvas.height;
if (!w || !h) return true;
const sw = Math.min(200, w), sh = Math.min(200, h);
const tmp = document.createElement('canvas');
tmp.width = sw; tmp.height = sh;
tmp.getContext('2d').drawImage(canvas, 0, 0, sw, sh);
const d = tmp.getContext('2d').getImageData(0, 0, sw, sh).data;
for (let i = 3; i < d.length; i += 4) if (d[i] > 0) return false;
return true;
} catch { return false; }
}
/** Same as `isMaskCanvasEmpty` but accepts a layer wrapper. */
export function isLayerEmpty(layer) {
if (!layer || !layer.canvas) return true;
return isMaskCanvasEmpty(layer.canvas);
}
/**
* Compact "now / 30s / 12m / 4h" relative-time string. Used in the
* editor's history panel labels.
*/
export function relTime(ts) {
if (!ts) return '';
const dt = (Date.now() - ts) / 1000;
if (dt < 5) return 'now';
if (dt < 60) return Math.round(dt) + 's';
if (dt < 3600) return Math.round(dt / 60) + 'm';
return Math.round(dt / 3600) + 'h';
}