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personal-website/src/scripts/ascii-shared.ts

316 lines
9.2 KiB
TypeScript

/**
* Shared types, constants, and utilities for ASCII rendering.
* Used by both WebGL renderer and UI components.
*/
// ============= Types =============
export interface AsciiOptions {
width?: number;
height?: number;
contrast?: number;
exposure?: number;
invert?: boolean;
saturation?: number;
gamma?: number;
charSet?: CharSetKey | string;
color?: boolean;
dither?: number;
edgeMode?: EdgeMode;
autoStretch?: boolean;
overlayStrength?: number;
aspectMode?: AspectMode;
denoise?: boolean;
fontAspectRatio?: number;
onProgress?: (progress: number) => void;
sharpen?: number;
edgeThreshold?: number;
shadows?: number;
highlights?: number;
scanlines?: number;
vignette?: number;
monoColor?: string;
backgroundColor?: string;
}
export interface AsciiResult {
output: string;
isHtml: boolean;
width: number;
height: number;
}
export type EdgeMode = 'none' | 'simple' | 'sobel' | 'canny';
export type CharSetKey = 'standard' | 'extended' | 'blocks' | 'minimal' | 'matrix' | 'dots' | 'shapes';
export type AspectMode = 'fit' | 'fill' | 'stretch';
export interface ImageMetadata {
color_dominant?: [number, number, number];
color_palette?: [number, number, number][];
has_fine_detail?: boolean;
}
export interface AsciiSettings {
exposure: number;
contrast: number;
saturation: number;
gamma: number;
invert: boolean;
color: boolean;
dither: number;
denoise: boolean;
edgeMode: number;
overlayStrength: number;
resolution: number;
charSet: CharSetKey;
sharpen: number;
edgeThreshold: number;
shadows: number;
highlights: number;
scanlines: number;
vignette: number;
monoColor: string;
backgroundColor: string;
}
// ============= Constants =============
export const CHAR_SETS: Record<CharSetKey, string> = {
standard: '@W%$NQ08GBR&ODHKUgSMw#Xbdp5q9C26APahk3EFVesm{}o4JZcjnuy[f1xi*7zYt(l/I\\v)T?]r><+"L;|!~:,-_.\' ',
extended: '░▒▓█▀▄▌▐│┤╡╢╖╕╣║╗╝╜╛┐└┴┬├─┼╞╟╚╔╩╦╠═╬╧╨╤╥╙╘╒╓╫╪┘┌ ',
blocks: '█▓▒░ ',
minimal: '#+-. ',
matrix: 'ハミヒーウシナモニサワツオリアホテマケメエカキムユラセネスタヌヘ1234567890:.=*+-<>',
dots: '⣿⣷⣯⣟⡿⢿⣻⣽⣾⣶⣦⣤⣄⣀⡀ ',
shapes: '@%#*+=-:. '
};
export const ASPECT_MODES: Record<string, AspectMode> = {
fit: 'fit',
fill: 'fill',
stretch: 'stretch'
};
export const EDGE_MODES: Record<string, EdgeMode> = {
none: 'none',
simple: 'simple',
sobel: 'sobel',
canny: 'canny'
};
// Short keys for UI
export const CHARSET_SHORT_MAP: Record<string, CharSetKey> = {
STD: 'standard',
EXT: 'extended',
BLK: 'blocks',
MIN: 'minimal',
DOT: 'dots',
SHP: 'shapes'
};
export const CHARSET_REVERSE_MAP: Record<CharSetKey, string> = Object.fromEntries(
Object.entries(CHARSET_SHORT_MAP).map(([k, v]) => [v, k])
) as Record<CharSetKey, string>;
// ============= Auto-Tune =============
export function autoTuneImage(img: HTMLImageElement, meta: ImageMetadata | null = null): Partial<AsciiOptions> {
if (typeof document === 'undefined') return {};
const canvas = document.createElement('canvas');
const ctx = canvas.getContext('2d');
if (!ctx) return {};
const size = 100;
canvas.width = size;
canvas.height = size;
ctx.drawImage(img, 0, 0, size, size);
const imageData = ctx.getImageData(0, 0, size, size);
const pixels = imageData.data;
const histogram = new Array(256).fill(0);
let totalLum = 0;
for (let i = 0; i < pixels.length; i += 4) {
const lum = Math.round(0.2126 * pixels[i] + 0.7152 * pixels[i + 1] + 0.0722 * pixels[i + 2]);
histogram[lum]++;
totalLum += lum;
}
const pixelCount = pixels.length / 4;
const avgLum = totalLum / pixelCount;
let p5: number | null = null, p95 = 255, count = 0;
for (let i = 0; i < 256; i++) {
count += histogram[i];
if (p5 === null && count > pixelCount * 0.05) p5 = i;
if (count > pixelCount * 0.95) { p95 = i; break; }
}
p5 = p5 ?? 0;
const midPoint = (p5 + p95) / 2;
let exposure = 128 / Math.max(midPoint, 10);
exposure = Math.max(0.4, Math.min(2.8, exposure));
const activeRange = p95 - p5;
let contrast = 1.1;
if (activeRange < 50) contrast = 2.5;
else if (activeRange < 100) contrast = 1.8;
else if (activeRange < 150) contrast = 1.4;
let invert = false;
let saturation = 1.2;
let useEdgeDetection = true;
if (meta) {
const { color_dominant, color_palette } = meta;
if (color_dominant) {
const [r, g, b] = color_dominant;
const domLum = 0.2126 * r + 0.7152 * g + 0.0722 * b;
if (domLum > 140) {
invert = true;
useEdgeDetection = false;
}
}
if (color_palette && Array.isArray(color_palette) && color_palette.length > 0) {
let totalSat = 0;
for (const [r, g, b] of color_palette) {
const max = Math.max(r, g, b);
const delta = max - Math.min(r, g, b);
const s = max === 0 ? 0 : delta / max;
totalSat += s;
}
const avgSat = totalSat / color_palette.length;
if (avgSat > 0.4) saturation = 1.6;
else if (avgSat < 0.1) saturation = 0.0;
else saturation = 1.2;
}
}
if (useEdgeDetection) {
let edgeLumSum = 0;
let edgeCount = 0;
for (let y = 0; y < size; y++) {
for (let x = 0; x < size; x++) {
if (x < 5 || x >= size - 5 || y < 5 || y >= size - 5) {
const i = (y * size + x) * 4;
edgeLumSum += 0.2126 * pixels[i] + 0.7152 * pixels[i + 1] + 0.0722 * pixels[i + 2];
edgeCount++;
}
}
}
const bgLum = edgeLumSum / edgeCount;
if (bgLum > 160) {
invert = true;
}
}
const gamma = avgLum < 80 ? 0.75 : avgLum > 200 ? 1.15 : 1.0;
let recommendedCharSet: CharSetKey = 'standard';
let denoise = false;
let dither = 0;
let edgeMode: EdgeMode = 'none';
let overlayStrength = 0.3;
const histogramPeaks = countHistogramPeaks(histogram, pixelCount);
const isHighContrast = activeRange > 180;
const isLowContrast = activeRange < 80;
const noiseLevel = estimateNoiseLevel(pixels, size);
const noiseThreshold = isLowContrast ? 12 : isHighContrast ? 30 : 20;
const midToneCount = histogram.slice(64, 192).reduce((a, b) => a + b, 0);
const hasGradients = midToneCount > pixelCount * 0.6 && histogramPeaks < 5;
if (isHighContrast || (meta?.has_fine_detail)) {
recommendedCharSet = 'extended';
overlayStrength = 0.2;
if (noiseLevel < noiseThreshold * 0.5) {
edgeMode = 'canny'; // Use Canny for high quality clean images
}
} else {
recommendedCharSet = 'standard';
}
if (isLowContrast || noiseLevel > noiseThreshold) {
denoise = true;
overlayStrength = isLowContrast ? 0.5 : 0.3;
// Avoid complex edge detection on noisy images
edgeMode = 'none';
}
if (hasGradients && !denoise) {
dither = 0.5; // Default dither strength
}
if (noiseLevel > noiseThreshold * 1.5) {
dither = 0;
denoise = true;
}
return {
exposure: parseFloat(exposure.toFixed(2)),
contrast,
invert,
gamma,
saturation: parseFloat(saturation.toFixed(1)),
charSet: recommendedCharSet,
denoise,
dither,
edgeMode,
overlayStrength
};
}
function countHistogramPeaks(histogram: number[], pixelCount: number): number {
const threshold = pixelCount * 0.02;
let peaks = 0;
let inPeak = false;
for (let i = 1; i < 255; i++) {
const isPeak = histogram[i] > histogram[i - 1] && histogram[i] > histogram[i + 1];
const isSignificant = histogram[i] > threshold;
if (isPeak && isSignificant && !inPeak) {
peaks++;
inPeak = true;
} else if (histogram[i] < threshold / 2) {
inPeak = false;
}
}
return peaks;
}
function estimateNoiseLevel(pixels: Uint8ClampedArray, size: number): number {
let totalVariance = 0;
const samples = 100;
for (let s = 0; s < samples; s++) {
const x = Math.floor(Math.random() * (size - 2)) + 1;
const y = Math.floor(Math.random() * (size - 2)) + 1;
const i = (y * size + x) * 4;
const center = 0.2126 * pixels[i] + 0.7152 * pixels[i + 1] + 0.0722 * pixels[i + 2];
const neighbors = [
(y - 1) * size + x,
(y + 1) * size + x,
y * size + (x - 1),
y * size + (x + 1)
].map(idx => {
const offset = idx * 4;
return 0.2126 * pixels[offset] + 0.7152 * pixels[offset + 1] + 0.0722 * pixels[offset + 2];
});
const avgNeighbor = neighbors.reduce((a, b) => a + b, 0) / 4;
totalVariance += Math.abs(center - avgNeighbor);
}
return totalVariance / samples;
}