pixelate.mjs

#!/usr/bin/env node
import sharp from 'sharp';
import { parseArgs } from 'node:util';

const { values } = parseArgs({
    options: {
        in:   { type: 'string' },
        out:  { type: 'string' },
        size: { type: 'string', default: '64' },
    },
});

if (!values.in || !values.out) {
    console.error('Usage: node scripts/pixelate.mjs --in input.png --out output.png [--size 128]');
    process.exit(1);
}

const s = Number(values.size);

// Each source frame comes from an independent AI generation, so the character
// isn't framed identically canvas-to-canvas (e.g. one walk frame may sit 30px
// further right than another). Trim the transparent padding down to the actual
// character silhouette first, then re-contain it bottom-anchored + horizontally
// centered — this keeps every frame's visual feet/ground-contact point at the
// same canvas position, matching CamperRenderer's fixed anchor(0.5, 1).
await sharp(values.in)
.trim({ background: { r: 0, g: 0, b: 0, alpha: 0 } })
.resize(s, s, {
    kernel: sharp.kernel.nearest,
    fit: 'contain',
    position: 'bottom',
    background: { r: 0, g: 0, b: 0, alpha: 0 },
})
.png()
.toFile(values.out);

console.log(`Saved: ${values.out} (${s}x${s})`);