// Shared SVG-to-PNG rasterization for the brand render scripts. The SVG is
// drawn into a canvas in a headless Chrome page, which reports the PNG and
// its own opaque-pixel count via --dump-dom — Chrome's one-shot screenshot
// mode intermittently captures blank or partially painted frames, so the
// callers verify dimensions and opaque coverage before writing anything.
import { execFileSync } from 'node:child_process'
import { writeFileSync } from 'node:fs'
import { join } from 'node:path'
import { pathToFileURL } from 'node:url'
/** Rasterize svgText at width x height; returns { opaque, png }. */
export function rasterize(chrome, work, name, svgText, width, height) {
const svgUri = `data:image/svg+xml;base64,${Buffer.from(svgText).toString('base64')}`
const wrapper = join(work, `wrap-${name}.html`)
writeFileSync(
wrapper,
``,
)
const dom = execFileSync(
chrome,
[
'--headless=new',
'--disable-gpu',
'--no-sandbox',
`--user-data-dir=${join(work, `profile-${name}`)}`,
'--virtual-time-budget=5000',
'--dump-dom',
pathToFileURL(wrapper).href,
],
// stderr ignored: headless Chrome logs harmless GPU-init noise there.
{ encoding: 'utf8', maxBuffer: 64 * 1024 * 1024, stdio: ['ignore', 'pipe', 'ignore'] },
)
const m = dom.match(/RESULT (\d+) (data:image\/png;base64,[A-Za-z0-9+/=]+)/)
if (!m) throw new Error(`${name}: no render result in page output`)
return { opaque: Number(m[1]), png: Buffer.from(m[2].split(',')[1], 'base64') }
}