Function findNextDiff

src/ink/screen.ts:1213–1224

* Scan for the next cell that differs between two Int32Arrays. * Returns the number of matching cells before the first difference, * or `count` if all cells match. Tiny and pure for JIT inlining.

(
  a: Int32Array,
  b: Int32Array,
  w0: number,
  count: number,
)

 * or `count` if all cells match. Tiny and pure for JIT inlining.
 */
function findNextDiff(
  a: Int32Array,
  b: Int32Array,
  w0: number,
  count: number,
): number {
  for (let i = 0; i < count; i++, w0 += 2) {
    const w1 = w0 | 1
    if (a[w0] !== b[w0] || a[w1] !== b[w1]) return i
  }
  return count
}

/**
 * Diff one row where both screens are in bounds.