Function diffDifferentWidth

src/ink/screen.ts:1746–1831

* Fallback: diff two screens with different widths (resize). * Separate indices for prev and next cells arrays.

(
  prev: Screen,
  next: Screen,
  startX: number,
  endX: number,
  startY: number,
  endY: number,
  cb: DiffCallback,
)

 * Separate indices for prev and next cells arrays.
 */
function diffDifferentWidth(
  prev: Screen,
  next: Screen,
  startX: number,
  endX: number,
  startY: number,
  endY: number,
  cb: DiffCallback,
): boolean {
  const prevWidth = prev.width
  const nextWidth = next.width
  const prevCells = prev.cells
  const nextCells = next.cells

  const prevCell: Cell = {
    char: ' ',
    styleId: 0,
    width: CellWidth.Narrow,
    hyperlink: undefined,
  }
  const nextCell: Cell = {
    char: ' ',
    styleId: 0,
    width: CellWidth.Narrow,
    hyperlink: undefined,
  }

  const prevStride = prevWidth << 1
  const nextStride = nextWidth << 1
  let prevRowCI = (startY * prevWidth + startX) << 1
  let nextRowCI = (startY * nextWidth + startX) << 1

  for (let y = startY; y < endY; y++) {
    const prevIn = y < prev.height
    const nextIn = y < next.height
    const prevEndX = prevIn ? Math.min(endX, prevWidth) : startX
    const nextEndX = nextIn ? Math.min(endX, nextWidth) : startX
    const bothEndX = Math.min(prevEndX, nextEndX)

    let prevCI = prevRowCI
    let nextCI = nextRowCI

    for (let x = startX; x < bothEndX; x++) {
      if (
        prevCells[prevCI] === nextCells[nextCI] &&
        prevCells[prevCI + 1] === nextCells[nextCI + 1]
      ) {
        prevCI += 2
        nextCI += 2
        continue
      }
      cellAtCI(prev, prevCI, prevCell)
      cellAtCI(next, nextCI, nextCell)
      prevCI += 2
      nextCI += 2
      if (cb(x, y, prevCell, nextCell)) return true
    }