Function createScreen

src/ink/screen.ts:487–529

(
  width: number,
  height: number,
  styles: StylePool,
  charPool: CharPool,
  hyperlinkPool: HyperlinkPool,
)

// ---

export function createScreen(
  width: number,
  height: number,
  styles: StylePool,
  charPool: CharPool,
  hyperlinkPool: HyperlinkPool,
): Screen {
  // Warn if dimensions are not valid integers (likely bad yoga layout output)
  warn.ifNotInteger(width, 'createScreen width')
  warn.ifNotInteger(height, 'createScreen height')

  // Ensure width and height are valid integers to prevent crashes
  if (!Number.isInteger(width) || width < 0) {
    width = Math.max(0, Math.floor(width) || 0)
  }
  if (!Number.isInteger(height) || height < 0) {
    height = Math.max(0, Math.floor(height) || 0)
  }

  const size = width * height

  // Allocate one buffer, two views: Int32Array for per-word access,
  // BigInt64Array for bulk fill in resetScreen/clearRegion.
  // ArrayBuffer is zero-filled, which is exactly the empty cell value:
  // [EMPTY_CHAR_INDEX=0, packWord1(emptyStyleId=0,0,0)=0].
  const buf = new ArrayBuffer(size << 3) // 8 bytes per cell
  const cells = new Int32Array(buf)
  const cells64 = new BigInt64Array(buf)

  return {
    width,
    height,
    cells,
    cells64,
    charPool,
    hyperlinkPool,
    emptyStyleId: styles.none,
    damage: undefined,
    noSelect: new Uint8Array(size),
    softWrap: new Int32Array(height),
    contentEnd: new Int32Array(height),
  }
}

/**
 * Reset an existing screen for reuse, avoiding allocation of new typed arrays.