Function visualWrap

src/tui/fullscreen.js:19–37

(str, maxVisualWidth)

// Split string into visual lines, each no wider than maxVisualWidth.
function visualWrap(str, maxVisualWidth) {
  if (str.length === 0) return [''];
  const lines = [];
  let current = '';
  let curWidth = 0;
  for (const ch of str) {
    const w = visualWidth(ch);
    if (curWidth + w > maxVisualWidth) {
      lines.push(current);
      current = ch;
      curWidth = w;
    } else {
      current += ch;
      curWidth += w;
    }
  }
  if (current.length > 0) lines.push(current);
  return lines;
}

// Compute cursor visual (line, col) from character index into str.
function visualCursorPosition(str, cursorIdx, maxVisualWidth) {