init claude-code

ink/measure-text.ts

@@ -0,0 +1,47 @@
+import { lineWidth } from './line-width-cache.js'
+
+type Output = {
+  width: number
+  height: number
+}
+
+// Single-pass measurement: computes both width and height in one
+// iteration instead of two (widestLine + countVisualLines).
+// Uses indexOf to avoid array allocation from split('\n').
+function measureText(text: string, maxWidth: number): Output {
+  if (text.length === 0) {
+    return {
+      width: 0,
+      height: 0,
+    }
+  }
+
+  // Infinite or non-positive width means no wrapping — each line is one visual line.
+  // Must check before the loop since Math.ceil(w / Infinity) = 0.
+  const noWrap = maxWidth <= 0 || !Number.isFinite(maxWidth)
+
+  let height = 0
+  let width = 0
+  let start = 0
+
+  while (start <= text.length) {
+    const end = text.indexOf('\n', start)
+    const line = end === -1 ? text.substring(start) : text.substring(start, end)
+
+    const w = lineWidth(line)
+    width = Math.max(width, w)
+
+    if (noWrap) {
+      height++
+    } else {
+      height += w === 0 ? 1 : Math.ceil(w / maxWidth)
+    }
+
+    if (end === -1) break
+    start = end + 1
+  }
+
+  return { width, height }
+}
+
+export default measureText