new: unicode.visualStrlen

assets/disk0/tvdos/TVDOS.SYS

@@ -1390,6 +1390,27 @@ unicode.println = (str) => {
     unicode.print(str+'\n\n')
 }
 
+unicode.strlen = (str) => {
+    // Convert string to an array of codepoints using spread operator
+    // This correctly handles surrogate pairs and counts each codepoint as one
+    return unicode.utf8toCodepoints(str).length
+}
+
+unicode.visualStrlen = (str) => {
+    function isTripleWidth(c) {
+        return (0xAC00 <= c && c <= 0xD7FF) && [1,4,8,10,13].includes(((c - 0xAC00) / 588)|0)
+    }
+
+    function isDoubleWidth(c) {
+        return (0x3000 <= c && c <= 0x303f) || (0x3100 <= c && c <= 0x312f) || (0x3200 <= c && c <= 0x33ff) ||
+        (0xAC00 <= c && c <= 0xD7FF) || (0xFE30 <= c && c <= 0xFE4F) || (0xFF00 <= c && c <= 0xff60)
+    }
+
+    // Convert string to an array of codepoints using spread operator
+    // This correctly handles surrogate pairs and counts each codepoint as one
+    return unicode.utf8toCodepoints(str).reduce((acc, c) => acc + (isTripleWidth(c) ? 3 : isDoubleWidth(c) ? 2 : 1), 0)
+}
+
 Object.freeze(unicode);
 
 ///////////////////////////////////////////////////////////////////////////////

assets/disk0/tvdos/include/playgui.mjs

@@ -22,33 +22,9 @@ function clearSubtitleArea() {
 }
 
 function getVisualLength(line) {
-    // Calculate the visual length of a line excluding formatting tags
+    // Remove HTML tags and count the remaining text using unicode.strlen()
-    let visualLength = 0
+    const withoutTags = line.replace(/<\/?[bi]>/gi, '')
-    let i = 0
+    return unicode.visualStrlen(withoutTags)
-
-    while (i < line.length) {
-        if (i < line.length - 2 && line[i] === '<') {
-            // Check for formatting tags and skip them
-            if (line.substring(i, i + 3).toLowerCase() === '<b>' ||
-                line.substring(i, i + 3).toLowerCase() === '<i>') {
-                i += 3  // Skip tag
-            } else if (i < line.length - 3 &&
-                      (line.substring(i, i + 4).toLowerCase() === '</b>' ||
-                       line.substring(i, i + 4).toLowerCase() === '</i>')) {
-                i += 4  // Skip closing tag
-            } else {
-                // Not a formatting tag, count the character
-                visualLength++
-                i++
-            }
-        } else {
-            // Regular character, count it
-            visualLength++
-            i++
-        }
-    }
-
-    return visualLength
 }
 
 function displayFormattedLine(line) {