🎨 Palette: Improve CLI HUD with score formatting and robust line clearing

.Jules/palette.md

@@ -29,3 +29,7 @@
 ## 2025-01-24 - Real-time Achievement Feedback in CLI
 **Learning:** In terminal-based games, displaying achievement progress (like a live high score) in real-time provides immediate tactile reward and engagement. Furthermore, inclusive UX means ensuring first-time players also receive "New Best" feedback, even when their initial record is zero.
 **Action:** Update session-high-score variables immediately upon record-breaking and display them in the live HUD. Ensure achievement conditions (`score > highscore`) don't exclude the first-time user experience.
+
+## 2026-05-31 - Robust CLI HUD Updates
+**Learning:** Utilizing the ANSI 'Erase in Line' escape sequence (`\033[K`) is a more robust UX practice than space padding for in-place terminal updates, as it guarantees the removal of all characters from the previous line regardless of length. Additionally, using thousands separators for numeric displays in CLI tools significantly improves readability as values escalate.
+**Action:** Use the `CLR_EOL` macro (targeting `\033[K`) and implement a `formatWithCommas` helper for all multi-digit numeric displays in CLI interfaces.

src/main.cpp

@@ -21,9 +21,21 @@
 #define CLR_NORM  "\033[1;32m"
 #define CLR_CTRL  "\033[1;33m"
 #define CLR_RESET "\033[0m"
+#define CLR_EOL   "\033[K"
 
 struct termios oldt;
 
+std::string formatWithCommas(long long value) {
+    std::string s = std::to_string(value);
+    int n = static_cast<int>(s.length());
+    int insertPosition = n - 3;
+    while (insertPosition > (value < 0 ? 1 : 0)) {
+        s.insert(insertPosition, ",");
+        insertPosition -= 3;
+    }
+    return s;
+}
+
 void restore_terminal(int signum) {
     tcsetattr(STDIN_FILENO, TCSANOW, &oldt);
     // Use write() and _exit() because they are async-signal-safe
@@ -77,7 +89,7 @@ int main() {
     std::cout << CLR_CTRL << "==========================\n      SPEED CLICKER\n==========================\n" << CLR_RESET;
 
     if (highscore > 0) {
-        std::cout << " Personal Best: " << CLR_SCORE << highscore << CLR_RESET << "\n\n";
+        std::cout << " Personal Best: " << CLR_SCORE << formatWithCommas(highscore) << CLR_RESET << "\n\n";
     }
 
     std::cout << "Controls:\n " << CLR_CTRL << "[h]" << CLR_RESET << " Toggle Hard Mode (10x Speed!)\n "
@@ -94,7 +106,7 @@ int main() {
     }
 
     for (int i = 3; i > 0; --i) {
-        std::cout << "\rStarting in " << CLR_CTRL << i << CLR_RESET << "... " << std::flush;
+        std::cout << "\rStarting in " << CLR_CTRL << i << CLR_RESET << "... " << CLR_EOL << std::flush;
         auto start_wait = std::chrono::steady_clock::now();
         while (std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::steady_clock::now() - start_wait).count() < 1000) {
             int elapsed = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::steady_clock::now() - start_wait).count();
@@ -108,7 +120,7 @@ int main() {
             }
         }
     }
-    std::cout << "\r" << CLR_NORM << "GO!             " << CLR_RESET << "\n" << std::flush;
+    std::cout << "\r" << CLR_NORM << "GO!" << CLR_RESET << CLR_EOL << "\n" << std::flush;
     std::this_thread::sleep_for(std::chrono::milliseconds(200));
     tcflush(STDIN_FILENO, TCIFLUSH);
 
@@ -141,10 +153,11 @@ int main() {
         }
 
         if (updateUI) {
-            std::cout << "\r" << CLR_SCORE << "Score: " << score << CLR_RESET << " | High: " << highscore << " "
+            std::cout << "\r" << CLR_SCORE << "Score: " << formatWithCommas(score) << CLR_RESET << " | "
+                      << CLR_SCORE << "High: " << formatWithCommas(highscore) << CLR_RESET << " "
                       << (hardMode ? CLR_HARD "[HARD MODE]" : CLR_NORM "[NORMAL MODE]")
-                      << (score > initialHighscore ? " NEW BEST! 🥳" : "")
-                      << "           " << std::flush;
+                      << (score > initialHighscore ? " " CLR_NORM "NEW BEST! 🥳" CLR_RESET : "")
+                      << CLR_EOL << std::flush;
             updateUI = false;
         }
     }
@@ -154,7 +167,7 @@ int main() {
     }
 
     tcsetattr(STDIN_FILENO, TCSANOW, &oldt);
-    std::cout << "\n\n" << CLR_SCORE << "Final Score: " << score << CLR_RESET << "\n";
+    std::cout << "\n\n" << CLR_SCORE << "Final Score: " << formatWithCommas(score) << CLR_RESET << "\n";
     if (score > initialHighscore) {
         std::cout << "Congratulations! A new personal best!\n";
     }