From 43761677de5f89990d01921e379212a5326ca1a5 Mon Sep 17 00:00:00 2001
From: drjones <indianaholmes1@icloud.com>
Date: Thu, 24 Sep 2026 20:51:48 -0700
Subject: [PATCH] Fix screen flicker: incremental menu redraw instead of full
 fillScreen every 60ms

---
 src/core/shell.cpp | 47 +++++++++++++++++++++++++++++-----------------
 src/core/shell.h   |  2 +-
 2 files changed, 31 insertions(+), 18 deletions(-)

diff --git a/src/core/shell.cpp b/src/core/shell.cpp
index 4cde5f5..80ee917 100644
--- a/src/core/shell.cpp
+++ b/src/core/shell.cpp
@@ -103,25 +103,38 @@ void Shell::begin() {
   add(makeActiveExploit());
   add(makeLogViewer());
   ui::bootSplash();
-  drawMenu();
+  drawMenu(true);
 }
 
-void Shell::drawMenu() {
+void Shell::drawMenu(bool force) {
   auto& d = M5.Display;
-  d.fillScreen(ui::bg());
-  ui::titleBar("Card-Crack", CARDCRACK_VERSION);
-  // animated selection glow bar
-  int y = ui::BODY_Y + sel * 12;
-  uint16_t sb = ui::mix(theme::active().panel, theme::active().accent, 0.25f + 0.25f * ui::pulse(900));
-  d.fillRect(0, y, ui::W, 12, sb);
-  for (int i = 0; i < nmods; i++) {
-    bool cur = i == sel;
-    uint16_t c = cur ? ui::accent() : ui::fg();
-    d.setTextColor(c, cur ? sb : ui::bg());
-    d.setCursor(5, ui::BODY_Y + i * 12 + 1);
+  if (force) {
+    d.fillScreen(ui::bg());
+    ui::titleBar("Card-Crack", CARDCRACK_VERSION);
+    d.setTextColor(ui::fg(), ui::bg());
+    d.setTextSize(1);
+    for (int i = 0; i < nmods; i++) {
+      d.setCursor(5, ui::BODY_Y + i * 12 + 1);
+      d.printf("  %-9s %s", mods[i]->name(), mods[i]->blurb());
+    }
+    ui::hintBar("; up  . down  enter open  home-lab only");
+  }
+  // Flicker-free: repaint ONLY the selection-bar strip (previous + current rows)
+  static int lastSel = -1;
+  int rows[2] = { lastSel, sel };
+  for (int k = 0; k < 2; k++) {
+    int i = rows[k];
+    if (i < 0 || i >= nmods) continue;
+    bool cur = (i == sel);
+    int y = ui::BODY_Y + i * 12;
+    uint16_t sb = cur ? ui::mix(theme::active().panel, theme::active().accent, 0.25f + 0.25f * ui::pulse(900)) : ui::bg();
+    d.fillRect(0, y, ui::W, 12, sb);
+    d.setTextColor(cur ? ui::accent() : ui::fg(), sb);
+    d.setTextSize(1);
+    d.setCursor(5, y + 1);
     d.printf("%c %-9s %s", cur ? char(0x10) : ' ', mods[i]->name(), mods[i]->blurb());
   }
-  ui::hintBar("; up  . down  enter open  home-lab only");
+  lastSel = sel;
 }
 
 void Shell::enter(int i) {
@@ -136,7 +149,7 @@ void Shell::enter(int i) {
 void Shell::back() {
   if (active >= 0) mods[active]->onExit();
   active = -1;
-  drawMenu();
+  drawMenu(true);
 }
 
 void Shell::loop() {
@@ -158,8 +171,8 @@ void Shell::loop() {
   }
 
   if (active < 0) {
-    // keep the menu selection breathing
-    if (millis() - lastTick > 60) { lastTick = millis(); drawMenu(); }
+    // keep the selection glow breathing — repaints only the bar strip (flicker-free)
+    if (millis() - lastTick > 90) { lastTick = millis(); drawMenu(false); }
     return;
   }
   if (millis() - lastTick > 33) {
diff --git a/src/core/shell.h b/src/core/shell.h
index 816c089..5facb71 100644
--- a/src/core/shell.h
+++ b/src/core/shell.h
@@ -14,7 +14,7 @@ private:
   int active = -1;          // -1 == in menu
   uint32_t lastTick = 0;
   void add(Module* m) { if (nmods < MAX) mods[nmods++] = m; }
-  void drawMenu();
+  void drawMenu(bool force = false);
   void enter(int i);
   void back();
 };