Fix race condition in display refresh locking

basic1.cpp

@@ -88,7 +88,7 @@ void core1_entry() {
     while (1) {
         // Wait for refresh request
         if (refresh_requested && refresh_buffer && refresh_display) {
-            refresh_in_progress = true;
+            // refresh_in_progress is already set by Core 0 to lock the buffer
             
             // Get local copies for safe access
             LowLevelDisplay* display = refresh_display;
@@ -100,7 +100,7 @@ void core1_entry() {
             
             // Clear flags
             refresh_requested = false;
-            refresh_in_progress = false;
+            refresh_in_progress = false; // Unlock buffer for Core 0
         }
         
         // Small delay to avoid busy-waiting
@@ -124,6 +124,10 @@ bool refresh_screen_async(const uint8_t *buffer, LowLevelDisplay* display) {
         return false;
     }
     
+    // Lock the buffer immediately on Core 0 to prevent race condition
+    // Core 1 will unlock it (set to false) when done
+    refresh_in_progress = true;
+    
     // Queue refresh on Core 1
     refresh_buffer = buffer;
     refresh_display = display;

games/lua_examples/snake.lua

@@ -110,12 +110,12 @@ function draw()
     
     -- Draw: MENU
     if state == STATE_MENU then
-        renderer.text_scaled(game.width(, 2) / 2 - 30, game.height() / 2 - 20, "SNAKE", true)
+        renderer.text(game.width() / 2 - 30, game.height() / 2 - 20, "SNAKE", true)
-        renderer.text_scaled(game.width(, 2) / 2 - 50, game.height() / 2, "Tap to Start", true)
+        renderer.text(game.width() / 2 - 50, game.height() / 2, "Tap to Start", true)
         
         if game.vars.high_score > 0 then
             local hs_text = "High: " .. tostring(game.vars.high_score)
-            renderer.text_scaled(game.width(, 2) / 2 - 30, game.height() / 2 + 20, hs_text, true)
+            renderer.text(game.width() / 2 - 30, game.height() / 2 + 20, hs_text, true)
         end
     
     -- Draw: PLAYING
@@ -134,16 +134,16 @@ function draw()
         
         -- Draw score
         local score_text = "Score: " .. tostring(game.vars.score)
-        renderer.text_scaled(5, 5, score_text, true, 2)
+        renderer.text(5, 5, score_text, true)
     
     -- Draw: GAME_OVER
     elseif state == STATE_GAME_OVER then
-        renderer.text_scaled(game.width(, 2) / 2 - 40, game.height() / 2 - 20, "GAME OVER", true)
+        renderer.text(game.width() / 2 - 40, game.height() / 2 - 20, "GAME OVER", true)
         
         local score_text = "Score: " .. tostring(game.vars.score)
-        renderer.text_scaled(game.width(, 2) / 2 - 40, game.height() / 2, score_text, true)
+        renderer.text(game.width() / 2 - 40, game.height() / 2, score_text, true)
         
-        renderer.text_scaled(game.width(, 2) / 2 - 60, game.height() / 2 + 20, "Tap to Continue", true)
+        renderer.text(game.width() / 2 - 60, game.height() / 2 + 20, "Tap to Continue", true)
     end
 end