Add warning to ExtUI Bed Mesh Screen. (#19397)

- Show a warning on the Mesh Bed Leveling screen if some points aren't probed.

Marlin/src/lcd/extui/lib/ftdi_eve_touch_ui/language/language_en.h

   PROGMEM Language_Str MSG_TOUCH_CALIBRATION_PROMPT = u8"Touch the dots to calibrate";
   PROGMEM Language_Str MSG_AUTOLEVEL_X_AXIS         = u8"Level X Axis";
   PROGMEM Language_Str MSG_BED_MAPPING_DONE         = u8"Bed mapping finished";
+  PROGMEM Language_Str MSG_BED_MAPPING_INCOMPLETE   = u8"Not all points probed";
   PROGMEM Language_Str MSG_LEVELING                 = u8"Leveling";
   PROGMEM Language_Str MSG_SHOW_MESH                = u8"Show Bed Mesh";
 

Marlin/src/lcd/extui/lib/ftdi_eve_touch_ui/screens/bed_mesh_screen.cpp

 void BedMeshScreen::onEntry() {
   screen_data.BedMeshScreen.highlightedTag = 0;
   screen_data.BedMeshScreen.count = GRID_MAX_POINTS;
-  screen_data.BedMeshScreen.showMappingDone = false;
+  screen_data.BedMeshScreen.message = screen_data.BedMeshScreen.MSG_NONE;
   BaseScreen::onEntry();
 }
 
      .tag(1).button( OKAY_POS, GET_TEXT_F(MSG_BUTTON_OKAY))
      .tag(0);
 
-  if (screen_data.BedMeshScreen.showMappingDone) {
-    cmd.text(MESSAGE_POS, GET_TEXT_F(MSG_BED_MAPPING_DONE));
+  switch(screen_data.BedMeshScreen.message) {
+    case screen_data.BedMeshScreen.MSG_MESH_COMPLETE:   cmd.text(MESSAGE_POS, GET_TEXT_F(MSG_BED_MAPPING_DONE)); break;
+    case screen_data.BedMeshScreen.MSG_MESH_INCOMPLETE: cmd.text(MESSAGE_POS, GET_TEXT_F(MSG_BED_MAPPING_INCOMPLETE)); break;
+    default: break;
   }
 }
 
     onRefresh();
 }
 
+bool BedMeshScreen::isMeshComplete(ExtUI::bed_mesh_t data) {
+  for (uint8_t y = 0; y < GRID_MAX_POINTS_Y; y++) {
+    for (uint8_t x = 0; x < GRID_MAX_POINTS_X; x++) {
+      if (isnan(data[x][y])) {
+        return false;
+      }
+    }
+  }
+  return true;
+}
+
 void BedMeshScreen::onMeshUpdate(const int8_t x, const int8_t y, const ExtUI::probe_state_t state) {
   switch(state) {
     case ExtUI::MESH_START:
       screen_data.BedMeshScreen.count = 0;
-      screen_data.BedMeshScreen.showMappingDone = false;
+      screen_data.BedMeshScreen.message = screen_data.BedMeshScreen.MSG_NONE;
       break;
     case ExtUI::MESH_FINISH:
+      if (screen_data.BedMeshScreen.count == GRID_MAX_POINTS && isMeshComplete(ExtUI::getMeshArray())) {
+        screen_data.BedMeshScreen.message = screen_data.BedMeshScreen.MSG_MESH_COMPLETE;
+      } else {
+        screen_data.BedMeshScreen.message = screen_data.BedMeshScreen.MSG_MESH_INCOMPLETE;
+      }
       screen_data.BedMeshScreen.count = GRID_MAX_POINTS;
-      screen_data.BedMeshScreen.showMappingDone = true;
       break;
     case ExtUI::PROBE_START:
       screen_data.BedMeshScreen.highlightedTag = pointToTag(x, y);

Marlin/src/lcd/extui/lib/ftdi_eve_touch_ui/screens/screen_data.h

     uint8_t   num_page;
     uint8_t   cur_page;
     #if ENABLED(SCROLL_LONG_FILENAMES) && (FTDI_API_LEVEL >= 810)
-    uint16_t  scroll_pos;
-    uint16_t  scroll_max;
+      uint16_t  scroll_pos;
+      uint16_t  scroll_max;
     #endif
   } FilesScreen;
   struct {
     struct base_numeric_adjustment_t placeholder;
     float e_rel[ExtUI::extruderCount];
   } MoveAxisScreen;
-#if HAS_MESH
-  struct {
-    bool    showMappingDone;
-    uint8_t count;
-    uint8_t highlightedTag;
-  } BedMeshScreen;
-#endif
-#if ENABLED(TOUCH_UI_DEVELOPER_MENU)
-  struct {
-    uint32_t next_watchdog_trigger;
-    const char*  message;
-  } StressTestScreen;
-#endif
-#if ENABLED(TOUCH_UI_COCOA_PRESS)
-  struct {
-    uint32_t start_ms;
-  } PreheatTimerScreen;
-#endif
-#if ENABLED(BABYSTEPPING)
-  struct {
-    struct base_numeric_adjustment_t placeholder;
-    xyz_int_t rel;
-    #if EXTRUDERS > 1
-      bool link_nozzles;
-    #endif
-    bool show_offsets;
-  } NudgeNozzleScreen;
-#endif
+  #if HAS_MESH
+    struct {
+      enum : uint8_t {
+        MSG_NONE,
+        MSG_MESH_COMPLETE,
+        MSG_MESH_INCOMPLETE
+      } message;
+      uint8_t count;
+      uint8_t highlightedTag;
+    } BedMeshScreen;
+  #endif
+  #if ENABLED(TOUCH_UI_DEVELOPER_MENU)
+    struct {
+      uint32_t next_watchdog_trigger;
+      const char*  message;
+    } StressTestScreen;
+  #endif
+  #if ENABLED(TOUCH_UI_COCOA_PRESS)
+    struct {
+      uint32_t start_ms;
+    } PreheatTimerScreen;
+  #endif
+  #if ENABLED(BABYSTEPPING)
+    struct {
+      struct base_numeric_adjustment_t placeholder;
+      xyz_int_t rel;
+      #if EXTRUDERS > 1
+        bool link_nozzles;
+      #endif
+      bool show_offsets;
+    } NudgeNozzleScreen;
+  #endif
 };
 
 extern screen_data_t screen_data;

Marlin/src/lcd/extui/lib/ftdi_eve_touch_ui/screens/screens.h

       static float getHightlightedValue();
       static void drawHighlightedPointValue();
       static void drawMesh(int16_t x, int16_t y, int16_t w, int16_t h, ExtUI::bed_mesh_t data, uint8_t opts, float autoscale_max = 0.1);
+      static bool isMeshComplete(ExtUI::bed_mesh_t data);
 
     public:
       static void onMeshUpdate(const int8_t x, const int8_t y, const float val);