butterflies: print egg counts after overlay update

src/modules/butterflies/butterflies_overlays.c

@@ -63,7 +63,22 @@ enum action_status bf_grid_overlay_update(const struct cats_configuration *conf,
                         }
                 }
         }
+
+        int64_t cells_with_eggs = 0;
+        double total_eggs = 0;
+        for (cats_dt_coord row = 0; row < rows; row++) {
+                for (cats_dt_coord col = 0; col < cols; col++) {
+                        float eggs = data->eggs[row][col];
+                        if (eggs > 0) {
+                                cells_with_eggs += 1;
+                                total_eggs += eggs;
+                        }
+
+                }
+        }
+
         log_message(LOG_INFO, "Overlay update: %ld excluded, %ld habitat ok, %ld resource ok, %ld habitat + resource ok",
                     cells_excluded, cells_habitat_ok, cells_resource_ok, cells_habitat_and_resource_ok);
+        log_message(LOG_INFO, "Overlay update %ld cells with eggs, total %f eggs, average %f eggs per cell", cells_with_eggs, total_eggs, total_eggs/(float) cells_with_eggs);
         return ACTION_RUN;
 }