Misc cleanup

core/src/mindustry/ai/BaseAI.java

@@ -209,6 +209,16 @@ public class BaseAI{
             }
             Tile wtile = world.tile(realX, realY);
 
+            if(tile.block instanceof PayloadConveyor || tile.block instanceof PayloadAcceptor){
+                //near a building
+                for(Point2 point : Edges.getEdges(tile.block.size)){
+                    var t = world.build(tile.x + point.x, tile.y + point.y);
+                    if(t != null){
+                        return false;
+                    }
+                }
+            }
+
             //may intersect AI path
             tmpTiles.clear();
             if(tile.block.solid && wtile != null && wtile.getLinkedTilesAs(tile.block, tmpTiles).contains(t -> path.contains(t.pos()))){

core/src/mindustry/ui/fragments/HudFragment.java

@@ -642,6 +642,7 @@ public class HudFragment extends Fragment{
             }
 
             void drawInner(Color color, float fract){
+                if(fract < 0) return;
                 if(flip){
                     x += width;
                     width = -width;

core/src/mindustry/world/blocks/power/NuclearReactor.java

@@ -30,12 +30,17 @@ public class NuclearReactor extends PowerGenerator{
     public Color lightColor = Color.valueOf("7f19ea");
     public Color coolColor = new Color(1, 1, 1, 0f);
     public Color hotColor = Color.valueOf("ff9575a3");
-    public float itemDuration = 120; //time to consume 1 fuel
-    public float heating = 0.01f; //heating per frame * fullness
-    public float smokeThreshold = 0.3f; //threshold at which block starts smoking
+    /** ticks to consume 1 fuel */
+    public float itemDuration = 120;
+    /** heating per frame * fullness */
+    public float heating = 0.01f;
+    /** threshold at which block starts smoking */
+    public float smokeThreshold = 0.3f;
+    /** heat threshold at which lights start flashing */
+    public float flashThreshold = 0.46f;
     public int explosionRadius = 19;
     public int explosionDamage = 1250;
-    public float flashThreshold = 0.46f; //heat threshold at which the lights start flashing
+    /** heat removed per unit of coolant */
     public float coolantPower = 0.5f;
 
     public @Load("@-top") TextureRegion topRegion;