add a method to get the heuristic at the goal

this alows the ETA to work with goals not ending with a heuristic of 0

GoalComposite, GoalRunAway and GoalNear are still missing

src/api/java/baritone/api/pathing/goals/Goal.java

@@ -54,4 +54,18 @@ public interface Goal {
     default double heuristic(BlockPos pos) {
         return heuristic(pos.getX(), pos.getY(), pos.getZ());
     }
+
+    /**
+    * Returns the heuristic at the goal.
+    * i.e. {@code heuristic() == heuristic(x,y,z)}
+    * when {@code isInGoal(x,y,z) == true}
+    * This is needed by {@code PathingBehavior#estimatedTicksToGoal} because
+    * some Goals actually do not have a heuristic of 0 when that condition is met
+    * 
+    * @return The estimate number of ticks to satisfy the goal when the goal
+    * is already satisfied
+    */
+    default double heuristic() {
+        return 0;
+    }
 }

src/api/java/baritone/api/pathing/goals/GoalInverted.java

@@ -45,6 +45,11 @@ public class GoalInverted implements Goal {
         return -origin.heuristic(x, y, z);
     }
 
+    @Override
+    public double heuristic() {
+        return Double.NEGATIVE_INFINITY;
+    }
+
     @Override
     public String toString() {
         return String.format("GoalInverted{%s}", origin.toString());

src/api/java/baritone/api/pathing/goals/GoalStrictDirection.java

@@ -64,6 +64,11 @@ public class GoalStrictDirection implements Goal {
         return heuristic;
     }
 
+    @Override
+    public double heuristic() {
+        return Double.NEGATIVE_INFINITY;
+    }
+
     @Override
     public String toString() {
         return String.format(

src/main/java/baritone/behavior/PathingBehavior.java

@@ -387,7 +387,7 @@ public final class PathingBehavior extends Behavior implements IPathingBehavior,
         if (current == start) {//can't check above because current and start can be equal even if currentPos and startPosition are not
             return Optional.empty();
         }
-        double eta = Math.abs(current) * ticksElapsedSoFar / Math.abs(start - current);
+        double eta = Math.abs(current - goal.heuristic()) * ticksElapsedSoFar / Math.abs(start - current);
         return Optional.of(eta);
     }