This is a simple mod fixing the bug MC-188328. This bug relates to boat pushing mechanics. This mod was primarily made as a POC on how to fix this bug, and as a way to confirm that my proposed fix to this bug would actually work.
In this section we use fabric mappings!
The bug stems from a supposed typo in the net.minecraft.entity.vehicle.boatEntity class. When the hitboxes of a boat and an entity collide the pushAwayFrom method is called:
@Override
public void pushAwayFrom(Entity entity) {
if (entity instanceof BoatEntity) {
if (entity.getBoundingBox().minY < this.getBoundingBox().maxY) {
super.pushAwayFrom(entity);
}
} else if (entity.getBoundingBox().minY <= this.getBoundingBox().minY) {
super.pushAwayFrom(entity);
}
}On line 7 we see the following:
else if (arg.getBoundingBox().minY <= this.getBoundingBox().minY)This part is only called when the entity it is trying to push away is not a boat. (e.g. animals, monsters etc). We can see that we are comparing entity.getBoundingBox().minY to this.getBoundingBox().minY.
Or in other words, we're comparing if the bottom of the entity hitbox is lower or on the same height as the bottom of the boat hitbox.
This results in the bug that when the entity's bottom of the hitbox is higher than the boats hitbox, the boat won't push the entity even though they're clearly touching and it should push.
This bug can be easily fixed by instead of checking if the bottom of the boat hitbox is lower, we check if the top hitbox is lower.
We do this by using redirect to change this.getBoundingBox().minY to this.getBoundingBox().maxY
Making it so the method becomes functionally the same as:
@Override
public void pushAwayFrom(Entity entity) {
if (entity instanceof BoatEntity) {
if (entity.getBoundingBox().minY < this.getBoundingBox().maxY) {
super.pushAwayFrom(entity);
}
} else if (entity.getBoundingBox().minY <= this.getBoundingBox().maxY) {
super.pushAwayFrom(entity);
}
}