From 1ce388ca0b977dd700d05a1756adc04714e3dccf Mon Sep 17 00:00:00 2001
From: "Dylan K. Taylor" <dktapps@pmmp.io>
Date: Sun, 19 Sep 2021 15:59:16 +0100
Subject: [PATCH] Liquid: add getMinAdjacentSourcesToFormSource(), remove
 circular dependency between Liquid and Water this unpleasantly-named method
 allows controlling the source-forming behaviour of liquids by changing the
 required number of adjacent sources that must be present in order for a new
 source to form. This allows stuff like non-infinite water.

---
 src/block/Liquid.php | 13 +++++++++++--
 src/block/Water.php  |  4 ++++
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/block/Liquid.php b/src/block/Liquid.php
index 677c3b0ae..6e3c8df35 100644
--- a/src/block/Liquid.php
+++ b/src/block/Liquid.php
@@ -249,6 +249,14 @@ abstract class Liquid extends Transparent{
 		return 1;
 	}
 
+	/**
+	 * Returns the number of source blocks of this liquid that must be horizontally adjacent to this block in order for
+	 * this block to become a source block itself, or null if the liquid does not exhibit source-forming behaviour.
+	 */
+	public function getMinAdjacentSourcesToFormSource() : ?int{
+		return null;
+	}
+
 	public function onNearbyBlockChange() : void{
 		if(!$this->checkForHarden()){
 			$this->position->getWorld()->scheduleDelayedBlockUpdate($this->position, $this->tickRate());
@@ -279,9 +287,10 @@ abstract class Liquid extends Transparent{
 				$falling = true;
 			}
 
-			if($this->adjacentSources >= 2 and $this instanceof Water){
+			$minAdjacentSources = $this->getMinAdjacentSourcesToFormSource();
+			if($minAdjacentSources !== null && $this->adjacentSources >= $minAdjacentSources){
 				$bottomBlock = $world->getBlockAt($this->position->x, $this->position->y - 1, $this->position->z);
-				if($bottomBlock->isSolid() or ($bottomBlock instanceof Water and $bottomBlock->isSource())){
+				if($bottomBlock->isSolid() or ($bottomBlock instanceof Liquid and $bottomBlock->isSameType($this) and $bottomBlock->isSource())){
 					$newDecay = 0;
 					$falling = false;
 				}
diff --git a/src/block/Water.php b/src/block/Water.php
index a516d4064..ff638a8f9 100644
--- a/src/block/Water.php
+++ b/src/block/Water.php
@@ -46,6 +46,10 @@ class Water extends Liquid{
 		return 5;
 	}
 
+	public function getMinAdjacentSourcesToFormSource() : ?int{
+		return 2;
+	}
+
 	public function onEntityInside(Entity $entity) : bool{
 		$entity->resetFallDistance();
 		if($entity->isOnFire()){