Implemented modifiers for crop growth speed

closes #6070

there are some unresolved questions about the growth speed of beetroots, pitcher plants and torchflower crops, but that's a topic for another commit.
this change also doesn't account for the light levels.

src/block/Crops.php

@@ -25,6 +25,7 @@ namespace pocketmine\block;
 
 use pocketmine\block\utils\AgeableTrait;
 use pocketmine\block\utils\BlockEventHelper;
+use pocketmine\block\utils\CropGrowthHelper;
 use pocketmine\block\utils\StaticSupportTrait;
 use pocketmine\item\Fertilizer;
 use pocketmine\item\Item;
@@ -66,7 +67,7 @@ abstract class Crops extends Flowable{
 	}
 
 	public function onRandomTick() : void{
-		if($this->age < self::MAX_AGE && mt_rand(0, 2) === 1){
+		if($this->age < self::MAX_AGE && CropGrowthHelper::canGrow($this)){
 			$block = clone $this;
 			++$block->age;
 			BlockEventHelper::grow($this, $block, null);

src/block/DoublePitcherCrop.php

@@ -24,6 +24,7 @@ declare(strict_types=1);
 namespace pocketmine\block;
 
 use pocketmine\block\utils\AgeableTrait;
+use pocketmine\block\utils\CropGrowthHelper;
 use pocketmine\data\runtime\RuntimeDataDescriber;
 use pocketmine\event\block\StructureGrowEvent;
 use pocketmine\item\Fertilizer;
@@ -34,7 +35,6 @@ use pocketmine\math\Facing;
 use pocketmine\math\Vector3;
 use pocketmine\player\Player;
 use pocketmine\world\BlockTransaction;
-use function mt_rand;
 
 final class DoublePitcherCrop extends DoublePlant{
 	use AgeableTrait {
@@ -101,9 +101,8 @@ final class DoublePitcherCrop extends DoublePlant{
 	}
 
 	public function onRandomTick() : void{
-		//TODO: the growth speed is influenced by farmland and nearby crops
 		//only the bottom half of the plant can grow randomly
-		if(mt_rand(0, 2) === 0 && !$this->top){
+		if(CropGrowthHelper::canGrow($this) && !$this->top){
 			$this->grow(null);
 		}
 	}

src/block/PitcherCrop.php

@@ -25,6 +25,7 @@ namespace pocketmine\block;
 
 use pocketmine\block\utils\AgeableTrait;
 use pocketmine\block\utils\BlockEventHelper;
+use pocketmine\block\utils\CropGrowthHelper;
 use pocketmine\block\utils\StaticSupportTrait;
 use pocketmine\event\block\StructureGrowEvent;
 use pocketmine\item\Fertilizer;
@@ -35,7 +36,6 @@ use pocketmine\math\Facing;
 use pocketmine\math\Vector3;
 use pocketmine\player\Player;
 use pocketmine\world\BlockTransaction;
-use function mt_rand;
 
 final class PitcherCrop extends Flowable{
 	use AgeableTrait;
@@ -97,8 +97,7 @@ final class PitcherCrop extends Flowable{
 	}
 
 	public function onRandomTick() : void{
-		//TODO: the growth speed is influenced by farmland and nearby crops
-		if(mt_rand(0, 2) === 0){
+		if(CropGrowthHelper::canGrow($this)){
 			$this->grow(null);
 		}
 	}

src/block/Stem.php

@@ -24,6 +24,7 @@ declare(strict_types=1);
 namespace pocketmine\block;
 
 use pocketmine\block\utils\BlockEventHelper;
+use pocketmine\block\utils\CropGrowthHelper;
 use pocketmine\data\runtime\RuntimeDataDescriber;
 use pocketmine\item\Item;
 use pocketmine\math\Facing;
@@ -63,7 +64,7 @@ abstract class Stem extends Crops{
 	}
 
 	public function onRandomTick() : void{
-		if($this->facing === Facing::UP && mt_rand(0, 2) === 1){
+		if($this->facing === Facing::UP && CropGrowthHelper::canGrow($this)){
 			$world = $this->position->getWorld();
 			if($this->age < self::MAX_AGE){
 				$block = clone $this;

src/block/TorchflowerCrop.php

@@ -24,6 +24,7 @@ declare(strict_types=1);
 namespace pocketmine\block;
 
 use pocketmine\block\utils\BlockEventHelper;
+use pocketmine\block\utils\CropGrowthHelper;
 use pocketmine\block\utils\StaticSupportTrait;
 use pocketmine\data\runtime\RuntimeDataDescriber;
 use pocketmine\item\Fertilizer;
@@ -32,7 +33,6 @@ use pocketmine\item\VanillaItems;
 use pocketmine\math\Facing;
 use pocketmine\math\Vector3;
 use pocketmine\player\Player;
-use function mt_rand;
 
 final class TorchflowerCrop extends Flowable{
 	use StaticSupportTrait;
@@ -79,7 +79,7 @@ final class TorchflowerCrop extends Flowable{
 	}
 
 	public function onRandomTick() : void{
-		if(mt_rand(0, 2) === 1){
+		if(CropGrowthHelper::canGrow($this)){
 			BlockEventHelper::grow($this, $this->getNextState(), null);
 		}
 	}

src/block/utils/CropGrowthHelper.php

@@ -0,0 +1,105 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+ */
+
+declare(strict_types=1);
+
+namespace pocketmine\block\utils;
+
+use pocketmine\block\Block;
+use pocketmine\block\Farmland;
+use function mt_rand;
+
+final class CropGrowthHelper{
+
+	private const ON_HYDRATED_FARMLAND_BONUS = 3;
+	private const ON_DRY_FARMLAND_BONUS = 1;
+	private const ADJACENT_HYDRATED_FARMLAND_BONUS = 3 / 4;
+	private const ADJACENT_DRY_FARMLAND_BONUS = 1 / 4;
+
+	private const IMPROPER_ARRANGEMENT_DIVISOR = 2;
+
+	private function __construct(){
+		//NOOP
+	}
+
+	/**
+	 * Returns the speed at which this crop will grow, depending on its surroundings.
+	 * The default is once every 26 random ticks.
+	 *
+	 * Things which influence this include nearby farmland (bonus for hydrated farmland) and the position of other
+	 * nearby crops of the same type (nearby crops of the same type will negatively influence growth speed unless
+	 * planted in rows and properly spaced apart).
+	 */
+	public static function calculateMultiplier(Block $block) : float{
+		$result = 1;
+
+		$position = $block->getPosition();
+
+		$world = $position->getWorld();
+		$baseX = $position->getFloorX();
+		$baseY = $position->getFloorY();
+		$baseZ = $position->getFloorZ();
+
+		$farmland = $world->getBlockAt($baseX, $baseY - 1, $baseZ);
+
+		if($farmland instanceof Farmland){
+			$result += $farmland->getWetness() > 0 ? self::ON_HYDRATED_FARMLAND_BONUS : self::ON_DRY_FARMLAND_BONUS;
+		}
+
+		$xRow = false;
+		$zRow = false;
+		$diagonalRow = false;
+		for($x = -1; $x <= 1; $x++){
+			for($z = -1; $z <= 1; $z++){
+				if($x === 0 && $z === 0){
+					continue;
+				}
+				$nextFarmland = $world->getBlockAt($baseX + $x, $baseY - 1, $baseZ + $z);
+
+				if($nextFarmland instanceof Farmland){
+					$result += $nextFarmland->getWetness() > 0 ? self::ADJACENT_HYDRATED_FARMLAND_BONUS : self::ADJACENT_DRY_FARMLAND_BONUS;
+				}
+
+				$nextCrop = $world->getBlockAt($baseX + $x, $baseY, $baseZ + $z);
+				if($nextCrop->hasSameTypeId($block)){
+					match(0){
+						$x => $xRow = true,
+						$z => $zRow = true,
+						default => $diagonalRow = true,
+					};
+				}
+			}
+		}
+
+		//crops can be arranged in rows, but the rows must not cross and must be spaced apart by at least one block
+		if(($xRow && $zRow) || $diagonalRow){
+			$result /= self::IMPROPER_ARRANGEMENT_DIVISOR;
+		}
+
+		return $result;
+	}
+
+	public static function canGrow(Block $block) : bool{
+		//while it may be tempting to use mt_rand(0, 25) < multiplier, this would make crops grow a bit faster than
+		//vanilla in most cases due to the remainder of 25 / multiplier not being discarded
+		return mt_rand(0, (int) (25 / self::calculateMultiplier($block))) === 0;
+	}
+}