GameRule-Extensions

# GameRule-Extensions An extension library to allow mod developers to more easily add custom gamerules, with additional datatype support. # Usage (Mod Developers Only) ## Adding a new game rule 1. Add the API jar as a dependency to your project. 2. Call `dev.rndmorris.gameruleexts.api.GameRulesApi.registerGameRule(...)` to add a new gamerule for your mod. The `api.rules` package contains basic implementations for declaring boolean, numerical, and string gamerules. 3. If necessary, write your own `IGameRule` implementation. ## Reading a game rule 1. Call `dev.rndmorris.gameruleexts.api.GameRulesApi.getGameRules(...)`. 2. The returned `IGameRules` object can be used to retrieve and update gamerules by their name. # Examples ## Creating and reading a gamerule ```java public class CommonProxy { // ... public void postInit(FMLPostInitializationEvent event) { GameRulesApi.registerGameRule(new FloatGameRule("grassCuttingSwordDamage", 90F)); } // ... } public class SwordGrassCutting extends ItemSword { // ... public boolean hitEntity(ItemStack stack, EntityLivingBase target, EntityLivingBase player) { final var gameRules = GameRulesApi.getGameRules(player.worldObj); target.attackEntityFrom(DamageSource.causePlayerDamage(player).setMagicDamage(), gameRules.getFloat("grassCuttingSwordDamage")); return super.hitEntity(stack, target, player); } // ... } ``` ## Creating a custom gamerule implementation Here's an example custom gamerule that maps enums to bytes. <details> ```java import java.util.Arrays; import java.util.Collection; import java.util.List; import java.util.stream.Collectors; import net.minecraft.command.ICommandSender; import net.minecraft.nbt.NBTTagCompound; import dev.rndmorris.gameruleexts.api.IGameRule; import dev.rndmorris.gameruleexts.api.IRuleValue; import dev.rndmorris.gameruleexts.api.values.EnumValue; public class ExampleCustomGameRule implements IGameRule { public enum ModDifficulty { EASY, MEDIUM, HARD; public static ModDifficulty fromByte(int val, ModDifficulty defaultValue) { return switch (val) { case 0 -> ModDifficulty.EASY; case 1 -> ModDifficulty.MEDIUM; case 2 -> ModDifficulty.HARD; default -> defaultValue; }; } public byte toByte() { return switch (this) { case EASY -> 0; case MEDIUM -> 1; case HARD -> 2; }; } } private final String name = "modDifficulty"; private final ModDifficulty defaultValue; private List<String> tabCompletionValues; public ExampleCustomGameRule(ModDifficulty defaultValue) { this.defaultValue = defaultValue; } @Override public String getName() { return name; } @Override public IRuleValue getDefaultValue() { return new EnumValue<>(defaultValue, ModDifficulty.class); } @Override public IRuleValue readValueFromNBT(NBTTagCompound tag) { if (!tag.hasKey(name)) { return getDefaultValue(); } final var value = ModDifficulty.fromByte(tag.getByte(name), defaultValue); return new EnumValue<>(value, ModDifficulty.class); } @Override public void writeValueToNBT(NBTTagCompound tag, IRuleValue value) { if (value instanceof EnumValue storedVal && storedVal.getValue() instanceof ModDifficulty enumVal) { tag.setByte(name, enumVal.toByte()); } } @Override public Collection<String> tabCompletionValues(ICommandSender commandSender) { if (tabCompletionValues == null) { tabCompletionValues = Arrays.stream(ModDifficulty.values()) .map(ModDifficulty::toString) .collect(Collectors.toList()); } return tabCompletionValues; } } ``` </details> # Credits * rndmorris (primary author) * The GTNH team, for the project template