Gas Generator

The Example Gas Turbine demonstrates when an addon-owned subclass is useful. DoriosCore's Generator continues to own the helper entity, energy, IO, scheduling, displays, and cleanup. ExampleGasGenerator adds only the meaning of its fuel gas and the conversion operation.

DoriosCore remains unchanged. In a real extension, rename ExampleCore to an addon-owned name such as MYADDON_CORE.

1. Prepare Example Hydrogen

The turbine requires the complete resource from Fluids and gases:

• gas type example_hydrogen
• filled and empty gas capsules
• registerGasItem() and registerGasHolder() mappings
• display items and textures utilitycraft:example_hydrogen_00 through _48
• BP entity utilitycraft:gas_tank_example_hydrogen
• matching RP client entity and texture

Missing display items cause GasStorage.display() to report an invalid item identifier. Missing physical entities prevent the gas from appearing in world tanks.

2. Create the addon-owned class

BP/scripts/ExampleCore/machinery/ExampleGasGenerator.js

// @ts-check

import { GasStorage, Generator } from "DoriosCore/index.js";

/** Generator specialization that owns one fixed gas fuel. */
export class ExampleGasGenerator extends Generator {
  /**
   * @param {import("@minecraft/server").Block} block
   * @param {import("DoriosCore/index.js").GeneratorSettings & {
   *   fuelGas?: string,
   *   energyPerGasUnit?: number
   * }} settings
   */
  constructor(block, settings) {
    super(block, settings);
    if (!this.valid) return;

    this.gas = GasStorage.initializeSingle(this.entity);
    this.fuelGas = settings.fuelGas ?? "example_hydrogen";
    this.energyPerGasUnit = Math.max(
      1,
      settings.energyPerGasUnit ?? 40,
    );

    if (this.gas.type === "empty") {
      this.gas.setType(this.fuelGas);
    }
  }

  /** Returns a player-facing problem or undefined when generation can run. */
  getFuelProblem() {
    if (this.gas.get() <= 0) return "No Gas";
    if (this.gas.type !== this.fuelGas) return "Invalid Gas";
    if (this.energy.getFreeSpace() <= 0) return "Energy Full";
    if (this.energy.getFreeSpace() < this.energyPerGasUnit) {
      return `Needs ${this.energyPerGasUnit} DE Free Space`;
    }
    return undefined;
  }

  /** Burns only enough gas to satisfy rate, fuel, and free-space limits. */
  burnGas() {
    if (this.getFuelProblem()) return 0;

    const consumed = Math.min(
      Math.floor(this.gas.get()),
      Math.floor(this.rate / this.energyPerGasUnit),
      Math.floor(this.energy.getFreeSpace() / this.energyPerGasUnit),
    );

    if (consumed <= 0) return 0;

    const produced = consumed * this.energyPerGasUnit;
    this.gas.consume(consumed);
    this.energy.add(produced);
    return produced;
  }
}

Class-owned settings

Setting	Default	Meaning
fuelGas	example_hydrogen	Exact gas type accepted by this subclass.
energyPerGasUnit	40	Dorios Energy produced per gas storage unit. Values below 1 become 1.

The subclass calls super() first and checks valid before creating GasStorage. Its burnGas() method contains one conversion rule that can be tested independently from block events and UI code.

Export it from the addon-owned core:

BP/scripts/ExampleCore/index.js

export * from "./machinery/ExampleGasGenerator.js";

3. Configure the block

BP/blocks/examples/example_gas_turbine.json

{
  "description": {
    "identifier": "utilitycraft:example_gas_turbine",
    "traits": {
      "minecraft:placement_direction": {
        "enabled_states": ["minecraft:cardinal_direction"],
        "y_rotation_offset": 180
      }
    },
    "states": {
      "utilitycraft:on": [false, true]
    }
  },
  "components": {
    "utilitycraft:gas_container": {},
    "utilitycraft:example_gas_turbine": {
      "entity": {
        "name": "example_gas_turbine",
        "type": "gas_generator",
        "inventory_size": 9,
        "fixed_gas_types": true
      },
      "generator": {
        "energy_cap": 128000,
        "rate_speed_base": 100,
        "gas_cap": 16000,
        "gas_types": 1
      },
      "fuelGas": "example_hydrogen",
      "energyPerGasUnit": 40
    },
    "minecraft:tick": {
      "interval_range": [4, 4]
    },
    "tag:dorios:generator": {},
    "tag:dorios:io": {},
    "tag:utilitycraft:io.example_gas_turbine": {},
    "tag:dorios:energy": {},
    "tag:dorios:gas": {}
  }
}

fuelGas and energyPerGasUnit are extra settings read by ExampleGasGenerator; they are not built-in DoriosCore Generator fields.

fixed_gas_types: true keeps the gas type tag when the amount reaches zero. The constructor assigns example_hydrogen, so normal IO cannot replace it with Example Exhaust or another gas.

Keep the complete template block's six face textures, cardinal rotations, on-state permutation, collision, mining settings, and tags.

Slot and index layout

Kind	Slot or index	Purpose
Energy display	slot 0	Stored Dorios Energy.
Label	slot 1	Live turbine status.
Gas display	slot 2	Hydrogen frame item.
Gas storage	index 0	Actual gas amount and type.
Gas IO buttons	slots 3–8	Six relative faces.

4. Register gas IO

BP/scripts/examples/generators/gasTurbine.js

// @ts-check

import {
  EnergyStorage,
  GasStorage,
  registerIOInterface,
} from "DoriosCore/index.js";
import * as DoriosLib from "DoriosLib/index.js";
import { ExampleGasGenerator } from "ExampleCore/index.js";

const BLOCK_ID = "utilitycraft:example_gas_turbine";
const GAS_INDEX = 0;
const GAS_DISPLAY_SLOT = 2;
const GAS_IO_BUTTON_SLOTS = [3, 8];

registerIOInterface(BLOCK_ID, {
  gases: {
    buttonSlots: GAS_IO_BUTTON_SLOTS,
    anyInputIndices: [GAS_INDEX],
    anyOutputIndices: [],
    modes: [
      { id: "disabled" },
      { id: "fuel", inputIndices: [GAS_INDEX] },
    ],
  },
});

Gas configuration uses gases, inputIndices, and storage index 0. The six UI button slots remain inventory slots 3–8.

5. Connect the block lifecycle

BP/scripts/examples/generators/gasTurbine.js

DoriosLib.registry.blockComponent(BLOCK_ID, {
  beforeOnPlayerPlace(event, { params: settings }) {
    ExampleGasGenerator.spawnEntity(event, settings, () => {
      const generator = new ExampleGasGenerator(event.block, {
        ...settings,
        ignoreTick: true,
      });
      if (!generator.valid) return;
      generator.gas.display(GAS_DISPLAY_SLOT);
    });
  },

  onTick({ block }, { params: settings }) {
    const generator = new ExampleGasGenerator(block, settings);
    if (!generator.valid) return;

    generator.processIO();
    generator.energy.transferToNetwork(generator.rate * 4);
    generator.gas.display(GAS_DISPLAY_SLOT);

    const problem = generator.getFuelProblem();
    if (problem) {
      generator.off();
      generator.displayEnergy();
      generator.setLabel(`§r§e${problem}`);
      return;
    }

    const produced = generator.burnGas();
    const producedPerTick = produced / generator.processingInterval;

    generator.gas.display(GAS_DISPLAY_SLOT);
    generator.on();
    generator.displayEnergy();
    generator.setLabel([
      "§r§aGas Turbine Running",
      `§r§7Hydrogen: §f${GasStorage.formatGas(generator.gas.get())}`,
      `§r§7Produced: §f${EnergyStorage.formatEnergyToText(producedPerTick)}/t`,
    ]);
  },

  onPlayerBreak(event) {
    ExampleGasGenerator.onDestroy(event);
  },
});

Static methods are inherited, so ExampleGasGenerator.spawnEntity() and .onDestroy() use the same DoriosCore lifecycle as Generator.

The ignoreTick: true instance is created only inside the post-spawn callback to initialize its fixed type and first display immediately. Ordinary tick instances remain scheduler-controlled.

6. Add the gas UI

RP/ui/example_machinery.json

{
  "gas_turbine_top": {
    "type": "collection_panel",
    "size": [162, 72],
    "offset": [-10, -40],
    "collection_name": "container_items",
    "$item_collection_name": "container_items",
    "controls": [
      { "machine_name@uc.machine_name": {} },
      { "machine_screen@uc.machine_small_screen": {} },
      {
        "machine_description@uc.text_label": {
          "collection_index": 1,
          "anchor_from": "top_left",
          "anchor_to": "top_left",
          "size": [48, 48],
          "$text_scale": 0.55,
          "offset": [14, 12]
        }
      },
      { "energy_bar@uc.energy_bar": { "offset": [32, 0], "$has_bg": false } },
      {
        "fuel@uc.fluid_bar": {
          "$collection_index": 2,
          "$has_bg": false,
          "offset": [54, 0]
        }
      },
      {
        "io@uc.io_tab": {
          "$has_item_io": false,
          "$has_fluid_io": false,
          "$has_gas_io": true,
          "$io_gases_modes_description": "ui.utilitycraft:io.example_gas_turbine.gases",
          "$io_top_texture": "textures/blocks/examples/gas_turbine_off_up",
          "$io_left_texture": "textures/blocks/examples/gas_turbine_off_west",
          "$io_front_texture": "textures/blocks/examples/gas_turbine_off_north",
          "$io_right_texture": "textures/blocks/examples/gas_turbine_off_east",
          "$io_bottom_texture": "textures/blocks/examples/gas_turbine_off_down",
          "$io_back_texture": "textures/blocks/examples/gas_turbine_off_south",
          "$io_gas_top_index": 3,
          "$io_gas_left_index": 4,
          "$io_gas_front_index": 5,
          "$io_gas_right_index": 6,
          "$io_gas_bottom_index": 7,
          "$io_gas_back_index": 8
        }
      },
      {
        "info@uc.info_tab": {
          "$info_description": "ui.utilitycraft:info.example_gas_turbine"
        }
      }
    ]
  }
}

UI Core uses the generic uc.fluid_bar renderer for the gas frame item. Gas IO is still configured independently with $has_gas_io, $io_gases_*, and $io_gas_* variables.

The template already routes entity.utilitycraft:example_gas_turbine.name to this panel and supplies:

RP/texts/en_US.lang

tile.utilitycraft:example_gas_turbine.name=Example Gas Turbine\n§o§9@UC: Addon Template
entity.utilitycraft:example_gas_turbine.name=Example Gas Turbine
ui.utilitycraft:info.example_gas_turbine=Consumes §uExample Hydrogen§8 to generate §sDorios Energy§8. Each gas unit provides 40 DE, and generation pauses when the gas tank is empty or energy storage is full.
ui.utilitycraft:io.example_gas_turbine.gases=§rGas I/O Modes:\n§r- §vHydrogen Fuel

7. Test the turbine

1. Insert an Example Hydrogen Capsule and confirm the frame changes without identifier errors.
2. Try Example Exhaust and confirm the fixed tank rejects it.
3. Set one face to fuel and pull Hydrogen from an adjacent gas tank.
4. Confirm each consumed gas unit produces exactly 40 DE in total.
5. Leave less than 40 DE of free space and confirm the turbine pauses without consuming gas.
6. Fill the energy buffer and confirm the turbine reports Energy Full.
7. Break and replace it in Survival and confirm energy and gas storage are restored.

Continue with Advanced Examples.