Areas and waypoints

This lesson makes a zone that reacts when a player enters or leaves it, and places a marker on the map. It assumes you finished the earlier lessons.

An area with modules

An area is a spatial zone. Behavior attaches to it through modules: small classes that run on enter, on leave, on tick, or when a block changes.

Import the area types and reach the area manager:

import de.luckymcdev.foundryengine.common.Common
import de.luckymcdev.foundryengine.common.area.Area
import de.luckymcdev.foundryengine.common.area.preset.AreaPreset
import de.luckymcdev.foundryengine.common.area.module.AreaEnterModule
import de.luckymcdev.foundryengine.common.area.module.AreaLeaveModule
import de.luckymcdev.foundryengine.common.area.module.AreaTickModule
import de.luckymcdev.foundryengine.common.util.color.Color
import net.minecraft.network.chat.Component
import net.minecraft.server.level.ServerPlayer
import net.minecraft.server.level.ServerLevel

void onLoad() {
    def manager = Common.getAreaManager()

    manager.registerModuleType(new MyEnterModule())
    manager.registerModuleType(new MyLeaveModule())
    manager.registerModuleType(new MyHealModule())
}

A module is a class that implements one of the module interfaces. Each interface needs an id() method that names the module, plus the behavior method.

static class MyEnterModule implements AreaEnterModule {
    Identifier id() { return id("my_enter") }
    void onEnter(ServerPlayer player, Area area) {
        player.sendSystemMessage(
                Component.literal("§aEntered area: ${area.id()}"))
    }
}

static class MyLeaveModule implements AreaLeaveModule {
    Identifier id() { return id("my_leave") }
    void onLeave(ServerPlayer player, Area area) {
        player.sendSystemMessage(
                Component.literal("§cLeft area: ${area.id()}"))
    }
}

The tick module runs on a schedule and can affect players inside the area:

static class MyHealModule implements AreaTickModule {
    Identifier id() { return id("my_heal") }
    void tick(ServerLevel level, Area area) {
        level.players().each { p ->
            if (area.contains(p.blockPosition()) && p.tickCount % 40 == 0) {
                p.heal(0.5f)
            }
        }
    }
}

The heal module reads as: every tick, look at each player, and if they stand inside the area and 40 ticks have passed, heal them half a heart.

Make a preset

A preset bundles the modules into a reusable area definition, with a color for the in-world rendering.

def preset = AreaPreset.builder(id("healing_zone"))
        .color(new Color(100, 200, 100))
        .module(id("my_enter"))
        .module(id("my_leave"))
        .module(id("my_heal"))
        .build()

manager.registerPreset(preset)

AreaPreset.builder(id) starts a preset. .module(...) attaches each module by its id. .build() finishes it, and registerPreset makes it available.

An area of this preset is then created in the world, either in game with the area tool or from a command. The guides Create an area recipe covers creating the actual zone.

A waypoint

A waypoint is a persistent marker at a position. It survives across sessions because it is saved data. A Waypoint is a record: a name, an icon character, a position, and a color.

import de.luckymcdev.foundryengine.common.waypoint.Waypoint

def manager = Common.getWaypointManager()

def wp = new Waypoint(
        "My Spot",
        "I",
        100, 80, 200,
        new Color(255, 255, 255))

Then register it for the current level:

manager.addWaypoint(player.level() as ServerLevel, wp)

addWaypoint stores the marker under the level's dimension and saves it. In game, waypoints render as markers over the world, and the /engine waypoint command manages them.

Next, author a cutscene.