components.go

package iteminternal

import (
	"github.com/df-mc/dragonfly/server/item"
	"github.com/df-mc/dragonfly/server/world"
	"strings"
)

// Components returns all the components of the given custom item. If the item has no components, a nil map and false
// are returned.
func Components(it world.CustomItem) map[string]any {
	category := it.Category()
	identifier, _ := it.EncodeItem()
	name := strings.Split(identifier, ":")[1]

	builder := NewComponentBuilder(it.Name(), identifier, category)

	if x, ok := it.(item.Armour); ok {
		builder.AddComponent("minecraft:armor", map[string]any{
			"protection": int32(x.DefencePoints()),
		})

		var slot string
		switch it.(type) {
		case item.HelmetType:
			slot = "slot.armor.head"
		case item.ChestplateType:
			slot = "slot.armor.chest"
		case item.LeggingsType:
			slot = "slot.armor.legs"
		case item.BootsType:
			slot = "slot.armor.feet"
		}
		builder.AddComponent("minecraft:wearable", map[string]any{
			"slot": slot,
		})
	}
	if x, ok := it.(item.Consumable); ok {
		builder.AddProperty("use_duration", int32(x.ConsumeDuration().Seconds()*20))
		builder.AddComponent("minecraft:food", map[string]any{
			"can_always_eat": x.AlwaysConsumable(),
		})

		if y, ok := it.(item.Drinkable); ok && y.Drinkable() {
			builder.AddProperty("use_animation", int32(2))
		} else {
			builder.AddProperty("use_animation", int32(1))
		}
	}
	if x, ok := it.(item.Cooldown); ok {
		builder.AddComponent("minecraft:cooldown", map[string]any{
			"category": name,
			"duration": float32(x.Cooldown().Seconds()),
		})
	}
	if x, ok := it.(item.Durable); ok {
		builder.AddComponent("minecraft:durability", map[string]any{
			"max_durability": int32(x.DurabilityInfo().MaxDurability),
		})
	}
	if x, ok := it.(item.MaxCounter); ok {
		builder.AddProperty("max_stack_size", int32(x.MaxCount()))
	}
	if x, ok := it.(item.OffHand); ok {
		builder.AddProperty("allow_off_hand", x.OffHand())
	}
	if x, ok := it.(item.Throwable); ok {
		// The data in minecraft:projectile is only used by vanilla server-side, but we must send at least an empty map
		// so the client will play the throwing animation.
		builder.AddComponent("minecraft:projectile", map[string]any{})
		builder.AddComponent("minecraft:throwable", map[string]any{
			"do_swing_animation": x.SwingAnimation(),
		})
	}
	if x, ok := it.(item.Glinted); ok {
		builder.AddProperty("foil", x.Glinted())
	}
	if x, ok := it.(item.HandEquipped); ok {
		builder.AddProperty("hand_equipped", x.HandEquipped())
	}
	itemScale := calculateItemScale(it)
	builder.AddComponent("minecraft:render_offsets", map[string]any{
		"main_hand": map[string]any{
			"first_person": map[string]any{
				"scale": itemScale,
			},
			"third_person": map[string]any{
				"scale": itemScale,
			},
		},
		"off_hand": map[string]any{
			"first_person": map[string]any{
				"scale": itemScale,
			},
			"third_person": map[string]any{
				"scale": itemScale,
			},
		},
	})

	return builder.Construct()
}

// calculateItemScale calculates the scale of the item to be rendered to the player according to the given size.
func calculateItemScale(it world.CustomItem) []float32 {
	width := float32(it.Texture().Bounds().Dx())
	height := float32(it.Texture().Bounds().Dy())
	var x, y, z float32 = 0.1, 0.1, 0.1
	if _, ok := it.(item.HandEquipped); ok {
		x, y, z = 0.075, 0.125, 0.075
	}
	newX := x / (width / 16)
	newY := y / (height / 16)
	newZ := z / (width / 16)
	return []float32{newX, newY, newZ}
}