up3

server/entity/experience_orb.go

@@ -0,0 +1,66 @@
+package entity
+
+import (
+	"github.com/df-mc/dragonfly/server/block/cube"
+	"github.com/df-mc/dragonfly/server/internal/nbtconv"
+	"github.com/df-mc/dragonfly/server/world"
+	"github.com/go-gl/mathgl/mgl64"
+	"math/rand/v2"
+	"slices"
+)
+
+// orbSplitSizes contains split sizes used for dropping experience orbs.
+var orbSplitSizes = []int{2477, 1237, 617, 307, 149, 73, 37, 17, 7, 3, 1}
+
+// NewExperienceOrbs takes in a position and an amount and automatically splits the amount into multiple orbs, returning
+// a slice of the created orbs.
+func NewExperienceOrbs(pos mgl64.Vec3, amount int) (orbs []*world.EntityHandle) {
+	for amount > 0 {
+		size := orbSplitSizes[slices.IndexFunc(orbSplitSizes, func(value int) bool {
+			return amount >= value
+		})]
+
+		orbs = append(orbs, NewExperienceOrb(world.EntitySpawnOpts{Position: pos}, size))
+		amount -= size
+	}
+	return
+}
+
+// NewExperienceOrb creates a new experience orb and returns it.
+func NewExperienceOrb(opts world.EntitySpawnOpts, xp int) *world.EntityHandle {
+	conf := experienceOrbConf
+	conf.Experience = xp
+	if opts.Velocity.Len() == 0 {
+		opts.Velocity = mgl64.Vec3{(rand.Float64()*0.2 - 0.1) * 2, rand.Float64() * 0.4, (rand.Float64()*0.2 - 0.1) * 2}
+	}
+	return opts.New(ExperienceOrbType, conf)
+}
+
+var experienceOrbConf = ExperienceOrbBehaviourConfig{
+	Gravity: 0.04,
+	Drag:    0.02,
+}
+
+// ExperienceOrbType is a world.EntityType implementation for ExperienceOrb.
+var ExperienceOrbType experienceOrbType
+
+type experienceOrbType struct{}
+
+func (t experienceOrbType) Open(tx *world.Tx, handle *world.EntityHandle, data *world.EntityData) world.Entity {
+	return &Ent{tx: tx, handle: handle, data: data}
+}
+
+func (experienceOrbType) EncodeEntity() string { return "minecraft:xp_orb" }
+func (experienceOrbType) BBox(world.Entity) cube.BBox {
+	return cube.Box(-0.125, 0, -0.125, 0.125, 0.25, 0.125)
+}
+
+func (experienceOrbType) DecodeNBT(m map[string]any, data *world.EntityData) {
+	conf := experienceOrbConf
+	conf.Experience = int(nbtconv.Int32(m, "Value"))
+	data.Data = conf.New()
+}
+
+func (experienceOrbType) EncodeNBT(data *world.EntityData) map[string]any {
+	return map[string]any{"Value": int32(data.Data.(*ExperienceOrbBehaviour).Experience())}
+}