up3

server/entity/splashable.go

@@ -0,0 +1,102 @@
+package entity
+
+import (
+	"github.com/df-mc/dragonfly/server/block/cube"
+	"github.com/df-mc/dragonfly/server/block/cube/trace"
+	"github.com/df-mc/dragonfly/server/entity/effect"
+	"github.com/df-mc/dragonfly/server/item/potion"
+	"github.com/df-mc/dragonfly/server/world"
+	"github.com/go-gl/mathgl/mgl64"
+	"time"
+)
+
+// SplashableBlock is a block that can be splashed with a splash bottle.
+type SplashableBlock interface {
+	world.Block
+	// Splash is called when a water bottle splashes onto a block.
+	Splash(tx *world.Tx, pos cube.Pos)
+}
+
+// SplashableEntity is an entity that can be splashed with a splash bottle.
+type SplashableEntity interface {
+	world.Entity
+	// Splash is called when a water bottle splashes onto an entity.
+	Splash(tx *world.Tx, pos mgl64.Vec3)
+}
+
+// potionSplash returns a function that creates a potion splash with a specific
+// duration multiplier and potion type.
+func potionSplash(durMul float64, pot potion.Potion, linger bool) func(e *Ent, tx *world.Tx, res trace.Result) {
+	return func(e *Ent, tx *world.Tx, res trace.Result) {
+		pos := e.Position()
+		effects := pot.Effects()
+		box := e.H().Type().BBox(e).Translate(pos)
+
+		if len(effects) > 0 {
+			for otherE := range filterLiving(tx.EntitiesWithin(box.GrowVec3(mgl64.Vec3{8.25, 4.25, 8.25}))) {
+				otherPos := otherE.Position()
+				if !otherE.H().Type().BBox(otherE).Translate(otherPos).IntersectsWith(box.GrowVec3(mgl64.Vec3{4.125, 2.125, 4.125})) {
+					continue
+				}
+
+				dist := otherPos.Sub(pos).Len()
+				if dist > 4 {
+					continue
+				}
+
+				f := 1 - dist/4
+				if entityResult, ok := res.(trace.EntityResult); ok && entityResult.Entity().H() == otherE.H() {
+					f = 1
+				}
+
+				splashed := otherE.(Living)
+				for _, eff := range effects {
+					if _, ok := eff.Type().(effect.LastingType); !ok {
+						splashed.AddEffect(effect.NewInstantWithPotency(eff.Type(), eff.Level(), f))
+						continue
+					}
+
+					dur := time.Duration(float64(eff.Duration()) * durMul * f)
+					if dur < time.Second {
+						continue
+					}
+					splashed.AddEffect(effect.New(eff.Type().(effect.LastingType), eff.Level(), dur))
+				}
+			}
+		} else if pot == potion.Water() {
+			switch result := res.(type) {
+			case trace.BlockResult:
+				blockPos := result.BlockPosition().Side(result.Face())
+				if tx.Block(blockPos) == fire() {
+					tx.SetBlock(blockPos, nil, nil)
+				}
+
+				for _, f := range cube.HorizontalFaces() {
+					if h := blockPos.Side(f); tx.Block(h) == fire() {
+						tx.SetBlock(h, nil, nil)
+					}
+
+					if b, ok := tx.Block(blockPos.Side(f)).(SplashableBlock); ok {
+						b.Splash(tx, blockPos.Side(f))
+					}
+				}
+
+				resultPos := result.BlockPosition()
+				if b, ok := tx.Block(resultPos).(SplashableBlock); ok {
+					b.Splash(tx, resultPos)
+				}
+			case trace.EntityResult:
+				// TODO: Damage endermen, blazes, striders and snow golems when implemented and rehydrate axolotls.
+			}
+
+			for otherE := range filterLiving(tx.EntitiesWithin(box.GrowVec3(mgl64.Vec3{8.25, 4.25, 8.25}))) {
+				if splashE, ok := otherE.(SplashableEntity); ok {
+					splashE.Splash(tx, otherE.Position())
+				}
+			}
+		}
+		if linger {
+			tx.AddEntity(NewAreaEffectCloud(world.EntitySpawnOpts{Position: pos}, pot))
+		}
+	}
+}