Implement mycelium

server/block/dirt.go

@@ -1,6 +1,9 @@
 package block
 
 import (
+	"math/rand/v2"
+
+	"github.com/df-mc/dragonfly/server/block/cube"
 	"github.com/df-mc/dragonfly/server/world"
 )
 
@@ -59,6 +62,37 @@ func (d Dirt) EncodeBlock() (string, map[string]any) {
 	return "minecraft:dirt", nil
 }
 
+// spreadDirt turns the block passed into dirt in low light and otherwise spreads it onto nearby dirt. It is
+// the random tick behaviour shared by grass blocks and mycelium. minY is the lowest vertical offset a spread
+// attempt may target.
+func spreadDirt(b world.Block, pos cube.Pos, tx *world.Tx, r *rand.Rand, minY int) {
+	aboveLight := tx.Light(pos.Side(cube.FaceUp))
+	if aboveLight < 4 {
+		tx.SetBlock(pos, Dirt{}, nil)
+		return
+	}
+	if aboveLight < 9 {
+		return
+	}
+
+	// A single uint32 is enough as only 28 bits are needed, 7 per iteration.
+	n := r.Uint32()
+
+	for range 4 {
+		x, y, z := int(n)%3, int(n>>2)%5, int(n>>5)%3
+		n >>= 7
+
+		spreadPos := pos.Add(cube.Pos{x - 1, y + minY, z - 1})
+		if tx.Light(spreadPos.Side(cube.FaceUp)) < 4 {
+			continue
+		}
+		if dirt, ok := tx.Block(spreadPos).(Dirt); !ok || dirt.Coarse {
+			continue
+		}
+		tx.SetBlock(spreadPos, b, nil)
+	}
+}
+
 // supportsVegetation checks if the vegetation can exist on the block.
 func supportsVegetation(vegetation, block world.Block) bool {
 	soil, ok := block.(Soil)

server/block/grass.go

@@ -47,36 +47,7 @@ func (g Grass) SoilFor(block world.Block) bool {
 
 // RandomTick handles the ticking of grass, which may or may not result in the spreading of grass onto dirt.
 func (g Grass) RandomTick(pos cube.Pos, tx *world.Tx, r *rand.Rand) {
-	aboveLight := tx.Light(pos.Side(cube.FaceUp))
-	if aboveLight < 4 {
-		// The light above the block is too low: The grass turns to dirt.
-		tx.SetBlock(pos, Dirt{}, nil)
-		return
-	}
-	if aboveLight < 9 {
-		// Don't attempt to spread if the light level is lower than 9.
-		return
-	}
-
-	// Generate a single uint32 as we only need 28 bits (7 bits each iteration).
-	n := r.Uint32()
-
-	// Four attempts to spread to another block.
-	for i := 0; i < 4; i++ {
-		x, y, z := int(n)%3, int(n>>2)%5, int(n>>5)%3
-		n >>= 7
-
-		spreadPos := pos.Add(cube.Pos{x - 1, y - 3, z - 1})
-		// Don't spread grass to locations where dirt is exposed to hardly any light.
-		if tx.Light(spreadPos.Side(cube.FaceUp)) < 4 {
-			continue
-		}
-		b := tx.Block(spreadPos)
-		if dirt, ok := b.(Dirt); !ok || dirt.Coarse {
-			continue
-		}
-		tx.SetBlock(spreadPos, g, nil)
-	}
+	spreadDirt(g, pos, tx, r, -3)
 }
 
 // BoneMeal ...

server/block/mycelium.go

@@ -0,0 +1,47 @@
+package block
+
+import (
+	"math/rand/v2"
+
+	"github.com/df-mc/dragonfly/server/block/cube"
+	"github.com/df-mc/dragonfly/server/world"
+)
+
+// Mycelium is a variant of dirt that covers the surface of the mushroom fields biome.
+type Mycelium struct {
+	solid
+}
+
+// SoilFor ...
+func (m Mycelium) SoilFor(block world.Block) bool {
+	switch block.(type) {
+	case ShortGrass, Fern, DoubleTallGrass, Flower, DoubleFlower, NetherSprouts, PinkPetals, SugarCane, DeadBush, BambooSapling, Bamboo:
+		return true
+	}
+	return false
+}
+
+// RandomTick ...
+func (m Mycelium) RandomTick(pos cube.Pos, tx *world.Tx, r *rand.Rand) {
+	spreadDirt(m, pos, tx, r, -2)
+}
+
+// Shovel ...
+func (Mycelium) Shovel() (world.Block, bool) {
+	return DirtPath{}, true
+}
+
+// BreakInfo ...
+func (m Mycelium) BreakInfo() BreakInfo {
+	return newBreakInfo(0.6, alwaysHarvestable, shovelEffective, silkTouchOneOf(Dirt{}, m))
+}
+
+// EncodeItem ...
+func (Mycelium) EncodeItem() (name string, meta int16) {
+	return "minecraft:mycelium", 0
+}
+
+// EncodeBlock ...
+func (Mycelium) EncodeBlock() (string, map[string]any) {
+	return "minecraft:mycelium", nil
+}

server/block/nether_sprouts.go

@@ -17,7 +17,7 @@ type NetherSprouts struct {
 // NeighbourUpdateTick ...
 func (n NetherSprouts) NeighbourUpdateTick(pos, _ cube.Pos, tx *world.Tx) {
 	if !supportsVegetation(n, tx.Block(pos.Side(cube.FaceDown))) {
-		breakBlock(n, pos, tx) // TODO: Nylium & mycelium
+		breakBlock(n, pos, tx) // TODO: Nylium
 	}
 }
 
@@ -28,7 +28,7 @@ func (n NetherSprouts) UseOnBlock(pos cube.Pos, face cube.Face, _ mgl64.Vec3, tx
 		return false
 	}
 	if !supportsVegetation(n, tx.Block(pos.Side(cube.FaceDown))) {
-		return false // TODO: Nylium & mycelium
+		return false // TODO: Nylium
 	}
 
 	place(tx, pos, n, user, ctx)

server/block/register.go

@@ -86,6 +86,7 @@ func init() {
 	world.RegisterBlock(MossCarpet{})
 	world.RegisterBlock(MudBricks{})
 	world.RegisterBlock(Mud{})
+	world.RegisterBlock(Mycelium{})
 	world.RegisterBlock(NetherBrickFence{})
 	world.RegisterBlock(NetherGoldOre{})
 	world.RegisterBlock(NetherQuartzOre{})
@@ -366,6 +367,7 @@ func init() {
 	world.RegisterItem(MudBricks{})
 	world.RegisterItem(MuddyMangroveRoots{})
 	world.RegisterItem(Mud{})
+	world.RegisterItem(Mycelium{})
 	world.RegisterItem(NetherBrickFence{})
 	world.RegisterItem(NetherGoldOre{})
 	world.RegisterItem(NetherQuartzOre{})