up3

server/block/vine.go

@@ -0,0 +1,325 @@
+package block
+
+import (
+	"github.com/df-mc/dragonfly/server/block/cube"
+	"github.com/df-mc/dragonfly/server/block/model"
+	"github.com/df-mc/dragonfly/server/item"
+	"github.com/df-mc/dragonfly/server/world"
+	"github.com/go-gl/mathgl/mgl64"
+	"math/rand/v2"
+)
+
+// Vines are climbable non-solid vegetation blocks that grow on walls.
+type Vines struct {
+	replaceable
+	transparent
+	empty
+	sourceWaterDisplacer
+
+	// NorthDirection is true if the vines are attached towards north.
+	NorthDirection bool
+	// EastDirection is true if the vines are attached towards east.
+	EastDirection bool
+	// SouthDirection is true if the vines are attached towards south.
+	SouthDirection bool
+	// WestDirection is true if the vines are attached towards west.
+	WestDirection bool
+}
+
+// CompostChance ...
+func (Vines) CompostChance() float64 {
+	return 0.5
+}
+
+// SideClosed ...
+func (Vines) SideClosed(cube.Pos, cube.Pos, *world.Tx) bool {
+	return false
+}
+
+// HasLiquidDrops ...
+func (Vines) HasLiquidDrops() bool {
+	return false
+}
+
+// FlammabilityInfo ...
+func (Vines) FlammabilityInfo() FlammabilityInfo {
+	return newFlammabilityInfo(15, 100, true)
+}
+
+// BreakInfo ...
+func (v Vines) BreakInfo() BreakInfo {
+	return newBreakInfo(0.2, func(t item.Tool) bool {
+		return t.ToolType() == item.TypeShears
+	}, axeEffective, oneOf(v))
+}
+
+// EntityInside ...
+func (Vines) EntityInside(_ cube.Pos, _ *world.Tx, e world.Entity) {
+	if fallEntity, ok := e.(fallDistanceEntity); ok {
+		fallEntity.ResetFallDistance()
+	}
+}
+
+// WithAttachment returns a Vines block with an attachment on the given cube.Direction.
+func (v Vines) WithAttachment(direction cube.Direction, attached bool) Vines {
+	switch direction {
+	case cube.North:
+		v.NorthDirection = attached
+		return v
+	case cube.East:
+		v.EastDirection = attached
+		return v
+	case cube.South:
+		v.SouthDirection = attached
+		return v
+	case cube.West:
+		v.WestDirection = attached
+		return v
+	}
+	panic("should never happen")
+}
+
+// Attachment returns the attachment of the vines at the given direction.
+func (v Vines) Attachment(direction cube.Direction) bool {
+	switch direction {
+	case cube.North:
+		return v.NorthDirection
+	case cube.East:
+		return v.EastDirection
+	case cube.South:
+		return v.SouthDirection
+	case cube.West:
+		return v.WestDirection
+	}
+	panic("should never happen")
+}
+
+// Attachments returns all attachments of the vines.
+func (v Vines) Attachments() (attachments []cube.Direction) {
+	for _, d := range cube.Directions() {
+		if v.Attachment(d) {
+			attachments = append(attachments, d)
+		}
+	}
+	return
+}
+
+// UseOnBlock ...
+func (v Vines) UseOnBlock(pos cube.Pos, face cube.Face, _ mgl64.Vec3, tx *world.Tx, user item.User, ctx *item.UseContext) bool {
+	if _, ok := tx.Block(pos).Model().(model.Solid); !ok || face.Axis() == cube.Y {
+		return false
+	}
+	pos, face, used := firstReplaceable(tx, pos, face, v)
+	if !used {
+		return false
+	}
+	if _, ok := tx.Block(pos).(Vines); ok {
+		// Do not overwrite existing vine block.
+		return false
+	}
+	//noinspection GoAssignmentToReceiver
+	v = v.WithAttachment(face.Direction().Opposite(), true)
+
+	place(tx, pos, v, user, ctx)
+	return placed(ctx)
+}
+
+// NeighbourUpdateTick ...
+func (v Vines) NeighbourUpdateTick(pos, _ cube.Pos, tx *world.Tx) {
+	above, updated := tx.Block(pos.Side(cube.FaceUp)), false
+	for _, d := range v.Attachments() {
+		if !v.canSpreadTo(tx, pos.Side(d.Face())) {
+			if o, ok := above.(Vines); !ok || !o.Attachment(d) {
+				//noinspection GoAssignmentToReceiver
+				v = v.WithAttachment(d, false)
+				updated = true
+			}
+		}
+	}
+	if !updated {
+		return
+	}
+	if len(v.Attachments()) == 0 {
+		breakBlock(v, pos, tx)
+		return
+	}
+	tx.SetBlock(pos, v, nil)
+}
+
+// RandomTick ...
+func (v Vines) RandomTick(pos cube.Pos, tx *world.Tx, r *rand.Rand) {
+	if r.Float64() > 0.25 {
+		// Vines have a 25% chance of spreading.
+		return
+	}
+
+	// Choose a random direction to spread.
+	face := cube.Face(r.IntN(len(cube.Faces())))
+	selectedPos := pos.Side(face)
+
+	// If a horizontal direction was chosen and the vine block is not already
+	// attached in that direction, attempt to spread in that direction.
+	if face.Axis() != cube.Y && !v.Attachment(face.Direction()) {
+		if !v.canSpread(tx, pos) {
+			// No further attempt to spread vertically will be made.
+			return
+		}
+		// Attempt to create a new vine block if there is a neighbouring air block
+		// in the chosen direction.
+		if _, ok := tx.Block(selectedPos).(Air); ok {
+			rightRotatedFace := face.RotateRight()
+			leftRotatedFace := face.RotateLeft()
+
+			attachedOnRight := v.Attachment(rightRotatedFace.Direction())
+			attachedOnLeft := v.Attachment(leftRotatedFace.Direction())
+
+			rightSelectedPos := selectedPos.Side(rightRotatedFace)
+			leftSelectedPos := selectedPos.Side(leftRotatedFace)
+
+			// Four attempts to create a new vine block will be made, in the
+			// following order:
+			// 1) If the current vine block is attached in the direction towards
+			//    the right ("clockwise") of the chosen direction, and a solid
+			//    block can support a vine on that direction in the selected
+			//    position, create a new vine block attached on that clockwise
+			//    direction at the selected position.
+			// 2) If the clockwise direction fails, try again with the left
+			//    ("counter-clockwise") direction.
+			// 3) If the current vine block is attached in the direction towards
+			//    the right of the chosen direction, the current vine block is
+			//    also backed by a solid block in that same direction, and the
+			//    block neighbouring the selected position in that direction is
+			//    air, spread into that air block onto the face opposite of the
+			//    chosen direction. The vine jumps from one face of a block onto
+			//    another as a result.
+			// 4) If the clockwise direction fails, try again with the left
+			//    direction.
+			if attachedOnRight && v.canSpreadTo(tx, rightSelectedPos) {
+				tx.SetBlock(selectedPos, (Vines{}).WithAttachment(rightRotatedFace.Direction(), true), nil)
+			} else if attachedOnLeft && v.canSpreadTo(tx, leftSelectedPos) {
+				tx.SetBlock(selectedPos, (Vines{}).WithAttachment(leftRotatedFace.Direction(), true), nil)
+			} else if _, ok = tx.Block(rightSelectedPos).(Air); ok && attachedOnRight && v.canSpreadTo(tx, pos.Side(rightRotatedFace)) {
+				tx.SetBlock(rightSelectedPos, (Vines{}).WithAttachment(face.Opposite().Direction(), true), nil)
+			} else if _, ok = tx.Block(leftSelectedPos).(Air); ok && attachedOnLeft && v.canSpreadTo(tx, pos.Side(leftRotatedFace)) {
+				tx.SetBlock(leftSelectedPos, (Vines{}).WithAttachment(face.Opposite().Direction(), true), nil)
+			}
+		} else if v.canSpreadTo(tx, selectedPos) {
+			// If the neighbouring block is solid, update the vine to be attached in that direction.
+			tx.SetBlock(pos, v.WithAttachment(face.Direction(), true), nil)
+		}
+		return
+	}
+
+	// If the chosen direction is Up and the position above is within the height
+	// limit, attempt to spread upwards.
+	if face == cube.FaceUp && selectedPos.OutOfBounds(tx.Range()) {
+		// Vines can only spread upwards into an air block.
+		if _, ok := tx.Block(selectedPos).(Air); ok {
+			if !v.canSpread(tx, pos) {
+				// No further attempt to spread down will be made.
+				return
+			}
+			newVines := Vines{}
+			for _, f := range cube.HorizontalFaces() {
+				// For each direction the current vine block is attached on,
+				// there is a 50% chance for the new above vine block to
+				// attach onto the direction, if there is also a solid block
+				// in that direction to support the vine.
+				if r.IntN(2) == 0 && v.Attachment(f.Direction()) && v.canSpreadTo(tx, selectedPos.Side(f)) {
+					newVines = newVines.WithAttachment(f.Direction(), true)
+				}
+			}
+			if len(newVines.Attachments()) > 0 {
+				tx.SetBlock(selectedPos, newVines, nil)
+			}
+			return
+		}
+	}
+
+	// If an attempt to spread horizontally or upwards has failed but not exited
+	// early, attempt to spread downwards.
+	selectedPos = pos.Side(cube.FaceDown)
+	if selectedPos.OutOfBounds(tx.Range()) {
+		return
+	}
+	newVines, vines := tx.Block(selectedPos).(Vines)
+	if _, ok := tx.Block(selectedPos).(Air); !ok && !vines {
+		// The block under the current vine block must be air or a vine block.
+		return
+	}
+	var changed bool
+	for _, f := range cube.HorizontalFaces() {
+		// For each direction the current vine block is attached on, there is a
+		// 50% chance for the below vine block to attach onto the direction if
+		// it is not already attached in that direction.
+		if r.IntN(2) == 0 && v.Attachment(f.Direction()) && !newVines.Attachment(f.Direction()) {
+			newVines, changed = newVines.WithAttachment(f.Direction(), true), true
+		}
+	}
+	if changed {
+		tx.SetBlock(selectedPos, newVines, nil)
+	}
+}
+
+// EncodeItem ...
+func (Vines) EncodeItem() (name string, meta int16) {
+	return "minecraft:vine", 0
+}
+
+// EncodeBlock ...
+func (v Vines) EncodeBlock() (string, map[string]any) {
+	var bits int
+	for i, ok := range []bool{v.SouthDirection, v.WestDirection, v.NorthDirection, v.EastDirection} {
+		if ok {
+			bits |= 1 << i
+		}
+	}
+	return "minecraft:vine", map[string]any{"vine_direction_bits": int32(bits)}
+}
+
+// canSpreadTo returns true if the vines can spread onto the block at the
+// given position. Vines may only spread onto fully solid blocks.
+func (Vines) canSpreadTo(tx *world.Tx, pos cube.Pos) bool {
+	_, ok := tx.Block(pos).Model().(model.Solid)
+	return ok
+}
+
+// canSpread returns true if the vines can spread from the given position. Vines
+// may only spread horizontally or upwards if there are fewer than 4 vines within
+// a 9x9x3 area centred around the Vines.
+func (v Vines) canSpread(tx *world.Tx, pos cube.Pos) bool {
+	var count int
+	for x := -4; x <= 4; x++ {
+		for z := -4; z <= 4; z++ {
+			for y := -1; y <= 1; y++ {
+				if _, ok := tx.Block(pos.Add(cube.Pos{x, y, z})).(Vines); ok {
+					count++
+					// The centre vine is counted, for a max of 4+1=5.
+					if count >= 5 {
+						return false
+					}
+				}
+			}
+		}
+	}
+	return true
+}
+
+// allVines ...
+func allVines() (b []world.Block) {
+	for _, north := range []bool{true, false} {
+		for _, east := range []bool{true, false} {
+			for _, south := range []bool{true, false} {
+				for _, west := range []bool{true, false} {
+					b = append(b, Vines{
+						NorthDirection: north,
+						EastDirection:  east,
+						SouthDirection: south,
+						WestDirection:  west,
+					})
+				}
+			}
+		}
+	}
+	return
+}