up3

server/block/string.go

@@ -0,0 +1,85 @@
+package block
+
+import (
+	"github.com/df-mc/dragonfly/server/block/cube"
+	"github.com/df-mc/dragonfly/server/item"
+	"github.com/df-mc/dragonfly/server/world"
+	"github.com/go-gl/mathgl/mgl64"
+)
+
+// String is an item obtained from spiders and cobwebs. When placed, it creates a tripwire that
+// detects entities passing through it.
+// TODO: Redstone functionality (entity detection, tripwire hook circuits, shears-disarm propagation).
+type String struct {
+	empty
+	transparent
+
+	// Attached is true if the tripwire is connected to valid tripwire hooks on both sides.
+	Attached bool
+	// Disarmed is true if the tripwire was cut using shears, preventing it from activating.
+	Disarmed bool
+	// Powered is true if the tripwire is currently activated by an entity passing through it.
+	Powered bool
+	// Suspended is true if the tripwire is not resting on a solid surface.
+	Suspended bool
+}
+
+// UseOnBlock places the string as a tripwire on the target surface.
+func (s String) UseOnBlock(pos cube.Pos, face cube.Face, _ mgl64.Vec3, tx *world.Tx, user item.User, ctx *item.UseContext) bool {
+	pos, _, canPlace := firstReplaceable(tx, pos, face, s)
+	if !canPlace {
+		return false
+	}
+	below := pos.Side(cube.FaceDown)
+	s.Suspended = !tx.Block(below).Model().FaceSolid(below, cube.FaceUp, tx)
+	place(tx, pos, s, user, ctx)
+	return placed(ctx)
+}
+
+// NeighbourUpdateTick ...
+func (s String) NeighbourUpdateTick(pos, _ cube.Pos, tx *world.Tx) {
+	below := pos.Side(cube.FaceDown)
+	suspended := !tx.Block(below).Model().FaceSolid(below, cube.FaceUp, tx)
+	if suspended != s.Suspended {
+		s.Suspended = suspended
+		tx.SetBlock(pos, s, nil)
+	}
+}
+
+// HasLiquidDrops ...
+func (s String) HasLiquidDrops() bool {
+	return true
+}
+
+// BreakInfo ...
+func (s String) BreakInfo() BreakInfo {
+	return newBreakInfo(0, alwaysHarvestable, nothingEffective, oneOf(String{}))
+}
+
+// EncodeItem ...
+func (s String) EncodeItem() (name string, meta int16) {
+	return "minecraft:string", 0
+}
+
+// EncodeBlock ...
+func (s String) EncodeBlock() (name string, properties map[string]any) {
+	return "minecraft:trip_wire", map[string]any{
+		"attached_bit":  boolByte(s.Attached),
+		"disarmed_bit":  boolByte(s.Disarmed),
+		"powered_bit":   boolByte(s.Powered),
+		"suspended_bit": boolByte(s.Suspended),
+	}
+}
+
+// allString ...
+func allString() (blocks []world.Block) {
+	for meta := 0; meta < 16; meta++ {
+		blocks = append(blocks, String{
+			Powered:   meta&0x1 != 0,
+			Suspended: meta&0x2 != 0,
+			Attached:  meta&0x4 != 0,
+			Disarmed:  meta&0x8 != 0,
+		})
+	}
+	return blocks
+}