add world module for in-memory block storage and integrate getblock command in messenger

2026-07-16 16:05:42 +02:00
parent 7baa9990cb
commit 7f878f40a1
2 changed files with 232 additions and 4 deletions
@@ -2,11 +2,16 @@ package messenger

 import (
 	"flag"
+	"fmt"
+	"strconv"
+	"strings"

 	"github.com/admin-else/strom/cmd/strom/cmd_util"
 	"github.com/admin-else/strom/mc/bot/chat"
 	"github.com/admin-else/strom/mc/bot/keepalive"
+	"github.com/admin-else/strom/mc/bot/world"
 	"github.com/admin-else/strom/mc/client"
+	"github.com/admin-else/strom/mc/data"
 	"github.com/admin-else/strom/mc/event"
 	"github.com/admin-else/strom/mc/proto"
 	"github.com/admin-else/strom/mc/proto_generated/v1_21_11"
@@ -20,7 +25,8 @@ var (

 type Messenger struct {
 	*proto.Conn
-	chat *chat.Module
+	chat  *chat.Module
+	world *world.Module
 }

 func (m *Messenger) OnChat(e *v1_21_11.PlayToClientPacketPlayerChat) (err error) {
@@ -39,7 +45,46 @@ func (m *Messenger) OnChatSystem(e *v1_21_11.PlayToClientPacketSystemChat) (err
 }

 func (m *Messenger) OnStdin(e event.Stdin) (err error) {
-	return m.chat.SendMessage(e.Val)
+	input := strings.TrimSpace(e.Val)
+	if strings.HasPrefix(input, ">say ") {
+		return m.chat.SendMessage(strings.TrimSpace(strings.TrimPrefix(input, ">say")))
+	}
+	if strings.HasPrefix(input, ">getblock ") {
+		return m.handleGetBlock(strings.TrimSpace(strings.TrimPrefix(input, ">getblock")))
+	}
+	return m.chat.SendMessage(input)
+}
+
+func (m *Messenger) handleGetBlock(args string) (err error) {
+	fields := strings.Fields(args)
+	if len(fields) != 3 {
+		m.Log.Info("getblock", "error", "expected >getblock <x> <y> <z>")
+		return nil
+	}
+
+	coords := make([]int64, 3)
+	for i, f := range fields {
+		coords[i], err = strconv.ParseInt(f, 10, 32)
+		if err != nil {
+			m.Log.Info("getblock", "error", fmt.Sprintf("bad coordinate %q", f))
+			return nil
+		}
+	}
+
+	stateId, err := m.world.GetBlock(int32(coords[0]), int32(coords[1]), int32(coords[2]))
+	if err != nil {
+		m.Log.Info("getblock", "error", err.Error())
+		return nil
+	}
+
+	block, ok := data.LookupBlockByStateId(m.Version, stateId)
+	if !ok {
+		m.Log.Info("getblock", "stateId", stateId, "name", "unknown")
+		return nil
+	}
+
+	m.Log.Info("getblock", "x", coords[0], "y", coords[1], "z", coords[2], "name", block.Name, "stateId", stateId)
+	return nil
 }

 func Run(args []string) (err error) {
@@ -62,9 +107,14 @@ func Run(args []string) (err error) {
 	if err != nil {
 		return
 	}
+
+	// Shareable world storage. Other bots can subscribe to the same World.
+	w := world.NewWorld(c.Version, -64, 384)
+
 	m := &Messenger{
-		Conn: c,
-		chat: chatMod,
+		Conn:  c,
+		chat:  chatMod,
+		world: world.Start(c, w),
 	}

 	event.StartListingStdin(m.Loop)
@@ -0,0 +1,178 @@
+package world
+
+import (
+	"bytes"
+	"errors"
+	"sync"
+
+	"github.com/admin-else/strom/mc/level"
+	"github.com/admin-else/strom/mc/proto"
+	"github.com/admin-else/strom/mc/proto_generated/v1_21_11"
+)
+
+var (
+	ChunkNotLoadedErr = errors.New("chunk not loaded")
+	OutOfBoundsErr    = errors.New("coordinates out of bounds")
+)
+
+// ChunkPos identifies a chunk column.
+type ChunkPos struct {
+	X, Z int32
+}
+
+// World stores a shareable in-memory view of the Minecraft world.
+// Multiple bots can subscribe to the same World and update it from their
+// respective connections.
+type World struct {
+	mu      sync.RWMutex
+	chunks  map[ChunkPos]*level.Chunk
+	version string
+	minY    int
+	height  int
+}
+
+// NewWorld creates a new World for the given protocol version and vertical
+// bounds. For a 1.21 overworld use minY=-64 and height=384.
+func NewWorld(version string, minY, height int) *World {
+	return &World{
+		chunks:  make(map[ChunkPos]*level.Chunk),
+		version: version,
+		minY:    minY,
+		height:  height,
+	}
+}
+
+// GetBlock returns the global block state ID at the given world coordinates.
+func (w *World) GetBlock(x, y, z int32) (stateId int32, err error) {
+	w.mu.RLock()
+	defer w.mu.RUnlock()
+	return w.getBlockLocked(x, y, z)
+}
+
+func (w *World) getBlockLocked(x, y, z int32) (stateId int32, err error) {
+	chunkX := floorDiv(x, level.ChunkWidth)
+	chunkZ := floorDiv(z, level.ChunkWidth)
+	chunk, ok := w.chunks[ChunkPos{chunkX, chunkZ}]
+	if !ok {
+		err = ChunkNotLoadedErr
+		return
+	}
+
+	sectionIndex := (int(y) - w.minY) / level.ChunkWidth
+	if sectionIndex < 0 || sectionIndex >= len(chunk.Sections) {
+		err = OutOfBoundsErr
+		return
+	}
+
+	lx, ly, lz := blockToLocal(x, y, z)
+	index := ly*level.ChunkWidth*level.ChunkWidth + lz*level.ChunkWidth + lx
+	return chunk.Sections[sectionIndex].Blocks.Get(index)
+}
+
+// SetBlock updates the global block state ID at the given world coordinates.
+func (w *World) SetBlock(x, y, z int32, stateId int32) (err error) {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+
+	chunkX := floorDiv(x, level.ChunkWidth)
+	chunkZ := floorDiv(z, level.ChunkWidth)
+	chunk, ok := w.chunks[ChunkPos{chunkX, chunkZ}]
+	if !ok {
+		return ChunkNotLoadedErr
+	}
+
+	sectionIndex := (int(y) - w.minY) / level.ChunkWidth
+	if sectionIndex < 0 || sectionIndex >= len(chunk.Sections) {
+		return OutOfBoundsErr
+	}
+
+	lx, ly, lz := blockToLocal(x, y, z)
+	index := ly*level.ChunkWidth*level.ChunkWidth + lz*level.ChunkWidth + lx
+	return chunk.Sections[sectionIndex].Blocks.Set(index, stateId)
+}
+
+// Module subscribes to chunk and block-change packets and updates a shared
+// World. Multiple Modules can point to the same World.
+type Module struct {
+	*proto.Conn
+	world *World
+}
+
+// GetBlock returns the block state ID at the given world coordinates via the
+// shared World.
+func (m *Module) GetBlock(x, y, z int32) (int32, error) {
+	return m.world.GetBlock(x, y, z)
+}
+
+// Start registers packet handlers on c that update the shared World w.
+func Start(c *proto.Conn, w *World) *Module {
+	m := &Module{Conn: c, world: w}
+	m.RegisterUntilLatest(m.onMapChunk)
+	m.RegisterUntilLatest(m.onBlockChange)
+	m.RegisterUntilLatest(m.onMultiBlockChange)
+	return m
+}
+
+func (m *Module) onMapChunk(p *v1_21_11.PlayToClientPacketMapChunk) (err error) {
+	chunk, err := level.ReadChunkFromChunkPacketData(
+		bytes.NewReader(p.ChunkData.Val),
+		m.world.version,
+		m.world.height,
+	)
+	if err != nil {
+		return
+	}
+
+	m.world.mu.Lock()
+	m.world.chunks[ChunkPos{p.X, p.Z}] = chunk
+	m.world.mu.Unlock()
+	return nil
+}
+
+func (m *Module) onBlockChange(p *v1_21_11.PlayToClientPacketBlockChange) (err error) {
+	return m.world.SetBlock(p.Location.X, int32(p.Location.Y), p.Location.Z, p.Type)
+}
+
+func (m *Module) onMultiBlockChange(p *v1_21_11.PlayToClientPacketMultiBlockChange) (err error) {
+	chunkX := p.ChunkCoordinates.X
+	chunkZ := p.ChunkCoordinates.Z
+	sectionY := p.ChunkCoordinates.Y
+
+	for _, record := range p.Records {
+		packedPos := record & 0xFFF
+		stateId := record >> 12
+
+		localX := (packedPos >> 8) & 0xF
+		localY := (packedPos >> 4) & 0xF
+		localZ := packedPos & 0xF
+
+		x := chunkX*level.ChunkWidth + int32(localX)
+		y := sectionY*level.ChunkWidth + int32(localY)
+		z := chunkZ*level.ChunkWidth + int32(localZ)
+
+		if err = m.world.SetBlock(x, y, z, stateId); err != nil {
+			return
+		}
+	}
+	return nil
+}
+
+func floorDiv(a, b int32) int32 {
+	return (a - ((a%b + b) % b)) / b
+}
+
+func blockToLocal(x, y, z int32) (lx, ly, lz int32) {
+	lx = x % level.ChunkWidth
+	if lx < 0 {
+		lx += level.ChunkWidth
+	}
+	ly = y % level.ChunkWidth
+	if ly < 0 {
+		ly += level.ChunkWidth
+	}
+	lz = z % level.ChunkWidth
+	if lz < 0 {
+		lz += level.ChunkWidth
+	}
+	return
+}