chunk builder

level/chunk_builder.go

@@ -0,0 +1,93 @@
+package level
+
+import (
+	"bytes"
+	"errors"
+
+	"github.com/admin-else/strom/data"
+	"github.com/admin-else/strom/util"
+)
+
+type ChunkBuilder struct {
+	Biomes, Blocks [][]int32
+	Bottom, Top    int32
+	Version        string
+}
+
+func NewChunkBuilder(bottom, top int32, version string) *ChunkBuilder {
+	return &ChunkBuilder{Bottom: bottom, Top: top, Version: version}
+}
+
+func NewOverworldChunkBuilder(version string) *ChunkBuilder {
+	return NewChunkBuilder(-64, 320, version)
+}
+
+func (cb *ChunkBuilder) ColumnHeight() int32 {
+	absBottom := cb.Bottom
+	if absBottom < 0 {
+		absBottom *= -1
+	}
+	return absBottom + cb.Top
+}
+
+func (cb *ChunkBuilder) FillAllById(block, biome int32) {
+	numSections := cb.ColumnHeight() / ChunkWidth
+	blockSection := util.MakeSingleValuedSlice(block, BlocksPerChunkSection)
+	biomeSection := util.MakeSingleValuedSlice(biome, BiomesPerChunkSection)
+	cb.Blocks = make([][]int32, numSections)
+	cb.Biomes = make([][]int32, numSections)
+	for i := range cb.Blocks {
+		cb.Blocks[i] = blockSection
+		cb.Biomes[i] = biomeSection
+	}
+	return
+}
+
+func (cb *ChunkBuilder) FillAll(biome, block string) (err error) {
+	blockData, ok := data.LookupBlockByName(cb.Version, block)
+	if !ok {
+		err = data.UnknownBlockNameErr
+		return
+	}
+	biomeData, ok := data.LookupBiomeByName(cb.Version, biome)
+	if !ok {
+		err = data.UnknownBiomeNameErr
+		return
+	}
+	cb.FillAllById(blockData.DefaultState, biomeData.Id)
+	return
+}
+
+var InvalidChunkPositionErr = errors.New("invalid chunk position")
+
+func (cb *ChunkBuilder) SetBlockId(x, y, z, id int32) (err error) {
+	if x < 0 || x >= ChunkWidth || z < 0 || z >= ChunkWidth || y < cb.Bottom || y >= cb.Top {
+		err = InvalidChunkPositionErr
+		return
+	}
+
+	y += cb.Bottom * -1
+	section := util.FloorDiv(y, ChunkWidth)
+	i := (y%ChunkWidth)*ChunkWidth*ChunkWidth + z*ChunkWidth + x
+	cb.Blocks[section][i] = id
+	return
+}
+
+func (cb *ChunkBuilder) SetBlock(x, y, z int32, block string) (err error) {
+	blockData, ok := data.LookupBlockByName(cb.Version, block)
+	if !ok {
+		err = data.UnknownBlockNameErr
+		return
+	}
+	return cb.SetBlockId(x, y, z, blockData.DefaultState)
+}
+
+func (cb *ChunkBuilder) Build() (data []byte, err error) {
+	b := bytes.NewBuffer(nil)
+	err = PackSections(cb.Blocks, cb.Biomes, cb.Version, b)
+	if err != nil {
+		return
+	}
+	data = b.Bytes()
+	return
+}

level/packet.go

@@ -12,7 +12,8 @@ import (
 )
 
 const (
-	BlocksPerChunkSection = 16 * 16 * 16
+	ChunkWidth            = 16
+	BlocksPerChunkSection = ChunkWidth * ChunkWidth * ChunkWidth
 	BiomesPerChunkSection = 4 * 4 * 4
 )