Moved bloch decoding and rendering from tilemapper to common.

common/block.go

@@ -1,11 +1,24 @@
 package common
 
 import (
+	"compress/zlib"
+	"encoding/binary"
 	"errors"
+	"io"
+	"io/ioutil"
+	"log"
 )
 
 // Error returned if a Producer has run to its end.
-var ErrNoMoreBlocks = errors.New("No more blocks.")
+var (
+	ErrNoMoreBlocks           = errors.New("No more blocks.")
+	ErrMapContentSizeMismatch = errors.New("Content size does not match.")
+)
+
+const (
+	mapBlockSize = 16
+	nodeCount    = mapBlockSize * mapBlockSize * mapBlockSize
+)
 
 type (
 	// Block data from Minetest database.
@@ -28,4 +41,185 @@ type (
 		// Closes the open database connections.
 		Close() error
 	}
+
+	DecodedBlock struct {
+		Version    byte
+		MapContent []byte
+		AirId      int32
+		IgnoreId   int32
+		IndexMap   map[int32]int32
+	}
 )
+
+// The content of the map and the meta data are compressed with zlib.
+// Unfortunately the byte length of this two structures are not stored
+// explicitly in the block data. To access the informations behind
+// them (e.g. the node id mappings) we have to count the bytes consumed
+// by the zlib reader and continue our extraction process behind this
+// offset. posBuf implements such a counting reader source.
+type posBuf struct {
+	Data []byte
+	Pos  int
+}
+
+func NewDecodedBlock(data []byte, nameIndex map[string]int32) (db *DecodedBlock, err error) {
+	version := data[0]
+
+	contentWidth := int(data[2])
+	paramsWidth := int(data[3])
+
+	uncompressedLen := nodeCount * (contentWidth + paramsWidth)
+
+	offset := 2
+	if version >= 22 {
+		offset = 4
+	}
+
+	buf := NewposBuf(data[offset:])
+	var zr io.ReadCloser
+	if zr, err = zlib.NewReader(buf); err != nil {
+		return
+	}
+
+	var mapContent []byte
+	mapContent, err = ioutil.ReadAll(zr)
+	zr.Close()
+	if err != nil {
+		return
+	}
+
+	if uncompressedLen != len(mapContent) {
+		err = ErrMapContentSizeMismatch
+		return
+	}
+
+	offset += buf.Pos
+	buf.Pos = 0
+	buf.Data = data[offset:]
+
+	if zr, err = zlib.NewReader(buf); err != nil {
+		return
+	}
+
+	// Discard the meta data.
+	_, err = io.Copy(ioutil.Discard, zr)
+	zr.Close()
+	if err != nil {
+		return
+	}
+
+	offset += buf.Pos
+
+	switch {
+	case version <= 21:
+		offset += 2
+	case version == 23:
+		offset++
+	case version == 24:
+		ver := data[offset]
+		offset++
+		if ver == 1 {
+			num := int(binary.BigEndian.Uint16(data[offset:]))
+			offset += 2 + 10*num
+		}
+	}
+
+	offset++
+	numStaticObjects := int(binary.BigEndian.Uint16(data[offset:]))
+	offset += 2
+	for i := 0; i < numStaticObjects; i++ {
+		offset += 13
+		dataSize := int(binary.BigEndian.Uint16(data[offset:]))
+		offset += dataSize + 2
+	}
+	offset += 4
+
+	airId, ignoreId := int32(-1), int32(-1)
+	indexMap := make(map[int32]int32)
+	if version >= 22 {
+		offset++
+		numMappings := int(binary.BigEndian.Uint16(data[offset:]))
+		offset += 2
+		for i := 0; i < numMappings; i++ {
+			nodeId := int32(binary.BigEndian.Uint16(data[offset:]))
+			offset += 2
+			nameLen := int(binary.BigEndian.Uint16(data[offset:]))
+			offset += 2
+			name := string(data[offset : offset+nameLen])
+			offset += nameLen
+			switch name {
+			case "air":
+				airId = nodeId
+			case "ignore":
+				ignoreId = nodeId
+			default:
+				if index, found := nameIndex[name]; found {
+					indexMap[nodeId] = index
+				} else {
+					log.Printf("Missing color entry for %s.", name)
+				}
+			}
+		}
+	}
+
+	db = &DecodedBlock{
+		Version:    version,
+		MapContent: mapContent,
+		AirId:      airId,
+		IgnoreId:   ignoreId,
+		IndexMap:   indexMap}
+
+	return
+}
+
+func (db *DecodedBlock) Content(x, y, z int) (content int32, found bool) {
+	pos := z<<8 + y<<4 + x
+
+	switch {
+	case db.Version >= 24:
+		pos <<= 1
+		content = int32(db.MapContent[pos])<<8 | int32(db.MapContent[pos+1])
+	case db.Version >= 20:
+		if db.MapContent[pos] <= 0x80 {
+			content = int32(db.MapContent[pos])
+		} else {
+			content = int32(db.MapContent[pos])<<4 | int32(db.MapContent[pos+0x2000])>>4
+		}
+	default:
+		return
+	}
+	if content != db.AirId && content != db.IgnoreId {
+		content, found = db.IndexMap[content]
+	}
+	return
+}
+
+func NewposBuf(data []byte) *posBuf {
+	return &posBuf{Data: data}
+}
+
+func (pb *posBuf) Read(p []byte) (int, error) {
+	pl := len(p)
+	ml := len(pb.Data)
+	if pb.Pos >= ml {
+		return 0, io.EOF
+	}
+	rest := ml - pb.Pos
+	if pl > rest {
+		copy(p, pb.Data[pb.Pos:])
+		pb.Pos = ml
+		return rest, io.EOF
+	}
+	copy(p, pb.Data[pb.Pos:pb.Pos+pl])
+	pb.Pos += pl
+	return pl, nil
+}
+
+func (pb *posBuf) ReadByte() (byte, error) {
+	if pb.Pos >= len(pb.Data) {
+		return 0, io.EOF
+	}
+	c := pb.Data[pb.Pos]
+	pb.Pos++
+	return c, nil
+}

common/renderer.go

@@ -2,15 +2,13 @@
 // Use of this source code is governed by the MIT license
 // that can be found in the LICENSE file.
 
-package main
+package common
 
 import (
 	"container/heap"
 	"image"
 	"image/color"
 	"math"
-
-	"bitbucket.org/s_l_teichmann/mtredisalize/common"
 )
 
 type Renderer struct {
@@ -27,14 +25,14 @@ type Renderer struct {
 
 type YOrder struct {
 	Renderer *Renderer
-	blocks   []*common.Block
+	blocks   []*Block
 	capacity int
 }
 
 func NewYOrder(renderer *Renderer, capacity int) *YOrder {
 	return &YOrder{
 		Renderer: renderer,
-		blocks:   make([]*common.Block, 0, capacity),
+		blocks:   make([]*Block, 0, capacity),
 		capacity: capacity}
 }
 
@@ -52,8 +50,8 @@ func copyData(data []byte) []byte {
 	return ndata
 }
 
-func (yo *YOrder) RenderBlock(block *common.Block, nameIndex map[string]int32) (err error) {
+func (yo *YOrder) RenderBlock(block *Block, nameIndex map[string]int32) (err error) {
-	var nblock *common.Block
+	var nblock *Block
 	if len(yo.blocks) == yo.capacity {
 		oblock := yo.blocks[0]
 		if oblock.Coord.Y < block.Coord.Y {
@@ -74,7 +72,7 @@ func (yo *YOrder) RenderBlock(block *common.Block, nameIndex map[string]int32) (
 		oblock.Coord = block.Coord
 		nblock = oblock
 	} else {
-		nblock = &common.Block{Coord: block.Coord, Data: copyData(block.Data)}
+		nblock = &Block{Coord: block.Coord, Data: copyData(block.Data)}
 	}
 
 	heap.Push(yo, nblock)
@@ -83,7 +81,7 @@ func (yo *YOrder) RenderBlock(block *common.Block, nameIndex map[string]int32) (
 
 func (yo *YOrder) Drain(nameIndex map[string]int32) (err error) {
 	for len(yo.blocks) > 0 {
-		if err = yo.Renderer.RenderBlock(heap.Pop(yo).(*common.Block), nameIndex); err != nil {
+		if err = yo.Renderer.RenderBlock(heap.Pop(yo).(*Block), nameIndex); err != nil {
 			return
 		}
 	}
@@ -104,7 +102,7 @@ func (yo *YOrder) Less(i, j int) bool {
 }
 
 func (yo *YOrder) Push(x interface{}) {
-	yo.blocks = append(yo.blocks, x.(*common.Block))
+	yo.blocks = append(yo.blocks, x.(*Block))
 }
 
 func (yo *YOrder) Pop() (x interface{}) {
@@ -145,7 +143,7 @@ func (r *Renderer) IsFilled() bool {
 	return r.filled == r.width<<4*r.height<<4
 }
 
-func (r *Renderer) RenderBlock(block *common.Block, nameIndex map[string]int32) (err error) {
+func (r *Renderer) RenderBlock(block *Block, nameIndex map[string]int32) (err error) {
 
 	bx := block.Coord.X - r.xOfs
 	bz := block.Coord.Z - r.zOfs

tilemapper/blockdecoder.go

@@ -1,204 +0,0 @@
-// Copyright 2014 by Sascha L. Teichmann
-// Use of this source code is governed by the MIT license
-// that can be found in the LICENSE file.
-
-package main
-
-import (
-	"compress/zlib"
-	"encoding/binary"
-	"errors"
-	"io"
-	"io/ioutil"
-	"log"
-)
-
-var (
-	ErrMapContentSizeMismatch = errors.New("Content size does not match.")
-)
-
-const (
-	mapBlockSize = 16
-	nodeCount    = mapBlockSize * mapBlockSize * mapBlockSize
-)
-
-type DecodedBlock struct {
-	Version    byte
-	MapContent []byte
-	AirId      int32
-	IgnoreId   int32
-	IndexMap   map[int32]int32
-}
-
-// The content of the map and the meta data are compressed with zlib.
-// Unfortunately the byte length of this two structures are not stored
-// explicitly in the block data. To access the informations behind
-// them (e.g. the node id mappings) we have to count the bytes consumed
-// by the zlib reader and continue our extraction process behind this
-// offset. PosBuf implements such a counting reader source.
-type PosBuf struct {
-	Data []byte
-	Pos  int
-}
-
-func NewDecodedBlock(data []byte, nameIndex map[string]int32) (db *DecodedBlock, err error) {
-	version := data[0]
-
-	contentWidth := int(data[2])
-	paramsWidth := int(data[3])
-
-	uncompressedLen := nodeCount * (contentWidth + paramsWidth)
-
-	offset := 2
-	if version >= 22 {
-		offset = 4
-	}
-
-	buf := NewPosBuf(data[offset:])
-	var zr io.ReadCloser
-	if zr, err = zlib.NewReader(buf); err != nil {
-		return
-	}
-
-	var mapContent []byte
-	mapContent, err = ioutil.ReadAll(zr)
-	zr.Close()
-	if err != nil {
-		return
-	}
-
-	if uncompressedLen != len(mapContent) {
-		err = ErrMapContentSizeMismatch
-		return
-	}
-
-	offset += buf.Pos
-	buf.Pos = 0
-	buf.Data = data[offset:]
-
-	if zr, err = zlib.NewReader(buf); err != nil {
-		return
-	}
-
-	// Discard the meta data.
-	_, err = io.Copy(ioutil.Discard, zr)
-	zr.Close()
-	if err != nil {
-		return
-	}
-
-	offset += buf.Pos
-
-	switch {
-	case version <= 21:
-		offset += 2
-	case version == 23:
-		offset++
-	case version == 24:
-		ver := data[offset]
-		offset++
-		if ver == 1 {
-			num := int(binary.BigEndian.Uint16(data[offset:]))
-			offset += 2 + 10*num
-		}
-	}
-
-	offset++
-	numStaticObjects := int(binary.BigEndian.Uint16(data[offset:]))
-	offset += 2
-	for i := 0; i < numStaticObjects; i++ {
-		offset += 13
-		dataSize := int(binary.BigEndian.Uint16(data[offset:]))
-		offset += dataSize + 2
-	}
-	offset += 4
-
-	airId, ignoreId := int32(-1), int32(-1)
-	indexMap := make(map[int32]int32)
-	if version >= 22 {
-		offset++
-		numMappings := int(binary.BigEndian.Uint16(data[offset:]))
-		offset += 2
-		for i := 0; i < numMappings; i++ {
-			nodeId := int32(binary.BigEndian.Uint16(data[offset:]))
-			offset += 2
-			nameLen := int(binary.BigEndian.Uint16(data[offset:]))
-			offset += 2
-			name := string(data[offset : offset+nameLen])
-			offset += nameLen
-			switch name {
-			case "air":
-				airId = nodeId
-			case "ignore":
-				ignoreId = nodeId
-			default:
-				if index, found := nameIndex[name]; found {
-					indexMap[nodeId] = index
-				} else {
-					log.Printf("Missing color entry for %s.", name)
-				}
-			}
-		}
-	}
-
-	db = &DecodedBlock{
-		Version:    version,
-		MapContent: mapContent,
-		AirId:      airId,
-		IgnoreId:   ignoreId,
-		IndexMap:   indexMap}
-
-	return
-}
-
-func (db *DecodedBlock) Content(x, y, z int) (content int32, found bool) {
-	pos := z<<8 + y<<4 + x
-
-	switch {
-	case db.Version >= 24:
-		pos <<= 1
-		content = int32(db.MapContent[pos])<<8 | int32(db.MapContent[pos+1])
-	case db.Version >= 20:
-		if db.MapContent[pos] <= 0x80 {
-			content = int32(db.MapContent[pos])
-		} else {
-			content = int32(db.MapContent[pos])<<4 | int32(db.MapContent[pos+0x2000])>>4
-		}
-	default:
-		return
-	}
-	if content != db.AirId && content != db.IgnoreId {
-		content, found = db.IndexMap[content]
-	}
-	return
-}
-
-func NewPosBuf(data []byte) *PosBuf {
-	return &PosBuf{Data: data}
-}
-
-func (pb *PosBuf) Read(p []byte) (int, error) {
-	pl := len(p)
-	ml := len(pb.Data)
-	if pb.Pos >= ml {
-		return 0, io.EOF
-	}
-	rest := ml - pb.Pos
-	if pl > rest {
-		copy(p, pb.Data[pb.Pos:])
-		pb.Pos = ml
-		return rest, io.EOF
-	}
-	copy(p, pb.Data[pb.Pos:pb.Pos+pl])
-	pb.Pos += pl
-	return pl, nil
-}
-
-func (pb *PosBuf) ReadByte() (byte, error) {
-	if pb.Pos >= len(pb.Data) {
-		return 0, io.EOF
-	}
-	c := pb.Data[pb.Pos]
-	pb.Pos++
-	return c, nil
-}

tilemapper/main.go

@@ -70,8 +70,8 @@ func main() {
 	q1x, q1y, q1z := int16(x), int16(y), int16(z)
 	q2x, q2y, q2z := q1x+int16(width)-1, q1y+int16(depth)-1, q1z+int16(height)-1
 
-	renderer := NewRenderer(q1x, q1z, width, height)
+	renderer := common.NewRenderer(q1x, q1z, width, height)
-	yOrder := NewYOrder(renderer, 512)
+	yOrder := common.NewYOrder(renderer, 512)
 
 	numBlocks := 0
 	drawBlock := func(block *common.Block) {
@@ -115,6 +115,6 @@ func main() {
 		log.Fatalf("writing image failed: %s", err)
 	}
 
-	fmt.Printf("num blocks: %d\n", numBlocks)
+	log.Printf("num blocks: %d\n", numBlocks)
-	fmt.Printf("rejected blocks: %d\n", renderer.Rejected)
+	log.Printf("rejected blocks: %d\n", renderer.Rejected)
 }