Made tilerender finally work. Needs performance tweaks.

tilemapper/blockdecoder.go

@@ -25,9 +25,9 @@ const (
 type DecodedBlock struct {
 	Version    byte
 	MapContent []byte
-	AirId      int
+	AirId      int32
-	IgnoreId   int
+	IgnoreId   int32
-	IndexMap   map[int]int
+	IndexMap   map[int32]int32
 }
 
 // The content of the map and the meta data are compressed with zlib.
@@ -41,7 +41,7 @@ type PosBuf struct {
 	Pos  int
 }
 
-func NewDecodedBlock(data []byte, nameIndex map[string]int) (db *DecodedBlock, err error) {
+func NewDecodedBlock(data []byte, nameIndex map[string]int32) (db *DecodedBlock, err error) {
 	version := data[0]
 
 	contentWidth := int(data[2])
@@ -113,14 +113,14 @@ func NewDecodedBlock(data []byte, nameIndex map[string]int) (db *DecodedBlock, e
 	}
 	offset += 4
 
-	airId, ignoreId := -1, -1
+	airId, ignoreId := int32(-1), int32(-1)
-	indexMap := make(map[int]int)
+	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 := int(binary.BigEndian.Uint16(data[offset:]))
+			nodeId := int32(binary.BigEndian.Uint16(data[offset:]))
 			offset += 2
 			nameLen := int(binary.BigEndian.Uint16(data[offset:]))
 			offset += 2
@@ -151,18 +151,18 @@ func NewDecodedBlock(data []byte, nameIndex map[string]int) (db *DecodedBlock, e
 	return
 }
 
-func (db *DecodedBlock) Content(x, y, z int) (content int, found bool) {
+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 = int(db.MapContent[pos])<<8 | int(db.MapContent[pos+1])
+		content = int32(db.MapContent[pos])<<8 | int32(db.MapContent[pos+1])
 	case db.Version >= 20:
 		if db.MapContent[pos] <= 0x80 {
-			content = int(db.MapContent[pos])
+			content = int32(db.MapContent[pos])
 		} else {
-			content = int(db.MapContent[pos])<<4 | int(db.MapContent[pos+0x2000])>>4
+			content = int32(db.MapContent[pos])<<4 | int32(db.MapContent[pos+0x2000])>>4
 		}
 	default:
 		return

tilemapper/colors.go

@@ -14,7 +14,7 @@ import (
 
 type Colors struct {
 	Colors    []color.RGBA
-	NameIndex map[string]int
+	NameIndex map[string]int32
 }
 
 func ParseColors(filename string) (colors *Colors, err error) {
@@ -25,7 +25,7 @@ func ParseColors(filename string) (colors *Colors, err error) {
 	}
 	defer file.Close()
 
-	nameIndex := make(map[string]int)
+	nameIndex := make(map[string]int32)
 	cols := make([]color.RGBA, 0, 2200)
 
 	scanner := bufio.NewScanner(file)
@@ -38,7 +38,7 @@ func ParseColors(filename string) (colors *Colors, err error) {
 		var name string
 		if n, _ := fmt.Sscanf(
 			line, "%s %d %d %d %d", &name, &c.R, &c.G, &c.B, &c.A); n > 0 {
-			idx := len(cols)
+			idx := int32(len(cols))
 			cols = append(cols, c)
 			nameIndex[name] = idx
 		}

tilemapper/main.go

@@ -81,4 +81,6 @@ func main() {
 	if err = SaveAsPNG(outfile, image); err != nil {
 		log.Fatalf("writing image failed: %s", err)
 	}
+
+	fmt.Printf("Rejected blocks: %d\n", renderer.RejectedBlocks)
 }

tilemapper/renderer.go

@@ -19,8 +19,9 @@ type Renderer struct {
 	zOfs           int16
 	yBuffer        []int32
 	cBuffer        []int32
-	filled  []byte
+	filled         []uint16
 	minYs          []int16
+	RejectedBlocks int
 }
 
 func NewRenderer(xOfs, zOfs int16, width, height int) (renderer *Renderer) {
@@ -28,60 +29,76 @@ func NewRenderer(xOfs, zOfs int16, width, height int) (renderer *Renderer) {
 	pixSize := dim * 16 * 16
 	yBuffer := make([]int32, pixSize)
 	cBuffer := make([]int32, pixSize)
-	filled := make([]byte, dim)
-	minYs := make([]int16, dim)
 
 	for i := 0; i < pixSize; i++ {
 		yBuffer[i] = math.MinInt32
 		cBuffer[i] = -1
 	}
 
-	for i := 0; i < dim; i++ {
-		minYs[i] = math.MinInt16
-	}
-
 	renderer = &Renderer{
 		width:   width,
 		height:  height,
 		xOfs:    xOfs,
 		zOfs:    zOfs,
 		yBuffer: yBuffer,
-		cBuffer: cBuffer,
+		cBuffer: cBuffer}
-		filled:  filled,
-		minYs:   minYs}
 	return
 }
 
-func (r *Renderer) RenderBlock(block *common.Block, nameIndex map[string]int) (err error) {
+func (r *Renderer) minY(x, z int16) (minY int32) {
-	// fmt.Printf("%d %d\n", r.xOfs, r.zOfs)
+	x -= r.xOfs
-	// fmt.Printf("%d %d\n", block.Coord.X, block.Coord.Z)
+	z -= r.zOfs
+	w := r.width << 4
+	ofs := int(z)*w<<4 + int(x)<<4
+	minY = int32(math.MaxInt32)
+	for yEnd := ofs + w<<4; ofs < yEnd; {
+		for xEnd := ofs + 16; ofs < xEnd; ofs++ {
+			y := r.yBuffer[ofs]
+			if y < minY {
+				minY = y
+			}
+		}
+		ofs += w - 16
+	}
+	return
+}
+
+func (r *Renderer) RenderBlock(block *common.Block, nameIndex map[string]int32) (err error) {
+
 	bx := block.Coord.X - r.xOfs
 	bz := block.Coord.Z - r.zOfs
-	dimIndex := (bx << 4) + bz
 	// We do not need to render the block if the whole 16x16 area
 	// is already filled and the block is strictly below.
-	if r.filled[dimIndex] == 0xff && r.minYs[dimIndex] > block.Coord.Y {
+	blockY := int32(block.Coord.Y) << 4
+	if blockY < r.minY(block.Coord.X, block.Coord.Z) {
+		r.RejectedBlocks++
 		return
 	}
 
+	// Decoding is pretty expensive so it that late.
 	var db *DecodedBlock
 	if db, err = NewDecodedBlock(block.Data, nameIndex); err != nil {
 		return
 	}
 
-	_ = db
+	w := r.width << 4
 
-	ay := int32(block.Coord.Y) << 4
+	ofs := int(bz)*w<<4 + int(bx)<<4
-
-	_ = ay
-
-	for x := 0; x < 16; x++ {
 	for z := 0; z < 16; z++ {
+		for x := 0; x < 16; x++ {
+			if currentY := r.yBuffer[ofs]; currentY < blockY {
 				for y := 15; y >= 0; y-- {
-				_, _, _ = x, y, z
+					if c, ok := db.Content(x, y, z); ok {
+						r.cBuffer[ofs] = c
+						r.yBuffer[ofs] = blockY + int32(y)
+						break
 					}
 				}
 			}
+			ofs++
+		}
+		ofs += w - 16
+	}
 
 	return
 }
@@ -90,7 +107,7 @@ func (r *Renderer) CreateImage(colors []color.RGBA, background color.RGBA) *imag
 	pw, ph := r.width<<4, r.height<<4
 	image := image.NewRGBA(image.Rect(0, 0, pw, ph))
 	ofs, numCols := 0, int32(len(colors))
-	for z := 0; z < ph; z++ {
+	for z := ph - 1; z >= 0; z-- {
 		for x := 0; x < pw; x++ {
 			colIdx := r.cBuffer[ofs]
 			if colIdx >= 0 && colIdx < numCols {