Write image tile to PNG file.

tilemapper/image.go

@@ -0,0 +1,24 @@
+// 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 (
+	"bufio"
+	"image"
+	"image/png"
+	"os"
+)
+
+func SaveAsPNG(path string, img image.Image) (err error) {
+	var file *os.File
+	if file, err = os.Create(path); err != nil {
+		return
+	}
+	writer := bufio.NewWriter(file)
+	err = png.Encode(writer, img)
+	writer.Flush()
+	file.Close()
+	return
+}

tilemapper/main.go

@@ -7,6 +7,7 @@ package main
 import (
 	"flag"
 	"fmt"
+	"image/color"
 	"log"
 
 	"bitbucket.org/s_l_teichmann/mtredisalize/common"
@@ -19,9 +20,11 @@ func main() {
 		x, y, z              int
 		width, height, depth int
 		colorsfile           string
+		outfile              string
 	)
 
 	flag.IntVar(&port, "port", 6379, "port to of mtredisalize server")
+	flag.IntVar(&port, "p", 6379, "port to of mtredisalize server (shorthand)")
 	flag.StringVar(&host, "host", "localhost", "host to mtredisalize server")
 	flag.IntVar(&x, "x", -9, "x of query cuboid")
 	flag.IntVar(&y, "y", -75, "y of query cuboid")
@@ -33,6 +36,8 @@ func main() {
 	flag.IntVar(&height, "h", 18, "height of query cuboid (shorthand)")
 	flag.IntVar(&depth, "d", 150, "depth of query cuboid (shorthand)")
 	flag.StringVar(&colorsfile, "colors", "colors.txt", "definition of colors")
+	flag.StringVar(&outfile, "output", "out.png", "image file of result")
+	flag.StringVar(&outfile, "o", "out.png", "image file of result (shorthand)")
 
 	flag.Parse()
 
@@ -43,8 +48,6 @@ func main() {
 		log.Fatalf("Cannot open color file: %s", err)
 	}
 
-	_ = colors
-
 	address := fmt.Sprintf("%s:%d", host, port)
 
 	var client *Client
@@ -59,32 +62,23 @@ func main() {
 	c1 := common.Coord{X: q1x, Y: q1y, Z: q1z}
 	c2 := common.Coord{X: q2x, Y: q2y, Z: q2z}
 	cuboid := common.Cuboid{P1: common.MinCoord(c1, c2), P2: common.MaxCoord(c1, c2)}
-	log.Printf("query cuboid: %s", cuboid)
 
-	numBlocks := 0
+	renderer := NewRenderer(q1x, q1z, width, height)
-	bytesTotal := int64(0)
 
-	versions := make(map[byte]int)
+	drawBlock := func(block *common.Block) {
-
+		if err := renderer.RenderBlock(block, colors.NameIndex); err != nil {
-	count := func(block *common.Block) {
+			log.Printf("WARN: rendering block failed: %s", err)
-		numBlocks++
-		bytesTotal += int64(len(block.Data))
-		if db, err := NewDecodedBlock(block.Data, colors.NameIndex); err == nil {
-			versions[db.Version]++
-		} else {
-			log.Printf("WARN: Decoding block failed: %s", err)
 		}
 	}
 
-	if err = client.QueryCuboid(cuboid, count); err != nil {
+	if err = client.QueryCuboid(cuboid, drawBlock); err != nil {
 		log.Fatalf("query failed: %s", err)
 	}
 
-	fmt.Printf("num of blocks: %d\n", numBlocks)
+	image := renderer.CreateImage(
-	fmt.Printf("num of bytes: %d\n", bytesTotal)
+		colors.Colors, color.RGBA{R: 0, G: 0, B: 0, A: 0xff})
 
-	fmt.Println("uses block versions:")
+	if err = SaveAsPNG(outfile, image); err != nil {
-	for version, count := range versions {
+		log.Fatalf("writing image failed: %s", err)
-		fmt.Printf("%d: %d\n", version, count)
 	}
 }

tilemapper/renderer.go

@@ -5,6 +5,8 @@
 package main
 
 import (
+	"image"
+	"image/color"
 	"math"
 
 	"bitbucket.org/s_l_teichmann/mtredisalize/common"
@@ -50,24 +52,26 @@ func NewRenderer(xOfs, zOfs int16, width, height int) (renderer *Renderer) {
 	return
 }
 
-func (r *Renderer) RenderBlock(coord common.Coord, data []byte, nameIndex map[string]int) (err error) {
+func (r *Renderer) RenderBlock(block *common.Block, nameIndex map[string]int) (err error) {
-	x := coord.X + r.xOfs
+	// fmt.Printf("%d %d\n", r.xOfs, r.zOfs)
-	z := coord.Z + r.zOfs
+	// fmt.Printf("%d %d\n", block.Coord.X, block.Coord.Z)
-	dimIndex := (x << 4) + z
+	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] > coord.Y {
+	if r.filled[dimIndex] == 0xff && r.minYs[dimIndex] > block.Coord.Y {
 		return
 	}
 
 	var db *DecodedBlock
-	if db, err = NewDecodedBlock(data, nameIndex); err != nil {
+	if db, err = NewDecodedBlock(block.Data, nameIndex); err != nil {
 		return
 	}
 
 	_ = db
 
-	ay := int32(coord.Y) << 4
+	ay := int32(block.Coord.Y) << 4
 
 	_ = ay
 
@@ -81,3 +85,21 @@ func (r *Renderer) RenderBlock(coord common.Coord, data []byte, nameIndex map[st
 
 	return
 }
+
+func (r *Renderer) CreateImage(colors []color.RGBA, background color.RGBA) *image.RGBA {
+	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 x := 0; x < pw; x++ {
+			colIdx := r.cBuffer[ofs]
+			if colIdx >= 0 && colIdx < numCols {
+				image.Set(x, z, colors[colIdx])
+			} else {
+				image.Set(x, z, background)
+			}
+			ofs++
+		}
+	}
+	return image
+}