Implement fetaure request issue #17

mtseeder and mtwebmapper got an option to set the background color where no nodes are generated, yet.

cmd/mtwebmapper/main.go

@@ -7,6 +7,7 @@ package main
 import (
 	"flag"
 	"fmt"
+	"image/color"
 	"log"
 	"net"
 	"net/http"
@@ -25,6 +26,7 @@ func main() {
 		redisPort      int
 		redisHost      string
 		colorsFile     string
+		bgColor        string
 		workers        int
 		transparent    bool
 		transparentDim float64
@@ -35,6 +37,9 @@ func main() {
 		yMin           int
 		yMax           int
 	)
+
+	defaultBgColor := common.ColorToHex(common.BackgroundColor)
+
 	flag.IntVar(&webPort, "web-port", 8808, "port of the web server")
 	flag.IntVar(&webPort, "p", 8808, "port of the web server (shorthand)")
 	flag.StringVar(&webHost, "web-host", "localhost", "address to bind web server")
@@ -54,6 +59,8 @@ func main() {
 	flag.IntVar(&workers, "workers", 1, "number of workers to render tiles")
 	flag.StringVar(&colorsFile, "colors", "colors.txt", "colors used to render map tiles.")
 	flag.StringVar(&colorsFile, "c", "colors.txt", "colors used to render map tiles (shorthand).")
+	flag.StringVar(&bgColor, "background", defaultBgColor, "background color")
+	flag.StringVar(&bgColor, "bg", defaultBgColor, "background color (shorthand)")
 	flag.BoolVar(&transparent, "transparent", false, "Render transparent blocks.")
 	flag.BoolVar(&transparent, "t", false, "Render transparent blocks (shorthand).")
 	flag.Float64Var(&transparentDim,
@@ -76,9 +83,16 @@ func main() {
 		common.PrintVersionAndExit()
 	}
 
+	var bg color.RGBA
+	var err error
+	if bg, err = common.ParseColor(bgColor); err != nil {
+		log.Printf("WARN: Cannot parse background color '%s': %s\n", bgColor, err)
+		bg = common.BackgroundColor
+	}
+
 	router := mux.NewRouter()
 
-	subBaseLine := newSubBaseLine(mapDir)
+	subBaseLine := newSubBaseLine(mapDir, bg)
 	router.Path("/map/{z:[0-9]+}/{x:[0-9]+}/{y:[0-9]+}.png").Handler(subBaseLine)
 
 	var btu baseTilesUpdates
@@ -116,7 +130,7 @@ func main() {
 			mapDir,
 			redisAddress,
 			allowedUpdateIps,
-			colors,
+			colors, bg,
 			yMin, yMax,
 			transparent,
 			workers,

cmd/mtwebmapper/subbaseline.go

@@ -7,6 +7,7 @@ package main
 import (
 	"fmt"
 	"image"
+	"image/color"
 	"image/png"
 	"log"
 	"net/http"
@@ -21,10 +22,11 @@ import (
 
 type subBaseLine struct {
 	mapDir string
+	bg     color.RGBA
 }
 
-func newSubBaseLine(mapDir string) *subBaseLine {
-	return &subBaseLine{mapDir: mapDir}
+func newSubBaseLine(mapDir string, bg color.RGBA) *subBaseLine {
+	return &subBaseLine{mapDir: mapDir, bg: bg}
 }
 
 func (sb *subBaseLine) ServeHTTP(rw http.ResponseWriter, r *http.Request) {
@@ -77,7 +79,7 @@ func (sb *subBaseLine) ServeHTTP(rw http.ResponseWriter, r *http.Request) {
 	xo := w * rx
 	yo := w * (parts - 1 - ry)
 
-	img := common.LoadPNG(baseTile)
+	img := common.LoadPNG(baseTile, sb.bg)
 
 	type subImage interface {
 		SubImage(image.Rectangle) image.Image

cmd/mtwebmapper/tilesupdater.go

@@ -7,6 +7,7 @@ package main
 import (
 	"encoding/json"
 	"image"
+	"image/color"
 	"image/draw"
 	"log"
 	"net"
@@ -34,6 +35,7 @@ type tileUpdater struct {
 	redisAddress string
 	ips          []net.IP
 	colors       *common.Colors
+	bg           color.RGBA
 	yMin, yMax   int16
 	workers      int
 	transparent  bool
@@ -71,6 +73,7 @@ func newTileUpdater(
 	mapDir, redisAddress string,
 	ips []net.IP,
 	colors *common.Colors,
+	bg color.RGBA,
 	yMin, yMax int,
 	transparent bool,
 	workers int,
@@ -83,6 +86,7 @@ func newTileUpdater(
 		ips:          ips,
 		changes:      map[xz]bool{},
 		colors:       colors,
+		bg:           bg,
 		yMin:         int16(yMin),
 		yMax:         int16(yMax),
 		transparent:  transparent,
@@ -171,11 +175,11 @@ func (tu *tileUpdater) doUpdates() {
 				continue
 			}
 			btc := common.NewBaseTileCreator(
-				client, tu.colors,
+				client, tu.colors, tu.bg,
 				tu.yMin, tu.yMax,
 				tu.transparent, baseDir, true)
 			done.Add(1)
-			go updateBaseTiles(jobs, btc, &done)
+			go tu.updateBaseTiles(jobs, btc, &done)
 		}
 
 		parentJobs := make(map[xz]uint16)
@@ -193,7 +197,7 @@ func (tu *tileUpdater) doUpdates() {
 			pJobs := make(chan xzm)
 			for i, n := 0, common.Min(len(parentJobs), tu.workers); i < n; i++ {
 				done.Add(1)
-				go updatePyramidTiles(level, tu.mapDir, pJobs, &done)
+				go tu.updatePyramidTiles(level, pJobs, &done)
 			}
 			ppJobs := make(map[xz]uint16)
 			for c, mask := range parentJobs {
@@ -212,13 +216,15 @@ func (tu *tileUpdater) doUpdates() {
 	}
 }
 
-func updatePyramidTiles(level int, baseDir string, jobs chan xzm, done *sync.WaitGroup) {
+func (tu *tileUpdater) updatePyramidTiles(
+	level int, jobs chan xzm, done *sync.WaitGroup) {
+
 	defer done.Done()
 	scratch := image.NewRGBA(image.Rect(0, 0, 256, 256))
 	resized := image.NewRGBA(image.Rect(0, 0, 128, 128))
 
 	for job := range jobs {
-		if err := updatePyramidTile(scratch, resized, level, baseDir, job); err != nil {
+		if err := tu.updatePyramidTile(scratch, resized, level, job); err != nil {
 			log.Printf("Updating pyramid tile failed: %s\n", err)
 		}
 	}
@@ -244,28 +250,29 @@ var ofs = [4][2]int{
 
 var windowSize = image.Pt(128, 128)
 
-func updatePyramidTile(scratch, resized *image.RGBA, level int, baseDir string, j xzm) error {
+func (tu *tileUpdater) updatePyramidTile(scratch, resized *image.RGBA, level int, j xzm) error {
 
 	var orig image.Image
 
 	origPath := filepath.Join(
-		baseDir,
+		tu.mapDir,
 		strconv.Itoa(level),
 		strconv.Itoa(int(j.P.X)),
 		strconv.Itoa(int(j.P.Z))+".png")
 
 	sr := resized.Bounds()
+	levelDir := strconv.Itoa(level + 1)
 	for i := uint16(0); i < 4; i++ {
 		if j.Mask&(1<<i) != 0 {
 			//log.Printf("level %d: modified %d\n", level, i)
 			o := ofs[i]
 			bx, bz := int(2*j.P.X), int(2*j.P.Z)
 			path := filepath.Join(
-				baseDir,
-				strconv.Itoa(level+1),
+				tu.mapDir,
+				levelDir,
 				strconv.Itoa(bx+o[0]),
 				strconv.Itoa(bz+o[1])+".png")
-			img := common.LoadPNG(path)
+			img := common.LoadPNG(path, tu.bg)
 			if err := rez.Convert(resized, img, common.ResizeFilter); err != nil {
 				return err
 			}
@@ -274,7 +281,7 @@ func updatePyramidTile(scratch, resized *image.RGBA, level int, baseDir string,
 		} else {
 			// Load lazy
 			if orig == nil {
-				orig = common.LoadPNG(origPath)
+				orig = common.LoadPNG(origPath, tu.bg)
 			}
 			//log.Printf("level %d: copied %d\n", level, i)
 			min := orig.Bounds().Min.Add(dps[i])
@@ -286,7 +293,10 @@ func updatePyramidTile(scratch, resized *image.RGBA, level int, baseDir string,
 	return common.SaveAsPNGAtomic(origPath, scratch)
 }
 
-func updateBaseTiles(jobs chan xz, btc *common.BaseTileCreator, done *sync.WaitGroup) {
+func (tu *tileUpdater) updateBaseTiles(
+	jobs chan xz,
+	btc *common.BaseTileCreator, done *sync.WaitGroup) {
+
 	defer btc.Close()
 	defer done.Done()
 	for job := range jobs {