Add a -transparent-dim=percent flag to set the extra dimming of transparent materials each depth meter.

cmd/mttilemapper/main.go

@@ -27,6 +27,7 @@ func main() {
 		shaded               bool
 		transparent          bool
 		cpuProfile           string
+		transparentDim       float64
 	)
 
 	flag.IntVar(&port, "port", 6379, "port to of mtredisalize server")
@@ -46,6 +47,9 @@ func main() {
 	flag.StringVar(&outfile, "o", "out.png", "image file of result (shorthand)")
 	flag.BoolVar(&shaded, "shaded", true, "draw relief")
 	flag.BoolVar(&transparent, "transparent", false, "render transparent blocks")
+	flag.Float64Var(
+		&transparentDim, "transparent-dim", common.DefaultTransparentDim*100,
+		"Extra dimming of transparent nodes every depth meter in percent (0-100).")
 	flag.StringVar(&cpuProfile, "cpuprofile", "", "write cpu profile to file")
 
 	flag.Parse()
@@ -66,6 +70,9 @@ func main() {
 		log.Fatalf("Cannot open color file: %s", err)
 	}
 
+	colors.TransparentDim = common.Clamp32f(
+		float32(transparentDim/100.0), 0.0, 100.0)
+
 	address := fmt.Sprintf("%s:%d", host, port)
 
 	var client *common.RedisClient