main.go

package main

import (
	"flag"
	"fmt"
	"image"
	"image/png"
	"os"

	"github.com/Hades32/height-map/pkg/height-map"
	"github.com/Hades32/height-map/pkg/log"

	"github.com/disintegration/gift"
	"github.com/itzg/go-flagsfiller"
)

type Config struct {
	In           string `usage:"The .hgt file to convert"`
	Out          string `usage:"The image file to create (only supports png at the moment)"`
	AutoImprove  bool   `default:"false" usage:"Will try to auto improve the image"`
	DebugEnabled bool   `default:"false" usage:"Show debug information"`
}

func main() {
	config := parseArguments()

	heightData, err := os.Open(config.In)
	if err != nil {
		fmt.Println("Couldn't open input file", err)
		os.Exit(1)
	}
	imageFile, err := os.Create(config.Out)
	if err != nil {
		fmt.Println("Couldn't create output file", err)
		os.Exit(1)
	}
	var img image.Image
	img, err = heightmap.Convert(heightData)
	if err != nil {
		fmt.Println("Couldn't convert file", err)
		os.Exit(1)
	}
	if config.AutoImprove {
		g := gift.New(gift.Contrast(30))
		dst := image.NewRGBA(g.Bounds(img.Bounds()))
		g.Draw(dst, img)
		img = dst
	}

	err = png.Encode(imageFile, img)
	if err != nil {
		fmt.Println("Couldn't write output file", err)
		os.Exit(1)
	}
}

func parseArguments() Config {
	var config Config
	filler := flagsfiller.New()
	err := filler.Fill(flag.CommandLine, &config)
	if err != nil {
		fmt.Println("Couldn't parse arguments", err)
		os.Exit(1)
	}
	flag.Parse()

	if config.In == "" || config.Out == "" {
		fmt.Println("A tool to convert SRTM height map data to grayscale pictures.")
		fmt.Println("Data can be retrieved from https://dds.cr.usgs.gov/srtm/version2_1/SRTM3/")
		flag.Usage()
		os.Exit(1)
	}

	log.DebugEnabled = config.DebugEnabled

	return config
}