support extracting a bbox instead of geojson [#68] (#78)

main.go

@@ -45,22 +45,17 @@ var cli struct {
 	} `cmd:"" help:"Fetch one tile from a local or remote archive and output on stdout."`
 
 	Extract struct {
-		Input     string  `arg:"" help:"Input local or remote archive."`
-		Output    string  `arg:"" help:"Output archive." type:"path"`
-		Bucket    string  `help:"Remote bucket of input archive."`
-		Region    string  `help:"local GeoJSON Polygon or MultiPolygon file for area of interest." type:"existingfile"`
-		Maxzoom   int8   `default:-1 help:"Maximum zoom level, inclusive."`
-		DownloadThreads int `default:4 help:"Number of download threads."`
-		DryRun    bool    `help:"Calculate tiles to extract, but don't download them."`
-		Overfetch float32 `default:0.05 help:"What ratio of extra data to download to minimize # requests; 0.2 is 20%"`
+		Input           string  `arg:"" help:"Input local or remote archive."`
+		Output          string  `arg:"" help:"Output archive." type:"path"`
+		Bucket          string  `help:"Remote bucket of input archive."`
+		Region          string  `help:"local GeoJSON Polygon or MultiPolygon file for area of interest." type:"existingfile"`
+		Bbox            string  `help:"bbox area of interest" type:"string"`
+		Maxzoom         int8    `default:-1 help:"Maximum zoom level, inclusive."`
+		DownloadThreads int     `default:4 help:"Number of download threads."`
+		DryRun          bool    `help:"Calculate tiles to extract, but don't download them."`
+		Overfetch       float32 `default:0.05 help:"What ratio of extra data to download to minimize # requests; 0.2 is 20%"`
 	} `cmd:"" help:"Create an archive from a larger archive for a subset of zoom levels or geographic region."`
 
-	Makesync struct {
-		Input        string `arg:"" type:"existingfile"`
-		BlockSize    int    `default:1000 help:"The block size, in # of tiles."`
-		HashFunction string `default:fnv1a help:"The hash function."`
-	} `cmd:"" help:"Generates an **experimental** sync control file (.pmtiles.sync) for a local archive."`
-
 	Stats struct {
 		Input string `arg:"" type:"existingfile"`
 	} `cmd:"" help:"Add a vector tile statistics file (.tilestats.tsv.gz) used for further analysis with DuckDB."`
@@ -131,7 +126,7 @@ func main() {
 		logger.Printf("Serving %s %s on port %d with Access-Control-Allow-Origin: %s\n", cli.Serve.Bucket, cli.Serve.Path, cli.Serve.Port, cli.Serve.Cors)
 		logger.Fatal(http.ListenAndServe(":"+strconv.Itoa(cli.Serve.Port), nil))
 	case "extract <input> <output>":
-		err := pmtiles.Extract(logger, cli.Extract.Bucket, cli.Extract.Input, cli.Extract.Maxzoom, cli.Extract.Region, cli.Extract.Output, cli.Extract.DownloadThreads, cli.Extract.Overfetch, cli.Extract.DryRun)
+		err := pmtiles.Extract(logger, cli.Extract.Bucket, cli.Extract.Input, cli.Extract.Maxzoom, cli.Extract.Region, cli.Extract.Bbox, cli.Extract.Output, cli.Extract.DownloadThreads, cli.Extract.Overfetch, cli.Extract.DryRun)
 		if err != nil {
 			logger.Fatalf("Failed to extract, %v", err)
 		}

pmtiles/extract.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"github.com/RoaringBitmap/roaring/roaring64"
 	"github.com/dustin/go-humanize"
+	"github.com/paulmach/orb"
 	"github.com/schollz/progressbar/v3"
 	"golang.org/x/sync/errgroup"
 	"io"
@@ -248,7 +249,7 @@ func MergeRanges(ranges []SrcDstRange, overfetch float32) (*list.List, uint64) {
 // 10. write the leaf directories (if any)
 // 11. Get all tiles, and write directly to the output.
 
-func Extract(logger *log.Logger, bucketURL string, key string, maxzoom int8, region_file string, output string, download_threads int, overfetch float32, dry_run bool) error {
+func Extract(logger *log.Logger, bucketURL string, key string, maxzoom int8, region_file string, bbox string, output string, download_threads int, overfetch float32, dry_run bool) error {
 	// 1. fetch the header
 
 	fmt.Println("WARNING: extract is an experimental feature and results may not be suitable for production use.")
@@ -297,16 +298,29 @@ func Extract(logger *log.Logger, bucketURL string, key string, maxzoom int8, reg
 	}
 
 	var relevant_set *roaring64.Bitmap
-	if region_file != "" {
+	if region_file != "" || bbox != "" {
+		if region_file != "" && bbox != "" {
+			return fmt.Errorf("Only one of region and bbox can be specified.")
+		}
 
-		// 2. construct a relevance bitmap
-		dat, _ := ioutil.ReadFile(region_file)
-		multipolygon, err := UnmarshalRegion(dat)
+		var multipolygon orb.MultiPolygon
 
-		if err != nil {
-			return err
+		if region_file != "" {
+			dat, _ := ioutil.ReadFile(region_file)
+			multipolygon, err = UnmarshalRegion(dat)
+
+			if err != nil {
+				return err
+			}
+		} else {
+			multipolygon, err = BboxRegion(bbox)
+			if err != nil {
+				return err
+			}
 		}
 
+		// 2. construct a relevance bitmap
+
 		bound := multipolygon.Bound()
 
 		boundary_set, interior_set := bitmapMultiPolygon(uint8(maxzoom), multipolygon)

pmtiles/region.go

@@ -4,8 +4,31 @@ import (
 	"fmt"
 	"github.com/paulmach/orb"
 	"github.com/paulmach/orb/geojson"
+	"strconv"
+	"strings"
 )
 
+func BboxRegion(bbox string) (orb.MultiPolygon, error) {
+	parts := strings.Split(bbox, ",")
+	min_lon, err := strconv.ParseFloat(parts[0], 64)
+	if err != nil {
+		return nil, err
+	}
+	min_lat, err := strconv.ParseFloat(parts[1], 64)
+	if err != nil {
+		return nil, err
+	}
+	max_lon, err := strconv.ParseFloat(parts[2], 64)
+	if err != nil {
+		return nil, err
+	}
+	max_lat, err := strconv.ParseFloat(parts[3], 64)
+	if err != nil {
+		return nil, err
+	}
+	return orb.MultiPolygon{{{{min_lon, max_lat}, {max_lon, max_lat}, {max_lon, min_lat}, {min_lon, min_lat}, {min_lon, max_lat}}}}, nil
+}
+
 func UnmarshalRegion(data []byte) (orb.MultiPolygon, error) {
 	fc, err := geojson.UnmarshalFeatureCollection(data)
 

pmtiles/region_test.go

@@ -5,6 +5,15 @@ import (
 	"testing"
 )
 
+func TestBboxRegion(t *testing.T) {
+	result, err := BboxRegion("-1.906033,50.680367,1.097501,52.304934")
+	assert.Nil(t, err)
+	assert.Equal(t, -1.906033, result[0][0][0][0])
+	assert.Equal(t, 52.304934, result[0][0][0][1])
+	assert.Equal(t, 1.097501, result[0][0][2][0])
+	assert.Equal(t, 50.680367, result[0][0][2][1])
+}
+
 func TestRawPolygonRegion(t *testing.T) {
 	result, err := UnmarshalRegion([]byte(`{
 		"type": "Polygon",