When generating the seed list, we need the grid for the bounds

Added the ability to specify the srid to use. It defaults to 4326.

Our old system normalized the bounds to grid, this meant that people could provide a bounds without the associated srid as
long as it was either 4326 or 3853. With the change over, we
were defaulting to 3853. This was the wrong default. Chanced the default 4326, and added ability to specify the srid.

We will check to see if the SRID is supported by proj. For now the only srid's that are supported are 4326 and 3853.

Author: gdey

README.md

@@ -27,7 +27,7 @@ Tegola is a vector tile server delivering [Mapbox Vector Tiles](https://github.c
 
 ```
 tegola is a vector tile server
-Version: v0.17.0
+Version: v0.21.0
 
 Usage:
   tegola [command]

cmd/tegola/cmd/cache/seed_purge.go

@@ -2,13 +2,15 @@ package cache
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"runtime"
 	"strings"
 
 	"github.com/go-spatial/cobra"
 	"github.com/go-spatial/geom"
 	"github.com/go-spatial/geom/slippy"
+	"github.com/go-spatial/proj"
 	"github.com/go-spatial/tegola/atlas"
 	"github.com/go-spatial/tegola/internal/build"
 	gdcmd "github.com/go-spatial/tegola/internal/cmd"
@@ -41,15 +43,17 @@ Use "{{.CommandPath}} [command] --help" for more information about a command.{{e
 
 // flag parameters
 var (
-	// the amount of concurrency to use. defaults to the number of CPUs on the machine
+	// cacheConcurrency is the amount of concurrency to use. defaults to the number of CPUs on the machine
 	cacheConcurrency int
-	// cache overwrite
+	// cacheOverwrite determines if we should overwrite already existing files or skip them
 	cacheOverwrite bool
-	// bounds to cache within. default -180, -85.0511, 180, 85.0511
+	// cacheBounds is the bounds that the cache is within. defaults to -180, -85.0511, 180, 85.0511
 	cacheBounds string
-	// name of the map
+	// cacheBoundsSRID is the srid of grid system that the bounds is at. Should Default to 4326
+	cacheBoundsSRID int
+	// cacheMap is the name of the map
 	cacheMap string
-	// while seeding, on log output for tiles that take longer than this (in milliseconds) to render
+	// cacheLogThreshold is cache threshold while seeding, to log output for tiles that take longer than this (in milliseconds) to render
 	cacheLogThreshold int64
 )
 
@@ -76,6 +80,7 @@ func init() {
 	SeedPurgeCmd.PersistentFlags().Int64VarP(&cacheLogThreshold, "log-threshold", "", 0, "during seeding, only log tiles that take this number of milliseconds or longer to render (default all tiles)")
 
 	SeedPurgeCmd.Flags().StringVarP(&cacheBounds, "bounds", "", "-180,-85.0511,180,85.0511", "lng/lat bounds to seed the cache with in the format: minx, miny, maxx, maxy")
+	SeedPurgeCmd.Flags().IntVarP(&cacheBoundsSRID, "bounds-srid", "", int(proj.EPSG4326), "the srid of the grid system for bounds.")
 
 	SeedPurgeCmd.PersistentPreRunE = seedPurgeCmdValidatePersistent
 	SeedPurgeCmd.PreRunE = seedPurgeCmdValidate
@@ -143,6 +148,15 @@ func seedPurgeCmdValidatePersistent(cmd *cobra.Command, args []string) error {
 }
 
 func seedPurgeCmdValidate(cmd *cobra.Command, args []string) (err error) {
+	// validate the cache-bounds-srid
+	if !proj.IsKnownConversionSRID(proj.EPSGCode(cacheBoundsSRID)) {
+		var str strings.Builder
+		str.WriteString(fmt.Sprintf("SRID=%d is not a know conversion  ePSG code\n known codes are:", cacheBoundsSRID))
+		for _, code := range proj.AvailableConversions() {
+			str.WriteString(fmt.Sprintf(" %d\n", int(code)))
+		}
+		return errors.New(str.String())
+	}
 
 	// validate and set bounds flag
 	boundsParts := strings.Split(strings.TrimSpace(cacheBounds), ",")
@@ -191,27 +205,31 @@ func seedPurgeCommand(_ *cobra.Command, _ []string) (err error) {
 		}
 	}()
 
+	grid := slippy.NewGrid(proj.EPSGCode(cacheBoundsSRID), 0)
+
 	log.Info("zoom list: ", zooms)
-	tileChannel := generateTilesForBounds(ctx, seedPurgeBounds, zooms)
+	tileChannel := generateTilesForBounds(ctx, seedPurgeBounds, zooms, grid)
 
 	return doWork(ctx, tileChannel, seedPurgeMaps, cacheConcurrency, seedPurgeWorker)
 }
 
-func generateTilesForBounds(ctx context.Context, bounds [4]float64, zooms []uint) *TileChannel {
+func generateTilesForBounds(ctx context.Context, bounds [4]float64, zooms []uint, grid slippy.TileGridder) *TileChannel {
 
 	tce := &TileChannel{
 		channel: make(chan slippy.Tile),
 	}
 
-	webmercatorGrid := slippy.NewGrid(3857, 0)
+	if grid == nil {
+		grid = slippy.NewGrid(proj.EPSGCode(cacheBoundsSRID), 0)
+	}
 
 	go func() {
 		defer tce.Close()
 
 		var extent geom.Extent = bounds
 		for _, z := range zooms {
 
-			tiles, err := slippy.FromBounds(webmercatorGrid, &extent, slippy.Zoom(z))
+			tiles, err := slippy.FromBounds(grid, &extent, slippy.Zoom(z))
 			if err != nil {
 				tce.setError(fmt.Errorf("got error trying to get tiles: %w", err))
 				tce.Close()

cmd/tegola/cmd/cache/seed_purge_generator_test.go

@@ -8,6 +8,7 @@ import (
 	"testing"
 
 	"github.com/go-spatial/geom/slippy"
+	"github.com/go-spatial/proj"
 )
 
 type sTiles []slippy.Tile
@@ -70,14 +71,15 @@ func TestGenerateTilesForBounds(t *testing.T) {
 		zooms  []uint
 		bounds [4]float64
 		tiles  sTiles
+		grid   slippy.TileGridder
 		err    error
 	}
 
 	fn := func(tc tcase) func(t *testing.T) {
 		return func(t *testing.T) {
 
 			// Setup up the generator.
-			tilechannel := generateTilesForBounds(context.Background(), tc.bounds, tc.zooms)
+			tilechannel := generateTilesForBounds(context.Background(), tc.bounds, tc.zooms, tc.grid)
 			tiles := make(sTiles, 0, len(tc.tiles))
 			for tile := range tilechannel.Channel() {
 				tiles = append(tiles, tile)
@@ -127,6 +129,28 @@ func TestGenerateTilesForBounds(t *testing.T) {
 				slippy.Tile{Z: 1, X: 1, Y: 1},
 			},
 		},
+		"min_zoom=1 max_zoom=1 bounds=5.9,45.8,10.5,47.8 WSG84": {
+			// see: https://github.com/go-spatial/tegola/issues/880#issuecomment-2556563251
+			zooms:  []uint{10},
+			bounds: [4]float64{5.9, 45.8, 10.5, 47.8},
+			grid:   slippy.NewGrid(proj.EPSG4326, 0),
+			tiles: sTiles{
+				slippy.Tile{Z: 10, X: 528, Y: 356}, slippy.Tile{Z: 10, X: 528, Y: 357}, slippy.Tile{Z: 10, X: 528, Y: 358}, slippy.Tile{Z: 10, X: 528, Y: 359}, slippy.Tile{Z: 10, X: 528, Y: 360}, slippy.Tile{Z: 10, X: 528, Y: 361}, slippy.Tile{Z: 10, X: 528, Y: 362}, slippy.Tile{Z: 10, X: 528, Y: 363}, slippy.Tile{Z: 10, X: 528, Y: 364}, slippy.Tile{Z: 10, X: 528, Y: 365},
+				slippy.Tile{Z: 10, X: 529, Y: 356}, slippy.Tile{Z: 10, X: 529, Y: 357}, slippy.Tile{Z: 10, X: 529, Y: 358}, slippy.Tile{Z: 10, X: 529, Y: 359}, slippy.Tile{Z: 10, X: 529, Y: 360}, slippy.Tile{Z: 10, X: 529, Y: 361}, slippy.Tile{Z: 10, X: 529, Y: 362}, slippy.Tile{Z: 10, X: 529, Y: 363}, slippy.Tile{Z: 10, X: 529, Y: 364}, slippy.Tile{Z: 10, X: 529, Y: 365},
+				slippy.Tile{Z: 10, X: 530, Y: 356}, slippy.Tile{Z: 10, X: 530, Y: 357}, slippy.Tile{Z: 10, X: 530, Y: 358}, slippy.Tile{Z: 10, X: 530, Y: 359}, slippy.Tile{Z: 10, X: 530, Y: 360}, slippy.Tile{Z: 10, X: 530, Y: 361}, slippy.Tile{Z: 10, X: 530, Y: 362}, slippy.Tile{Z: 10, X: 530, Y: 363}, slippy.Tile{Z: 10, X: 530, Y: 364}, slippy.Tile{Z: 10, X: 530, Y: 365},
+				slippy.Tile{Z: 10, X: 531, Y: 356}, slippy.Tile{Z: 10, X: 531, Y: 357}, slippy.Tile{Z: 10, X: 531, Y: 358}, slippy.Tile{Z: 10, X: 531, Y: 359}, slippy.Tile{Z: 10, X: 531, Y: 360}, slippy.Tile{Z: 10, X: 531, Y: 361}, slippy.Tile{Z: 10, X: 531, Y: 362}, slippy.Tile{Z: 10, X: 531, Y: 363}, slippy.Tile{Z: 10, X: 531, Y: 364}, slippy.Tile{Z: 10, X: 531, Y: 365},
+				slippy.Tile{Z: 10, X: 532, Y: 356}, slippy.Tile{Z: 10, X: 532, Y: 357}, slippy.Tile{Z: 10, X: 532, Y: 358}, slippy.Tile{Z: 10, X: 532, Y: 359}, slippy.Tile{Z: 10, X: 532, Y: 360}, slippy.Tile{Z: 10, X: 532, Y: 361}, slippy.Tile{Z: 10, X: 532, Y: 362}, slippy.Tile{Z: 10, X: 532, Y: 363}, slippy.Tile{Z: 10, X: 532, Y: 364}, slippy.Tile{Z: 10, X: 532, Y: 365},
+				slippy.Tile{Z: 10, X: 533, Y: 356}, slippy.Tile{Z: 10, X: 533, Y: 357}, slippy.Tile{Z: 10, X: 533, Y: 358}, slippy.Tile{Z: 10, X: 533, Y: 359}, slippy.Tile{Z: 10, X: 533, Y: 360}, slippy.Tile{Z: 10, X: 533, Y: 361}, slippy.Tile{Z: 10, X: 533, Y: 362}, slippy.Tile{Z: 10, X: 533, Y: 363}, slippy.Tile{Z: 10, X: 533, Y: 364}, slippy.Tile{Z: 10, X: 533, Y: 365},
+				slippy.Tile{Z: 10, X: 534, Y: 356}, slippy.Tile{Z: 10, X: 534, Y: 357}, slippy.Tile{Z: 10, X: 534, Y: 358}, slippy.Tile{Z: 10, X: 534, Y: 359}, slippy.Tile{Z: 10, X: 534, Y: 360}, slippy.Tile{Z: 10, X: 534, Y: 361}, slippy.Tile{Z: 10, X: 534, Y: 362}, slippy.Tile{Z: 10, X: 534, Y: 363}, slippy.Tile{Z: 10, X: 534, Y: 364}, slippy.Tile{Z: 10, X: 534, Y: 365},
+				slippy.Tile{Z: 10, X: 535, Y: 356}, slippy.Tile{Z: 10, X: 535, Y: 357}, slippy.Tile{Z: 10, X: 535, Y: 358}, slippy.Tile{Z: 10, X: 535, Y: 359}, slippy.Tile{Z: 10, X: 535, Y: 360}, slippy.Tile{Z: 10, X: 535, Y: 361}, slippy.Tile{Z: 10, X: 535, Y: 362}, slippy.Tile{Z: 10, X: 535, Y: 363}, slippy.Tile{Z: 10, X: 535, Y: 364}, slippy.Tile{Z: 10, X: 535, Y: 365},
+				slippy.Tile{Z: 10, X: 536, Y: 356}, slippy.Tile{Z: 10, X: 536, Y: 357}, slippy.Tile{Z: 10, X: 536, Y: 358}, slippy.Tile{Z: 10, X: 536, Y: 359}, slippy.Tile{Z: 10, X: 536, Y: 360}, slippy.Tile{Z: 10, X: 536, Y: 361}, slippy.Tile{Z: 10, X: 536, Y: 362}, slippy.Tile{Z: 10, X: 536, Y: 363}, slippy.Tile{Z: 10, X: 536, Y: 364}, slippy.Tile{Z: 10, X: 536, Y: 365},
+				slippy.Tile{Z: 10, X: 537, Y: 356}, slippy.Tile{Z: 10, X: 537, Y: 357}, slippy.Tile{Z: 10, X: 537, Y: 358}, slippy.Tile{Z: 10, X: 537, Y: 359}, slippy.Tile{Z: 10, X: 537, Y: 360}, slippy.Tile{Z: 10, X: 537, Y: 361}, slippy.Tile{Z: 10, X: 537, Y: 362}, slippy.Tile{Z: 10, X: 537, Y: 363}, slippy.Tile{Z: 10, X: 537, Y: 364}, slippy.Tile{Z: 10, X: 537, Y: 365},
+				slippy.Tile{Z: 10, X: 538, Y: 356}, slippy.Tile{Z: 10, X: 538, Y: 357}, slippy.Tile{Z: 10, X: 538, Y: 358}, slippy.Tile{Z: 10, X: 538, Y: 359}, slippy.Tile{Z: 10, X: 538, Y: 360}, slippy.Tile{Z: 10, X: 538, Y: 361}, slippy.Tile{Z: 10, X: 538, Y: 362}, slippy.Tile{Z: 10, X: 538, Y: 363}, slippy.Tile{Z: 10, X: 538, Y: 364}, slippy.Tile{Z: 10, X: 538, Y: 365},
+				slippy.Tile{Z: 10, X: 539, Y: 356}, slippy.Tile{Z: 10, X: 539, Y: 357}, slippy.Tile{Z: 10, X: 539, Y: 358}, slippy.Tile{Z: 10, X: 539, Y: 359}, slippy.Tile{Z: 10, X: 539, Y: 360}, slippy.Tile{Z: 10, X: 539, Y: 361}, slippy.Tile{Z: 10, X: 539, Y: 362}, slippy.Tile{Z: 10, X: 539, Y: 363}, slippy.Tile{Z: 10, X: 539, Y: 364}, slippy.Tile{Z: 10, X: 539, Y: 365},
+				slippy.Tile{Z: 10, X: 540, Y: 356}, slippy.Tile{Z: 10, X: 540, Y: 357}, slippy.Tile{Z: 10, X: 540, Y: 358}, slippy.Tile{Z: 10, X: 540, Y: 359}, slippy.Tile{Z: 10, X: 540, Y: 360}, slippy.Tile{Z: 10, X: 540, Y: 361}, slippy.Tile{Z: 10, X: 540, Y: 362}, slippy.Tile{Z: 10, X: 540, Y: 363}, slippy.Tile{Z: 10, X: 540, Y: 364}, slippy.Tile{Z: 10, X: 540, Y: 365},
+				slippy.Tile{Z: 10, X: 541, Y: 356}, slippy.Tile{Z: 10, X: 541, Y: 357}, slippy.Tile{Z: 10, X: 541, Y: 358}, slippy.Tile{Z: 10, X: 541, Y: 359}, slippy.Tile{Z: 10, X: 541, Y: 360}, slippy.Tile{Z: 10, X: 541, Y: 361}, slippy.Tile{Z: 10, X: 541, Y: 362}, slippy.Tile{Z: 10, X: 541, Y: 363}, slippy.Tile{Z: 10, X: 541, Y: 364}, slippy.Tile{Z: 10, X: 541, Y: 365},
+			},
+		},
 	}
 
 	for name, tc := range tests {