Add some testing

.github/workflows/ci.yml

@@ -45,3 +45,5 @@ jobs:
         run: $HOME/go/bin/gocyclo -over 19 $(find . -iname '*.go' -type f)
       - name: fmt
         run: test -z $(gofmt -s -l $(find . -iname '*.go' -type f))
+      - name: test
+        run: go test ./...

.gitignore

@@ -1 +1,2 @@
 *.png
+.DS_Store

context.go

@@ -634,6 +634,10 @@ func (m *Context) RenderWithBounds() (image.Image, s2.Rect, error) {
 }
 
 func (m *Context) renderLayer(gc *gg.Context, zoom int, trans *Transformer, tileSize int, provider *TileProvider) error {
+	if provider.IsNone() {
+		return nil
+	}
+
 	var wg sync.WaitGroup
 	tiles := (1 << uint(zoom))
 	fetchedTiles := make(chan *Tile)

context_test.go

@@ -0,0 +1,52 @@
+package sm
+
+import (
+	"image/color"
+	"testing"
+
+	"github.com/golang/geo/s2"
+)
+
+func TestRenderEverything(t *testing.T) {
+	width := 640
+	height := 480
+
+	ctx := NewContext()
+	ctx.SetSize(width, height)
+	ctx.SetTileProvider(NewTileProviderNone())
+	ctx.SetBackground(color.RGBA{255, 255, 255, 255})
+
+	coords1 := s2.LatLngFromDegrees(48.123, 7.0)
+	coords2 := s2.LatLngFromDegrees(48.987, 8.0)
+	coords3 := s2.LatLngFromDegrees(47.987, 7.5)
+	coords4 := s2.LatLngFromDegrees(48.123, 9.0)
+
+	p := make([]s2.LatLng, 0, 3)
+	p = append(p, coords1)
+	p = append(p, coords2)
+	p = append(p, coords3)
+	path := NewPath(p, color.RGBA{0, 0, 255, 255}, 4.0)
+
+	a := make([]s2.LatLng, 0, 3)
+	a = append(a, coords1)
+	a = append(a, coords3)
+	a = append(a, coords4)
+	area := NewArea(a, color.RGBA{255, 0, 0, 255}, color.RGBA{255, 255, 0, 50}, 3.0)
+
+	marker := NewMarker(coords1, color.RGBA{255, 0, 0, 255}, 16.0)
+	circle := NewCircle(coords2, color.RGBA{0, 255, 0, 255}, color.RGBA{0, 255, 0, 100}, 10000.0, 2.0)
+
+	ctx.AddObject(area)
+	ctx.AddObject(path)
+	ctx.AddObject(marker)
+	ctx.AddObject(circle)
+
+	img, err := ctx.Render()
+	if err != nil {
+		t.Errorf("failed to render: %v", err)
+	}
+
+	if img.Bounds().Dx() != width || img.Bounds().Dy() != height {
+		t.Errorf("unexpected image size: %d x %d; expected %d x %d", img.Bounds().Dx(), img.Bounds().Dy(), width, height)
+	}
+}

examples/idl/main.go

@@ -0,0 +1,34 @@
+// This is an example on how to use a multiline attribution string.
+
+package main
+
+import (
+	"image/color"
+
+	sm "github.com/flopp/go-staticmaps"
+	"github.com/fogleman/gg"
+	"github.com/golang/geo/s2"
+)
+
+func main() {
+	ctx := sm.NewContext()
+	ctx.SetSize(1920, 1080)
+
+	newyork := sm.NewMarker(s2.LatLngFromDegrees(40.641766, -73.780968), color.RGBA{255, 0, 0, 255}, 16.0)
+	hongkong := sm.NewMarker(s2.LatLngFromDegrees(22.308046, 113.918480), color.RGBA{0, 0, 255, 255}, 16.0)
+	ctx.AddObject(newyork)
+	ctx.AddObject(hongkong)
+	path := make([]s2.LatLng, 0, 2)
+	path = append(path, newyork.Position)
+	path = append(path, hongkong.Position)
+	ctx.AddObject(sm.NewPath(path, color.RGBA{0, 255, 0, 255}, 4.0))
+
+	img, err := ctx.Render()
+	if err != nil {
+		panic(err)
+	}
+
+	if err := gg.SavePNG("idl.png", img); err != nil {
+		panic(err)
+	}
+}

tile_provider.go

@@ -18,7 +18,14 @@ type TileProvider struct {
 	APIKey         string
 }
 
+func (t TileProvider) IsNone() bool {
+	return len(t.URLPattern) == 0
+}
+
 func (t *TileProvider) getURL(shard string, zoom, x, y int, apikey string) string {
+	if t.IsNone() {
+		return ""
+	}
 	return fmt.Sprintf(t.URLPattern, shard, zoom, x, y, apikey)
 }
 
@@ -145,6 +152,17 @@ func NewTileProviderArcgisWorldImagery() *TileProvider {
 	return t
 }
 
+// NewTileNone creates a TileProvider struct that does not provide any tiles
+func NewTileProviderNone() *TileProvider {
+	t := new(TileProvider)
+	t.Name = "none"
+	t.Attribution = ""
+	t.TileSize = 256
+	t.URLPattern = ""
+	t.Shards = []string{}
+	return t
+}
+
 // GetTileProviders returns a map of all available TileProviders
 func GetTileProviders(thunderforestApiKey string) map[string]*TileProvider {
 	m := make(map[string]*TileProvider)
@@ -162,6 +180,7 @@ func GetTileProviders(thunderforestApiKey string) map[string]*TileProvider {
 		NewTileProviderCartoDark(),
 		NewTileProviderArcgisWorldImagery(),
 		NewTileProviderWikimedia(),
+		NewTileProviderNone(),
 	}
 
 	for _, tp := range list {