blank tile

server/tilerenderer/blank.go

@@ -0,0 +1,25 @@
+package tilerenderer
+
+
+import (
+  "image"
+	"image/draw"
+	"image/png"
+  "image/color"
+  "bytes"
+)
+
+func CreateBlankTile(c color.RGBA) ([]byte){
+  rect := image.Rectangle{
+    image.Point{0, 0},
+    image.Point{IMG_SIZE, IMG_SIZE},
+  }
+
+  img := image.NewNRGBA(rect)
+  draw.Draw(img, rect, &image.Uniform{c}, image.ZP, draw.Src)
+
+  buf := new(bytes.Buffer)
+  png.Encode(buf, img)
+
+  return buf.Bytes()
+}

server/web/tiles.go

@@ -3,6 +3,8 @@ package web
 import (
 	"mapserver/app"
 	"mapserver/coords"
+	"mapserver/tilerenderer"
+	"image/color"
 	"net/http"
 	"strconv"
 	"strings"
@@ -37,7 +39,8 @@ func (t *Tiles) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
 		resp.Header().Add("content-type", "image/png")
 
 		if tile == nil {
-			//TODO: blank tile
+			resp.Write(tilerenderer.CreateBlankTile(color.RGBA{0,0,0,0}))
+			//TODO: cache/layer color
 
 		} else {
 			resp.Write(tile.Data)