Shrink 2x and shift down so we can see the whole set

Fix 0x zoom - dividing by 0 is not fun

render.go

@@ -18,7 +18,7 @@ import (
 )
 
 const (
-	Size       = 256
+	Size       = 128
 	Iterations = (1<<16 - 1) / 128
 )
 
@@ -54,8 +54,8 @@ func computeThread() {
 	for p := range queue {
 		val := mandelbrot(
 			complex(
-				(float64(p.x)/Size+float64(p.tileX))/float64(uint(1<<p.tileZoom)),
-				(float64(p.y)/Size+float64(p.tileY))/float64(uint(1<<p.tileZoom)),
+				(float64(p.x)/Size+float64(p.tileX))/float64(uint(1<<(p.tileZoom-1))),
+				(float64(p.y)/Size+float64(p.tileY))/float64(uint(1<<(p.tileZoom-1))),
 			),
 		)
 		p.out.SetRGBA(p.x, p.y, colors[val])
@@ -110,7 +110,8 @@ func renderTile(w http.ResponseWriter, r *http.Request) {
 
 	for x := 0; x < Size; x++ {
 		for y := 0; y < Size; y++ {
-			queue <- pixel{img, x, y, tileX, tileY, uint16(tileZoom), &wg}
+
+			queue <- pixel{img, x, y, tileX - int64(1<<tileZoom-1) - 1, tileY, uint16(tileZoom), &wg}
 		}
 	}
 
@@ -119,7 +120,7 @@ func renderTile(w http.ResponseWriter, r *http.Request) {
 	/*
 		ip := GetOutboundIP()
 		addLabel(img, 20, 30, fmt.Sprintf("rendered by \n%s", ip.String()))
-		//addLabel(img, 20, 30, fmt.Sprintf("%s/%s/%s.png", components[1], components[2], components[3]))
+		addLabel(img, 20, 30, fmt.Sprintf("%s/%s/%s.png", components[1], components[2], components[3]))
 	*/
 	w.Header().Set("Content-Type", "image/png")
 	png.Encode(w, img)
@@ -213,6 +214,7 @@ func addLabel(img *image.RGBA, x, y int, label string) {
 	d.DrawString(label)
 }
 
+
 func GetOutboundIP() net.IP {
 	conn, err := net.Dial("udp", "8.8.8.8:80")
 	if err != nil {