From ba0ef17b0652dd4f34578f075d5d07894dcde11a Mon Sep 17 00:00:00 2001
From: Steven Polley <himself@stevenpolley.net>
Date: Thu, 2 Aug 2018 23:34:39 -0600
Subject: [PATCH] Shrink 2x and shift down so we can see the whole set Fix 0x
 zoom - dividing by 0 is not fun

---
 render.go | 12 +++++++-----
 web.go    |  8 ++++----
 2 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/render.go b/render.go
index 0f0b945..6b30f73 100644
--- a/render.go
+++ b/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 {
diff --git a/web.go b/web.go
index 8a9ec0f..a89c99b 100644
--- a/web.go
+++ b/web.go
@@ -23,10 +23,10 @@ var mandelbrotTypeOptions = {
 	getTileUrl: function(coord, zoom) {
 		return '/mandelbrot/' + zoom + '/' + coord.x + '/' + coord.y + '.png';
 	},
-	tileSize: new google.maps.Size(256, 256),
-	maxZoom: (1<<16) - 1,
-	minZoom: 0,
-	name: 'Mandelbrot'
+	tileSize: new google.maps.Size(128, 128),
+	maxZoom: (1<<16),
+	minZoom: 1,
+	name: '0xdeadbeef Mandel Mapper'
 };
 	
 var mandelbrotMapType = new google.maps.ImageMapType(mandelbrotTypeOptions);