Add web sub project

2018-07-30 22:41:10 -06:00
parent 818cd906ac
commit 1d3581370a
2 changed files with 178 additions and 0 deletions
--- a/web/render.go
+++ b/web/render.go
@@ -0,0 +1,114 @@
+package main
+
+import (
+	"image"
+	"image/color"
+	"image/png"
+	"log"
+	"math/cmplx"
+	"net/http"
+	"runtime"
+	"strconv"
+	"strings"
+	"sync"
+)
+
+const (
+	Size       = 256
+	Iterations = (1<<16 - 1) / Brighten
+	Brighten   = 1024
+)
+
+func mandelbrot(c complex128) uint16 {
+	var z complex128
+
+	for i := 0; i < Iterations; i++ {
+		z = z*z + c
+		if cmplx.IsNaN(z) {
+			return uint16(i)
+		}
+	}
+
+	return Iterations
+}
+
+type pixel struct {
+	out          *image.Gray16
+	x, y         int
+	tileX, tileY int64
+	tileZoom     uint8
+	wg           *sync.WaitGroup
+}
+
+var queue = make(chan pixel)
+
+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)),
+			),
+		)
+		p.out.SetGray16(p.x, p.y, color.Gray16{val * Brighten})
+
+		p.wg.Done()
+	}
+}
+
+func main() {
+	runtime.GOMAXPROCS(runtime.NumCPU())
+
+	for i := 0; i < runtime.GOMAXPROCS(0); i++ {
+		go computeThread()
+	}
+
+	log.Fatal(http.ListenAndServe(":6161", nil))
+}
+
+func renderTile(w http.ResponseWriter, r *http.Request) {
+	components := strings.Split(r.URL.Path, "/")[1:]
+
+	if len(components) != 4 || components[0] != "mandelbrot" || components[3][len(components[3])-4:] != ".png" {
+		w.WriteHeader(http.StatusNotFound)
+		return
+	}
+	components[3] = components[3][:len(components[3])-4]
+
+	tileX, err := strconv.ParseInt(components[2], 10, 64)
+	if err != nil {
+		w.WriteHeader(http.StatusNotFound)
+		return
+	}
+	tileY, err := strconv.ParseInt(components[3], 10, 64)
+	if err != nil {
+		w.WriteHeader(http.StatusNotFound)
+		return
+	}
+	tileZoom, err := strconv.ParseUint(components[1], 10, 8)
+	if err != nil {
+		w.WriteHeader(http.StatusNotFound)
+		return
+	}
+
+	var wg sync.WaitGroup
+
+	wg.Add(Size * Size)
+
+	img := image.NewGray16(image.Rect(0, 0, Size, Size))
+
+	for x := 0; x < Size; x++ {
+		for y := 0; y < Size; y++ {
+			queue <- pixel{img, x, y, tileX, tileY, uint8(tileZoom), &wg}
+		}
+	}
+
+	wg.Wait()
+
+	w.Header().Set("Content-Type", "image/png")
+	png.Encode(w, img)
+}
+
+func init() {
+	http.HandleFunc("/mandelbrot/", renderTile)
+}
--- a/web/web.go
+++ b/web/web.go
@@ -0,0 +1,64 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+)
+
+func init() {
+	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/" {
+			w.Header().Set("Location", "/")
+			w.WriteHeader(http.StatusMovedPermanently)
+			return
+		}
+
+		fmt.Fprintf(w, `<!DOCTYPE html>
+<html>
+<head>
+<title>Mandelbrot Map</title>
+<script src="https://maps.googleapis.com/maps/api/js?sensor=false"></script>
+<script>
+var mandelbrotTypeOptions = {
+	getTileUrl: function(coord, zoom) {
+		return '/mandelbrot/' + zoom + '/' + coord.x + '/' + coord.y + '.png';
+	},
+	tileSize: new google.maps.Size(256, 256),
+	maxZoom: (1<<8) - 1,
+	minZoom: 0,
+	name: 'Mandelbrot'
+};
+	
+var mandelbrotMapType = new google.maps.ImageMapType(mandelbrotTypeOptions);
+		
+function initialize() {
+	var mapOptions = {
+		center: new google.maps.LatLng(0, 0),
+		zoom: 1,
+		streetViewControl: false,
+		mapTypeControlOptions: {
+			mapTypeIds: ['mandelbrot']
+		}
+	};
+	
+	var map = new google.maps.Map(document.getElementById('map_canvas'), mapOptions);
+	map.mapTypes.set('mandelbrot', mandelbrotMapType);
+	map.setMapTypeId('mandelbrot');
+}
+</script>
+<style>
+#map_canvas {
+	position: absolute !important;
+	left: 0 !important;
+	right: 0 !important;
+	top: 0 !important;
+	bottom: 0 !important;
+}
+</style>
+</head>
+<body onload="initialize()">
+<div id="map_canvas"></div>
+</body>
+</html>`)
+	})
+}