[ADD] map : script for download tiles (openstreetmap)

README.md

@@ -13,5 +13,8 @@ Capture en png la fenetre demande en parametre qui correspond a id windows defin
 Project fait par rapport au site de lecture de mangas en ligne (lelscano.com//mangas/dr-stone/). Il recupere les images du site pour en cree des archives d'extension cbz pour une lecture hors ligne.
 
 -> mysqltojson
-Creation d'un server json end mode api base sur mysql
+Creation d'un server json end mode api base sur MySQL
+
+=> map
+Script de téléchargement des tiles de openstreetmap
 

map/downloadOpenMapStreet.go

@@ -0,0 +1,97 @@
+package main
+
+import (
+    "fmt"
+    "io"
+    "net/http"
+    "os"
+    "path/filepath"
+    "sync"
+    "time"
+)
+
+func downloadTile(z, x, y int, wg *sync.WaitGroup, ch chan string, sem chan struct{}) {
+    defer wg.Done()
+    defer func() { <-sem }() // Release the semaphore slot
+
+    client := &http.Client{}
+
+    // Create a new request to the OpenStreetMap tile URL
+    url := fmt.Sprintf("https://tile.openstreetmap.org/%d/%d/%d.png", z, x, y)
+    req, err := http.NewRequest("GET", url, nil)
+    if err != nil {
+        ch <- fmt.Sprintf("Error creating request: %v", err)
+        return
+    }
+
+    // Set the User-Agent header
+    req.Header.Set("User-Agent", "MyTileDownloader/1.0")
+
+    // Make the request
+    response, err := client.Do(req)
+    if err != nil {
+        ch <- fmt.Sprintf("Error making request: %v", err)
+        return
+    }
+
+    defer response.Body.Close()
+
+    if response.StatusCode == http.StatusNotFound {
+        ch <- fmt.Sprintf("Tile %d/%d/%d not found (404)\n", z, x, y)
+        return
+    }
+
+    if response.StatusCode != http.StatusOK {
+        ch <- fmt.Sprintf("Failed to download tile %d/%d/%d: %s\n", z, x, y, response.Status)
+        return
+    }
+
+    // Create the destination directory
+    tilePath := filepath.Join(fmt.Sprintf("%d", z), fmt.Sprintf("%d", x), fmt.Sprintf("%d", y)+".png")
+    os.MkdirAll(filepath.Dir(tilePath), os.ModePerm)
+
+    outFile, err := os.Create(tilePath)
+    if err != nil {
+        ch <- fmt.Sprintf("Error creating file: %v", err)
+        return
+    }
+    defer outFile.Close()
+
+    _, err = io.Copy(outFile, response.Body)
+    if err != nil {
+        ch <- fmt.Sprintf("Error saving file: %v", err)
+        return
+    }
+    ch <- fmt.Sprintf("Downloaded tile: z %d, x %d, y %d\n", z, x, y)
+}
+
+func main() {
+    var wg sync.WaitGroup
+    ch := make(chan string)
+    sem := make(chan struct{}, 1500) // Semaphore with 1500 slots
+
+    // Goroutine to print messages from the channel
+    go func() {
+        for msg := range ch {
+            fmt.Print(msg)
+        }
+    }()
+    i := 0
+    j := 0
+    for z := 10; z < 19; z++ {
+        finz := 1 << z // equivalent to 2^z
+        for x := i; x < finz; x++ {
+            for y := j; y < finz; y++ {
+                wg.Add(1)
+                sem <- struct{}{} // Acquire a semaphore slot
+                go downloadTile(z, x, y, &wg, ch, sem)
+                time.Sleep(15 * time.Millisecond) // Pause between starting new goroutines
+            }
+    	    j = 0
+            i = 0
+        }
+    }
+
+    wg.Wait()
+    close(ch)
+}