dynmapDownload.cs

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Net;
using System.Runtime.InteropServices;
using System.Threading.Tasks;
using System.Windows.Forms;
using Flurl;
using Newtonsoft.Json;

namespace MapCreator
{
    public partial class MainForm : Form
    {
        DynmapConfig Config;
        string URL;

        public MainForm() { InitializeComponent(); }

        private void LoadBtn_Click(object sender, EventArgs e)
        {
            // Add http to url if it's not already there
            URL = urlBx.Text;
            if (!URL.Contains("http")) { URL = "http://" + URL; urlBx.Text = URL; }

            // Load /up/configuration of the dynmap
            try
            {
                using (var wc = new WebClient())
                {
                    var cont = wc.DownloadString(Url.Combine(URL, "/up/configuration"));
                    Config = JsonConvert.DeserializeObject<DynmapConfig>(cont);
                }
            } 
            catch (Exception ex)
            {
                MessageBox.Show("Either that url doesn't exist or it's not a dynmap.\n\n" + ex.Message, 
                    "Failed to load map configuration.", MessageBoxButtons.OK);
                return;
            }

            // Populate list box component on the form so that user can select which one they want
            mapList.Items.Clear();
            foreach (var w in Config.Worlds)
            {
                foreach (var m in w.Maps)
                {
                    mapList.Items.Add($"{w.Name}/{m.Name}");
                }
            }
            mapList.SelectedIndex = 0;
            Console.WriteLine("Loaded map config.");
        }

        // Every time a change is made to the coordinates inputed, show a preview
        private void MapList_SelectedIndexChanged(object _, EventArgs _2) { UpdatePreview(); }
        private void Coordinate_ValueChanged(object _, EventArgs _2) { UpdatePreview(); }
        public void UpdatePreview()
        {
            Console.WriteLine("Updated preview.");
            var selected = mapList.SelectedIndex;
            if (selected == -1) { downloadBtn.Enabled = false; goto failed; }
            downloadBtn.Enabled = true;

            var sel = mapList.SelectedItem.ToString().Split('/');
            var world = sel[0];
            var mapName = sel[1];
            var map = Config.Worlds.First(w => w.Name == world).Maps.First(m => m.Name == mapName);


            var minX = (float)Math.Min(x1Bx.Value, x2Bx.Value);
            var maxX = (float)Math.Max(x1Bx.Value, x2Bx.Value);
            var minZ = (float)Math.Min(z1Bx.Value, z2Bx.Value);
            var maxZ = (float)Math.Max(z1Bx.Value, z2Bx.Value);

            var tileMinX = (int)((minX * map.PixelsPerBlock) / 128);
            var tileMaxX = (int)((maxX * map.PixelsPerBlock) / 128);
            var tileMinZ = (int)((minZ * map.PixelsPerBlock) / 128);
            var tileMaxZ = (int)((maxZ * map.PixelsPerBlock) / 128);

            previewTL.Image = GetTile(tileMinX, tileMinZ, world, map.Prefix);
            previewTR.Image = GetTile(tileMaxX, tileMinZ, world, map.Prefix);
            previewBR.Image = GetTile(tileMaxX, tileMaxZ, world, map.Prefix);
            previewBL.Image = GetTile(tileMinX, tileMaxZ, world, map.Prefix);

            return;
            failed:;
            previewBL.Image = null;
            previewBR.Image = null;
            previewTL.Image = null;
            previewTR.Image = null;
            return;
        }

        // Get's a specified tile coordinate image
        public Bitmap GetTile(int x, int z, string world, string mapPrefix)
        {
            z = -z;
            try
            {
                var url = Url.Combine(URL, $"/tiles/{world}/{mapPrefix}/{x >> 5}_{z >> 5}/{x}_{z}.png");
                return new Bitmap(WebRequest.Create(url).GetResponse().GetResponseStream());
            }
            catch (Exception e)
            {
                MessageBox.Show("Failed to fetch tile: \n\n" + e.Message + "\n\n" + e.StackTrace);
                return null;
            }
        }

        // This is for showing/hiding the console while downloading is happening
        [DllImport("kernel32.dll", ExactSpelling = true)]
        public static extern IntPtr GetConsoleWindow();
        [DllImport("user32.dll")]
        [return: MarshalAs(UnmanagedType.Bool)]
        public static extern bool SetForegroundWindow(IntPtr hWnd);

        // Begin a tile range download
        private void DownloadBtn_Click(object sender, EventArgs e)
        {
            // Hide the form and show the console
            Hide();
            SetForegroundWindow(GetConsoleWindow());
            Console.WriteLine("Starting...");

            // User picks location to save final exported image
            var saveToPath = "";
            var dia = new SaveFileDialog()
            {
                Filter = "PNG Image | *.png",
                DefaultExt = "PNG",
                FileName = "exportedMap.png",
            };
            if (dia.ShowDialog() == DialogResult.OK)
            {
                saveToPath = dia.FileName;
            }
            else { Show(); return; }

            // Get the selected map's info
            var selected = mapList.SelectedIndex;
            if (selected == -1) { return; }

            var sel = mapList.SelectedItem.ToString().Split('/');
            var world = sel[0];
            var mapName = sel[1];
            var map = Config.Worlds.First(w => w.Name == world).Maps.First(m => m.Name == mapName);

            // Get the user-inputed world-coordinate range
            var minX = (float)Math.Min(x1Bx.Value, x2Bx.Value);
            var maxX = (float)Math.Max(x1Bx.Value, x2Bx.Value);
            var minZ = (float)Math.Min(z1Bx.Value, z2Bx.Value);
            var maxZ = (float)Math.Max(z1Bx.Value, z2Bx.Value);

            // Convert world coordinates to tile coordinates.
            // "PixelsPerBlock" is just the map's 'scale' property.
            var tileMinX = (int)((minX * map.PixelsPerBlock) / 128);
            var tileMaxX = (int)((maxX * map.PixelsPerBlock) / 128);
            var tileMinZ = (int)((minZ * map.PixelsPerBlock) / 128);
            var tileMaxZ = (int)((maxZ * map.PixelsPerBlock) / 128);

            // Create bitmap to export
            Bitmap final;
            Graphics g;
            var size = (128 * (tileMaxX - tileMinX), 128 * (tileMaxZ - tileMinZ)); // This is the final image size
            try
            {
                final = new Bitmap(size.Item1, size.Item2);
                g = Graphics.FromImage(final);
            }
            catch
            { // This error happens when the user creates an export too large, generally a memory error
                MessageBox.Show($"Failed to create final bitmap. You probably have a " +
                    $"selection that's too large.\n\nAttempted image size: {size.Item1}, {size.Item2}");
                Show();
                return;
            }

            var totalTiles = (tileMaxX - tileMinX) * (tileMaxZ - tileMinZ);

            var tiles = new Dictionary<(int, int), Bitmap>();

            // Download all the tiles in the range, and save them to the to-export image
            Console.WriteLine("Beginning download...");
            var start = DateTime.Now;
            var i = 0;
            for (var x = tileMinX; x <= tileMaxX; x++)
            {
                Parallel.For(tileMinZ, tileMaxZ + 1, new ParallelOptions() { MaxDegreeOfParallelism = 16 }, z =>
                {
                    tiles.Add((x, z), GetTile(x, z, world, map.Prefix));
                    i++;
                    if (i % 100 == 0)
                    {
                        var elapsed = DateTime.Now - start;
                        var ticksPerTile = elapsed.Ticks / i;
                        var endEstimate = ticksPerTile * (totalTiles - i) / 10000000L;
                        Console.WriteLine($"{i}/{totalTiles} - {endEstimate} seconds remaining");
                    }
                });
            }

            Console.WriteLine("Download complete, creating final image...");
            foreach (var p in tiles)
            {
                if (p.Value is null) { continue; }
                g.DrawImage(p.Value, (p.Key.Item1 - tileMinX) * 128, (p.Key.Item2 - tileMinZ) * 128);
            }

            Console.WriteLine("Exporting to `" + saveToPath + "`...");
            final.Save(saveToPath);

            Console.WriteLine("Done!");
            Show();
        }
    }
}