Moves demo to Examples folder

Assets/Examples/ImageSlideshow/Frame/SlideshowFrame.cs

@@ -0,0 +1,118 @@
+using UdonSharp;
+using UnityEngine;
+using UnityEngine.UI;
+using VRC.SDK3.Image;
+using VRC.SDK3.StringLoading;
+using VRC.SDKBase;
+using VRC.Udon.Common.Interfaces;
+
+[UdonBehaviourSyncMode(BehaviourSyncMode.None)]
+public class SlideshowFrame : UdonSharpBehaviour
+{
+    [SerializeField, Tooltip("URLs of images to load")]
+    private VRCUrl[] imageUrls;
+    
+    [SerializeField, Tooltip("URL of text file containing captions for images, one caption per line.")]
+    private VRCUrl stringUrl;
+    
+    [SerializeField, Tooltip("Renderer to show downloaded images on.")]
+    private new Renderer renderer;
+    
+    [SerializeField, Tooltip("Text field for captions.")]
+    private Text field;
+    
+    [SerializeField, Tooltip("Duration in seconds until the next image is shown.")]
+    private float slideDurationSeconds = 10f;
+    
+    private int _loadedIndex = -1;
+    private VRCImageDownloader _imageDownloader;
+    private IUdonEventReceiver _udonEventReceiver;
+    private string[] _captions = new string[0];
+    private Texture2D[] _downloadedTextures;
+    
+    private void Start()
+    {
+        // Downloaded textures will be cached in a texture array.
+        _downloadedTextures = new Texture2D[imageUrls.Length];
+        
+        // It's important to store the VRCImageDownloader as a variable, to stop it from being garbage collected!
+        _imageDownloader = new VRCImageDownloader();
+        
+        // To receive Image and String loading events, 'this' is casted to the type needed
+        _udonEventReceiver = (IUdonEventReceiver)this;
+        
+        // Captions are downloaded once. On success, OnImageLoadSuccess() will be called.
+        VRCStringDownloader.LoadUrl(stringUrl, _udonEventReceiver);
+        
+        // Load the next image. Then do it again, and again, and...
+        LoadNextRecursive();
+    }
+
+    public void LoadNextRecursive()
+    {
+        LoadNext();
+        SendCustomEventDelayedSeconds(nameof(LoadNextRecursive), slideDurationSeconds);
+    }
+    
+    private void LoadNext()
+    {
+        // All clients share the same server time. That's used to sync the currently displayed image.
+        _loadedIndex = (int)(Networking.GetServerTimeInMilliseconds() / 1000f / slideDurationSeconds) % imageUrls.Length;
+
+        var nextTexture = _downloadedTextures[_loadedIndex];
+        
+        if (nextTexture != null)
+        {
+            // Image already downloaded! No need to download it again.
+            renderer.sharedMaterial.mainTexture = nextTexture;
+        }
+        else
+        {
+            var rgbInfo = new TextureInfo();
+            rgbInfo.GenerateMipMaps = true;
+            _imageDownloader.DownloadImage(imageUrls[_loadedIndex], renderer.material, _udonEventReceiver, rgbInfo);
+        }
+        
+        UpdateCaptionText();
+    }
+
+    private void UpdateCaptionText()
+    {
+        if (_loadedIndex < _captions.Length)
+        {
+            field.text = _captions[_loadedIndex];
+        }
+        else
+        {
+            field.text = "";
+        }
+    }
+
+    public override void OnStringLoadSuccess(IVRCStringDownload result)
+    {
+        _captions = result.Result.Split('\n');
+        UpdateCaptionText();
+    }
+
+    public override void OnStringLoadError(IVRCStringDownload result)
+    {
+        Debug.LogError($"Could not load string {result.Error}");
+    }
+
+    public override void OnImageLoadSuccess(IVRCImageDownload result)
+    {
+        Debug.Log($"Image loaded: {result.SizeInMemoryBytes} bytes.");
+        
+        _downloadedTextures[_loadedIndex] = result.Result;
+    }
+
+    public override void OnImageLoadError(IVRCImageDownload result)
+    {
+        Debug.Log($"Image not loaded: {result.Error.ToString()}: {result.ErrorMessage}.");
+    }
+
+    private void OnDestroy()
+    {
+        _imageDownloader.Dispose();
+    }
+}