From 8270bda7879ce9854afe5e8a36feb7b08e857d13 Mon Sep 17 00:00:00 2001
From: TheXamlGuy <dan_clark@outlook.com>
Date: Wed, 3 Jul 2024 09:15:37 +0100
Subject: [PATCH] Fixed a bug where we if the bitmap needs resizing and
 cropping, we need to seek the stream back to the begining

---
 Toolkit.Avalonia/ImageResizer.cs | 40 +++++++++++++-------------------
 1 file changed, 16 insertions(+), 24 deletions(-)

diff --git a/Toolkit.Avalonia/ImageResizer.cs b/Toolkit.Avalonia/ImageResizer.cs
index fbfcfdd..0a83456 100644
--- a/Toolkit.Avalonia/ImageResizer.cs
+++ b/Toolkit.Avalonia/ImageResizer.cs
@@ -6,52 +6,44 @@ namespace Toolkit.Avalonia;
 public class ImageResizer : 
     IImageResizer
 {
-    public Bitmap Resize(Stream stream,
-        int targetWidth,
-        int targetHeight,
-        bool maintainAspectRatio)
+    public Bitmap Resize(Stream stream, int targetWidth, int targetHeight, bool maintainAspectRatio)
     {
         Bitmap bitmap = new(stream);
 
         if (bitmap.Size.Width != targetWidth || bitmap.Size.Height != targetHeight)
         {
-            using SKBitmap sKBitmap = SKBitmap.Decode(stream);
-            SKBitmap? cropped = null;
-            bitmap.Dispose();
+            stream.Seek(0, SeekOrigin.Begin);
 
+            using SKBitmap sKBitmap = SKBitmap.Decode(stream);
             float widthRatio = (float)targetWidth / sKBitmap.Width;
             float heightRatio = (float)targetHeight / sKBitmap.Height;
-            float scale = maintainAspectRatio ? Math.Max(widthRatio, heightRatio) : Math.Min(widthRatio, heightRatio);
+            float scale = maintainAspectRatio ? Math.Min(widthRatio, heightRatio) : Math.Max(widthRatio, heightRatio);
 
             int newWidth = (int)(sKBitmap.Width * scale);
             int newHeight = (int)(sKBitmap.Height * scale);
 
-            using SKBitmap resized = new(newWidth, newHeight);
-            using SKCanvas canvas = new(resized);
-
-            canvas.Clear(SKColors.Transparent);
-            canvas.DrawBitmap(sKBitmap, new SKRect(0, 0, newWidth, newHeight));
+            using SKBitmap resized = sKBitmap.Resize(new SKImageInfo(newWidth, newHeight), SKFilterQuality.High);
 
+            SKBitmap cropped = resized;
             if (maintainAspectRatio)
             {
-                int cropX = (newWidth - targetWidth) / 2;
-                int cropY = (newHeight - targetHeight) / 2;
+                int cropX = (resized.Width - targetWidth) / 2;
+                int cropY = (resized.Height - targetHeight) / 2;
 
                 cropped = new SKBitmap(targetWidth, targetHeight);
-                using SKCanvas croppedCanvas = new(cropped);
-                SKRect cropRect = new(cropX, cropY, cropX + targetWidth, cropY + targetHeight);
-                croppedCanvas.Clear(SKColors.Transparent);
-                croppedCanvas.DrawBitmap(resized, cropRect, new SKRect(0, 0, targetWidth, targetHeight));
-            }
-            else
-            {
-                cropped = resized;
+                using (SKCanvas croppedCanvas = new(cropped))
+                {
+                    SKRect srcRect = new(cropX, cropY, cropX + targetWidth, cropY + targetHeight);
+                    SKRect destRect = new(0, 0, targetWidth, targetHeight);
+                    croppedCanvas.DrawBitmap(resized, srcRect, destRect);
+                }
             }
 
             using SKImage image = SKImage.FromBitmap(cropped);
-            using MemoryStream outputStream = new();
+            using MemoryStream outputStream = new MemoryStream();
             image.Encode(SKEncodedImageFormat.Png, 100).SaveTo(outputStream);
             outputStream.Seek(0, SeekOrigin.Begin);
+            bitmap.Dispose();
 
             return new Bitmap(outputStream);
         }