improve premultiplication performance

2 files changed, 4 insertions, 2 deletions

diff --git a/docs/release-notes.md b/docs/release-notes.md
index 55339d57..6c9a9649 100644
--- a/docs/release-notes.md
+++ b/docs/release-notes.md
@@ -7,6 +7,7 @@
   * MacOS files starting with `._` are now ignored and can no longer cause skipped mods.
   * Simplified paranoid warning logs and reduced their log level.
   * Reduced startup time when loading mod DLLs (thanks to ZaneYork!).
+  * Reduced processing time when a mod loads many unpacked images (thanks to Entoarox!).
   * Fixed `BadImageFormatException` error detection.
   * Fixed black maps on Android for mods which use `.tmx` files.
 
diff --git a/src/SMAPI/Framework/ContentManagers/ModContentManager.cs b/src/SMAPI/Framework/ContentManagers/ModContentManager.cs
index fda80a83..cfda55b9 100644
--- a/src/SMAPI/Framework/ContentManagers/ModContentManager.cs
+++ b/src/SMAPI/Framework/ContentManagers/ModContentManager.cs
@@ -246,10 +246,11 @@ namespace StardewModdingAPI.Framework.ContentManagers
             texture.GetData(data);
             for (int i = 0; i < data.Length; i++)
             {
-                if (data[i].A == byte.MinValue || data[i].A == byte.MaxValue)
+                var pixel = data[i];
+                if (pixel.A == byte.MinValue || pixel.A == byte.MaxValue)
                     continue; // no need to change fully transparent/opaque pixels
 
-                data[i] = Color.FromNonPremultiplied(data[i].ToVector4());
+                 data[i] = new Color(pixel.R * pixel.A / byte.MaxValue, pixel.G * pixel.A / byte.MaxValue, pixel.B * pixel.A / byte.MaxValue, pixel.A); // slower version: Color.FromNonPremultiplied(data[i].ToVector4())
             }
 
             texture.SetData(data);