From e68b7a5edeb2f6c1a4830d90d5b54a8140afcea3 Mon Sep 17 00:00:00 2001
From: morkt <morkt@users.noreply.github.com>
Date: Thu, 7 Sep 2023 12:32:52 +0400
Subject: [PATCH] (BMP): inverted alpha channel.

commented out for now, as there's no way to correctly recognize it.
---
 GameRes/ImageBMP.cs | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/GameRes/ImageBMP.cs b/GameRes/ImageBMP.cs
index 9c8af046..8ee0c054 100644
--- a/GameRes/ImageBMP.cs
+++ b/GameRes/ImageBMP.cs
@@ -220,6 +220,13 @@ namespace GameRes
                 file.Read (pixels, dst, stride);
                 for (int x = 3; !has_alpha && x < stride; x += 4)
                     has_alpha = pixels[dst+x] != 0;
+                /* // sometimes alpha channel is inverted
+                for (int x = 3; x < stride; x += 4)
+                {
+                    pixels[dst+x] ^= 0xFF;
+                    has_alpha = has_alpha || pixels[dst+x] != 0;
+                }
+                */
             }
             PixelFormat format = has_alpha ? PixelFormats.Bgra32 : PixelFormats.Bgr32;
             return ImageData.Create (info, format, null, pixels, stride);