From 12b15812f294907c5aa9b2616087817e400c7869 Mon Sep 17 00:00:00 2001
From: TuxSH <1922548+TuxSH@users.noreply.github.com>
Date: Wed, 30 Jul 2025 12:53:46 +0200
Subject: [PATCH] rosalina: make sure pixel data is aligned in screenshots

---
 sysmodules/rosalina/source/draw.c  | 12 ++++++++----
 sysmodules/rosalina/source/menus.c |  5 +++--
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/sysmodules/rosalina/source/draw.c b/sysmodules/rosalina/source/draw.c
index 84d8d811..ed1d9982 100644
--- a/sysmodules/rosalina/source/draw.c
+++ b/sysmodules/rosalina/source/draw.c
@@ -268,14 +268,18 @@ static inline void Draw_WriteUnaligned(u8 *dst, u32 tmp, u32 size)
 void Draw_CreateBitmapHeader(u8 *dst, u32 width, u32 heigth)
 {
     static const u8 bmpHeaderTemplate[54] = {
-        0x42, 0x4D, 0xCC, 0xCC, 0xCC, 0xCC, 0x00, 0x00, 0x00, 0x00, 0x36, 0x00, 0x00, 0x00, 0x28, 0x00,
-        0x00, 0x00, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0x01, 0x00, 0x18, 0x00, 0x00, 0x00,
-        0x00, 0x00, 0xCC, 0xCC, 0xCC, 0xCC, 0x12, 0x0B, 0x00, 0x00, 0x12, 0x0B, 0x00, 0x00, 0x00, 0x00,
+        // BITMAPFILEHEADER
+        0x42, 0x4D, 0xCC, 0xCC, 0xCC, 0xCC, 0x00, 0x00, 0x00, 0x00, 0x40 /* data offset */, 0x00, 0x00, 0x00,
+
+        // BITMAPINFOHEADER
+        0x28, 0x00, 0x00, 0x00, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0x01, 0x00, 0x18, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0xCC, 0xCC, 0xCC, 0xCC, 0x12, 0x0B, 0x00, 0x00, 0x12, 0x0B, 0x00, 0x00, 0x00, 0x00,
         0x00, 0x00, 0x00, 0x00, 0x00, 0x00
     };
 
     memcpy(dst, bmpHeaderTemplate, 54);
-    Draw_WriteUnaligned(dst + 2, 54 + 3 * width * heigth, 4);
+    memset(dst + 54, 0, 64 - 54);
+    Draw_WriteUnaligned(dst + 2, 64 + 3 * width * heigth, 4);
     Draw_WriteUnaligned(dst + 0x12, width, 4);
     Draw_WriteUnaligned(dst + 0x16, heigth, 4);
     Draw_WriteUnaligned(dst + 0x22, 3 * width * heigth, 4);
diff --git a/sysmodules/rosalina/source/menus.c b/sysmodules/rosalina/source/menus.c
index 569cf22d..4f45492d 100644
--- a/sysmodules/rosalina/source/menus.c
+++ b/sysmodules/rosalina/source/menus.c
@@ -273,7 +273,8 @@ static Result RosalinaMenu_WriteScreenshot(IFile *file, u32 width, bool top, boo
 
     u8 *buf = framebufferCache;
     Draw_CreateBitmapHeader(framebufferCache, width, numLinesScaled);
-    buf += 54;
+    const u32 headerSize = 0x40;
+    buf += headerSize;
 
     u32 y = 0;
     // Our buffer might be smaller than the size of the screenshot...
@@ -287,7 +288,7 @@ static Result RosalinaMenu_WriteScreenshot(IFile *file, u32 width, bool top, boo
 
         s64 t1 = svcGetSystemTick();
         timeSpentConvertingScreenshot += t1 - t0;
-        TRY(IFile_Write(file, &total, framebufferCache, (y == 0 ? 54 : 0) + lineSize * nlines * scaleFactorY, 0)); // don't forget to write the header
+        TRY(IFile_Write(file, &total, framebufferCache, (y == 0 ? headerSize : 0) + lineSize * nlines * scaleFactorY, 0)); // don't forget to write the header
         timeSpentWritingScreenshot += svcGetSystemTick() - t1;
 
         y += nlines;