From a845f03686cfb7df5d892a54d3af32fdcb7c5eed Mon Sep 17 00:00:00 2001
From: Gericom <fnouwt2@gmail.com>
Date: Sat, 27 Jun 2026 14:51:40 +0200
Subject: [PATCH] DSi banners with missing DSi part now fall back to the DS
 icon (Fixes #70)

---
 CHANGELOG.md                                  |  4 ++
 .../romBrowser/FileType/Nds/NdsFileIcon.cpp   | 38 ++++++++++++++++++-
 2 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4e65f35..f9fc9fe 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Fixed
+- Top screen cover is now displayed/hidden correctly when placed partially or fully off-screen
+- DSi banners with missing DSi part now fall back to the DS icon
+
 ## [v1.3.0] - 18 Apr 2026
 
 ### Added
diff --git a/arm9/source/romBrowser/FileType/Nds/NdsFileIcon.cpp b/arm9/source/romBrowser/FileType/Nds/NdsFileIcon.cpp
index 2126d67..326026f 100644
--- a/arm9/source/romBrowser/FileType/Nds/NdsFileIcon.cpp
+++ b/arm9/source/romBrowser/FileType/Nds/NdsFileIcon.cpp
@@ -7,12 +7,48 @@
 #include "gui/palette/DirectPalette.h"
 #include "NdsFileIcon.h"
 
+static uint16_t sCrc16Table[] =
+{
+    0x0000, 0xC0C1, 0xC181, 0x0140, 0xC301, 0x03C0, 0x0280, 0xC241, 0xC601, 0x06C0, 0x0780, 0xC741, 0x0500,
+    0xC5C1, 0xC481, 0x0440, 0xCC01, 0x0CC0, 0x0D80, 0xCD41, 0x0F00, 0xCFC1, 0xCE81, 0x0E40, 0x0A00, 0xCAC1,
+    0xCB81, 0x0B40, 0xC901, 0x09C0, 0x0880, 0xC841, 0xD801, 0x18C0, 0x1980, 0xD941, 0x1B00, 0xDBC1, 0xDA81,
+    0x1A40, 0x1E00, 0xDEC1, 0xDF81, 0x1F40, 0xDD01, 0x1DC0, 0x1C80, 0xDC41, 0x1400, 0xD4C1, 0xD581, 0x1540,
+    0xD701, 0x17C0, 0x1680, 0xD641, 0xD201, 0x12C0, 0x1380, 0xD341, 0x1100, 0xD1C1, 0xD081, 0x1040, 0xF001,
+    0x30C0, 0x3180, 0xF141, 0x3300, 0xF3C1, 0xF281, 0x3240, 0x3600, 0xF6C1, 0xF781, 0x3740, 0xF501, 0x35C0,
+    0x3480, 0xF441, 0x3C00, 0xFCC1, 0xFD81, 0x3D40, 0xFF01, 0x3FC0, 0x3E80, 0xFE41, 0xFA01, 0x3AC0, 0x3B80,
+    0xFB41, 0x3900, 0xF9C1, 0xF881, 0x3840, 0x2800, 0xE8C1, 0xE981, 0x2940, 0xEB01, 0x2BC0, 0x2A80, 0xEA41,
+    0xEE01, 0x2EC0, 0x2F80, 0xEF41, 0x2D00, 0xEDC1, 0xEC81, 0x2C40, 0xE401, 0x24C0, 0x2580, 0xE541, 0x2700,
+    0xE7C1, 0xE681, 0x2640, 0x2200, 0xE2C1, 0xE381, 0x2340, 0xE101, 0x21C0, 0x2080, 0xE041, 0xA001, 0x60C0,
+    0x6180, 0xA141, 0x6300, 0xA3C1, 0xA281, 0x6240, 0x6600, 0xA6C1, 0xA781, 0x6740, 0xA501, 0x65C0, 0x6480,
+    0xA441, 0x6C00, 0xACC1, 0xAD81, 0x6D40, 0xAF01, 0x6FC0, 0x6E80, 0xAE41, 0xAA01, 0x6AC0, 0x6B80, 0xAB41,
+    0x6900, 0xA9C1, 0xA881, 0x6840, 0x7800, 0xB8C1, 0xB981, 0x7940, 0xBB01, 0x7BC0, 0x7A80, 0xBA41, 0xBE01,
+    0x7EC0, 0x7F80, 0xBF41, 0x7D00, 0xBDC1, 0xBC81, 0x7C40, 0xB401, 0x74C0, 0x7580, 0xB541, 0x7700, 0xB7C1,
+    0xB681, 0x7640, 0x7200, 0xB2C1, 0xB381, 0x7340, 0xB101, 0x71C0, 0x7080, 0xB041, 0x5000, 0x90C1, 0x9181,
+    0x5140, 0x9301, 0x53C0, 0x5280, 0x9241, 0x9601, 0x56C0, 0x5780, 0x9741, 0x5500, 0x95C1, 0x9481, 0x5440,
+    0x9C01, 0x5CC0, 0x5D80, 0x9D41, 0x5F00, 0x9FC1, 0x9E81, 0x5E40, 0x5A00, 0x9AC1, 0x9B81, 0x5B40, 0x9901,
+    0x59C0, 0x5880, 0x9841, 0x8801, 0x48C0, 0x4980, 0x8941, 0x4B00, 0x8BC1, 0x8A81, 0x4A40, 0x4E00, 0x8EC1,
+    0x8F81, 0x4F40, 0x8D01, 0x4DC0, 0x4C80, 0x8C41, 0x4400, 0x84C1, 0x8581, 0x4540, 0x8701, 0x47C0, 0x4680,
+    0x8641, 0x8201, 0x42C0, 0x4380, 0x8341, 0x4100, 0x81C1, 0x8081, 0x4040
+};
+
+static u16 getCrc16(const void* data, u32 length)
+{
+    u16 result = 0xFFFF;
+    for (u32 i = 0; i < length; i++)
+    {
+        result = (result >> 8) ^ sCrc16Table[(result ^ ((u8*)data)[i]) & 0xFF];
+    }
+
+    return result;
+}
+
 NdsFileIcon::NdsFileIcon(const nds_banner_t* banner)
     : _banner(banner), _animTokenIdx(0), _lastAnimToken(0)
     , _animLength(0), _loop(false)
 {
     _animated = _banner->header.version >= NDS_BANNER_VERSION_103
-             && _banner->animation.animTokens[0].duration != 0;
+             && _banner->animation.animTokens[0].duration != 0
+             && getCrc16(&_banner->animation, sizeof(_banner->animation)) == _banner->header.version103AnimCrc;
     if (_animated)
     {
         _lastAnimToken = NDS_BANNER_ANIM_TOKEN_COUNT - 1;