From 395ed3b7853b446fa77768786eae09b215731570 Mon Sep 17 00:00:00 2001
From: Holger Schemel <info@artsoft.org>
Date: Wed, 28 Feb 2024 16:08:06 +0100
Subject: [PATCH] added loading both level packages and single levels in BDCFF
 format

---
 src/files.c | 31 +++++++++++++++++++++++++++----
 1 file changed, 27 insertions(+), 4 deletions(-)

diff --git a/src/files.c b/src/files.c
index b1bbc43e..433f6813 100644
--- a/src/files.c
+++ b/src/files.c
@@ -2067,6 +2067,27 @@ static void ActivateLevelTemplate(void)
   }
 }
 
+static boolean checkForPackageFromBasename_BD(char *basename)
+{
+  // check for native BD level file extensions
+  if (!strSuffixLower(basename, ".bd") &&
+      !strSuffixLower(basename, ".bdr") &&
+      !strSuffixLower(basename, ".brc") &&
+      !strSuffixLower(basename, ".gds"))
+    return FALSE;
+
+  // check for standard single-level BD files (like "001.bd")
+  if (strSuffixLower(basename, ".bd") &&
+      strlen(basename) == 6 &&
+      basename[0] >= '0' && basename[0] <= '9' &&
+      basename[1] >= '0' && basename[1] <= '9' &&
+      basename[2] >= '0' && basename[2] <= '9')
+    return FALSE;
+
+  // this is a level package in native BD file format
+  return TRUE;
+}
+
 static char *getLevelFilenameFromBasename(char *basename)
 {
   static char *filename = NULL;
@@ -2102,10 +2123,7 @@ static int getFileTypeFromBasename(char *basename)
     return LEVEL_FILE_TYPE_SB;
 
   // check for typical filename of a Boulder Dash (GDash) level package file
-  if (strSuffixLower(basename, ".bd") ||
-      strSuffixLower(basename, ".bdr") ||
-      strSuffixLower(basename, ".brc") ||
-      strSuffixLower(basename, ".gds"))
+  if (checkForPackageFromBasename_BD(basename))
     return LEVEL_FILE_TYPE_BD;
 
   // ---------- try to determine file type from filesize ----------
@@ -2367,6 +2385,11 @@ static void determineLevelFileInfo_Filename(struct LevelFileInfo *lfi)
   if (fileExists(lfi->filename))
     return;
 
+  // check for native Boulder Dash level file
+  setLevelFileInfo_FormatLevelFilename(lfi, LEVEL_FILE_TYPE_BD, "%03d.bd", nr);
+  if (fileExists(lfi->filename))
+    return;
+
   // check for Emerald Mine level file (V1)
   setLevelFileInfo_FormatLevelFilename(lfi, LEVEL_FILE_TYPE_EM, "a%c%c",
 				       'a' + (nr / 10) % 26, '0' + nr % 10);
-- 
2.34.1