move asset dir functions to another file

and get them out of the engine

src/engine/assetDir.cpp

@@ -0,0 +1,152 @@
+/**
+ * Furnace Tracker - multi-system chiptune tracker
+ * Copyright (C) 2021-2025 tildearrow and contributors
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "assetDir.h"
+#include "../ta-log.h"
+
+void moveAsset(std::vector<DivAssetDir>& dir, int before, int after) {
+  if (before<0 || after<0) return;
+  for (DivAssetDir& i: dir) {
+    for (size_t j=0; j<i.entries.size(); j++) {
+      // erase matching entry
+      if (i.entries[j]==before) {
+        i.entries[j]=after;
+      } else if (i.entries[j]==after) {
+        i.entries[j]=before;
+      }
+    }
+  }
+}
+
+void removeAsset(std::vector<DivAssetDir>& dir, int entry) {
+  if (entry<0) return;
+  for (DivAssetDir& i: dir) {
+    for (size_t j=0; j<i.entries.size(); j++) {
+      // erase matching entry
+      if (i.entries[j]==entry) {
+        i.entries.erase(i.entries.begin()+j);
+        j--;
+      } else if (i.entries[j]>entry) {
+        i.entries[j]--;
+      }
+    }
+  }
+}
+
+void checkAssetDir(std::vector<DivAssetDir>& dir, size_t entries) {
+  bool* inAssetDir=new bool[entries];
+  memset(inAssetDir,0,entries*sizeof(bool));
+
+  for (DivAssetDir& i: dir) {
+    for (size_t j=0; j<i.entries.size(); j++) {
+      // erase invalid entry
+      if (i.entries[j]<0 || i.entries[j]>=(int)entries) {
+        i.entries.erase(i.entries.begin()+j);
+        j--;
+        continue;
+      }
+
+      // erase duplicate entry
+      if (inAssetDir[i.entries[j]]) {
+        i.entries.erase(i.entries.begin()+j);
+        j--;
+        continue;
+      }
+      
+      // mark entry as present
+      inAssetDir[i.entries[j]]=true;
+    }
+  }
+
+  // get unsorted directory
+  DivAssetDir* unsortedDir=NULL;
+  for (DivAssetDir& i: dir) {
+    if (i.name.empty()) {
+      unsortedDir=&i;
+      break;
+    }
+  }
+
+  // add missing items to unsorted directory
+  for (size_t i=0; i<entries; i++) {
+    if (!inAssetDir[i]) {
+      // create unsorted directory if it doesn't exist
+      if (unsortedDir==NULL) {
+        dir.push_back(DivAssetDir(""));
+        unsortedDir=&(*dir.rbegin());
+      }
+      unsortedDir->entries.push_back(i);
+    }
+  }
+
+  delete[] inAssetDir;
+}
+
+void putAssetDirData(SafeWriter* w, std::vector<DivAssetDir>& dir) {
+  size_t blockStartSeek, blockEndSeek;
+
+  w->write("ADIR",4);
+  blockStartSeek=w->tell();
+  w->writeI(0);
+
+  w->writeI(dir.size());
+
+  for (DivAssetDir& i: dir) {
+    w->writeString(i.name,false);
+    w->writeS(i.entries.size());
+    for (int j: i.entries) {
+      w->writeC(j);
+    }
+  }
+
+  blockEndSeek=w->tell();
+  w->seek(blockStartSeek,SEEK_SET);
+  w->writeI(blockEndSeek-blockStartSeek-4);
+  w->seek(0,SEEK_END);
+}
+
+DivDataErrors readAssetDirData(SafeReader& reader, std::vector<DivAssetDir>& dir) {
+  char magic[4];
+  reader.read(magic,4);
+  if (memcmp(magic,"ADIR",4)!=0) {
+    logV("header is invalid: %c%c%c%c",magic[0],magic[1],magic[2],magic[3]);
+    return DIV_DATA_INVALID_HEADER;
+  }
+  reader.readI(); // reserved
+
+  unsigned int numDirs=reader.readI();
+
+  dir.reserve(numDirs);
+  for (unsigned int i=0; i<numDirs; i++) {
+    DivAssetDir d;
+
+    d.name=reader.readString();
+    unsigned short numEntries=reader.readS();
+
+    d.entries.reserve(numEntries);
+    for (unsigned short j=0; j<numEntries; j++) {
+      d.entries.push_back(((unsigned char)reader.readC()));
+    }
+
+    dir.push_back(d);
+  }
+
+  return DIV_DATA_SUCCESS;
+}
+