lib: insert padding when listing objects too

Fixes a number of repacking issues with larger SI files

lib/interleaf.cpp

@@ -449,6 +449,13 @@ Interleaf::Error Interleaf::Write(FileBase *f) const
 
 void Interleaf::WriteObject(FileBase *f, const Object *o) const
 {
+  size_t projected_end = f->pos() + o->CalculateMaximumDiskSize();
+  size_t this_buf = f->pos()/m_BufferSize;
+  size_t end_buf = projected_end/m_BufferSize;
+  if (this_buf != end_buf) {
+    WritePadding(f, (end_buf * m_BufferSize) - f->pos());
+  }
+
   RIFF::Chk mxob = RIFF::BeginChunk(f, RIFF::MxOb);
 
   f->WriteU16(o->type_);

lib/object.cpp

@@ -277,6 +277,35 @@ size_t Object::GetFileBodySize() const
   return s;
 }
 
+size_t Object::CalculateMaximumDiskSize() const
+{
+  size_t s = 0;
+
+  s += 108;
+  s += presenter_.size() + 1;
+  s += name_.size() + 1;
+  s += extra_.size();
+
+  if (type_ != MxOb::Presenter && type_ != MxOb::World && type_ != MxOb::Animation) {
+    s += filename_.size() + 1;
+    s += 24;
+
+    if (filetype_ == MxOb::WAV) {
+      s += 4;
+    }
+  }
+
+  if (this->HasChildren()) {
+    s += 16;
+
+    for (size_t i = 0; i < this->GetChildCount(); i++) {
+      s += static_cast<Object*>(this->GetChildAt(i))->CalculateMaximumDiskSize();
+    }
+  }
+
+  return s;
+}
+
 Object *Object::FindSubObjectWithID(uint32_t id)
 {
   if (this->id() == id) {

lib/object.h

@@ -38,6 +38,8 @@ public:
   const std::string &filename() const { return filename_; }
   const ChunkedData &data() const { return data_; }
 
+  size_t CalculateMaximumDiskSize() const;
+
   Object *FindSubObjectWithID(uint32_t id);
 
   MxOb::Type type_;