MxMIDIPresenter: add members to match size

CMakeLists.txt

@@ -123,6 +123,7 @@ add_library(lego1 SHARED
   LEGO1/mxloopingflcpresenter.cpp
   LEGO1/mxloopingsmkpresenter.cpp
   LEGO1/mxmediapresenter.cpp
+  LEGO1/mxmidipresenter.cpp
   LEGO1/mxmusicpresenter.cpp
   LEGO1/mxnotificationmanager.cpp
   LEGO1/mxomni.cpp

LEGO1/mxmidipresenter.cpp

@@ -0,0 +1,16 @@
+#include "mxmidipresenter.h"
+
+#include "decomp.h"
+
+DECOMP_STATIC_ASSERT(sizeof(MxMIDIPresenter) == 88);
+
+// OFFSET: LEGO1 0x100c25e0
+MxMIDIPresenter::MxMIDIPresenter() {
+  Init();
+}
+
+// OFFSET: LEGO1 0x100c2820
+void MxMIDIPresenter::Init()
+{
+  m_unk54 = 0;
+}

LEGO1/mxmidipresenter.h

@@ -6,6 +6,11 @@
 // VTABLE 0x100dca20
 class MxMIDIPresenter : public MxMusicPresenter
 {
+public:
+  MxMIDIPresenter();
+private:
+  void Init();
+  undefined4 m_unk54;
 };
 
 #endif // MXMIDIPRESENTER_H