Further midi file support.

src/audio/midi/MidiEvent.cpp

@@ -1,6 +1,37 @@
 #include "MidiEvent.h"
 
 MidiEvent::MidiEvent()
+    : mTimeDelta(0)
 {
 
 }
+
+void MidiEvent::SetTimeDelta(int delta)
+{
+    mTimeDelta = delta;
+}
+
+std::shared_ptr<MidiEvent> MidiEvent::Create()
+{
+    return std::make_shared<MidiEvent>();
+}
+
+bool MidiEvent::IsMetaEvent(char c)
+{
+    return (c & META_EVENT) == META_EVENT;
+}
+
+bool MidiEvent::IsSysExEvent(char c)
+{
+    return IsNormalSysExEvent(c) || IsDividedSysExEvent(c);
+}
+
+bool MidiEvent::IsNormalSysExEvent(char c)
+{
+    return (c & SYSEX_EVENT) == SYSEX_EVENT;
+}
+
+bool MidiEvent::IsDividedSysExEvent(char c)
+{
+    return (c & DIVIDED_SYSEX_EVENT) == DIVIDED_SYSEX_EVENT;
+}