From c31a609399c2e05a50a5df8be10049903521c9e7 Mon Sep 17 00:00:00 2001
From: Tim Redfern <tim@gray.(none)>
Date: Thu, 1 Nov 2012 21:10:31 +0000
Subject: initial commit

---
 vfg/src/music.cpp | 91 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 91 insertions(+)
 create mode 100755 vfg/src/music.cpp

(limited to 'vfg/src/music.cpp')

diff --git a/vfg/src/music.cpp b/vfg/src/music.cpp
new file mode 100755
index 0000000..82e953e
--- /dev/null
+++ b/vfg/src/music.cpp
@@ -0,0 +1,91 @@
+#include "music.h"
+
+//event times & durations are absolute integer milliseconds
+
+note::note(int n,int v,int d){
+	num=n;
+	velocity=v;
+	duration=d;
+}
+void musicscore::parseMidi(string filename){
+	// millis = 60000 / (BPM * PPQ)
+	// BPM = 60000000 / MQPN (last 3 bytes of midi tempoSet)
+	// http://www.lastrayofhope.com/2009/12/23/midi-delta-time-ticks-to-seconds/
+	// presume no change in time signature?
+
+	//2 passes:: extract notes & set abs times, then scan for
+
+	float wt=ofGetElapsedTimef();
+
+	float BPM=120.0f;
+	//input:: MPQN :: default 500000
+	float MPQN=60000000.0f/BPM;
+	//unknown:: ticks per quarter note
+	int TPQN=96;
+	//want:: seconds per tick in float
+	float SPT =(MPQN/1000000.0f)/TPQN;
+
+	float time=0; //counts up in float seconds but converts to millis for map index
+
+	map<int,note*> events;
+
+	if( !XML.loadFile(filename) ){
+		printf("unable to load %s check data/ folder\n",filename.c_str());
+	}else{
+		if(XML.pushTag("MidiFile")) {
+			for (int i=0;i<XML.getNumTags("TrackChunk");i++) {
+				XML.pushTag("TrackChunk",i);
+					for (int i=0;i<XML.getNumTags("Event");i++) {
+						time+=(SPT*XML.getAttribute("Event", "DeltaTimeTicks",0,i));
+						if (XML.getAttribute("Event", "Label","",i)=="TempoSet") {
+							string data=XML.getAttribute("Event", "Data","",i);
+							char* endptr;
+							int d1=strtoul(data.substr(6,2).c_str(),&endptr,16);
+							int d2=strtoul(data.substr(9,2).c_str(),&endptr,16);
+							int d3=strtoul(data.substr(12,2).c_str(),&endptr,16);
+							int MPQN=(d1<<16)+(d2<<8)+d3;
+							SPT =(MPQN/1000000.0f)/TPQN;
+							//printf("Tempo change: seconds per tick now: %f\n",SPT);
+						}
+						if (XML.getAttribute("Event", "Label","",i)=="NoteOn"||XML.getAttribute("Event", "Label","",i)=="NoteOff") {
+							string data=XML.getAttribute("Event", "Data","",i);
+							char* endptr;
+							int d1=strtoul(data.substr(0,2).c_str(),&endptr,16);
+							int d2=strtoul(data.substr(3,2).c_str(),&endptr,16);
+							int id=strtoul(XML.getAttribute("Event", "Id","",i).c_str(),&endptr,16);
+							if (id==128||id==144) events[(int)(time*1000.0f)]=new note(d1,d2,id); //noteon/off
+						}
+					}
+				XML.popTag();
+			}
+
+		}
+		XML.popTag();
+	}
+	//iterate events and compute durations now the absolute times are established: extract to notes
+	map<int,note*>::iterator iter1;
+	map<int,note*>::iterator iter2;
+
+    for (iter1 = events.begin(); iter1 != events.end(); ++iter1) {
+        if (iter1->second->duration==144) {
+            iter1->second->duration=0;
+            iter2=iter1;
+            while (++iter2 != events.end()) {
+                if ((iter1->second->num==iter2->second->num)&&(iter2->second->duration==128)) {
+                    iter1->second->duration=iter2->first-iter1->first;
+                    notes[iter1->first]=iter1->second;
+                    //printf("%i: noteon %i %i\n",iter1->first,iter1->second->num,iter1->second->duration);
+                    break;
+                }
+            }
+        }
+    }
+    printf("processed %s: %i notes in %f seconds\n",filename.c_str(),notes.size(),ofGetElapsedTimef()-wt);
+}
+
+song::song(string backfile,string melfile,string notefile) {
+	backing.loadSound(backfile);
+	melody.loadSound(melfile);
+	notes.parseMidi(notefile);
+	bpm=bpm; //can be used to set tempo eventually? keeps everything simple to do it this way
+}
-- 
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