# HG changeset patch
# User Robert McIntyre <rlm@mit.edu>
# Date 1335379591 18000
# Node ID 067ea3f0d9514e3d9b05ebbd4e84e4da7f1b65b8
# Parent  20a9d5faf47cfed80b80923eecf1fd6db2ae3152
can now play midi files with two tracks.

diff -r 20a9d5faf47c -r 067ea3f0d951 clojure/com/aurellem/run/music.clj
--- a/clojure/com/aurellem/run/music.clj	Wed Apr 25 13:09:06 2012 -0500
+++ b/clojure/com/aurellem/run/music.clj	Wed Apr 25 13:46:31 2012 -0500
@@ -390,27 +390,29 @@
    :duration length
    :volume 0})
 
-(defn midi->mini-midi [#^File midi-file]
+(defn commands
+  "return all events where #(= (:command %) command)"
+  [command s]
+  (filter #(= command (:command %)) s))
+
+(defn midi-track->mini-midi [#^File midi-file track-num]
   (let [midi-events (parse-midi midi-file)
 
-        note-on-events
-        (filter #(= :Note_on_c (:command %)) midi-events)
-        note-off-events
-        (filter #(= :Note_off_c (:command %)) midi-events)
+        note-on-events  (commands :Note_on_c  midi-events)
+        note-off-events (commands :Note_off_c midi-events)
 
-        channel-1-on
-        (sort-by :time
-                 (filter #(= 1 (:channel (:args %)))
-                  note-on-events))
-        channel-1-off
-        (sort-by :time
-                 (filter #(= 1 (:channel (:args %)))
-                         note-off-events))
+        select-channel
+        (fn [n s]
+          (sort-by :time (filter #(= n (:channel (:args %))) s)))
+
+        channel-on (select-channel track-num note-on-events)
         
+        channel-off (select-channel track-num note-off-events)
         
-        tempo (:args (first (filter #(= :Tempo (:command %)) midi-events)))
-        division (:division
-                  (:args (first (filter #(= :Header (:command %)) midi-events))))
+        
+        tempo (:args (first (commands :Tempo midi-events)))
+        division
+        (:division (:args (first (commands :Header midi-events))))
 
         notes
         (map
@@ -423,7 +425,7 @@
             :volume (int (/ (:velocity (:args note-on)) 10))
             :time-stamp (/ (* (/ tempo division)
                               (:time note-on)) 1e6)})
-         channel-1-on channel-1-off)
+         channel-on channel-off)
 
         silences
         (map (fn [note-1 note-2]
@@ -437,9 +439,8 @@
              notes)
         
         notes-with-silence
-        (filter (comp not zero? :duration) (interleave silences notes))
-        ]
-
+        (filter (comp not zero? :duration)
+                (interleave silences notes))]
     (map
      (fn [note-event]
        (note-codes (:frequency note-event)
@@ -447,6 +448,27 @@
                    (int (* (:duration note-event) 0x100))))
      notes-with-silence)))
 
+(defn midi->mini-midi [#^File midi-file]
+  {:track-1 (flatten (midi-track->mini-midi midi-file 1))
+   :track-2 (flatten (midi-track->mini-midi midi-file 2))})
+
+(defn play-midi [#^File midi-file]
+  (let [track-1-target 0xA000
+        track-2-target 0xB000
+        program-target 0xC000
+        mini-midi (midi->mini-midi midi-file)
+        long-silence (flatten (note-codes 20 0 9001))]
+    
+    (-> (second (music-base))
+        (set-memory-range track-1-target long-silence)
+        (set-memory-range track-2-target long-silence)
+        (set-memory-range track-1-target (:track-1 mini-midi))
+        (set-memory-range track-2-target (:track-2 mini-midi))
+        (set-memory-range program-target (music-kernel))
+        (PC! program-target))))
+
+
+  
 
 (def C4 (partial note-codes 261.63))
 (def D4 (partial note-codes 293.66))
@@ -477,6 +499,7 @@
         (PC! program-target))))
 
 
+
 ;; (defn test-note [music-bytes]
 ;;   (-> (set-memory-range (second (music-base))
 ;;                         0xC000 (concat (clear-music-registers)