# HG changeset patch
# User Robert McIntyre <rlm@mit.edu>
# Date 1335174355 18000
# Node ID 7bd806c4dbb608cca06d028a4bec0f232fa6ad99
# Parent  971bd1774eab957857beeed74c1067dcc745dd66
changed assembly to handle mini-midi messages of different lengths.

diff -r 971bd1774eab -r 7bd806c4dbb6 clojure/com/aurellem/run/music.clj
--- a/clojure/com/aurellem/run/music.clj	Tue Apr 17 06:53:48 2012 -0500
+++ b/clojure/com/aurellem/run/music.clj	Mon Apr 23 04:45:55 2012 -0500
@@ -62,6 +62,44 @@
     (store (Integer/parseInt "00000000" 2) 0xFF22)
     (store (Integer/parseInt "00000000" 2) 0xFF23)]))
 
+
+;; mini-midi syntax
+
+;; codes
+;; note-code == 0x00
+;; change-duty-code = 0x01
+;; silence-code = 0x02
+
+;; silence format
+;;  2 bytes
+;;  [silence-code (0x02)]
+;;  [duration-8-bits]
+
+;; note data format
+;;  4 bytes
+;;  [note-code (0x00)]
+;;  [volume-4-bits 0 frequency-high-3-bits]
+;;  [frequengy-low-8-bits]
+;;  [duration-8-bits]
+
+;; change-duty-format
+;;  2 bytes
+;;  [change-duty-code (0x01)]
+;;  [new-duty]
+
+(defn do-message
+  "Read the message which starts at the current value of HL and do
+   what it says. Duration is left in A, and HL is advanced
+   appropraitely."
+  []
+
+  )
+
+
+
+
+
+
 (defn play-note
   "Play the note referenced by HL in the appropiate channel.
    Leaves desired-duration in A."
@@ -82,14 +120,12 @@
    0xE0
    0x18   ;; set frequency-low-bits
 
-   0x7E   ;; load duration
-   0x2B   ;; 
-   0x2B   ;; HL-2 -> HL
+   0x2A   ;; load duration
    ]) 
 
 (defn music-step []
   (flatten
-   [(play-note)
+   [
     0xF5 ;; push A
     0xF0
     0x05 ;; load current ticks
@@ -112,33 +148,13 @@
     ;;   go to next note ; set current set ticks to 0.
 
     0x20
-    0x05
+    (+ (count (play-note)) 2)
 
-    0x23
-    0x23
-    0x23 ;; HL + 3 -> HL
+    (play-note)
     
     0x0E
     0x00])) ;; 0->C (current-ticks)
 
-(defn test-timer []
-  (flatten
-   [0x3E
-    0x01
-    0xE0
-    0x06 ;; set TMA to 0
-    
-    0x3E
-    (Integer/parseInt "00000100" 2)
-    0xE0
-    0x07 ;; set TAC to 16384 Hz and activate timer
-    
-    (repeat
-     500
-     [0xF0
-      0x05])]))
-
-
 (defn music-kernel []
   (flatten
    [(clear-music-registers)
@@ -161,9 +177,10 @@
     0xE0
     0x07 ;; set TAC to 65536 Hz and activate timer
 
-    0xF0
-    0x07
-    
+
+    0xAF ;; initialiaze A to zero
+
+
     (music-step)
     0x18
     (->signed-8-bit (+ (- (count (music-step)))
@@ -188,8 +205,59 @@
    0xA6 0x55 0xFF
    0x00 0x00 0xFF
    ])
-   
-   
+
+(defn frequency-code->frequency
+  [code]
+  (assert (<= 0 code 2047))
+  (/ 131072 (- 2048 code)))
+
+(defn clamp [x low high]
+  (cond  (> x high) high
+         (< x low)  low
+         true x))
+
+(defn frequency->frequency-code
+  [frequency]
+  (clamp
+   (Math/round
+    (float
+     (/ (- (* 2048 frequency) 131072) frequency)))
+   0x00 2048))
+    
+(defn note-codes [frequency volume duration]
+  (assert (<= 0 volume 0xF))
+  (assert (<= 0 duration 0xFF))
+  (let [frequency-code
+        (frequency->frequency-code frequency)
+        volume&high-frequency
+        (+ (bit-shift-left volume 4)
+           (bit-shift-right frequency-code 8))
+        low-frequency
+        (bit-and 0xFF frequency-code)]
+    [volume&high-frequency
+     low-frequency
+     duration]))
+
+(def C4 (partial note-codes 261.63))
+(def D4 (partial note-codes 293.66))
+(def E4 (partial note-codes 329.63))
+(def F4 (partial note-codes 349.23))
+(def G4 (partial note-codes 392))
+(def A4 (partial note-codes 440))
+(def B4 (partial note-codes 493.88))
+(def C5 (partial note-codes 523.3))
+
+(def scale
+  (flatten
+   [(C4 0xF 0x40)
+    (D4 0xF 0x40)
+    (E4 0xF 0x40)
+    (F4 0xF 0x40)
+    (G4 0xF 0x40)
+    (A4 0xF 0x40)
+    (B4 0xF 0x40)
+    (C5 0xF 0x40)]))
+                 
 (defn play-music [music-bytes]
   (let [program-target 0xC000
         music-target 0xD000]
@@ -220,3 +288,19 @@
 (defn trippy []
   (run-moves (play-music many-notes ) (repeat 8000 [])))
 
+(defn test-timer []
+  (flatten
+   [0x3E
+    0x01
+    0xE0
+    0x06 ;; set TMA to 0
+    
+    0x3E
+    (Integer/parseInt "00000100" 2)
+    0xE0
+    0x07 ;; set TAC to 16384 Hz and activate timer
+    
+    (repeat
+     500
+     [0xF0
+      0x05])]))