# HG changeset patch
# User Robert McIntyre <rlm@mit.edu>
# Date 1331199684 21600
# Node ID c88ad4f6d9b4338e61250988403909e78661709d
# Parent  39928bf4622d3d933c540c5d2b79aa311881266a
can now write proper vbm files from clojure

diff -r 39928bf4622d -r c88ad4f6d9b4 clojure/com/aurellem/vbm.clj
--- a/clojure/com/aurellem/vbm.clj	Thu Mar 08 02:47:09 2012 -0600
+++ b/clojure/com/aurellem/vbm.clj	Thu Mar 08 03:41:24 2012 -0600
@@ -15,9 +15,9 @@
 
 (defn repair-vbm
   "Two 0's must be inserted after every reset."
-  [vbm-seq]
+  [vbm-masks]
   (loop [fixed []
-         pending vbm-seq]
+         pending vbm-masks]
     (if (empty? pending) fixed
         (let [mask (first pending)]
           (if (not= 0x0000 (bit-and mask (button-code :reset)))
@@ -38,7 +38,58 @@
   (reset)
   (dorun (map step (vbm-masks vbm))))
 
+(defn convert-buttons
+  "To write a vbm file, we must remove the last two buttons after any
+   reset event."
+  [buttons]
+  (loop [fixed []
+         pending buttons]
+    (if (empty? pending) fixed
+        (let [mask (first pending)]
+          (if (contains? (first pending) :reset)
+            (recur (conj fixed mask) (drop 3 pending))
+            (recur (conj fixed mask) (next pending)))))))
 
+(def vbm-header
+  (byte-array
+   (map
+    byte
+    [86 66 77 26 1 0 0 0 105 74 88 79 89 1 0 0 0 0 0 0 0 1 2 112 0 0 0
+     0 0 0 0 0 1 0 0 0 80 79 75 69 77 79 78 32 89 69 76 76 1 -105 124 4
+     3 0 0 0 0 0 0 0 0 1 0 0 95 95 95 95 95 95 95 95 95 95 95 95 95 95
+     95 95 82 111 98 101 114 116 32 32 77 99 73 110 116 121 114 101 95
+     95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95
+     95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95
+     95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95
+     95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95
+     95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95
+     95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95
+     95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95 95
+     95 95 95 95])))
+
+(def vbm-trailer
+  (byte-array
+   (map byte [0])))
+
+(defn buttons->vbm-bytes [buttons]
+  (let [bytes-in-ints
+        (map button-mask (convert-buttons buttons))
+        high-bits (map #(bit-shift-right (bit-and 0xFF00 %) 8)
+                       bytes-in-ints)
+        low-bits (map #(bit-and 0xFF %) bytes-in-ints)
+        convert-byte (fn [i] (byte (if (>= i 128) (- i 256) i)))
+        contents
+        (byte-array
+         (concat
+          vbm-header
+          (map convert-byte (interleave high-bits low-bits))
+          vbm-trailer))]
+    contents))
+        
+(defn write-vbm [buttons #^File out]
+  (clojure.java.io/copy (buttons->vbm-bytes buttons) out))
+    
+  
          
     
   
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