Sequencer.beatsFromSamples added - preset tweaks to generateFileRefs in presetBuilder

Author: eljeff

AudioKit/Common/Nodes/Playback/Sampler/AKAUPresetBuilder.swift

@@ -467,7 +467,7 @@ public class AKAUPresetBuilder{
         templateStr.appendContentsOf("        <dict>\n")
         return templateStr
     }
-    static public func generateFileRef(wavRef:Int, samplePath:String)->String{
+    static public func generateFileRef(wavRef:Int = 268435457, samplePath:String)->String{
         var templateStr:String = ""
         templateStr.appendContentsOf("            <key>Sample:\(wavRef)</key>\n")
         templateStr.appendContentsOf("            <string>\(samplePath)</string>\n")

AudioKit/Common/Nodes/Playback/Sequencer/AKSequencer.swift

@@ -451,4 +451,12 @@ public class AKSequencer {
             CAShow(sequencePointer)
         }
     }
+    
+    public static func beatsFromSamples(samples:Int, fs:Int, bpm:Double)->Double{
+        let timeInSecs = Double(samples)/Double(fs)
+        let beatsPerSec = bpm/60.0
+        let beatLenInSecs = Double(1.0/beatsPerSec)
+        let numBeats = timeInSecs/beatLenInSecs
+        return numBeats
+    }
 }