added tetris theme

src/main/kotlin/music/Filter/Filter.kt

@@ -1,38 +0,0 @@
-package music.Filter
-
-import music.Params.SAMPLES
-import music.Signal
-
-typealias Filter = (Signal) -> (Signal)
-
-object Filters {
-    fun easeIn(signal: Signal): Signal {
-        val len = kotlin.math.min(SAMPLES / 64, signal.size)
-        val start = signal.slice(0 until len)
-        val end = signal.slice(len until signal.size)
-
-        return (start.withIndex().map { i -> (i.value * (i.index / len.toFloat())).toInt() } + end).toTypedArray();
-    }
-
-    fun easeOut(signal: Signal): Signal {
-        val len = kotlin.math.min(SAMPLES / 64, signal.size)
-        val sep = signal.size - len - 1;
-        val start = signal.slice(0 until sep)
-        val end = signal.slice(sep until signal.size)
-
-        return (start + end.withIndex().map { i -> (i.value * ((len - i.index) / len.toFloat())).toInt() }).toTypedArray();
-    }
-
-    fun ease(signal: Signal): Signal {
-        val len = kotlin.math.min(SAMPLES / 64, signal.size / 2)
-        val sep = signal.size - len - 1;
-        val start = signal.slice(0 until len)
-        val mid = signal.slice(len until sep)
-        val end = signal.slice(sep until signal.size)
-
-        return (start.withIndex().map { i -> (i.value * (i.index / len.toFloat())).toInt() }
-                + mid
-                + end.withIndex().map { i -> (i.value * ((len - i.index) / len.toFloat())).toInt() }
-                ).toTypedArray();
-    }
-}

src/main/kotlin/music/Main.kt

@@ -1,8 +1,10 @@
 package music
 
-import music.Filter.Filters
 import music.Params.SAMPLES
-import music.generators.ToneGenerator
+import music.filter.EchoFilter
+import music.filter.FilterQueue
+import music.filter.Limiter
+import music.generators.EasedToneGenerator
 import javax.sound.sampled.AudioFormat
 import javax.sound.sampled.AudioSystem
 import javax.sound.sampled.DataLine
@@ -11,6 +13,7 @@ import javax.sound.sampled.SourceDataLine
 object Params {
     const val SAMPLES = 44100
     const val PI = kotlin.math.PI.toFloat()
+    const val MAX_VAL = 32767 // 2**15 - 1
     val CORES = Runtime.getRuntime().availableProcessors()
 }
 
@@ -23,9 +26,115 @@ fun main() {
     line.open(format)
     line.start()
 
-    val gen = ToneGenerator(.2f, -24, WaveformTransformations::sawtooth)
+    //val gen = ToneGenerator(.2f, -24, WaveformTransformation.SAWTOOTH)
+
+    val bpm = 60;
+    val volume = 0.1f;
+    val tetrisSound = { volume: Float, tone: Int -> EasedToneGenerator(volume, tone, WaveformTransformation.SQUARE) }
+
+
+    // C C# D D# E F F# G G# A A# B  C
+    // C Db D Eb E F Gb G Ab A Bb B  C
+    // 0 1  2 3  4 5 6  7 8  9 10 11 12
+
+    // TETRIS
+    // base notes
+    val bar1 = Bar(8, bpm);
+
+    val rightHand = Melody(tetrisSound, volume/ 2, -1);
+
+    rightHand.add("E", 1f)
+            .add("E", 1f)
+            .add("A", 1f)
+            .add("A", 1f)
+            .add("Ab", 1f)
+            .add("E", 1f)
+            .add("A", 1.5f)
+            .applyTo(bar1)
+
+    val leftHand = Melody(tetrisSound, volume, 0)
+
+    leftHand.add("E", .5f)
+            .add(-1, .25f)
+            .add("C", .25f) // 1
+            .add("D", .5f)
+            .add("C", .25f)
+            .add(-1, .25f) // 2
+            .add(-3, .25)
+            .pause(.25)
+            .add(-3, .25)
+            .add("C", 0.25) // 3
+            .add("E", .5)
+            .add(2, 0.25)
+            .add(0, 0.25) // 4
+            .add(-1, 0.5)
+            .pause(0.25)
+            .add("C", 0.25) // 5
+            .add("D", 0.5)
+            .add("E",0.5) // 6
+            .add("C", 0.5)
+            .add(-3, 0.25)
+            .pause(0.25)        // 7
+            .add(-3, 0.5)
+            .applyTo(bar1)
+
+
+    val bar2 = Bar(8, bpm);
+
+    rightHand.reset()
+    leftHand.reset()
+
+    rightHand.add("D", 1f)
+            .add("D", 1f)
+            .add("C", 1f)
+            .add("C", 1f)
+            .add("E", 1f)
+            .add("E", 1f)
+            .add("A", 2f)
+            .applyTo(bar2)
+
+    leftHand.pause(0.25)
+            .add("D", .5)
+            .add("F", .25) // 1
+            .add("A", .5)
+            .add("G", .25)
+            .add("F", .25) // 2
+            .add("E", 0.5)
+            .pause(.25)
+            .add("C", .25) // 3
+            .add("E", .5)
+            .add("D", .25)
+            .add("C", .25) // 4
+            .add(-1, .25)
+            .pause(.25)
+            .add(-1, .25)
+            .add("C",.25) // 5
+            .add("D", .5)
+            .add("E", .5) // 6
+            .add("C", .5)
+            .add("A", .25, offset = -1)
+            .pause(0.25) // 7
+            .add("A", 0.5, offset = -1)
+            .applyTo(bar2)
+    // D F A G F E
+    // C E D C B
+    // B C D E C A A
+
+
+    val echo = EchoFilter(SAMPLES / 12, .9f)
+    val limiter = Limiter(.9f);
+
+
+    val filters = FilterQueue(echo, limiter)
+
+
+    //println(output.size / SAMPLES.toFloat())
+
+    var output = filters.stream(bar1.getSignal())
+    line.write(output.toBytes(), 0, output.size * 2)
+    output = filters.stream(bar2.getSignal())
+    line.write(output.toBytes(), 0, output.size * 2)
+
 
-    val signal = Filters.ease(gen.get(Samples(2)))
 
-    line.write(signal.toBytes(), 0, signal.size * 2)
 }

src/main/kotlin/music/Melody.kt

@@ -0,0 +1,71 @@
+package music
+
+import music.generators.Generator
+import music.generators.ToneGenerator
+
+class Melody(val getGen: (volume: Float, tone: Int) -> (Generator), val volume: Float, val offset: Int = 0) {
+
+    val tones = mutableSetOf<Beat>()
+    var pos = 0f
+
+    fun add(tone: String, len: Double, offset: Int? = null): Melody {
+        return add(tone, len.toFloat(), offset)
+    }
+    fun add(tone: Int, len: Double, offset: Int? = null): Melody {
+        return add(tone, len.toFloat(), offset)
+    }
+    fun add(tone: String, len: Float, offset: Int? = null): Melody {
+        return add(toneFromString(tone), len, offset)
+    }
+    fun add(tone: Int, len: Float, offset: Int? = null): Melody {
+        val ofs = offset ?: this.offset;
+        tones.add(Beat(getGen(volume, tone + (ofs * 12)), len, pos))
+        pos += len
+        return this
+    }
+
+    fun pause(len: Float): Melody {
+        pos += len
+        return this
+    }
+    fun pause(len: Double): Melody {
+        pos += len.toFloat()
+        return this
+    }
+
+    fun applyTo(bar: Bar) {
+        for (tone in tones) {
+            bar.tones.add(tone)
+        }
+    }
+
+    fun reset() {
+        pos = 0f
+        tones.removeAll { true }
+    }
+
+    companion object {
+        // C C# D D# E F F# G G# A A# B  C
+        // C Db D Eb E F Gb G Ab A Bb B  C
+        // 0 1  2 3  4 5 6  7 8  9 10 11 12
+        private val tones = mapOf(
+                "C" to 0,
+                "Db" to 1, "C#" to 1,
+                "D" to 2,
+                "D#" to 3, "Eb" to 3,
+                "E" to 4,
+                "F" to 5,
+                "F#" to 6, "Gb" to 6,
+                "G" to 7,
+                "G#" to 8, "Ab" to 8,
+                "A" to 9,
+                "A#" to 10, "Bb" to 10,
+                "B" to 11
+        )
+
+        fun toneFromString(tone: String, offset: Int = 0): Int {
+            return Companion.tones[tone]?.plus(offset * 12)!!
+        }
+    }
+
+}

src/main/kotlin/music/Samples.kt

@@ -1,11 +1,14 @@
 package music
 
 import music.Params.SAMPLES
+import kotlin.math.absoluteValue
 
 typealias Samples = Array<Float>
 
-fun Samples(len: Int, start: Int = 0): Samples =
-        Samples(len * SAMPLES) { i -> start.toFloat() + (i / SAMPLES.toFloat())}
+fun Samples(len: Float, start: Float = 0f): Samples =
+        Samples((len * SAMPLES).toInt()) { i -> start + (i / SAMPLES.toFloat())}
+
+fun Samples(len: Int, start: Float = 0f): Samples = Samples(len.toFloat(), start)
 
 fun Samples.map(mapper: (Float) -> (Float)): Samples =
     Array(size) { mapper(this[it]) }
@@ -17,7 +20,10 @@ fun Samples.sin(): Samples =
     map { kotlin.math.sin(it) }
 
 fun Samples.mod(num: Int): Samples =
-    map { it % num }
+        map { it % num }
+
+fun Samples.abs(): Samples =
+        map { it.absoluteValue }
 
 operator fun Samples.times(scalar: Float): Samples =
     if (scalar == 1f) this else map { it * scalar }

src/main/kotlin/music/Signal.kt

@@ -1,31 +1,58 @@
 package music
 
+import music.Params.MAX_VAL
 import music.Params.PI
-import kotlin.math.pow
-
 
 /**
  * A Signal is string of Integer values which describe a curve, they go from - MAX_VAL to MAX_VAL
  */
 typealias Signal = Array<Int>
 
-val MAX_VAL = 2f.pow(15) - 1
-
 fun Signal.toBytes(): ByteArray =
     Array(size * 2) { i -> (this[i/2] shr ((i % 2) * 8)).toByte() }.toByteArray()
 
 fun Signal(samples: Samples): Signal =
         Signal(samples.size) {i -> (samples[i] * MAX_VAL).toInt() }
 
-object WaveformTransformations {
-    fun sine(samples: Samples, volume: Float): Signal
-            = Signal(((samples * (2f * PI)).sin()) * volume)
+enum class WaveformTransformation {
+    SINE {
+        override fun apply(samples: Samples, volume: Float): Signal
+                = Signal(((samples * (2f * PI)).sin()) * volume)
+    },
+    SQUARE {
+        override fun apply(samples: Samples, volume: Float): Signal
+                = Signal(samples.times(2f).ceil().mod(2).times(2f).minus(1f) * (volume))
+    },
+    SAWTOOTH {
+        override fun apply(samples: Samples, volume: Float): Signal
+                = Signal(((samples * 2f).mod(2) - 1f) * volume)
+    },
+    TRIANGLE {
+        override fun apply(samples: Samples, volume: Float): Signal
+                = Signal(samples.times(4f).mod(4).minus(2f).abs().minus(1f) * (volume))
+    };
 
-    fun square(samples: Samples, volume: Float): Signal
-            = Signal((((samples * (2f * PI)).sin() / 1f).ceil() * 2f + 1f) * volume)
-
-    fun sawtooth(samples: Samples, volume: Float): Signal
-            = Signal(((samples + 1f).mod(2) - 1f) * volume)
+    open fun apply(samples: Samples, volume: Float): Signal = Signal(samples * volume)
 }
 
-typealias WaveformTransformation = (Samples, Float) -> (Signal)
+fun Signal.map(mapper: (Int) -> (Int)): Signal =
+        Array(size) { mapper(this[it]) }
+
+operator fun Signal.times(scalar: Float): Signal =
+        if (scalar == 1f) this else map { (it * scalar).toInt() }
+
+operator fun Signal.plus(value: Int): Signal =
+        map { it + value }
+
+operator fun Signal.minus(value: Int): Signal =
+        map { it - value }
+
+operator fun Signal.div(value: Float): Signal =
+        map { (it / value).toInt() }
+
+
+fun Signal.join(start: Int, signal: Signal): Signal
+    = (this.sliceArray(0 until start)
+        + signal.withIndex().map { i -> this.elementAtOrElse(i.index + start) {0} + i.value }
+        + this.sliceArray(start + signal.size until this.size))
+

src/main/kotlin/music/Track.kt

@@ -1,5 +1,35 @@
 package music
 
+import music.Params.SAMPLES
+import music.filter.EaseFilter
+import music.filter.FilterQueue
+import music.generators.Generator
+import java.util.logging.Filter
+
+
 class Track {
 
+
+
+
+}
+
+class Bar(val beats: Int, val bpm: Int) {
+
+    val bps = bpm / 60f
+    val tones = mutableSetOf<Beat>()
+
+    fun getSignal():Signal {
+        var base = Signal((SAMPLES * beats / bps).toInt()) {0}
+        for (tone in tones) {
+            base = base.join((SAMPLES * tone.start / bps).toInt(), tone.getSignal(bps))
+        }
+
+        return base;
+    }
+}
+
+class Beat(private val generator: Generator, private val duration: Float, val start: Float) {
+    fun getSignal(bps: Float): Signal =
+        generator.get(Samples(duration / bps, start / bps))
 }

src/main/kotlin/music/filter/Compressor.kt

@@ -0,0 +1,10 @@
+package music.filter
+
+import music.Signal
+
+class Compressor(val threshold: Int, val ratio: Float, val outputGain: Float):Filter {
+
+    override fun stream(signal: Signal): Signal {
+        return signal;
+    }
+}

src/main/kotlin/music/filter/EchoFilter.kt

@@ -0,0 +1,24 @@
+package music.filter
+
+import music.Signal
+import music.map
+import music.div
+import music.times
+import java.util.*
+import kotlin.math.absoluteValue
+import kotlin.math.pow
+import kotlin.math.sign
+
+class EchoFilter(delay: Int, private val volume: Float = 0.5f): Filter {
+    private var cache: Queue<Int> = LinkedList(List(delay) {0})
+
+    override fun stream(signal: Signal): Signal =
+        signal.map(this::apply)
+
+    private fun apply(value: Int): Int {
+        val effect = value + cache.remove()
+        cache.add(effect.toFloat().absoluteValue.pow(volume).toInt() * effect.sign)
+        return effect;
+    }
+
+}

src/main/kotlin/music/filter/Filter.kt

@@ -0,0 +1,53 @@
+package music.filter
+
+import music.Signal
+
+interface Filter {
+    fun stream(signal: Signal): Signal
+}
+
+
+
+
+
+
+enum class EaseFilter(val duration: Int = 32): Filter {
+    IN {
+        override fun stream (signal: Signal): Signal {
+            val len = kotlin.math.min(duration, signal.size)
+            val start = signal.slice(0 until len)
+            val end = signal.slice(len until signal.size)
+
+            return (start.withIndex().map { i -> (i.value * (i.index / len.toFloat())).toInt() } + end).toTypedArray();
+        }
+    },
+
+    OUT {
+        override fun stream(signal: Signal): Signal {
+            val len = kotlin.math.min(duration, signal.size)
+            val sep = signal.size - len - 1;
+            val start = signal.slice(0 until sep)
+            val end = signal.slice(sep until signal.size)
+
+            return (start + end.withIndex().map { i -> (i.value * ((len - i.index) / len.toFloat())).toInt() }).toTypedArray();
+        }
+    },
+
+    INOUT {
+        override fun stream(signal: Signal): Signal {
+            val len = kotlin.math.min(duration, signal.size / 2)
+            val sep = signal.size - len - 1;
+            val start = signal.slice(0 until len)
+            val mid = signal.slice(len until sep)
+            val end = signal.slice(sep until signal.size)
+
+            return (start.withIndex().map { i -> (i.value * (i.index / len.toFloat())).toInt() }
+                    + mid
+                    + end.withIndex().map { i -> (i.value * ((len - i.index) / len.toFloat())).toInt() }
+                    ).toTypedArray();
+        }
+    };
+
+    override fun stream(signal: Signal): Signal = signal
+}
+

src/main/kotlin/music/filter/FilterQueue.kt

@@ -0,0 +1,8 @@
+package music.filter
+
+import music.Signal
+
+class FilterQueue(private vararg val filters: Filter): Filter {
+    override fun stream(signal: Signal): Signal =
+            filters.fold(signal, {acc, filter -> filter.stream(acc)})
+}

src/main/kotlin/music/filter/Limiter.kt

@@ -0,0 +1,14 @@
+package music.filter
+
+import music.Params.MAX_VAL
+import music.Signal
+import music.map
+import kotlin.math.max
+import kotlin.math.min
+
+class Limiter(val threshold: Float): Filter {
+    val maxVal = (MAX_VAL * threshold).toInt()
+
+    override fun stream(signal: Signal): Signal =
+            signal.map { max(min(it, maxVal), - maxVal) }
+}

src/main/kotlin/music/generators/Drum.kt

@@ -0,0 +1,22 @@
+package music.generators
+
+import music.*
+import music.Params.SAMPLES
+import music.filter.EchoFilter
+import music.filter.FilterQueue
+import kotlin.math.max
+
+class Drum(volume: Float, tone: Int = -36): Generator{
+    val kickLen = (SAMPLES * 0.08).toInt();
+    val filter = FilterQueue(EchoFilter(kickLen, .7f));
+
+    val gen1 = EasedToneGenerator(volume, tone, WaveformTransformation.SINE)
+    val gen2 = EasedToneGenerator(volume / 2, tone + 12, WaveformTransformation.SINE)
+
+    override fun get(samples: Samples): Signal {
+        val kick1 = gen1.get(samples.sliceArray(0 until kickLen))
+        val kick2 = gen2.get(samples.sliceArray(0 until (kickLen / 2)))
+
+        return filter.stream(kick1.join(0, kick2) + Signal(max(samples.size - kickLen, 0)) {0}) / 1.5f;
+    }
+}

src/main/kotlin/music/generators/Generator.kt

@@ -4,12 +4,8 @@ import music.Samples
 import music.Signal
 import music.WaveformTransformation
 
-abstract class Generator(private val volume: Float, private val waveform: WaveformTransformation) {
-
-    fun get(samples: Samples): Signal {
-        return waveform(generate(samples), volume)
-    }
-
-    protected abstract fun generate(samples: Samples): Samples
+interface Generator {
+    fun get(samples: Samples): Signal
 }
 
+

src/main/kotlin/music/generators/ToneGenerator.kt

@@ -3,11 +3,19 @@ package music.generators
 import music.Samples
 import music.Signal
 import music.WaveformTransformation
+import music.filter.EaseFilter
 import music.times
 import kotlin.math.pow
+import kotlin.math.sign
 
-open class ToneGenerator(volume: Float, private val tone: Int, waveform: WaveformTransformation) : Generator(volume, waveform) {
-    override fun generate(samples: Samples): Samples =
+open class ToneGenerator(private val volume: Float, private val tone: Int, private val waveform: WaveformTransformation) : Generator {
+    override fun get(samples: Samples): Signal {
+        return applyEffects(waveform.apply(generate(samples), volume))
+    }
+
+    protected open fun applyEffects(signal: Signal): Signal = signal
+
+    protected open fun generate(samples: Samples): Samples =
         samples * getFreqOfTone(tone)
 
     protected fun getFreqOfTone(tone: Float): Float =
@@ -19,4 +27,9 @@ open class ToneGenerator(volume: Float, private val tone: Int, waveform: Wavefor
     companion object {
         private const val F0: Float = 440f;
     }
+}
+
+class EasedToneGenerator(volume: Float, tone: Int, waveform: WaveformTransformation) : ToneGenerator(volume, tone, waveform) {
+    override fun applyEffects(signal: Signal): Signal =
+         EaseFilter.INOUT.stream(signal)
 }

src/test/kotlin/music/filter/EaseFilterTest.kt

@@ -0,0 +1,25 @@
+package music.filter
+
+import music.Samples
+import music.WaveformTransformation
+import music.generators.ToneGenerator
+import org.junit.Test
+import kotlin.test.assertEquals
+
+class EaseFilterTest {
+    @Test
+    fun testOutputLength() {
+        val gen = ToneGenerator(1f, 0, WaveformTransformation.SINE);
+        val samples = Samples(1)
+        val signal = gen.get(samples)
+
+
+        assertEquals(samples.size, signal.size, "Generated samples should have same size as input")
+
+        for (filter in EaseFilter.values()) {
+            assertEquals(samples.size, filter.stream(signal).size, "Filter $filter should not increase length")
+        }
+
+
+    }
+}