From 726a0337c5d1bb423d36d03c9fa9a6895fe9062e Mon Sep 17 00:00:00 2001
From: xtex <xtexchooser@duck.com>
Date: Sun, 30 Jul 2023 10:17:21 +0800
Subject: [PATCH] feat: drop-out for drum-like instruments

---
 .../quaedam/projection/music/Composer.kt      | 22 ++++++++++++++++---
 .../quaedam/projection/music/MusicPlayer.kt   |  8 +++++--
 2 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/common/src/main/kotlin/quaedam/projection/music/Composer.kt b/common/src/main/kotlin/quaedam/projection/music/Composer.kt
index 0fb2881..5432a2f 100644
--- a/common/src/main/kotlin/quaedam/projection/music/Composer.kt
+++ b/common/src/main/kotlin/quaedam/projection/music/Composer.kt
@@ -1,5 +1,6 @@
 package quaedam.projection.music
 
+import net.minecraft.world.level.block.state.properties.NoteBlockInstrument
 import kotlin.math.abs
 import kotlin.random.Random
 import kotlin.random.nextInt
@@ -8,17 +9,32 @@ import kotlin.random.nextInt
  * The composer for music.
  * rhythmRandom is used for a better rhythm sync between different instruments.
  */
-class Composer(val noteRandom: Random, val rhythmRandom: Random) {
+class Composer(val noteRandom: Random, val rhythmRandom: Random, val instrument: NoteBlockInstrument) {
 
     data class Note(val note: Int, val volume: Float, val time: Int)
 
     val baseTime = arrayOf(5, 5, 3, 3, 4, 4, 2, 2, 8).random(rhythmRandom)
     val baseNote = noteRandom.nextInt(5..19)
 
-    fun composeMusic() = decorate(
-        (0..rhythmRandom.nextInt(5)).flatMap { composeSection() }
+    val mayDropOut = instrument in arrayOf(
+        NoteBlockInstrument.BASEDRUM,
+        NoteBlockInstrument.HAT,
+        NoteBlockInstrument.SNARE,
     )
 
+    fun composeMusic(): List<Note> {
+        var note = (0..rhythmRandom.nextInt(4)).flatMap { composeSection() }
+        note = decorate(note)
+        if (mayDropOut && rhythmRandom.nextInt(3) != 0) {
+            val dropRate = rhythmRandom.nextInt(2..4)
+            note = note.chunked(dropRate).map {
+                val first = it.first()
+                Note(first.note, first.volume, it.sumOf { note -> note.time })
+            }
+        }
+        return note
+    }
+
     fun decorate(notes: List<Note>) = notes.map {
         if (noteRandom.nextInt(4) == 0) {
             doDecorate(it)
diff --git a/common/src/main/kotlin/quaedam/projection/music/MusicPlayer.kt b/common/src/main/kotlin/quaedam/projection/music/MusicPlayer.kt
index 04a6f55..13d8748 100644
--- a/common/src/main/kotlin/quaedam/projection/music/MusicPlayer.kt
+++ b/common/src/main/kotlin/quaedam/projection/music/MusicPlayer.kt
@@ -31,14 +31,18 @@ class MusicPlayer(val seed: Long, val level: Level, val pos: BlockPos, val start
         tag.getLong(TAG_STARTED_AT)
     )
 
-    var notes = Composer(Random(seed), Random(startedAt / 20 * 15)).composeMusic().toMutableList()
+    var notes = Composer(
+        noteRandom = Random(seed),
+        rhythmRandom = Random(startedAt / 20 * 15),
+        instrument = level.getBlockState(pos).getValue(BlockStateProperties.NOTEBLOCK_INSTRUMENT)
+    ).composeMusic().toMutableList()
     val totalTime = notes.sumOf { it.time }.toLong()
     var remainingTime = totalTime
     val isEnd get() = remainingTime <= 0 || notes.isEmpty()
     var noteTime = 0
 
     init {
-        var currentRemaining = totalTime - (level.gameTime - startedAt)
+        val currentRemaining = totalTime - (level.gameTime - startedAt)
         while (remainingTime > currentRemaining) {
             // seek to current position
             remainingTime -= fetchNote().time