Add floorMod function for Float

test-plugin/src/main/kotlin/space/uranos/testplugin/TestPlugin.kt

@@ -14,6 +14,7 @@ import space.uranos.net.event.SessionAfterLoginEvent
 import space.uranos.player.GameMode
 import space.uranos.plugin.Plugin
 import space.uranos.testplugin.anvil.AnvilWorld
+import space.uranos.util.RGBColor
 import space.uranos.util.secondsToTicks
 import space.uranos.world.Biome
 import space.uranos.world.Chunk
@@ -21,7 +22,6 @@ import space.uranos.world.Dimension
 import space.uranos.world.VoxelLocation
 import space.uranos.world.block.GreenWoolBlock
 import space.uranos.world.block.RedWoolBlock
-import java.awt.Color
 
 class TestPlugin: Plugin("Test", "1.0.0") {
     override fun onEnable() {
@@ -35,10 +35,10 @@ class TestPlugin: Plugin("Test", "1.0.0") {
         val biome = Biome(
             "test:test",
             Biome.Precipitation.NONE,
-            Color.GREEN,
-            Color.BLACK,
-            Color.ORANGE,
-            Color.GRAY,
+            RGBColor(0xFF0000),
+            RGBColor(0x000000),
+            RGBColor(0x00FF00),
+            RGBColor(0x444444),
             Biome.MoodSound(2, 0.0, "minecraft:entity.pig.ambient", 1),
             0.0f,
             10f

uranos-api/src/main/kotlin/space/uranos/util/FloatFloorMod.kt

@@ -0,0 +1,15 @@
+/*
+ * Copyright 2020-2021 Moritz Ruth and Uranos contributors
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file
+ */
+
+package space.uranos.util
+
+fun floorMod(dividend: Float, divisor: Float): Float {
+    if (divisor == 0f) throw ArithmeticException("divisor cannot be 0")
+
+    val mod = dividend % divisor
+
+    if (mod != 0f && ((mod < 0 && divisor > 0) || (mod > 0 && divisor < 0))) return mod + divisor
+    return mod
+}

uranos-api/src/test/kotlin/space/uranos/util/FloatFloorModTest.kt

@@ -0,0 +1,28 @@
+package space.uranos.util
+
+import org.junit.jupiter.api.Test
+import strikt.api.expectThat
+import strikt.api.expectThrows
+import strikt.assertions.isEqualTo
+import strikt.assertions.isTrue
+
+class FloatFloorModTest {
+    @Test
+    fun `throws an error when divisor is 0`() {
+        expectThrows<ArithmeticException> { floorMod(0f, 0f) }
+        expectThrows<ArithmeticException> { floorMod(20f, 0f) }
+        expectThrows<ArithmeticException> { floorMod(-20f, 0f) }
+    }
+
+    @Test
+    fun `returns correct results`() {
+        expectThat(floorMod(0f, 1f) == 0f).isTrue()
+        expectThat(floorMod(20f, 1f) == 0f).isTrue()
+        expectThat(floorMod(-20f, 1f) == 0f).isTrue()
+
+        expectThat(floorMod(110f, 100f)).isEqualTo(10f)
+        expectThat(floorMod(-110f, 100f)).isEqualTo(90f)
+        expectThat(floorMod(110f, -100f)).isEqualTo(-90f)
+        expectThat(floorMod(-110f, -100f)).isEqualTo(-10f)
+    }
+}

uranos-packet-codecs/src/main/kotlin/space/uranos/net/packet/play/IncomingPlayerPositionPacketCodec.kt

@@ -8,6 +8,7 @@ package space.uranos.net.packet.play
 import io.netty.buffer.ByteBuf
 import space.uranos.Position
 import space.uranos.net.packet.IncomingPacketCodec
+import space.uranos.util.floorMod
 
 object IncomingPlayerPositionPacketCodec :
     IncomingPacketCodec<IncomingPlayerPositionPacket>(0x13, IncomingPlayerPositionPacket::class) {
@@ -16,8 +17,7 @@ object IncomingPlayerPositionPacketCodec :
             msg.readDouble(),
             msg.readDouble(),
             msg.readDouble(),
-            Math.floorMod((360 - msg.readFloat()).toInt(), 360)
-                .toFloat(), // TODO: Higher precision (do not use Math.floorMod)
+            floorMod(msg.readFloat(), 360f),
             msg.readFloat()
         ),
         msg.readBoolean()

uranos-packet-codecs/src/main/kotlin/space/uranos/net/packet/play/PlayerOrientationPacketCodec.kt

@@ -7,12 +7,12 @@ package space.uranos.net.packet.play
 
 import io.netty.buffer.ByteBuf
 import space.uranos.net.packet.IncomingPacketCodec
+import space.uranos.util.floorMod
 
 object PlayerOrientationPacketCodec :
     IncomingPacketCodec<PlayerOrientationPacket>(0x14, PlayerOrientationPacket::class) {
     override fun decode(msg: ByteBuf): PlayerOrientationPacket = PlayerOrientationPacket(
-        Math.floorMod((360 - msg.readFloat()).toInt(), 360)
-            .toFloat(), // TODO: Higher precision (do not use Math.floorMod),
+        floorMod(msg.readFloat(), 360f),
         msg.readFloat(),
         msg.readBoolean()
     )

uranos-server/src/main/kotlin/space/uranos/net/UranosSession.kt

@@ -156,7 +156,7 @@ class UranosSession(val channel: io.netty.channel.Channel, val server: UranosSer
         scope.launch {
             if (state == State.Disconnected) return@launch
             if (!expected && currentProtocol != HandshakingProtocol && currentProtocol != StatusProtocol)
-                logger trace "The client disconnected unexpectedly"
+                logger trace "The client disconnected unexpectedly" // TODO: This is sometimes logged multiple times
 
             packetsAdapter.stopProcessingIncomingPackets()
             coroutineContext.cancel(DisconnectedCancellationException())