Changes to our snowstorm implementation to be more accurate when using EmitterPlanes or rotations in general.

common/src/main/kotlin/com/cobblemon/mod/common/api/snowstorm/ParticleCameraMode.kt

@@ -10,7 +10,9 @@ package com.cobblemon.mod.common.api.snowstorm
 
 import com.cobblemon.mod.common.api.codec.CodecMapped
 import com.cobblemon.mod.common.api.data.ArbitrarilyMappedSerializableCompanion
+import com.cobblemon.mod.common.api.orientation.OrientationController
 import com.cobblemon.mod.common.client.render.MatrixWrapper
+import com.cobblemon.mod.common.util.math.geometry.toRadians
 import com.cobblemon.mod.common.util.math.hamiltonProduct
 import com.cobblemon.mod.common.util.set
 import com.mojang.math.Axis
@@ -26,6 +28,7 @@ import kotlin.math.pow
 import kotlin.math.sqrt
 import net.minecraft.world.phys.Vec3
 import org.joml.AxisAngle4d
+import org.joml.AxisAngle4f
 import org.joml.Quaternionf
 import org.joml.Vector3f
 
@@ -88,7 +91,7 @@ class RotateXYZCameraMode : ParticleCameraMode {
         cameraPitch: Float,
         viewDirection: Vec3
     ): Quaternionf {
-        val i = if (angle == 0.0f) 0F else Mth.lerp(deltaTicks, prevAngle, angle)
+        val i = Mth.lerp(deltaTicks, prevAngle, angle)
         val q = Quaternionf(cameraAngle)
         q.hamiltonProduct(Axis.ZP.rotationDegrees(i))
         return q
@@ -122,7 +125,7 @@ class RotateYCameraMode : ParticleCameraMode {
         cameraPitch: Float,
         viewDirection: Vec3
     ): Quaternionf {
-        val i = if (angle == 0F) 0F else Mth.lerp(deltaTicks, prevAngle, angle)
+        val i = Mth.lerp(deltaTicks, prevAngle, angle)
         val q2 = Axis.YP.rotationDegrees(-cameraYaw)
         q2.hamiltonProduct(Axis.ZP.rotationDegrees(i))
         q2.hamiltonProduct(Axis.YP.rotationDegrees(180F))
@@ -160,7 +163,7 @@ class LookAtXYZ : ParticleCameraMode {
         cameraPitch: Float,
         viewDirection: Vec3
     ): Quaternionf {
-        val i = if (angle == 0F) 0F else Mth.lerp(deltaTicks, prevAngle, angle)
+        val i = Mth.lerp(deltaTicks, prevAngle, angle)
         val rotation = Quaternionf()
         rotation.hamiltonProduct(Axis.YP.rotationDegrees(-cameraYaw - 180))
         rotation.hamiltonProduct(Axis.XP.rotationDegrees(cameraPitch))
@@ -190,7 +193,7 @@ class LookAtY : ParticleCameraMode {
         cameraPitch: Float,
         viewDirection: Vec3
     ): Quaternionf {
-        val i = if (angle == 0F) 0F else Mth.lerp(deltaTicks, prevAngle, angle)
+        val i = Mth.lerp(deltaTicks, prevAngle, angle)
         val q2 = Axis.YP.rotationDegrees(-cameraYaw + 180)
         q2.hamiltonProduct(Axis.ZP.rotationDegrees(i))
         return q2
@@ -257,15 +260,11 @@ class EmitterYZPlane : ParticleCameraMode {
         cameraPitch: Float,
         viewDirection: Vec3
     ): Quaternionf {
-        val rotation = Quaternionf(0F, 0F, 0F, 1F)
-
-        val quat = AxisAngle4d(rotation)
-        matrixWrapper.matrix.getRotation(quat)
-        rotation.set(quat)
-
-        rotation.hamiltonProduct(Axis.YP.rotationDegrees(180F)) // Don't worry about it.
-        rotation.hamiltonProduct(Axis.YP.rotationDegrees(90F))
-        return rotation
+        val i = Mth.lerp(deltaTicks, prevAngle, angle)
+        val forward = matrixWrapper.matrix.transformDirection(OrientationController.LEFT)
+        val q = Quaternionf(AxisAngle4f(i.toRadians(), forward))
+        q.mul(Axis.YP.rotationDegrees(90F))
+        return q
     }
 
     override fun <T> encode(ops: DynamicOps<T>) = CODEC.encodeStart(ops, this)
@@ -296,14 +295,11 @@ class EmitterXZPlane : ParticleCameraMode {
         cameraPitch: Float,
         viewDirection: Vec3
     ): Quaternionf {
-        val rotation = Quaternionf(0F, 0F, 0F, 1F)
-
-        val quat = AxisAngle4d(rotation)
-        matrixWrapper.matrix.getRotation(quat)
-        rotation.set(quat)
-        rotation.hamiltonProduct(Axis.YP.rotationDegrees(180F)) // Don't worry about it.
-        rotation.hamiltonProduct(Axis.XP.rotationDegrees(-90F))
-        return rotation
+        val i = Mth.lerp(deltaTicks, prevAngle, angle)
+        val up = matrixWrapper.matrix.transformDirection(OrientationController.UP)
+        val q = Quaternionf(AxisAngle4f(-i.toRadians(), up))
+        q.mul(Axis.XP.rotationDegrees(-90F))
+        return q
     }
 
     override fun <T> encode(ops: DynamicOps<T>) = CODEC.encodeStart(ops, this)
@@ -334,15 +330,11 @@ class EmitterXYPlane : ParticleCameraMode {
         cameraPitch: Float,
         viewDirection: Vec3
     ): Quaternionf {
-        val rotation = Quaternionf(0F, 0F, 0F, 1F)
-
-        val quat = AxisAngle4d(rotation)
-        matrixWrapper.matrix.getRotation(quat)
-        rotation.set(quat)
-
-        rotation.hamiltonProduct(Axis.YP.rotationDegrees(180F)) // Don't worry about it.
-
-        return rotation
+        val i = Mth.lerp(deltaTicks, prevAngle, angle)
+        val forward = matrixWrapper.matrix.transformDirection(OrientationController.FORWARDS)
+        val q = Quaternionf(AxisAngle4f(i.toRadians(), forward))
+        q.mul(Axis.ZP.rotationDegrees(90F))
+        return q
     }
 
     override fun <T> encode(ops: DynamicOps<T>) = CODEC.encodeStart(ops, this)

common/src/main/kotlin/com/cobblemon/mod/common/api/snowstorm/ParticleRotation.kt

@@ -24,7 +24,6 @@ import com.mojang.serialization.DynamicOps
 import com.mojang.serialization.codecs.PrimitiveCodec
 import com.mojang.serialization.codecs.RecordCodecBuilder
 import net.minecraft.network.RegistryFriendlyByteBuf
-import kotlin.math.abs
 
 interface ParticleRotation : CodecMapped {
     companion object : ArbitrarilyMappedSerializableCompanion<ParticleRotation, ParticleRotationType>(
@@ -40,9 +39,7 @@ interface ParticleRotation : CodecMapped {
 
     val type: ParticleRotationType
 
-    fun getInitialRotation(runtime: MoLangRuntime): Double
-    fun getInitialAngularVelocity(runtime: MoLangRuntime): Double
-    fun getAngularVelocity(runtime: MoLangRuntime, angle: Double, angularVelocity: Double): Double
+    fun getAngle(runtime: MoLangRuntime, age: Int): Double
 }
 
 class ParametricParticleRotation(var expression: Expression = NumberExpression(0.0)): ParticleRotation {
@@ -59,9 +56,12 @@ class ParametricParticleRotation(var expression: Expression = NumberExpression(0
 
     override val type = ParticleRotationType.PARAMETRIC
     override fun <T> encode(ops: DynamicOps<T>) = CODEC.encodeStart(ops, this)
-    override fun getInitialRotation(runtime: MoLangRuntime) = runtime.resolveDouble(expression)
-    override fun getInitialAngularVelocity(runtime: MoLangRuntime) = 0.0
-    override fun getAngularVelocity(runtime: MoLangRuntime, angle: Double, angularVelocity: Double) = runtime.resolveDouble(expression) - angle
+    override fun getAngle(
+        runtime: MoLangRuntime,
+        age: Int,
+    ): Double {
+        return runtime.resolveDouble(expression)
+    }
 
     override fun readFromBuffer(buffer: RegistryFriendlyByteBuf) {
         expression = MoLang.createParser(buffer.readString()).parseExpression()
@@ -92,19 +92,12 @@ class DynamicParticleRotation(
         }
     }
 
+    var angularVelocity: Double? = null
+
     override val type = ParticleRotationType.DYNAMIC
     override fun <T> encode(ops: DynamicOps<T>) = CODEC.encodeStart(ops, this)
-    override fun getInitialRotation(runtime: MoLangRuntime) = runtime.resolveDouble(startRotation)
-    override fun getInitialAngularVelocity(runtime: MoLangRuntime) = runtime.resolveDouble(speed) / 20
-    override fun getAngularVelocity(runtime: MoLangRuntime, angle: Double, angularVelocity: Double): Double {
-        val acceleration = runtime.resolveDouble(acceleration)
-        val nextVelocity = angularVelocity * 20 + acceleration
-        val drag = nextVelocity * runtime.resolveDouble(drag)
-        return angularVelocity + (if (abs(drag) > abs(nextVelocity)) {
-            0.0
-        } else {
-            nextVelocity - drag - angularVelocity * 20
-        })
+    override fun getAngle(runtime: MoLangRuntime, age: Int): Double {
+        return getInitialRotation(runtime) + getAngularVelocity(runtime) * age
     }
 
     override fun readFromBuffer(buffer: RegistryFriendlyByteBuf) {
@@ -120,6 +113,18 @@ class DynamicParticleRotation(
         buffer.writeString(acceleration.getString())
         buffer.writeString(drag.getString())
     }
+
+    fun getInitialRotation(runtime: MoLangRuntime) = runtime.resolveDouble(startRotation)
+    fun getInitialAngularVelocity(runtime: MoLangRuntime) = runtime.resolveDouble(speed) / 20
+    fun getAngularVelocity(runtime: MoLangRuntime): Double {
+        if (angularVelocity == null) angularVelocity = getInitialAngularVelocity(runtime)
+
+        val drag = runtime.resolveDouble(drag)
+        var acceleration = runtime.resolveDouble(acceleration)
+        acceleration += -drag * angularVelocity!!
+        val nextVelocity = angularVelocity!! + acceleration / 20
+        return nextVelocity
+    }
 }
 
 enum class ParticleRotationType {

common/src/main/kotlin/com/cobblemon/mod/common/client/render/SnowstormParticle.kt

@@ -60,7 +60,6 @@ class SnowstormParticle(
     val sprite = getSpriteFromAtlas()
 
     val particleTextureSheet: ParticleRenderType
-    var angularVelocity = 0.0
     var colliding = false
 
     var texture = storm.effect.particle.texture
@@ -110,9 +109,8 @@ class SnowstormParticle(
 
     init {
         setParticleSpeed(initialVelocity.x, initialVelocity.y, initialVelocity.z)
-        roll = -storm.effect.particle.rotation.getInitialRotation(runtime).toFloat()
+        roll = -storm.effect.particle.rotation.getAngle(runtime, 0).toFloat()
         oRoll = roll
-        angularVelocity = storm.effect.particle.rotation.getInitialAngularVelocity(runtime)
         friction = 1F
         lifetime = (runtime.resolveDouble(storm.effect.particle.maxAge) * 20).toInt()
         storm.particles.add(this)
@@ -247,9 +245,8 @@ class SnowstormParticle(
         setParticleAgeInRuntime()
         storm.effect.curves.forEach { it.apply(runtime) }
         runtime.execute(storm.effect.particle.updateExpressions)
-        angularVelocity = storm.effect.particle.rotation.getAngularVelocity(runtime, -roll.toDouble(), angularVelocity) / 20
 
-        if (age >= lifetime || runtime.resolveBoolean(storm.effect.particle.killExpression)) {
+        if (age > lifetime || runtime.resolveBoolean(storm.effect.particle.killExpression)) {
             runExpirationEvents()
             remove()
             return
@@ -261,8 +258,8 @@ class SnowstormParticle(
             yd = velocity.y
             zd = velocity.z
             oRoll = roll
-            // Subtract because Bedrock particles are counter-clockwise and Java Edition is clockwise.
-            roll = oRoll - angularVelocity.toFloat()
+            // negative because Bedrock particles are counter-clockwise and Java Edition is clockwise.
+            roll = -storm.effect.particle.rotation.getAngle(runtime, age).toFloat()
         }
 
         viewDirection = storm.effect.particle.viewDirection.getDirection(