feat: add int providers

Author: tksimeji

modules/value-providers/build.gradle.kts

@@ -0,0 +1,117 @@
+package net.azisaba.serialization
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+import kotlin.math.PI
+import kotlin.math.cos
+import kotlin.math.ln
+import kotlin.math.sqrt
+import kotlin.random.Random
+
+@Serializable
+sealed interface IntProvider {
+    fun sample(random: Random): Int
+
+    @Serializable
+    @SerialName("Constant")
+    data class Constant(val value: Int) : IntProvider {
+        override fun sample(random: Random): Int = value
+    }
+
+    @Serializable
+    @SerialName("Uniform")
+    data class Uniform(val minInclusive: Int, val maxInclusive: Int) : IntProvider {
+        init {
+            require(maxInclusive >= minInclusive) {
+                "maxInclusive must be greater than or equal to minInclusive: [$minInclusive, $maxInclusive]"
+            }
+        }
+
+        override fun sample(random: Random): Int = random.nextInt(minInclusive, maxInclusive + 1)
+    }
+
+    @Serializable
+    @SerialName("BiasedToBottom")
+    data class BiasedToBottom(val minInclusive: Int, val maxInclusive: Int) : IntProvider {
+        init {
+            require(maxInclusive >= minInclusive) {
+                "maxInclusive must be greater than or equal to minInclusive: [$minInclusive, $maxInclusive]"
+            }
+        }
+
+        override fun sample(random: Random): Int =
+            minInclusive + random.nextInt(random.nextInt(maxInclusive - minInclusive + 1) + 1)
+    }
+
+    @Serializable
+    @SerialName("Clamped")
+    data class Clamped(
+        val source: IntProvider,
+        val minInclusive: Int,
+        val maxInclusive: Int,
+    ) : IntProvider {
+        init {
+            require(maxInclusive >= minInclusive) {
+                "maxInclusive must be greater than or equal to minInclusive: [$minInclusive, $maxInclusive]"
+            }
+        }
+
+        override fun sample(random: Random): Int = source.sample(random).coerceIn(minInclusive, maxInclusive)
+    }
+
+    @Serializable
+    @SerialName("ClampedNormal")
+    data class ClampedNormal(
+        val mean: Float,
+        val deviation: Float,
+        val minInclusive: Int,
+        val maxInclusive: Int,
+    ) : IntProvider {
+        init {
+            require(maxInclusive >= minInclusive) {
+                "maxInclusive must be greater than or equal to minInclusive: [$minInclusive, $maxInclusive]"
+            }
+        }
+
+        override fun sample(random: Random): Int =
+            (random.nextGaussian().toFloat() * deviation + mean)
+                .coerceIn(minInclusive.toFloat(), maxInclusive.toFloat())
+                .toInt()
+
+        private fun Random.nextGaussian(): Double {
+            val u1 = nextDouble()
+            val u2 = nextDouble()
+            return sqrt(-2.0 * ln(u1)) * cos(2.0 * PI * u2)
+        }
+    }
+
+    @Serializable
+    @SerialName("WeightedList")
+    data class WeightedList(val distribution: List<Entry>) : IntProvider {
+        init {
+            require(distribution.isNotEmpty()) {
+                "distribution must not be empty"
+            }
+            require(distribution.all { it.weight > 0 }) {
+                "distribution weights must be greater than 0"
+            }
+        }
+
+        override fun sample(random: Random): Int {
+            val totalWeight = distribution.sumOf(Entry::weight)
+            val roll = random.nextInt(totalWeight)
+            var accumulatedWeight = 0
+            for (entry in distribution) {
+                accumulatedWeight += entry.weight
+                if (roll < accumulatedWeight) {
+                    return entry.provider.sample(random)
+                }
+            }
+
+            return distribution.last().provider.sample(random)
+        }
+
+        @Serializable
+        data class Entry(val provider: IntProvider, val weight: Int)
+    }
+}

modules/value-providers/src/main/kotlin/net/azisaba/serialization/IntProvider.kt

@@ -5,3 +5,4 @@ rootProject.name = "minecraft-serialization"
 
 include("modules:adventure")
 include("modules:joml")
+include("modules:value-providers")