diff --git a/README.md b/README.md
index 601c04c..e9ecda7 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,7 @@ repositories {
 }
 
 dependencies {
-    implementation("me.alex_s168:blitz:0.24.1")
+    implementation("me.alex_s168:blitz:0.25")
 }
 ```
 
diff --git a/build.gradle.kts b/build.gradle.kts
index 5a82abe..d519e2a 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -2,10 +2,11 @@ plugins {
     kotlin("jvm") version "1.9.21"
     application
     `maven-publish`
+    id("org.jetbrains.dokka") version "2.0.0"
 }
 
 group = "me.alex_s168"
-version = "0.24.1"
+version = "0.25"
 
 repositories {
     mavenCentral()
diff --git a/src/main/kotlin/blitz/Defer.kt b/src/main/kotlin/blitz/Defer.kt
index 2b24f81..44281e7 100644
--- a/src/main/kotlin/blitz/Defer.kt
+++ b/src/main/kotlin/blitz/Defer.kt
@@ -1,5 +1,7 @@
 package blitz
 
+import blitz.collections.RefVec
+
 fun interface DeferScope {
     fun defer(block: () -> Unit)
 }
@@ -28,9 +30,9 @@ interface ExecutionScope: DeferScope {
 }
 
 fun <R> resourceScoped(block: ExecutionScope.() -> R): R {
-    val defer = mutableListOf<() -> Unit>()
-    val onError = mutableListOf<() -> Unit>()
-    val scope = ExecutionScope.create(defer::add, onError::add) {
+    val defer = RefVec<() -> Unit>()
+    val onError = RefVec<() -> Unit>()
+    val scope = ExecutionScope.create(defer::pushBack, onError::pushBack) {
         throw Exception("Manual error triggered")
     }
     val ex: Exception
diff --git a/src/main/kotlin/blitz/Either.kt b/src/main/kotlin/blitz/Either.kt
index 8fd6e09..602f5aa 100644
--- a/src/main/kotlin/blitz/Either.kt
+++ b/src/main/kotlin/blitz/Either.kt
@@ -1,14 +1,19 @@
 package blitz
 
+import blitz.annotations.DontAccessManually
+
+@Suppress("UNCHECKED_CAST", "NOTHING_TO_INLINE")
 class Either<A: Any, B: Any> private constructor(
     aIn: A?, bIn: B?
 ) {
     /** DO NOT SET MANUALLY!!! */
     @JvmField
+    @DontAccessManually
     var a: A? = aIn
 
     /** DO NOT SET MANUALLY!!! */
     @JvmField
+    @DontAccessManually
     var b: B? = bIn
 
     override fun equals(other: Any?): Boolean =
@@ -42,7 +47,10 @@ class Either<A: Any, B: Any> private constructor(
     }
 }
 
+@Suppress("NOTHING_TO_INLINE")
 inline fun <A: Any, B: Any> Either<A, B>.isA() = a != null
+
+@Suppress("NOTHING_TO_INLINE")
 inline fun <A: Any, B: Any> Either<A, B>.isB() = b != null
 
 inline fun <A: Any, B: Any> Either<A, B>.getAOr(prov: Provider<A>): A =
diff --git a/src/main/kotlin/blitz/Endian.kt b/src/main/kotlin/blitz/Endian.kt
index edb2c6b..b61ad93 100644
--- a/src/main/kotlin/blitz/Endian.kt
+++ b/src/main/kotlin/blitz/Endian.kt
@@ -3,17 +3,30 @@ package blitz
 import java.nio.ByteBuffer
 import java.nio.ByteOrder
 
-enum class Endian {
-    LITTLE,
-    BIG
-    ;
+@JvmInline
+value class Endian private constructor(val little: Boolean) {
+    companion object {
+        @Deprecated("Renamed", replaceWith = ReplaceWith("Little"))
+        val LITTLE = Endian(little = true)
+        @JvmStatic
+        val Little = Endian(little = true)
 
-    infix fun encodeLittle(little: ByteArray) =
-        if (this == BIG) little.reversedArray()
+        @Deprecated("Renamed", replaceWith = ReplaceWith("Big"))
+        val BIG = Endian(little = false)
+        @JvmStatic
+        val Big = Endian(little = false)
+    }
+
+    inline val big get() = !little
+
+    @Suppress("NOTHING_TO_INLINE")
+    inline infix fun encodeLittle(little: ByteArray) =
+        if (this.big) little.reversedArray()
         else little
 
-    fun toNIO(): ByteOrder =
-        if (this == LITTLE) ByteOrder.LITTLE_ENDIAN
+    @Suppress("NOTHING_TO_INLINE")
+    inline fun toNIO(): ByteOrder =
+        if (this.little) ByteOrder.LITTLE_ENDIAN
         else ByteOrder.BIG_ENDIAN
 }
 
@@ -22,8 +35,12 @@ fun ByteBuffer.order(endian: Endian): ByteBuffer =
 
 fun Long.toBytes(endian: Endian) =
     endian encodeLittle
-            toInt().toBytes(Endian.LITTLE) +
-            toInt().shr(32).toBytes(Endian.LITTLE)
+            toInt().toBytes(Endian.Little) +
+            toInt().shr(32).toBytes(Endian.Little)
+
+@Suppress("NOTHING_TO_INLINE")
+inline fun ULong.toBytes(endian: Endian) =
+    toLong().toBytes(endian)
 
 fun Int.toBytes(endian: Endian) =
     endian encodeLittle byteArrayOf(
@@ -33,19 +50,22 @@ fun Int.toBytes(endian: Endian) =
         this.shr(24).and(0xFF).toByte()
     )
 
-fun UInt.toBytes(endian: Endian) =
+@Suppress("NOTHING_TO_INLINE")
+inline fun UInt.toBytes(endian: Endian) =
     toInt().toBytes(endian)
 
 fun Short.toBytes(endian: Endian) =
-    endian encodeLittle toInt().toBytes(Endian.LITTLE).copyOf(2)
+    endian encodeLittle toInt().toBytes(Endian.Little).copyOf(2)
 
-fun UShort.toBytes(endian: Endian) =
+@Suppress("NOTHING_TO_INLINE")
+inline fun UShort.toBytes(endian: Endian) =
     toShort().toBytes(endian)
 
 fun Byte.toBytes() =
     byteArrayOf(this)
 
-fun UByte.toBytes() =
+@Suppress("NOTHING_TO_INLINE")
+inline fun UByte.toBytes() =
     toByte().toBytes()
 
 // TODO: no cheat
@@ -68,8 +88,10 @@ fun ByteArray.toLong(endian: Endian) =
 fun ByteArray.toULong(endian: Endian) =
     toLong(endian).toULong()
 
-fun ByteArray.toByte() =
+@Suppress("NOTHING_TO_INLINE")
+inline fun ByteArray.toByte() =
     this[0]
 
-fun ByteArray.toUByte() =
+@Suppress("NOTHING_TO_INLINE")
+inline fun ByteArray.toUByte() =
     this[0].toUByte()
\ No newline at end of file
diff --git a/src/main/kotlin/blitz/IO.kt b/src/main/kotlin/blitz/IO.kt
deleted file mode 100644
index 1a50780..0000000
--- a/src/main/kotlin/blitz/IO.kt
+++ /dev/null
@@ -1,13 +0,0 @@
-package blitz
-
-@Deprecated(
-    level = DeprecationLevel.ERROR,
-    message = "Will be removed in the future!",
-    replaceWith = ReplaceWith(
-        "Terminal.warn",
-        "blitz.term.Terminal"
-    )
-)
-fun warn(msg: String) {
-    System.err.println(msg)
-}
\ No newline at end of file
diff --git a/src/main/kotlin/blitz/OperationChain.kt b/src/main/kotlin/blitz/OperationChain.kt
deleted file mode 100644
index f92342d..0000000
--- a/src/main/kotlin/blitz/OperationChain.kt
+++ /dev/null
@@ -1,87 +0,0 @@
-package blitz
-
-import blitz.collections.selfInitializingSequence
-
-class OperationChain<I, O> private constructor(
-    private val impl: Impl = Impl()
-) {
-    private var until = 0
-
-    private class Impl {
-        val seqe = mutableListOf<(Sequence<Any?>) -> Sequence<Any?>>()
-
-        var finalized = false
-
-        fun add(op: Operator<*, *>) {
-            seqe += { seq: Sequence<Any?> ->
-                seq.map(op as Operator<Any?, Any?>)
-            }
-        }
-
-        fun addFlat(op: Operator<*, Sequence<*>>) {
-            seqe += { seq: Sequence<Any?> ->
-                seq.flatMap(op as Operator<Any?, Sequence<Any?>>)
-            }
-        }
-    }
-
-    fun <NO> map(op: Operator<O, NO>): OperationChain<I, NO> =
-        OperationChain<I, NO>(impl.also { it.add(op) })
-            .also { it.until = this.until + 1 }
-
-    fun <NO> flatMap(op: Operator<O, Sequence<NO>>): OperationChain<I, NO> =
-        OperationChain<I, NO>(impl.also { it.addFlat(op) })
-            .also { it.until = this.until + 1 }
-
-    fun <NO> map(op: OperationChain<O, NO>): OperationChain<I, NO> {
-        if (!op.impl.finalized)
-            throw Exception("Can not map un-finalized operation chain onto operation chain!")
-        return flatMap(op::process)
-    }
-
-    fun <NO> modifier(op: Operator<Sequence<O>, Sequence<NO>>): OperationChain<I, NO> =
-        OperationChain<I, NO>(impl.also { it.seqe.add(op as (Sequence<Any?>) -> Sequence<Any?>) })
-            .also { it.until = this.until + 1 }
-
-    fun finalize(): OperationChain<I, O> {
-        if (impl.finalized)
-            throw Exception("Can't finalize a finalized OperationChain!")
-        impl.finalized = true
-        return this
-    }
-
-    fun process(v: I): Sequence<O> =
-        selfInitializingSequence {
-            var seq = sequenceOf<Any?>(v)
-            impl.seqe
-                .asSequence()
-                .take(until)
-                .forEach { op ->
-                    seq = op(seq)
-                }
-            seq as Sequence<O>
-        }
-
-    fun processAll(v: Sequence<I>): Sequence<O> =
-        v.flatMap { process(it) }
-
-    companion object {
-        internal fun <I> create(): OperationChain<I, I> =
-            OperationChain()
-    }
-}
-
-fun <T, O> Sequence<T>.map(chain: OperationChain<T, O>): Sequence<O> =
-    chain.processAll(this)
-
-fun <I> chain(): OperationChain<I, I> =
-    OperationChain.create()
-
-fun <I, O> OperationChain<I, O>.chunked(size: Int): OperationChain<I, List<O>> =
-    modifier { it.chunked(size) }
-
-fun <I, O, R> OperationChain<I, O>.chunked(size: Int, transform: (List<O>) -> R): OperationChain<I, R> =
-    modifier { it.chunked(size, transform) }
-
-fun <I, O> OperationChain<I, O>.filter(predicate: (O) -> Boolean): OperationChain<I, O> =
-    modifier { it.filter(predicate) }
\ No newline at end of file
diff --git a/src/main/kotlin/blitz/Switch.kt b/src/main/kotlin/blitz/Switch.kt
index ba936f7..906f7be 100644
--- a/src/main/kotlin/blitz/Switch.kt
+++ b/src/main/kotlin/blitz/Switch.kt
@@ -5,6 +5,7 @@ data class SwitchCase<C, T: Any, R>(
     val then: (T) -> R,
 )
 
+@Suppress("NOTHING_TO_INLINE")
 inline infix fun <C, T: Any, R> ((C)->Pair<Boolean, T?>).case(noinline then: (T) -> R) =
     SwitchCase(this, then)
 
diff --git a/src/main/kotlin/blitz/Types.kt b/src/main/kotlin/blitz/Types.kt
index d3ae566..21430e2 100644
--- a/src/main/kotlin/blitz/Types.kt
+++ b/src/main/kotlin/blitz/Types.kt
@@ -1,5 +1,3 @@
 package blitz
 
-typealias Provider<T> = () -> T
-
-typealias Operator<I, O> = (I) -> O
\ No newline at end of file
+typealias Provider<T> = () -> T
\ No newline at end of file
diff --git a/src/main/kotlin/blitz/Utils.kt b/src/main/kotlin/blitz/Utils.kt
index 567b07a..863da5e 100644
--- a/src/main/kotlin/blitz/Utils.kt
+++ b/src/main/kotlin/blitz/Utils.kt
@@ -1,7 +1,7 @@
 package blitz
 
 fun unreachable(): Nothing =
-    error("this should be unreachable")
+    throw UnsupportedOperationException("this should be unreachable")
 
 inline fun <reified R> Any?.cast(): R? =
-    this?.let { if (it is R) it else null }
\ No newline at end of file
+    this?.let { it as? R }
\ No newline at end of file
diff --git a/src/main/kotlin/blitz/annotations/Access.kt b/src/main/kotlin/blitz/annotations/Access.kt
new file mode 100644
index 0000000..4be6038
--- /dev/null
+++ b/src/main/kotlin/blitz/annotations/Access.kt
@@ -0,0 +1,4 @@
+package blitz.annotations
+
+@Retention(AnnotationRetention.SOURCE)
+annotation class DontAccessManually
\ No newline at end of file
diff --git a/src/main/kotlin/blitz/annotations/Mutability.kt b/src/main/kotlin/blitz/annotations/Mutability.kt
new file mode 100644
index 0000000..c8223ec
--- /dev/null
+++ b/src/main/kotlin/blitz/annotations/Mutability.kt
@@ -0,0 +1,25 @@
+package blitz.annotations
+
+/**
+ * The target class is mutable.
+ * Mutable methods should be annotated with [Mutate]
+ *
+ * @see Immutable
+ */
+@Target(AnnotationTarget.CLASS)
+@Retention(AnnotationRetention.SOURCE)
+annotation class Mutable
+
+@Target(AnnotationTarget.FUNCTION)
+@Retention(AnnotationRetention.SOURCE)
+annotation class Mutate
+
+/**
+ * The target class has no mutability that can be detected from outside.
+ * It can have for example a mutable cache, but it should not affect the values of future reads.
+ *
+ * @see Mutable
+ */
+@Target(AnnotationTarget.CLASS)
+@Retention(AnnotationRetention.SOURCE)
+annotation class Immutable
\ No newline at end of file
diff --git a/src/main/kotlin/blitz/collections/ByteVec.kt b/src/main/kotlin/blitz/collections/ByteVec.kt
index ad6f169..0ef64f5 100644
--- a/src/main/kotlin/blitz/collections/ByteVec.kt
+++ b/src/main/kotlin/blitz/collections/ByteVec.kt
@@ -135,7 +135,7 @@ class ByteVec(private val initCap: Int = 0): Vec<Byte>, ByteBatchSequence {
         array[index] = value
     }
 
-    override fun idx(value: Byte): Int =
+    override fun indexOf(value: Byte): Int =
         array.indexOf(value)
 
     companion object {
diff --git a/src/main/kotlin/blitz/collections/CharVec.kt b/src/main/kotlin/blitz/collections/CharVec.kt
index 2b98969..4ffd0bb 100644
--- a/src/main/kotlin/blitz/collections/CharVec.kt
+++ b/src/main/kotlin/blitz/collections/CharVec.kt
@@ -135,7 +135,7 @@ class CharVec(private val initCap: Int = 0): Vec<Char>, BatchSequence<Char> {
         array[index] = value
     }
 
-    override fun idx(value: Char): Int =
+    override fun indexOf(value: Char): Int =
         array.indexOf(value)
 
     companion object {
diff --git a/src/main/kotlin/blitz/collections/Dense16x16BoolMap.kt b/src/main/kotlin/blitz/collections/Dense16x16BoolMap.kt
index 12a4192..1ee3a1c 100644
--- a/src/main/kotlin/blitz/collections/Dense16x16BoolMap.kt
+++ b/src/main/kotlin/blitz/collections/Dense16x16BoolMap.kt
@@ -3,6 +3,8 @@ package blitz.collections
 import kotlin.contracts.ExperimentalContracts
 import kotlin.contracts.contract
 
+// TODO: rewrite to math package
+
 @JvmInline
 @OptIn(ExperimentalUnsignedTypes::class)
 value class Dense16x16BoolMap(
diff --git a/src/main/kotlin/blitz/collections/IntVec.kt b/src/main/kotlin/blitz/collections/IntVec.kt
index c59c029..eac7e81 100644
--- a/src/main/kotlin/blitz/collections/IntVec.kt
+++ b/src/main/kotlin/blitz/collections/IntVec.kt
@@ -132,7 +132,7 @@ class IntVec(private val initCap: Int = 0): Vec<Int>, BatchSequence<Int> {
         array[index] = value
     }
 
-    override fun idx(value: Int): Int =
+    override fun indexOf(value: Int): Int =
         array.indexOf(value)
 
     companion object {
diff --git a/src/main/kotlin/blitz/collections/Iter.kt b/src/main/kotlin/blitz/collections/Iter.kt
new file mode 100644
index 0000000..71a029a
--- /dev/null
+++ b/src/main/kotlin/blitz/collections/Iter.kt
@@ -0,0 +1,3 @@
+package blitz.collections
+
+typealias Iter<T> = ((T) -> Unit) -> Unit
\ No newline at end of file
diff --git a/src/main/kotlin/blitz/collections/IterUtils.kt b/src/main/kotlin/blitz/collections/IterUtils.kt
index a51608d..882f4a8 100644
--- a/src/main/kotlin/blitz/collections/IterUtils.kt
+++ b/src/main/kotlin/blitz/collections/IterUtils.kt
@@ -33,6 +33,7 @@ fun <T> generateIterator(fn: () -> T?): Iterator<T> =
 /**
  * Can't explain this function. Look at the source of [blitz.parse.tokenize] as an example
  */
+@Deprecated("tf is this")
 fun <T, R> Iterator<T>.funnyMap(fn: (UnGettableIterator<T>) -> R?): Iterator<R> {
     val iter = asUnGettable()
     return generateIterator { fn(iter) }
@@ -50,4 +51,17 @@ fun <T> Iterator<T>.collect(to: Vec<T>): Vec<T> {
         to.pushBack(it)
     }
     return to
+}
+
+inline fun <T> Iterator<T>.collect(crossinline consumer: (T) -> Unit) {
+    forEachRemaining {
+        consumer(it)
+    }
+}
+
+fun <T> Iter<T>.collect(to: Vec<T>): Vec<T> {
+    this {
+        to.pushBack(it)
+    }
+    return to
 }
\ No newline at end of file
diff --git a/src/main/kotlin/blitz/collections/LongVec.kt b/src/main/kotlin/blitz/collections/LongVec.kt
index d8a51c4..dad66b5 100644
--- a/src/main/kotlin/blitz/collections/LongVec.kt
+++ b/src/main/kotlin/blitz/collections/LongVec.kt
@@ -132,7 +132,7 @@ class LongVec(private val initCap: Int = 0): Vec<Long>, BatchSequence<Long> {
         array[index] = value
     }
 
-    override fun idx(value: Long): Int =
+    override fun indexOf(value: Long): Int =
         array.indexOf(value)
 
     companion object {
diff --git a/src/main/kotlin/blitz/collections/Matrix.kt b/src/main/kotlin/blitz/collections/Matrix.kt
index 09bf86c..a81dee8 100644
--- a/src/main/kotlin/blitz/collections/Matrix.kt
+++ b/src/main/kotlin/blitz/collections/Matrix.kt
@@ -1,8 +1,12 @@
 package blitz.collections
 
+import blitz.annotations.Mutable
 import blitz.str.MutMultiLineString
 import kotlin.math.min
 
+// TODO: rewrite to Array2o
+
+@Mutable
 class Matrix<T>(
     val width: Int,
     val height: Int,
diff --git a/src/main/kotlin/blitz/collections/RefVec.kt b/src/main/kotlin/blitz/collections/RefVec.kt
index 00064ae..8a9f87c 100644
--- a/src/main/kotlin/blitz/collections/RefVec.kt
+++ b/src/main/kotlin/blitz/collections/RefVec.kt
@@ -1,6 +1,6 @@
 package blitz.collections
 
-@Suppress("UNCHECKED_CAST")
+@Suppress("UNCHECKED_CAST", "NOTHING_TO_INLINE")
 class RefVec<T>(private val initCap: Int = 0): Vec<T> {
     override var size = 0
     @JvmField var _cap = initCap
@@ -23,7 +23,7 @@ class RefVec<T>(private val initCap: Int = 0): Vec<T> {
     inline fun copyIntoArray(arr: Array<Any?>, destOff: Int = 0, startOff: Int = 0) =
         _array?.copyInto(arr, destOff, startOff, size)
 
-    override inline fun copy(): RefVec<T> =
+    override fun copy(): RefVec<T> =
         RefVec<T>(size).also {
             it._array?.let { copyIntoArray(it) }
         }
@@ -101,7 +101,7 @@ class RefVec<T>(private val initCap: Int = 0): Vec<T> {
     inline fun <R> map(fn: (T) -> R): MutableList<R> =
         MutableList(size) { fn(this[it]) }
 
-    override fun idx(value: T): Int =
+    override fun indexOf(value: T): Int =
         _array?.indexOf(value) ?: -1
 
     companion object {
diff --git a/src/main/kotlin/blitz/collections/ShortVec.kt b/src/main/kotlin/blitz/collections/ShortVec.kt
index 23914dd..600aeff 100644
--- a/src/main/kotlin/blitz/collections/ShortVec.kt
+++ b/src/main/kotlin/blitz/collections/ShortVec.kt
@@ -132,7 +132,7 @@ class ShortVec(private val initCap: Int = 0): Vec<Short>, BatchSequence<Short> {
         array[index] = value
     }
 
-    override fun idx(value: Short): Int =
+    override fun indexOf(value: Short): Int =
         array.indexOf(value)
 
     companion object {
diff --git a/src/main/kotlin/blitz/collections/Tree.kt b/src/main/kotlin/blitz/collections/Tree.kt
index a70aa2a..b778c29 100644
--- a/src/main/kotlin/blitz/collections/Tree.kt
+++ b/src/main/kotlin/blitz/collections/Tree.kt
@@ -1,5 +1,6 @@
 package blitz.collections
 
+@Deprecated("Results in unreadable code. Use custom tree instead")
 class Tree<T> {
     var root: Node<T>? = null
 
@@ -27,6 +28,7 @@ class Tree<T> {
     }
 }
 
+@Deprecated("Results in unreadable code. Use custom tree instead")
 class Node<T>(
     var value: T? = null,
     var children: MutableList<Node<T>> = mutableListOf()
@@ -74,6 +76,7 @@ class Node<T>(
     }
 }
 
+@Deprecated("Results in unreadable code. Use custom tree instead")
 interface TreeTraverser<T> {
     fun process(node: Node<T>): Boolean /* true if continue, false if stop */
 
diff --git a/src/main/kotlin/blitz/collections/Vec.kt b/src/main/kotlin/blitz/collections/Vec.kt
index 99e8542..5940183 100644
--- a/src/main/kotlin/blitz/collections/Vec.kt
+++ b/src/main/kotlin/blitz/collections/Vec.kt
@@ -38,7 +38,7 @@ interface Vec<T>: IndexableSequence<T> {
 
     fun clear()
 
-    fun idx(value: T): Int {
+    fun indexOf(value: T): Int {
         for (i in 0 until size) {
             if (this[i] == value)
                 return i
diff --git a/src/main/kotlin/blitz/math/Aabb3f.kt b/src/main/kotlin/blitz/math/Aabb3f.kt
new file mode 100644
index 0000000..1e76198
--- /dev/null
+++ b/src/main/kotlin/blitz/math/Aabb3f.kt
@@ -0,0 +1,57 @@
+package blitz.math
+
+data class Aabb3f(
+    @JvmField val min: Vec3f,
+    @JvmField val max: Vec3f,
+) {
+    inline val height get() = max.y - min.y
+    inline val width get() = max.x - min.x
+    inline val depth get() = max.z - min.z
+
+    companion object {
+        fun from(other: Aabb3s) =
+            Aabb3f(
+                Vec3f(other.min.x.toFloat(), other.min.y.toFloat(), other.min.z.toFloat()),
+                Vec3f(other.max.x.toFloat(), other.max.y.toFloat(), other.max.z.toFloat())
+            )
+    }
+
+    /**
+     * A vector representing the size of the box. (width, height, depth)
+     */
+    val size: Vec3f get() =
+        Vec3f(width, height, depth)
+
+    operator fun contains(point: Vec3f) =
+        point.x >= min.x && point.x <= max.x &&
+                point.y >= min.y && point.y <= max.y &&
+                point.z >= min.z && point.z <= max.z
+
+    operator fun rangeTo(other: Aabb3f): Aabb3f =
+        Aabb3f(
+            min = Vec3f(
+                minOf(min.x, other.min.x),
+                minOf(min.y, other.min.y),
+                minOf(min.z, other.min.z)
+            ),
+            max = Vec3f(
+                maxOf(max.x, other.max.x),
+                maxOf(max.y, other.max.y),
+                maxOf(max.z, other.max.z)
+            )
+        )
+
+    operator fun rangeTo(other: Vec3f) =
+        Aabb3f(
+            min = Vec3f(
+                minOf(min.x, other.x),
+                minOf(min.y, other.y),
+                minOf(min.z, other.z)
+            ),
+            max = Vec3f(
+                maxOf(max.x, other.x),
+                maxOf(max.y, other.y),
+                maxOf(max.z, other.z)
+            )
+        )
+}
\ No newline at end of file
diff --git a/src/main/kotlin/blitz/math/Aabb3s.kt b/src/main/kotlin/blitz/math/Aabb3s.kt
new file mode 100644
index 0000000..7fc859b
--- /dev/null
+++ b/src/main/kotlin/blitz/math/Aabb3s.kt
@@ -0,0 +1,90 @@
+package blitz.math
+
+import blitz.Endian
+import blitz.annotations.Immutable
+import blitz.toBytes
+import blitz.toLong
+import kotlin.contracts.ExperimentalContracts
+import kotlin.contracts.InvocationKind
+import kotlin.contracts.contract
+
+@Immutable
+@Suppress("NOTHING_TO_INLINE")
+
+@OptIn(ExperimentalContracts::class)
+class Aabb3s private constructor(
+    val min: Vec3s,
+    val max: Vec3s
+) {
+    inline fun copy(min: Vec3s = this.min, max: Vec3s = this.max) =
+        of(min, max)
+
+    override fun equals(other: Any?): Boolean =
+        other is Aabb3s && other.min == min && other.max == max
+
+    override fun hashCode(): Int =
+        31 * min.hashCode() + max.hashCode()
+
+    override fun toString(): String =
+        "($min, $max)"
+
+    operator fun contains(point: Vec3s): Boolean =
+        point.x in min.x..max.x && point.y in min.y..max.y && point.z in min.z..max.z
+
+    operator fun contains(other: Aabb3s): Boolean =
+        contains(other.min) && contains(other.max)
+
+    operator fun rangeTo(include: Vec3s): Aabb3s {
+        val actualMin = Vec3s(minOf(min.x, include.x), minOf(min.y, include.y), minOf(min.z, include.z))
+        val actualMax = Vec3s(maxOf(max.x, include.x), maxOf(max.y, include.y), maxOf(max.z, include.z))
+        return Aabb3s(actualMin, actualMax)
+    }
+
+    operator fun rangeTo(include: Aabb3s): Aabb3s {
+        val actualMin = Vec3s(minOf(min.x, include.min.x), minOf(min.y, include.min.y), minOf(min.z, include.min.z))
+        val actualMax = Vec3s(maxOf(max.x, include.max.x), maxOf(max.y, include.max.y), maxOf(max.z, include.max.z))
+        return Aabb3s(actualMin, actualMax)
+    }
+
+    operator fun plus(off: Vec3s) =
+        Aabb3s(min + off, max + off)
+
+    operator fun minus(off: Vec3s) =
+        Aabb3s(min - off, max - off)
+
+    inline fun iter(consumer: (Vec3s) -> Unit) {
+        for (y in min.y..max.y) {
+            for (x in min.x..max.x) {
+                for (z in min.z..max.z) {
+                    consumer(Vec3s(x, y, z))
+                }
+            }
+        }
+    }
+
+    inline fun serialize(put: (ByteArray) -> Unit) {
+        contract {
+            callsInPlace(put, InvocationKind.AT_LEAST_ONCE)
+        }
+
+        min.packed.toBytes(Endian.Little).let(put)
+        max.packed.toBytes(Endian.Little).let(put)
+    }
+
+    companion object {
+        fun of(a: Vec3s, b: Vec3s): Aabb3s =
+            Aabb3s(a, a)..b
+
+
+        @OptIn(ExperimentalContracts::class)
+        inline fun deserialize(get: (Int) -> ByteArray): Aabb3s {
+            contract {
+                callsInPlace(get, InvocationKind.AT_LEAST_ONCE)
+            }
+
+            val min = Vec3s.from(get(8).toLong(Endian.LITTLE).toULong())
+            val max = Vec3s.from(get(8).toLong(Endian.LITTLE).toULong())
+            return of(min, max)
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/main/kotlin/blitz/math/Anglef.kt b/src/main/kotlin/blitz/math/Anglef.kt
new file mode 100644
index 0000000..6f6c1c6
--- /dev/null
+++ b/src/main/kotlin/blitz/math/Anglef.kt
@@ -0,0 +1,51 @@
+package blitz.math
+
+@JvmInline
+value class Anglef(
+    val radians: Float
+) {
+    val degrees get() =
+        radians * 180f / Math.PI.toFloat()
+
+    val gradians get() =
+        radians * 200f / Math.PI.toFloat()
+
+    fun normalized() =
+        Anglef(radians % (2 * Math.PI.toFloat()))
+
+    operator fun plus(other: Anglef) =
+        Anglef(radians + other.radians)
+
+    operator fun minus(other: Anglef) =
+        Anglef(radians - other.radians)
+
+    operator fun times(other: Anglef) =
+        Anglef(radians * other.radians)
+
+    operator fun div(other: Anglef) =
+        Anglef(radians / other.radians)
+
+    operator fun times(other: Float) =
+        Anglef(radians * other)
+
+    operator fun div(other: Float) =
+        Anglef(radians / other)
+
+    operator fun unaryMinus() =
+        Anglef(-radians)
+
+    override fun toString(): String {
+        return "$degrees°"
+    }
+
+    companion object {
+        fun fromRadians(radians: Float) =
+            Anglef(radians)
+
+        fun fromDegrees(degrees: Float) =
+            Anglef(degrees * Math.PI.toFloat() / 180f)
+
+        fun fromGradians(gradians: Float) =
+            Anglef(gradians * Math.PI.toFloat() / 200f)
+    }
+}
\ No newline at end of file
diff --git a/src/main/kotlin/blitz/math/BitInts.kt b/src/main/kotlin/blitz/math/BitInts.kt
new file mode 100644
index 0000000..a607cfe
--- /dev/null
+++ b/src/main/kotlin/blitz/math/BitInts.kt
@@ -0,0 +1,41 @@
+package blitz.math
+
+import blitz.annotations.Immutable
+
+@Immutable
+@JvmInline
+@Suppress("NOTHING_TO_INLINE")
+value class U3(val value: UByte) {
+    override fun toString() =
+        value.toString()
+
+    inline fun toU4() = U4(value)
+}
+
+@Immutable
+@JvmInline
+@Suppress("NOTHING_TO_INLINE")
+value class U4(val value: UByte) {
+    override fun toString() =
+        value.toString()
+
+    inline fun toU3() = U3(value and 0b111u)
+}
+
+
+/** two U4 values packed => UByte */
+@Immutable
+@JvmInline
+@Suppress("NOTHING_TO_INLINE")
+value class Vec2u4(val packed: UByte) {
+    inline val x : U4 get() = U4((packed.toUInt() shr 4).toUByte())
+    inline val y : U4 get() = U4(packed and 0b111u)
+
+    constructor(x: U4, y: U4): this((x.value.toUInt() shl 4 or
+            y.value.toUInt()).toUByte())
+
+    override fun toString() = "($x, $y)"
+
+    inline fun component1() = x
+    inline fun component2() = y
+}
\ No newline at end of file
diff --git a/src/main/kotlin/blitz/math/Direction.kt b/src/main/kotlin/blitz/math/Direction.kt
new file mode 100644
index 0000000..e881057
--- /dev/null
+++ b/src/main/kotlin/blitz/math/Direction.kt
@@ -0,0 +1,29 @@
+package blitz.math
+
+import blitz.unreachable
+
+/** only 6 directions -> only needs 3 bits */
+@JvmInline
+value class Direction(
+    val idx: U3
+) {
+    companion object {
+        val UP = Direction(U3(0u))
+        val DOWN = Direction(U3(1u))
+        val NORTH = Direction(U3(2u))
+        val EAST = Direction(U3(3u))
+        val SOUTH = Direction(U3(4u))
+        val WEST = Direction(U3(5u))
+    }
+
+    override fun toString() =
+        when (this) {
+            UP -> "Up"
+            DOWN -> "Down"
+            NORTH -> "North"
+            EAST -> "East"
+            SOUTH -> "South"
+            WEST -> "West"
+            else -> unreachable()
+        }
+}
\ No newline at end of file
diff --git a/src/main/kotlin/blitz/math/Lerp.kt b/src/main/kotlin/blitz/math/Interpolate.kt
similarity index 62%
rename from src/main/kotlin/blitz/math/Lerp.kt
rename to src/main/kotlin/blitz/math/Interpolate.kt
index 2aa353c..18bd8a8 100644
--- a/src/main/kotlin/blitz/math/Lerp.kt
+++ b/src/main/kotlin/blitz/math/Interpolate.kt
@@ -3,8 +3,14 @@ package blitz.math
 infix fun Pair<Int, Int>.lerpi(t: Double): Double =
     (1.0f - t) * first + second * t
 
+infix fun Pair<Int, Int>.lerpi(t: Float): Float =
+    (1.0f - t) * first + second * t
+
 infix fun Pair<Double, Double>.lerpd(t: Double): Double =
     (1.0f - t) * first + second * t
 
 infix fun Pair<Float, Float>.lerpf(t: Double): Double =
     (1.0f - t) * first + second * t
+
+infix fun Pair<Float, Float>.lerpf(t: Float): Float =
+    (1.0f - t) * first + second * t
diff --git a/src/main/kotlin/blitz/math/PackedVoxelShape3i.kt b/src/main/kotlin/blitz/math/PackedVoxelShape3i.kt
new file mode 100644
index 0000000..0c004a5
--- /dev/null
+++ b/src/main/kotlin/blitz/math/PackedVoxelShape3i.kt
@@ -0,0 +1,146 @@
+package blitz.math
+
+import blitz.annotations.Mutable
+import blitz.annotations.Mutate
+import blitz.test.annotations.Test
+import blitz.test.util.requireEqual
+import kotlin.contracts.ExperimentalContracts
+import kotlin.contracts.contract
+
+/**
+ * use this only for small-ish voxel shapes: 16x16, 32x16, etc
+ *
+ * size needs to be known at construction
+ */
+@Mutable
+@JvmInline
+@OptIn(ExperimentalContracts::class)
+@Suppress("NOTHING_TO_INLINE")
+value class PackedVoxelShape3i(
+    val packed: LongArray,
+) {
+    inline val sizes4x4x4 get() =
+        Vec3s.from(packed[0].toULong())
+
+    val sizes get() =
+        Vec3s(sizes4x4x4.x * 4.toShort(), sizes4x4x4.y * 4.toShort(), sizes4x4x4.z * 4.toShort())
+
+    inline fun index4x4x4(x: Int, y: Int, z: Int) =
+        1 + x + sizes4x4x4.x.toInt() * (y + sizes4x4x4.y.toInt() * z)
+
+    operator fun get(x: Int, y: Int, z: Int): Boolean {
+        require(Vec3s(x, y, z).allComponents(sizes) { a, sz -> a < sz })
+        return VoxelShape4x4x4i(packed[index4x4x4(x / 4, y / 4, z / 4)])[x % 4, y % 4, z % 4]
+    }
+
+    inline operator fun get(idx: Vec3s) =
+        get(idx.x.toInt(), idx.y.toInt(), idx.z.toInt())
+
+    @Mutate
+    operator fun set(x: Int, y: Int, z: Int, value: Boolean) {
+        require(Vec3s(x, y, z).allComponents(sizes) { a, sz -> a < sz }) { "index out of bounds: ($x, $y, $z) for $sizes" }
+        val idx = index4x4x4(x / 4, y / 4, z / 4)
+        packed[idx] = VoxelShape4x4x4i(packed[idx]).set(x % 4, y % 4, z % 4, value).packed
+    }
+
+    @Mutate
+    inline operator fun set(idx: Vec3s, value: Boolean) =
+        set(idx.x.toInt(), idx.y.toInt(), idx.z.toInt(), value)
+
+    inline fun iterChunks(consumer: (Vec3s, VoxelShape4x4x4i) -> Unit) {
+        contract {
+            callsInPlace(consumer)
+        }
+
+        sizes4x4x4.asSizeIterate {
+            consumer(it,
+                VoxelShape4x4x4i(
+                    packed[index4x4x4(it.x.toInt(), it.y.toInt(), it.z.toInt())]))
+        }
+    }
+
+    inline fun iterSetVoxels(consumer: (Vec3s) -> Unit) {
+        contract {
+            callsInPlace(consumer)
+        }
+
+        iterChunks { cp, chunk ->
+            chunk.iterSetVoxels { off ->
+                consumer(cp * 4 + off)
+            }
+        }
+    }
+
+    fun layerEmpty(y: Int): Boolean {
+        val cy = y / 4
+        for (cx in 0..<sizes4x4x4.x) {
+            for (cz in 0..<sizes4x4x4.z) {
+                val chunk = VoxelShape4x4x4i(packed[index4x4x4(cx, cy, cz)])
+                if (chunk.empty) continue
+                val layer = chunk[y % 4]
+                if (!layer.empty) return false
+            }
+        }
+        return true
+    }
+
+    inline fun iterNonEmptyLayers(consumer: (Short) -> Unit) {
+        contract {
+            callsInPlace(consumer)
+        }
+
+        for (y in 0..<sizes4x4x4.y * 4) {
+            if (!layerEmpty(y)) {
+                consumer(y.toShort())
+            }
+        }
+    }
+
+    inline fun copy() = PackedVoxelShape3i(packed.copyOf())
+
+    override fun toString(): String {
+        val out = StringBuilder()
+        iterNonEmptyLayers { y ->
+            out.append("layer $y:\n")
+            for (x in 0..<sizes.x) {
+                out.append("  ")
+                for (z in 0..<sizes.z) {
+                    out.append(if (this[x, y.toInt(), z]) '#' else '.')
+                }
+                out.append('\n')
+            }
+        }
+        return out.toString()
+    }
+
+    fun aabb(): Aabb3s? {
+        var out: Aabb3s? = null
+        iterChunks { cp, chunk ->
+            chunk.aabb()?.let {
+                val x = it + cp * 4
+                out = out?.let { it..x } ?: x
+            }
+        }
+        return out
+    }
+
+    companion object {
+        fun of(size: Vec3s): PackedVoxelShape3i {
+            val sizes4x4x4 = size.ceilDiv(4)
+            val obj = PackedVoxelShape3i(LongArray(sizes4x4x4.x.toInt() * sizes4x4x4.y.toInt() * sizes4x4x4.z.toInt() + 1))
+            obj.packed[0] = sizes4x4x4.packed.toLong()
+            return obj
+        }
+    }
+
+    object _tests {
+        @Test
+        fun aabbCorrect() {
+            val voxels = of(Vec3s(8, 6, 8))
+            voxels[3,2,1] = true
+            voxels[6,2,2] = true
+            voxels[7,4,2] = true
+            requireEqual(voxels.aabb(), Aabb3s.of(Vec3s(3, 2, 1), Vec3s(7, 4, 2)))
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/main/kotlin/blitz/math/Vec3f.kt b/src/main/kotlin/blitz/math/Vec3f.kt
new file mode 100644
index 0000000..ea2731d
--- /dev/null
+++ b/src/main/kotlin/blitz/math/Vec3f.kt
@@ -0,0 +1,98 @@
+package blitz.math
+
+import blitz.Endian
+import blitz.annotations.Immutable
+import blitz.toBytes
+import blitz.toInt
+import blitz.unreachable
+import kotlin.contracts.ExperimentalContracts
+import kotlin.contracts.InvocationKind
+import kotlin.contracts.contract
+
+@Immutable
+@OptIn(ExperimentalContracts::class)
+@Suppress("NOTHING_TO_INLINE")
+data class Vec3f(
+    @JvmField val x: Float,
+    @JvmField val y: Float,
+    @JvmField val z: Float
+) {
+
+    inline fun serialize(put: (ByteArray) -> Unit) {
+        contract {
+            callsInPlace(put, InvocationKind.AT_LEAST_ONCE)
+        }
+
+        x.toRawBits().toBytes(Endian.Little).let(put)
+        y.toRawBits().toBytes(Endian.Little).let(put)
+        z.toRawBits().toBytes(Endian.Little).let(put)
+    }
+
+    companion object {
+        inline fun from(s: Vec3s) =
+            Vec3f(s.x.toFloat(), s.y.toFloat(), s.z.toFloat())
+
+        val Zero = Vec3f(0f, 0f, 0f)
+
+
+        @OptIn(ExperimentalContracts::class)
+        inline fun deserialize(get: (Int) -> ByteArray): Vec3f {
+            contract {
+                callsInPlace(get, InvocationKind.AT_LEAST_ONCE)
+            }
+
+            return Vec3f(
+                get(4).toInt(Endian.Little).let(Float::fromBits),
+                get(4).toInt(Endian.Little).let(Float::fromBits),
+                get(4).toInt(Endian.Little).let(Float::fromBits),
+            )
+        }
+    }
+
+    override fun toString() =
+        "($x, $y, $z)"
+
+
+    fun rotate(direction: Direction): Vec3f =
+        when (direction) {
+            Direction.DOWN -> Vec3f(x, -z, y)
+            Direction.UP -> Vec3f(x, z, -y)
+            Direction.NORTH -> Vec3f(x, y, z)
+            Direction.SOUTH -> Vec3f(-x, y, -z)
+            Direction.WEST -> Vec3f(z, y, -x)
+            Direction.EAST -> Vec3f(-z, y, x)
+            else -> unreachable()
+        }
+
+    inline operator fun plus(r: Vec3f): Vec3f =
+        Vec3f(this.x + r.x, this.y + r.y, this.z + r.z)
+
+    inline operator fun minus(r: Vec3f): Vec3f =
+        Vec3f(this.x - r.x, this.y - r.y, this.z - r.z)
+
+    inline operator fun times(r: Vec3f): Vec3f =
+        Vec3f(this.x * r.x, this.y * r.y, this.z * r.z)
+
+    inline operator fun div(r: Vec3f): Vec3f =
+        Vec3f(this.x / r.x, this.y / r.y, this.z / r.z)
+
+    inline infix fun dot(r: Vec3f) =
+        this.x * r.x + this.y * r.y + this.z * r.z
+
+    inline fun product() = x * y * z
+
+    inline operator fun unaryMinus() =
+        Vec3f(-x, -y, -z)
+
+    inline fun allComponents(fn: (Float) -> Boolean) =
+        fn(x) && fn(y) && fn(z)
+
+    inline fun anyComponents(fn: (Float) -> Boolean) =
+        fn(x) || fn(y) || fn(z)
+
+    inline fun allComponents(other: Vec3f, fn: (Float, Float) -> Boolean) =
+        fn(x, other.x) && fn(y, other.y) && fn(z, other.z)
+
+    inline fun anyComponent(other: Vec3f, fn: (Float, Float) -> Boolean) =
+        fn(x, other.x) || fn(y, other.y) || fn(z, other.z)
+}
\ No newline at end of file
diff --git a/src/main/kotlin/blitz/math/Vec3s.kt b/src/main/kotlin/blitz/math/Vec3s.kt
new file mode 100644
index 0000000..ff93203
--- /dev/null
+++ b/src/main/kotlin/blitz/math/Vec3s.kt
@@ -0,0 +1,136 @@
+package blitz.math
+
+import blitz.annotations.Immutable
+import blitz.unreachable
+import blitz.test.annotations.Test
+import kotlin.contracts.ExperimentalContracts
+import kotlin.contracts.contract
+
+@Immutable
+@JvmInline
+@OptIn(ExperimentalContracts::class)
+@Suppress("NOTHING_TO_INLINE")
+value class Vec3s private constructor(val backing: Vec4s) {
+    inline val x: Short get() = backing.x
+    inline val y: Short get() = backing.y
+    inline val z: Short get() = backing.z
+
+    inline val packed: ULong get() = backing.packed
+
+    companion object {
+        fun from(xyz: Vec4s) =
+            Vec3s(Vec4s(xyz.packed and 0xFFFF_FFFF_FFFF_0000uL))
+
+        inline fun from(packed: ULong) =
+            from(Vec4s(packed))
+
+        inline fun from(v: Vec3f) =
+            Vec3s(v.x.toInt(), v.y.toInt(), v.z.toInt())
+
+        @JvmStatic
+        private fun Int.toShortThrow() = toShort().also {
+            if (it.toInt() != this) throw IllegalArgumentException("Value $this cannot be represented as Short")
+        }
+
+        val Zero = Vec3s(0, 0, 0)
+    }
+
+    @Suppress("UNUSED")
+    object _tests {
+        @Test
+        fun fromPackedCorrect() {
+            require(from(Vec4s(1,2,3,4).packed) == Vec3s(1,2,3))
+        }
+
+        @Test
+        fun serialFormatStable() {
+            require(Vec4s(1,2,3,4).packed == 0x0001_0002_0003_0004uL)
+            require(Vec4s(0x0001_0002_0003_0004uL) == Vec4s(1,2,3,4))
+        }
+    }
+
+    constructor(x: Short, y: Short, z: Short): this(Vec4s(x, y, z, 0))
+    constructor(x: Int, y: Int, z: Int): this(Vec4s(x.toShortThrow(), y.toShortThrow(), z.toShortThrow(), 0))
+
+    override fun toString() = "($x, $y, $z)"
+
+    inline operator fun component1() = x
+    inline operator fun component2() = y
+    inline operator fun component3() = z
+
+    inline fun asSizeIterate(consumer: (Vec3s) -> Unit) {
+        contract {
+            callsInPlace(consumer)
+        }
+
+        for (z in 0..<z) {
+            for (x in 0..<x) {
+                for (y in 0..<y) {
+                    consumer(Vec3s(x, y, z))
+                }
+            }
+        }
+    }
+
+    fun rotate(direction: Direction): Vec3s =
+        when (direction) {
+            Direction.DOWN -> Vec3s(x, (-z).toShort(), y)
+            Direction.UP -> Vec3s(x, z, (-y).toShort())
+            Direction.NORTH -> Vec3s(x, y, z)
+            Direction.SOUTH -> Vec3s((-x).toShort(), y, (-z).toShort())
+            Direction.WEST -> Vec3s(z, y, (-x).toShort())
+            Direction.EAST -> Vec3s((-z).toShort(), y, x)
+            else -> unreachable()
+        }
+
+    inline operator fun plus(r: Vec3s): Vec3s =
+        Vec3s(this.x + r.x, this.y + r.y, this.z + r.z)
+
+    inline operator fun minus(r: Vec3s): Vec3s =
+        Vec3s(this.x - r.x, this.y - r.y, this.z - r.z)
+
+    inline operator fun times(r: Vec3s): Vec3s =
+        Vec3s(this.x * r.x, this.y * r.y, this.z * r.z)
+
+    inline operator fun plus(off: Short): Vec3s =
+        Vec3s(this.x + off, this.y + off, this.z + off)
+
+    inline operator fun minus(off: Short): Vec3s =
+        Vec3s(this.x - off, this.y - off, this.z - off)
+
+    operator fun times(value: Float): Vec3s =
+        Vec3s((x * value).toInt().toShortThrow(), (y * value).toInt().toShortThrow(), (z * value).toInt().toShortThrow())
+
+    operator fun times(value: Short): Vec3s =
+        Vec3s(x * value, y * value, z * value)
+
+    operator fun div(value: Float): Vec3s =
+        Vec3s((x / value).toInt().toShortThrow(), (y / value).toInt().toShortThrow(), (z / value).toInt().toShortThrow())
+
+    operator fun div(value: Short): Vec3s =
+        Vec3s(x / value, y / value, z / value)
+
+    fun ceilDiv(value: Short): Vec3s =
+        Vec3s(
+            if (x >= 0) (x / value) + 1 else (x / value),
+            if (y >= 0) (y / value) + 1 else (y / value),
+            if (z >= 0) (z / value) + 1 else (z / value)
+        )
+
+    inline fun product() = x.toInt() * y.toInt() * z.toInt()
+
+    inline operator fun unaryMinus() =
+        Vec3s(-x, -y, -z)
+
+    inline fun allComponents(fn: (Short) -> Boolean) =
+        fn(x) && fn(y) && fn(z)
+
+    inline fun anyComponents(fn: (Short) -> Boolean) =
+        fn(x) || fn(y) || fn(z)
+
+    inline fun allComponents(other: Vec3s, fn: (Short, Short) -> Boolean) =
+        fn(x, other.x) && fn(y, other.y) && fn(z, other.z)
+
+    inline fun anyComponent(other: Vec3s, fn: (Short, Short) -> Boolean) =
+        fn(x, other.x) || fn(y, other.y) || fn(z, other.z)
+}
diff --git a/src/main/kotlin/blitz/math/Vec4s.kt b/src/main/kotlin/blitz/math/Vec4s.kt
new file mode 100644
index 0000000..a4119e6
--- /dev/null
+++ b/src/main/kotlin/blitz/math/Vec4s.kt
@@ -0,0 +1,26 @@
+package blitz.math
+
+import blitz.annotations.Immutable
+
+@Immutable
+@JvmInline
+@Suppress("NOTHING_TO_INLINE")
+value class Vec4s(val packed: ULong) {
+    inline val x: Short get() = (packed shr 48).toUShort().toShort()
+    inline val y: Short get() = (packed shr 32).toUShort().toShort()
+    inline val z: Short get() = (packed shr 16).toUShort().toShort()
+    inline val w: Short get() = packed.toUShort().toShort()
+
+    constructor(x: Short, y: Short, z: Short, w: Short): this(
+        (x.toUShort().toULong() shl 48) or
+                (y.toUShort().toULong() shl 32) or
+                (z.toUShort().toULong() shl 16) or
+                w.toUShort().toULong())
+
+    override fun toString() = "($x, $y, $z, $w)"
+
+    inline operator fun component1() = x
+    inline operator fun component2() = y
+    inline operator fun component3() = z
+    inline operator fun component4() = w
+}
\ No newline at end of file
diff --git a/src/main/kotlin/blitz/math/VoxelShape4x4i.kt b/src/main/kotlin/blitz/math/VoxelShape4x4i.kt
new file mode 100644
index 0000000..64823c0
--- /dev/null
+++ b/src/main/kotlin/blitz/math/VoxelShape4x4i.kt
@@ -0,0 +1,40 @@
+package blitz.math
+
+import blitz.annotations.Immutable
+import kotlin.experimental.and
+import kotlin.experimental.or
+
+@Immutable
+@JvmInline
+@Suppress("NOTHING_TO_INLINE")
+value class VoxelShape4x4i(
+    val packed: Short,
+) {
+    fun bitIndexFor(x: Int, y: Int): Int {
+        require(x in 0..3 && y in 0..3) { "index out of bounds: ($x, $y) for 4x4" }
+        return 4 * y + x
+    }
+
+    inline operator fun get(x: Int, y: Int): Boolean =
+        (packed.toUShort().toInt() and (1 shl bitIndexFor(x, y))) != 0
+
+    inline fun set(x: Int, y: Int, value: Boolean): VoxelShape4x4i {
+        val mask = 1 shl bitIndexFor(x, y)
+        return VoxelShape4x4i((if (value)
+            packed.toUShort().toInt() or mask
+        else
+            packed.toUShort().toInt() and mask.inv()).toShort())
+    }
+
+    inline operator fun plus(other: VoxelShape4x4i) =
+        VoxelShape4x4i(packed or other.packed)
+
+    inline operator fun times(other: VoxelShape4x4i) =
+        VoxelShape4x4i(packed and other.packed)
+
+    inline val empty get() = packed.toInt() == 0
+
+    companion object {
+        val Air = VoxelShape4x4i(0)
+    }
+}
diff --git a/src/main/kotlin/blitz/math/VoxelShape4x4x4i.kt b/src/main/kotlin/blitz/math/VoxelShape4x4x4i.kt
new file mode 100644
index 0000000..537fa2b
--- /dev/null
+++ b/src/main/kotlin/blitz/math/VoxelShape4x4x4i.kt
@@ -0,0 +1,93 @@
+package blitz.math
+
+import blitz.annotations.Immutable
+import blitz.test.annotations.Test
+import blitz.test.util.requireEqual
+import kotlin.contracts.ExperimentalContracts
+import kotlin.contracts.contract
+
+@Immutable
+@JvmInline
+@OptIn(ExperimentalContracts::class)
+@Suppress("NOTHING_TO_INLINE")
+value class VoxelShape4x4x4i(
+    val packed: Long
+) {
+    operator fun get(y: Int): VoxelShape4x4i {
+        require(y in 0..3) { "layer index out of bounds: y=$y (expected 0..3)" }
+        val shift = 16 * y
+        return VoxelShape4x4i(((packed ushr shift) and 0xFFFFL).toShort())
+    }
+
+    fun set(y: Int, value: VoxelShape4x4i): VoxelShape4x4x4i {
+        require(y in 0..3) { "layer index out of bounds: y=$y (expected 0..3)" }
+        val shift = 16 * y
+        val clearMask = (0xFFFFL shl shift).inv()
+        val slice = ((value.packed.toUShort().toLong() and 0xFFFFL) shl shift)
+        return VoxelShape4x4x4i((packed and clearMask) or slice)
+    }
+
+    inline operator fun plus(other: VoxelShape4x4x4i) =
+        VoxelShape4x4x4i(packed or other.packed)
+
+    inline operator fun times(other: VoxelShape4x4x4i) =
+        VoxelShape4x4x4i(packed and other.packed)
+
+    inline operator fun get(x: Int, y: Int, z: Int): Boolean =
+        this[y][x, z]
+
+    inline fun set(x: Int, y: Int, z: Int, value: Boolean) =
+        set(y, this[y].set(x, z, value))
+
+    inline val empty get() = packed == 0L
+
+    inline fun iterSetVoxels(consumer: (Vec3s) -> Unit) {
+        contract {
+            callsInPlace(consumer)
+        }
+
+        if (empty) return
+
+        for (y in 0..<4) {
+            for (x in 0..<4) {
+                for (z in 0..<4) {
+                    if (this[x, y, z]) {
+                        consumer(Vec3s(x, y, z))
+                    }
+                }
+            }
+        }
+    }
+
+    fun aabb(): Aabb3s? {
+        if (empty) return null
+        val minBit = packed.countTrailingZeroBits()
+        val maxBit = 63 - packed.countLeadingZeroBits()
+        return Aabb3s.of(
+            bitToPos(minBit),
+            bitToPos(maxBit)
+        )
+    }
+
+    companion object {
+        val AIR = VoxelShape4x4x4i(0)
+
+        private fun bitToPos(bit: Int): Vec3s {
+            //  bit = x + 4 * z + 16 * y
+            val pos2 = bit % 16
+            val x = pos2 % 4
+            val z = pos2 / 4
+            return Vec3s(x.toShort(), (bit / 16).toShort(), z.toShort())
+        }
+    }
+
+    object _test {
+        @Test
+        fun aabbCorrect() {
+            val x = AIR
+                .set(2, 3, 1, true)
+                .set(3, 3, 1, true)
+            requireEqual(x.aabb(), Aabb3s.of(Vec3s(2, 3, 1), Vec3s(3, 3, 1)))
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/main/kotlin/blitz/parse/JSON.kt b/src/main/kotlin/blitz/parse/JSON.kt
index dfe6163..c3ccf24 100644
--- a/src/main/kotlin/blitz/parse/JSON.kt
+++ b/src/main/kotlin/blitz/parse/JSON.kt
@@ -3,10 +3,12 @@ package blitz.parse
 import blitz.collections.RefVec
 import blitz.collections.contents
 import blitz.parse.comb2.*
+import blitz.test.annotations.Test
+import blitz.test.util.requireEqual
 import blitz.unreachable
 
+@Suppress("NOTHING_TO_INLINE")
 object JSON {
-
     val jsonBool: Parser<Char, Element> = choose {
         it(mapValue(seq("true".toList())) { Element.newBool(true) })
         it(mapValue(seq("false".toList())) { Element.newBool(false) })
@@ -116,31 +118,72 @@ object JSON {
     inline fun Element.uncheckedAsObj(): Map<String, Element> =
         _boxed as Map<String, Element>
 
-    inline fun Element.asNum(): Double {
+    fun Element.asNum(): Double {
         require(kind == Element.NUM) { "Element is not a Number" }
         return _num
     }
 
-    inline fun Element.asBool(): Boolean {
+    fun Element.asBool(): Boolean {
         require(kind == Element.BOOL) { "Element is not a Boolean" }
         return _bool
     }
 
-    inline fun Element.asArr(): RefVec<Element> {
+    fun Element.asArr(): RefVec<Element> {
         require(kind == Element.ARR) { "Element is not an Array" }
         return _boxed as RefVec<Element>
     }
 
-    inline fun Element.asStr(): String {
+    fun Element.asStr(): String {
         require(kind == Element.STR) { "Element is not a String" }
         return _boxed as String
     }
 
-    inline fun Element.asObj(): Map<String, Element> {
+    fun Element.asObj(): Map<String, Element> {
         require(kind == Element.OBJ) { "Element is not an Object" }
         return _boxed as Map<String, Element>
     }
 
     fun parse(string: String): ParseResult<Element> =
         jsonElement.run(string.toList())
+
+    object _tests {
+        @Test
+        fun parseJsonNumber() {
+            parse("-1.351").assertA().asNum()
+                .requireEqual(-1.351)
+        }
+
+        @Test
+        fun parseJsonBool() {
+            parse("true").assertA().asBool()
+                .requireEqual(true)
+            parse("false").assertA().asBool()
+                .requireEqual(false)
+        }
+
+        @Test
+        fun parseJsonNull() {
+            parse("null").assertA().kind
+                .requireEqual(Element.NULL)
+        }
+
+        @Test
+        fun parseJsonStr() {
+            parse("\"Hello\\\n\\\"aworld\"").assertA().asStr()
+                .requireEqual("Hello\n\"aworld")
+        }
+
+        @Test
+        fun parseJsonArr() {
+            parse("[1, 2, 3,\n 4]").assertA().asArr()
+                .map { it.asNum() }.contents.requireEqual(listOf(1.0,2.0,3.0,4.0).contents)
+        }
+
+        @Test
+        fun parseJsonObj() {
+            val obj = parse("{\"a\": 1, \"b\": 2}").assertA().asObj()
+            obj.map { it.value.asNum() }.contents.requireEqual(listOf(1.0,2.0).contents)
+            obj.map { it.key }.contents.requireEqual(listOf("a","b").contents)
+        }
+    }
 }
\ No newline at end of file
diff --git a/src/main/kotlin/blitz/term/Terminal.kt b/src/main/kotlin/blitz/term/Terminal.kt
index 08179b9..2e15583 100644
--- a/src/main/kotlin/blitz/term/Terminal.kt
+++ b/src/main/kotlin/blitz/term/Terminal.kt
@@ -77,17 +77,6 @@ object Terminal {
         System.err.println(encodeString(str, *modes))
     }
 
-    @Deprecated(
-        "Use errln instead!",
-        ReplaceWith(
-            "errln(str, *modes)",
-            "blitz.term.Terminal.errln"
-        )
-    )
-    fun warn(str: String, vararg modes: AnsiiMode) {
-        errln(str, *modes)
-    }
-
     object Cursor {
         fun savePos() {
             print(escape + "7")
diff --git a/src/main/kotlin/blitz/test/annotations/Test.kt b/src/main/kotlin/blitz/test/annotations/Test.kt
new file mode 100644
index 0000000..726d818
--- /dev/null
+++ b/src/main/kotlin/blitz/test/annotations/Test.kt
@@ -0,0 +1,5 @@
+package blitz.test.annotations
+
+@Target(AnnotationTarget.FUNCTION, AnnotationTarget.CLASS)
+@Retention(AnnotationRetention.SOURCE)
+annotation class Test
diff --git a/src/main/kotlin/blitz/test/util/Asserts.kt b/src/main/kotlin/blitz/test/util/Asserts.kt
new file mode 100644
index 0000000..dcab9bc
--- /dev/null
+++ b/src/main/kotlin/blitz/test/util/Asserts.kt
@@ -0,0 +1,7 @@
+package blitz.test.util
+
+fun requireEqual(a: Any?, b: Any?) =
+    require(a == b) { "Expected $a to be equal to $b"}
+
+fun <T> T.requireEqual(other: T) =
+    requireEqual(this, other)
\ No newline at end of file
diff --git a/src/test/kotlin/map.kt b/src/test/kotlin/map.kt
index 65561c0..e0b39e4 100644
--- a/src/test/kotlin/map.kt
+++ b/src/test/kotlin/map.kt
@@ -4,6 +4,8 @@ import blitz.collections.I2HashMapKey
 import blitz.collections.contents
 import kotlin.test.Test
 
+// TODO: port tests to sanetest
+
 class Maps {
     @Test
     fun i2hashmap() {