[orx-kdtree] Make orx-kdtree a multiplatform module

orx-kdtree/src/commonMain/kotlin/Mappers.kt

@@ -0,0 +1,61 @@
+package org.openrndr.extra.kdtree
+import org.openrndr.math.Vector2
+import org.openrndr.math.IntVector2
+import org.openrndr.math.Vector3
+import org.openrndr.math.Vector4
+import kotlin.jvm.JvmName
+
+/** built-in mapper for [Vector2] */
+fun vector2Mapper(v: Vector2, dimension: Int): Double {
+    return when (dimension) {
+        0 -> v.x
+        else -> v.y
+    }
+}
+
+fun intVector2Mapper(v: IntVector2, dimension: Int): Double {
+    return when (dimension) {
+        0 -> v.x.toDouble()
+        else -> v.y.toDouble()
+    }
+}
+
+
+/** built-in mapper for [Vector3] */
+fun vector3Mapper(v: Vector3, dimension: Int): Double {
+    return when (dimension) {
+        0 -> v.x
+        1 -> v.y
+        else -> v.z
+    }
+}
+
+/** built-in mapper for [Vector4] */
+fun vector4Mapper(v: Vector4, dimension: Int): Double {
+    return when (dimension) {
+        0 -> v.x
+        1 -> v.y
+        2 -> v.z
+        else -> v.w
+    }
+}
+
+
+
+@JvmName("kdTreeVector2")
+fun Iterable<Vector2>.kdTree(): KDTreeNode<Vector2> {
+    val items = this.toMutableList()
+    return buildKDTree(items, 2, ::vector2Mapper)
+}
+
+@JvmName("kdTreeVector3")
+fun Iterable<Vector3>.kdTree(): KDTreeNode<Vector3> {
+    val items = this.toMutableList()
+    return buildKDTree(items, 3, ::vector3Mapper)
+}
+
+@JvmName("kdTreeVector4")
+fun Iterable<Vector4>.kdTree(): KDTreeNode<Vector4> {
+    val items = this.toMutableList()
+    return buildKDTree(items, 4, ::vector4Mapper)
+}