Trying to make Scenery more "kotlinesque", starting by refactoring the first "Basic" test:

- added some fake constructors call for initializing the object directly after the instantiation
- added an `inline reified` counterpart for `Image.fromResource`
- added an `Image::toTexture` function
- added the operator overloading `plusAssign` for adding element(s) to the scene
- minors

Author: elect86

src/main/kotlin/graphics/scenery/Box.kt

@@ -7,6 +7,8 @@ import org.joml.Vector3f
 import java.lang.IllegalArgumentException
 import kotlin.jvm.JvmOverloads
 
+inline fun Box(sizes: Vector3f = Vector3f(1.0f, 1.0f, 1.0f), insideNormals: Boolean = false, block: Box.() -> Unit): Box = Box(sizes, insideNormals).apply(block)
+
 /**
  * Constructs a Box [Node] with the dimensions given in [sizes]
  *

src/main/kotlin/graphics/scenery/DetachedHeadCamera.kt

@@ -13,6 +13,8 @@ import kotlin.math.PI
 import kotlin.math.atan
 import kotlin.reflect.KProperty
 
+inline fun DetachedHeadCamera(block: DetachedHeadCamera.() -> Unit): DetachedHeadCamera = DetachedHeadCamera().apply(block)
+
 /**
  * Detached Head Camera is a Camera subclass that tracks the head orientation
  * in addition to general orientation - useful for HMDs

src/main/kotlin/graphics/scenery/Node.kt

@@ -21,6 +21,7 @@ import java.util.concurrent.CopyOnWriteArrayList
 import java.util.concurrent.locks.ReentrantLock
 import java.util.function.Consumer
 import kotlin.collections.ArrayList
+import kotlin.collections.Collection
 
 interface Node : Networkable {
     var name: String
@@ -137,6 +138,23 @@ interface Node : Networkable {
     /** Unique ID of the Node */
     fun getUuid(): UUID
 
+    /**
+     * Attaches a child node to this node.
+     *
+     * @param[child] The child to attach to this node.
+     */
+    operator fun plusAssign(child: Node) = addChild(child)
+
+    /**
+     * Attaches the given children nodes to this node.
+     *
+     * @param[children] The children to attach to this node.
+     */
+    operator fun plusAssign(children: Collection<Node>) {
+        for (child in children)
+            addChild(child)
+    }
+
     /**
      * Attaches a child node to this node.
      *
@@ -184,12 +202,12 @@ interface Node : Networkable {
      */
     fun generateBoundingBox(): OrientedBoundingBox? {
         val geometry = geometryOrNull()
-        if(geometry == null) {
+        return if(geometry == null) {
             logger.warn("$name: Assuming 3rd party BB generation")
-            return boundingBox
+            boundingBox
         } else {
             boundingBox = geometry.generateBoundingBox(children)
-            return boundingBox
+            boundingBox
         }
     }
 

src/main/kotlin/graphics/scenery/PointLight.kt

@@ -6,6 +6,8 @@ import graphics.scenery.utils.extensions.xyz
 import org.joml.Vector3f
 import org.joml.Vector4f
 
+inline fun PointLight(radius: Float = 5.0f, block: PointLight.() -> Unit): PointLight = PointLight(radius).apply(block)
+
 /**
  * Point light class.
  *

src/main/kotlin/graphics/scenery/utils.kt

@@ -0,0 +1,7 @@
+package graphics.scenery
+
+inline operator fun <M : Mesh> M.invoke(init: M.() -> Unit): M {
+    apply(init)
+    return this
+}
+

src/main/kotlin/graphics/scenery/utils/Image.kt

@@ -1,6 +1,9 @@
 package graphics.scenery.utils
 
+import graphics.scenery.textures.Texture
 import graphics.scenery.volumes.Colormap
+import net.imglib2.type.numeric.integer.UnsignedByteType
+import org.joml.Vector3i
 import org.lwjgl.system.MemoryUtil
 import java.awt.Color
 import java.awt.color.ColorSpace
@@ -9,7 +12,6 @@ import java.awt.image.*
 import java.io.BufferedInputStream
 import java.io.IOException
 import java.io.InputStream
-import java.lang.RuntimeException
 import java.nio.ByteBuffer
 import java.nio.ByteOrder
 import java.util.*
@@ -23,6 +25,17 @@ import javax.imageio.ImageIO
  */
 open class Image(val contents: ByteBuffer, val width: Int, val height: Int, val depth: Int = 1) {
 
+    fun toTexture(
+        repeatUVW: Triple<Texture.RepeatMode, Texture.RepeatMode, Texture.RepeatMode> = Texture.RepeatMode.Repeat.all(),
+        borderColor: Texture.BorderColor = Texture.BorderColor.OpaqueBlack,
+        normalized: Boolean = true,
+        mipmap: Boolean = true,
+        minFilter: Texture.FilteringMode = Texture.FilteringMode.Linear,
+        maxFilter: Texture.FilteringMode = Texture.FilteringMode.Linear,
+        usage: HashSet<Texture.UsageType> = hashSetOf(Texture.UsageType.Texture)
+    ): Texture {
+        return Texture(Vector3i(width, height, depth),4, UnsignedByteType(), contents, repeatUVW, borderColor, normalized, mipmap, usageType = usage, minFilter = minFilter, maxFilter = maxFilter)
+    }
     companion object {
         protected val logger by lazyLogger()
 
@@ -98,6 +111,14 @@ open class Image(val contents: ByteBuffer, val width: Int, val height: Int, val
             return Image(imageData, bi.width, bi.height)
         }
 
+        /**
+         * Creates an Image from a resource given in [path], with [baseClass] as basis for the search path.
+         * [path] is expected to end in an extension (e.g., ".png"), such that the file type can be determined.
+         */
+        inline fun <reified K> fromResource(path: String): Image {
+            return fromStream(K::class.java.getResourceAsStream(path), path.substringAfterLast(".").lowercase())
+        }
+
         /**
          * Creates an Image from a resource given in [path], with [baseClass] as basis for the search path.
          * [path] is expected to end in an extension (e.g., ".png"), such that the file type can be determined.

src/test/kotlin/graphics/scenery/tests/examples/basic/ArcballExample.kt

@@ -19,60 +19,56 @@ class ArcballExample : SceneryBase("ArcballExample") {
     override fun init() {
         renderer = hub.add(Renderer.createRenderer(hub, applicationName, scene, 1024, 1024))
 
-        val cam: Camera = DetachedHeadCamera()
-        with(cam) {
+        val cam: Camera = DetachedHeadCamera {
             spatial {
                 position = Vector3f(0.0f, 0.0f, 2.5f)
             }
             perspectiveCamera(70.0f, windowWidth, windowHeight)
 
             targeted = true
             target = Vector3f(0.0f, 0.0f, 0.0f)
-
-            scene.addChild(this)
         }
+        scene += cam
 
-        val camlight = PointLight(3.0f)
-        camlight.intensity = 5.0f
-        cam.addChild(camlight)
-
-        val box = Box(Vector3f(1.0f, 1.0f, 1.0f))
+        val camlight = PointLight(3.0f) {
+            intensity = 5.0f
+        }
+        cam += camlight
 
-        with(box) {
+        val box = Box(Vector3f(1.0f, 1.0f, 1.0f)) {
             spatial {
                 position = Vector3f(0.0f, 0.0f, 0.0f)
             }
             material {
                 ambient = Vector3f(1.0f, 0.0f, 0.0f)
                 diffuse = Vector3f(0.0f, 1.0f, 0.0f)
-                textures["diffuse"] = Texture.fromImage(Image.fromResource("textures/helix.png", TexturedCubeExample::class.java))
+                textures["diffuse"] = Image.fromResource<TexturedCubeExample>("textures/helix.png").toTexture()
                 specular = Vector3f(1.0f, 1.0f, 1.0f)
             }
-
-            scene.addChild(this)
         }
+        scene += box
 
-        val lights = (0..2).map {
-            PointLight(radius = 15.0f)
-        }.map { light ->
-            light.spatial {
-                position = Random.random3DVectorFromRange(-3.0f, 3.0f)
+        val lights = List(3) {
+            PointLight(radius = 15.0f) {
+                spatial {
+                    position = Random.random3DVectorFromRange(-3.0f, 3.0f)
+                }
+                emissionColor = Random.random3DVectorFromRange(0.2f, 0.8f)
+                intensity = Random.randomFromRange(0.1f, 0.8f)
             }
-            light.emissionColor = Random.random3DVectorFromRange(0.2f, 0.8f)
-            light.intensity = Random.randomFromRange(0.1f, 0.8f)
-            light
         }
 
-        val floor = Box(Vector3f(500.0f, 0.05f, 500.0f))
-        floor.spatial {
-            position = Vector3f(0.0f, -1.0f, 0.0f)
-        }
-        floor.material {
-            diffuse = Vector3f(1.0f, 1.0f, 1.0f)
+        val floor = Box(Vector3f(500.0f, 0.05f, 500.0f)) {
+            spatial {
+                position = Vector3f(0.0f, -1.0f, 0.0f)
+            }
+            material {
+                diffuse = Vector3f(1.0f, 1.0f, 1.0f)
+            }
         }
-        scene.addChild(floor)
+        scene += floor
 
-        lights.forEach(scene::addChild)
+        scene += lights
     }
 
     override fun inputSetup() {