/kmedialayer

SUPERSEDED BY KORGE: https://github.com/korlibs/korge - Kotlin Multiplatform equivalent to SDL+OpenGL: exposes Window creation, OpenGL and Input API to platform-common: JVM(lwjgl3), JS(webgl), Android(GLES20), Native-win(WIN32/GDI+/WGL), Native-macos(Cocoa/GL)

Primary LanguageKotlinOtherNOASSERTION

KMediaLayer

Offers an OpenGL/OpenGL|ES compatible interface and some functions for windowing, input and image loading as common.

Supports:

  • Android (NOT WORKING YET unsupported)
  • JS (webgl)
  • JVM (lwjgl3)
  • NATIVE-WINDOWS (WIN32, GDI+, WGL without additional dependencies)
  • NATIVE-MACOS (Cocoa without additional dependencies)

The intended normal workflow is to prototype using the JVM version, and then generate native executables or the JS version for the web.

Low level API:

object Kml {
    fun application(windowConfig: WindowConfig, listener: KMLWindowListener)

    fun <T> launch(context: CoroutineContext = EmptyCoroutineContext, callback: suspend () -> T): Job<T>
    fun currentTimeMillis(): Double
    suspend fun delay(ms: Int): Unit
    fun enqueue(task: () -> Unit): Unit
    suspend fun decodeImage(path: String): KmlNativeImageData
    suspend fun decodeImage(data: ByteArray): KmlNativeImageData
    suspend fun loadFileBytes(path: String, range: LongRange? = null): ByteArray
    suspend fun writeFileBytes(path: String, data: ByteArray, offset: Long? = null): Unit
}

The "application":

open class KMLWindowListener {
    open suspend fun init(gl: KmlGl): Unit
    open fun render(gl: KmlGl): Unit
    open fun keyUpdate(key: Key, pressed: Boolean)
    open fun gamepadUpdate(button: Int, pressed: Boolean, ratio: Double)
    open fun mouseUpdateMove(x: Int, y: Int)
    open fun mouseUpdateButton(button: Int, pressed: Boolean)
    open fun resized(width: Int, height: Int)
}

The window configuration:

data class WindowConfig(
    val width: Int = 640,
    val height: Int = 480,
    val title: String = "KMediaLayer"
)
// Offers the webgl API without the gl prefix:
interface KmlGl {
    // ...
    fun drawArrays(mode: Int, first: Int, count: Int): Unit
    fun drawElements(mode: Int, count: Int, type: Int, indices: Int): Unit
    fun enable(cap: Int): Unit
    fun enableVertexAttribArray(index: Int): Unit
    fun finish(): Unit
    fun flush(): Unit
    // ...
}

Scene API

The Scene API offers an API similar to the Swift's SpriteKit, Flash or Unity. There is a tree of view nodes, each node has properties and allow to attach components. There are components for handling mouse and key events

JobQueue

JobQueue exposes an API to enqueue asynchronous processes.

val queue = JobQueue()
queue { view.moveBy(16.0, 16.0, time = 0.5) }

Depending on the task in hand you can enqueue more tasks, or discard some of the elements in the queue.

queue.discard() // Discard all the tasks in the queue that has not started
queue.cancel()  // Discards all the tasks and cancels the current task 
queue.cancel(complete = true) // Discards all the tasks and cancels the current task, signaling with a complete = true

Signaling cancelations with complete = true makes some task like tweening to jump to the target state.