Busy.png makes a nice loading icon

src/main/kotlin/ru/dbotthepony/kstarbound/client/StarboundClient.kt

@@ -62,6 +62,7 @@ import ru.dbotthepony.kstarbound.math.roundTowardsNegativeInfinity
 import ru.dbotthepony.kstarbound.math.roundTowardsPositiveInfinity
 import ru.dbotthepony.kstarbound.util.BlockableEventLoop
 import ru.dbotthepony.kstarbound.util.formatBytesShort
+import ru.dbotthepony.kstarbound.util.supplyAsync
 import ru.dbotthepony.kstarbound.world.ChunkState
 import ru.dbotthepony.kstarbound.world.Direction
 import ru.dbotthepony.kstarbound.world.RayDirection
@@ -78,12 +79,14 @@ import java.nio.ByteBuffer
 import java.nio.ByteOrder
 import java.time.Duration
 import java.util.*
+import java.util.concurrent.CompletableFuture
 import java.util.concurrent.ForkJoinPool
 import java.util.concurrent.ForkJoinWorkerThread
 import java.util.concurrent.TimeUnit
 import java.util.concurrent.atomic.AtomicInteger
 import java.util.concurrent.locks.ReentrantLock
 import java.util.function.Consumer
+import java.util.function.Function
 import java.util.function.IntConsumer
 import kotlin.collections.ArrayList
 import kotlin.concurrent.withLock
@@ -335,6 +338,33 @@ class StarboundClient private constructor(val clientID: Int) : BlockableEventLoo
 		texture
 	}
 
+	val busyTexture: CompletableFuture<GLTexture2D> by lazy(LazyThreadSafetyMode.NONE) {
+		Starbound.IO_EXECUTOR.supplyAsync {
+			MemoryStack.stackPush().use { stack ->
+				val pWidth = stack.mallocInt(1)
+				val pHeight = stack.mallocInt(1)
+				val pChannels = stack.mallocInt(1)
+
+				val readFromDisk = readInternalBytes("starbound_busy.png")
+				val buff = ByteBuffer.allocateDirect(readFromDisk.size)
+				buff.put(readFromDisk)
+				buff.position(0)
+
+				val data = STBImage.stbi_load_from_memory(buff, pWidth, pHeight, pChannels, 4)
+					?: throw IllegalStateException("Unable to decode starbound_busy.png")
+
+				(pWidth[0] to pHeight[0]) to data
+			}
+		}.thenApplyAsync(Function { (size, data) ->
+			val (w, h) = size
+			val texture = GLTexture2D(w, h, GL_RGBA8)
+
+			texture.upload(GL_RGBA, GL_UNSIGNED_BYTE, data)
+			texture.textureMagFilter = GL_NEAREST
+			texture
+		}, this)
+	}
+
 	val missingTexture by lazy(LazyThreadSafetyMode.NONE) {
 		val texture = GLTexture2D(8, 8, GL_RGB8)
 		val buffer = ByteBuffer.allocateDirect(3 * 8 * 8)
@@ -621,26 +651,14 @@ class StarboundClient private constructor(val clientID: Int) : BlockableEventLoo
 
 	private var renderedLoadingScreen = false
 
-	private fun renderLoadingScreen() {
-		performOpenGLCleanup()
-		updateViewportParams()
-
-		clearColor = RGBAColor.BLACK
-		glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT)
-
+	private fun renderBusyDots() {
 		val min = viewportHeight.coerceAtMost(viewportWidth)
 		val size = min * 0.02f
 
 		val program = programs.positionColor
 		val builder = program.builder
 
-		uberShaderPrograms.forValidRefs { it.viewMatrix = viewportMatrixScreen }
-		fontShaderPrograms.forValidRefs { it.viewMatrix = viewportMatrixScreen }
-
-		stack.clear(Matrix3f.identity())
-
 		program.colorMultiplier = RGBAColor.WHITE
-
 		builder.builder.begin(GeometryType.QUADS)
 
 		if (dotCountdown-- <= 0) {
@@ -664,6 +682,69 @@ class StarboundClient private constructor(val clientID: Int) : BlockableEventLoo
 		builder.builder.centeredQuad(viewportWidth * 0.5f - size * 2f, viewportHeight * 0.5f, size, size) { color(a) }
 		builder.builder.centeredQuad(viewportWidth * 0.5f + size * 2f, viewportHeight * 0.5f, size, size) { color(c) }
 
+		program.use()
+		builder.upload()
+		builder.draw()
+	}
+
+	private fun renderBusyLogo() {
+		val min = viewportHeight.coerceAtMost(viewportWidth)
+		val size = min * 0.0035f
+		val width = size * 46f
+		val height = size * 28f
+
+		val program = programs.positionTexture
+		val builder = program.builder
+
+		program.texture0 = 0
+		textures2D[0] = busyTexture.get()
+		program.colorMultiplier = RGBAColor.WHITE
+
+		builder.builder.begin(GeometryType.QUADS)
+
+		val x = viewportWidth * 0.5f
+		val y = viewportHeight * 0.5f
+
+		val index = ((System.nanoTime() / 40_000_000L) % 29L) / 29f
+
+		builder.builder.vertex(x - width, y - height).uv(index, 0f)
+		builder.builder.vertex(x - width, y + height).uv(index, 1f)
+		builder.builder.vertex(x + width, y + height).uv(index + 1f / 29f, 1f)
+		builder.builder.vertex(x + width, y - height).uv(index + 1f / 29f, 0f)
+
+		program.use()
+		builder.upload()
+		builder.draw()
+	}
+
+	fun renderBusyIcon() {
+		if (busyTexture.isDone && !busyTexture.isCompletedExceptionally) {
+			renderBusyLogo()
+		} else {
+			renderBusyDots()
+		}
+	}
+
+	private fun renderLoadingScreen() {
+		performOpenGLCleanup()
+		updateViewportParams()
+
+		clearColor = RGBAColor.BLACK
+		glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT)
+
+		uberShaderPrograms.forValidRefs { it.viewMatrix = viewportMatrixScreen }
+		fontShaderPrograms.forValidRefs { it.viewMatrix = viewportMatrixScreen }
+
+		stack.clear(Matrix3f.identity())
+
+		renderBusyIcon()
+
+		val program = programs.positionColor
+		val builder = program.builder
+
+		program.colorMultiplier = RGBAColor.WHITE
+
+		builder.builder.begin(GeometryType.QUADS)
 		builder.builder.quad(0f, viewportHeight - 20f, viewportWidth * Starbound.loadingProgress.toFloat(), viewportHeight.toFloat()) { color(RGBAColor.GREEN) }
 
 		GLFW.glfwSetWindowTitle(window, "KStarbound: ${Starbound.loadingProgressText}")
@@ -671,7 +752,6 @@ class StarboundClient private constructor(val clientID: Int) : BlockableEventLoo
 
 		val runtime = Runtime.getRuntime()
 
-		//if (runtime.maxMemory() <= 4L * 1024L * 1024L * 1024L) {
 		builder.builder.centeredQuad(viewportWidth * 0.5f, viewportHeight * 0.1f, viewportWidth * 0.7f, 2f) { color(RGBAColor.WHITE) }
 		builder.builder.centeredQuad(viewportWidth * 0.5f, viewportHeight * 0.1f + 20f, viewportWidth * 0.7f, 2f) { color(RGBAColor.WHITE) }
 		builder.builder.centeredQuad(viewportWidth * (0.5f - 0.35f), viewportHeight * 0.1f + 10f, 2f, 20f) { color(RGBAColor.WHITE) }
@@ -687,7 +767,6 @@ class StarboundClient private constructor(val clientID: Int) : BlockableEventLoo
 			leftEdge + viewportWidth * 0.7f * ((runtime.totalMemory() - runtime.freeMemory()) / runtime.maxMemory().toDouble()).toFloat(),
 			viewportHeight * 0.1f + 19f
 		) { color(RGBAColor(29, 140, 160)) }
-		//}
 
 		if (fontInitialized) {
 			drawPerformanceBasic(true)