Merge pull request #36603 from m4gr3d/implement_vk_surface_view

Provide a Vulkan surface view base implementation

4 files changed, 466 insertions, 0 deletions

diff --git a/platform/android/java/lib/build.gradle b/platform/android/java/lib/build.gradle
index eb97484b9c..4b5873ce25 100644
--- a/platform/android/java/lib/build.gradle
+++ b/platform/android/java/lib/build.gradle
@@ -2,6 +2,7 @@ apply plugin: 'com.android.library'
 
 dependencies {
     implementation libraries.supportCoreUtils
+    implementation libraries.kotlinStdLib
 }
 
 def pathToRootDir = "../../../../"
diff --git a/platform/android/java/lib/src/org/godotengine/godot/vulkan/VkRenderer.kt b/platform/android/java/lib/src/org/godotengine/godot/vulkan/VkRenderer.kt
new file mode 100644
index 0000000000..67faad8ddd
--- /dev/null
+++ b/platform/android/java/lib/src/org/godotengine/godot/vulkan/VkRenderer.kt
@@ -0,0 +1,99 @@
+/*************************************************************************/
+/*  VkRenderer.kt                                                        */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+@file:JvmName("VkRenderer")
+package org.godotengine.godot.vulkan
+
+import android.view.Surface
+
+/**
+ * Responsible to setting up and driving the Vulkan rendering logic.
+ *
+ * <h3>Threading</h3>
+ * The renderer will be called on a separate thread, so that rendering
+ * performance is decoupled from the UI thread. Clients typically need to
+ * communicate with the renderer from the UI thread, because that's where
+ * input events are received. Clients can communicate using any of the
+ * standard Java techniques for cross-thread communication, or they can
+ * use the  [VkSurfaceView.queueOnVkThread] convenience method.
+ *
+ * @see [VkSurfaceView.startRenderer]
+ */
+internal class VkRenderer {
+
+	/**
+	 * Called when the surface is created and signals the beginning of rendering.
+	 */
+	fun onVkSurfaceCreated(surface: Surface) {
+		nativeOnVkSurfaceCreated(surface)
+	}
+
+	/**
+	 * Called after the surface is created and whenever its size changes.
+	 */
+	fun onVkSurfaceChanged(surface: Surface, width: Int, height: Int) {
+		nativeOnVkSurfaceChanged(surface, width, height)
+	}
+
+	/**
+	 * Called to draw the current frame.
+	 */
+	fun onVkDrawFrame() {
+		nativeOnVkDrawFrame()
+	}
+
+	/**
+	 * Called when the rendering thread is resumed.
+	 */
+	fun onVkResume() {
+		nativeOnVkResume()
+	}
+
+	/**
+	 * Called when the rendering thread is paused.
+	 */
+	fun onVkPause() {
+		nativeOnVkPause()
+	}
+
+	/**
+	 * Called when the rendering thread is destroyed and used as signal to tear down the Vulkan logic.
+	 */
+	fun onVkDestroy() {
+		nativeOnVkDestroy()
+	}
+
+	private external fun nativeOnVkSurfaceCreated(surface: Surface)
+	private external fun nativeOnVkSurfaceChanged(surface: Surface, width: Int, height: Int)
+	private external fun nativeOnVkResume()
+	private external fun nativeOnVkDrawFrame()
+	private external fun nativeOnVkPause()
+	private external fun nativeOnVkDestroy()
+}
diff --git a/platform/android/java/lib/src/org/godotengine/godot/vulkan/VkSurfaceView.kt b/platform/android/java/lib/src/org/godotengine/godot/vulkan/VkSurfaceView.kt
new file mode 100644
index 0000000000..1c594f3201
--- /dev/null
+++ b/platform/android/java/lib/src/org/godotengine/godot/vulkan/VkSurfaceView.kt
@@ -0,0 +1,136 @@
+/*************************************************************************/
+/*  VkSurfaceView.kt                                                     */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+@file:JvmName("VkSurfaceView")
+package org.godotengine.godot.vulkan
+
+import android.content.Context
+import android.view.SurfaceHolder
+import android.view.SurfaceView
+
+/**
+ * An implementation of SurfaceView that uses the dedicated surface for
+ * displaying Vulkan rendering.
+ * <p>
+ * A [VkSurfaceView] provides the following features:
+ * <p>
+ * <ul>
+ * <li>Manages a surface, which is a special piece of memory that can be
+ * composited into the Android view system.
+ * <li>Accepts a user-provided [VkRenderer] object that does the actual rendering.
+ * <li>Renders on a dedicated [VkThread] thread to decouple rendering performance from the
+ * UI thread.
+ * </ul>
+ */
+internal class VkSurfaceView(context: Context) : SurfaceView(context), SurfaceHolder.Callback {
+
+	companion object {
+		fun checkState(expression: Boolean, errorMessage: Any) {
+			check(expression) { errorMessage.toString() }
+		}
+	}
+
+	/**
+	 * Thread used to drive the vulkan logic.
+	 */
+	private val vkThread: VkThread by lazy {
+		VkThread(this, renderer)
+	}
+
+	/**
+	 * Performs the actual rendering.
+	 */
+	private lateinit var renderer: VkRenderer
+
+	init {
+		isClickable = true
+		holder.addCallback(this)
+	}
+
+	/**
+	 * Set the [VkRenderer] associated with the view, and starts the thread that will drive the vulkan
+	 * rendering.
+	 *
+	 * This method should be called once and only once in the life-cycle of [VkSurfaceView].
+	 */
+	fun startRenderer(renderer: VkRenderer) {
+		checkState(!this::renderer.isInitialized, "startRenderer must only be invoked once")
+		this.renderer = renderer
+		vkThread.start()
+	}
+
+	/**
+	 * Queues a runnable to be run on the Vulkan rendering thread.
+	 *
+	 * Must not be called before a [VkRenderer] has been set.
+	 */
+	fun queueOnVkThread(runnable: Runnable) {
+		vkThread.queueEvent(runnable)
+	}
+
+	/**
+	 * Resumes the rendering thread.
+	 *
+	 * Must not be called before a [VkRenderer] has been set.
+	 */
+	fun onResume() {
+		vkThread.onResume()
+	}
+
+	/**
+	 * Pauses the rendering thread.
+	 *
+	 * Must not be called before a [VkRenderer] has been set.
+	 */
+	fun onPause() {
+		vkThread.onPause()
+	}
+
+	/**
+	 * Tear down the rendering thread.
+	 *
+	 * Must not be called  before a [VkRenderer] has been set.
+	 */
+	fun onDestroy() {
+		vkThread.blockingExit()
+	}
+
+	override fun surfaceChanged(holder: SurfaceHolder, format: Int, width: Int, height: Int) {
+		vkThread.onSurfaceChanged(width, height)
+	}
+
+	override fun surfaceDestroyed(holder: SurfaceHolder) {
+		vkThread.onSurfaceDestroyed()
+	}
+
+	override fun surfaceCreated(holder: SurfaceHolder) {
+		vkThread.onSurfaceCreated()
+	}
+}
diff --git a/platform/android/java/lib/src/org/godotengine/godot/vulkan/VkThread.kt b/platform/android/java/lib/src/org/godotengine/godot/vulkan/VkThread.kt
new file mode 100644
index 0000000000..2e332840bf
--- /dev/null
+++ b/platform/android/java/lib/src/org/godotengine/godot/vulkan/VkThread.kt
@@ -0,0 +1,230 @@
+/*************************************************************************/
+/*  VkThread.kt                                                          */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+@file:JvmName("VkThread")
+package org.godotengine.godot.vulkan
+
+import android.util.Log
+import java.util.concurrent.locks.ReentrantLock
+import kotlin.concurrent.withLock
+
+/**
+ * Thread implementation for the [VkSurfaceView] onto which the vulkan logic is ran.
+ *
+ * The implementation is modeled after [android.opengl.GLSurfaceView]'s GLThread.
+ */
+internal class VkThread(private val vkSurfaceView: VkSurfaceView, private val vkRenderer: VkRenderer) : Thread(TAG) {
+
+	companion object {
+		private val TAG = VkThread::class.java.simpleName
+	}
+
+	/**
+	 * Used to run events scheduled on the thread.
+	 */
+	private val eventQueue = ArrayList<Runnable>()
+
+	/**
+	 * Used to synchronize interaction with other threads (e.g: main thread).
+	 */
+	private val lock = ReentrantLock()
+	private val lockCondition = lock.newCondition()
+
+	private var shouldExit = false
+	private var exited = false
+	private var rendererInitialized = false
+	private var rendererResumed = false
+	private var resumed = false
+	private var hasSurface = false
+	private var width = 0
+	private var height = 0
+
+	/**
+	 * Determine when drawing can occur on the thread. This usually occurs after the
+	 * [android.view.Surface] is available, the app is in a resumed state.
+	 */
+	private val readyToDraw
+		get() = hasSurface && resumed
+
+	private fun threadExiting() {
+		lock.withLock {
+			exited = true
+			lockCondition.signalAll()
+		}
+	}
+
+	/**
+	 * Queue an event on the [VkThread].
+	 */
+	fun queueEvent(event: Runnable) {
+		lock.withLock {
+			eventQueue.add(event)
+			lockCondition.signalAll()
+		}
+	}
+
+	/**
+	 * Request the thread to exit and block until it's done.
+	 */
+	fun blockingExit() {
+		lock.withLock {
+			shouldExit = true
+			lockCondition.signalAll()
+			while (!exited) {
+				try {
+					Log.i(TAG, "Waiting on exit for $name")
+					lockCondition.await()
+				} catch (ex: InterruptedException) {
+					currentThread().interrupt()
+				}
+			}
+		}
+	}
+
+	/**
+	 * Invoked when the app resumes.
+	 */
+	fun onResume() {
+		lock.withLock {
+			resumed = true
+			lockCondition.signalAll()
+		}
+	}
+
+	/**
+	 * Invoked when the app pauses.
+	 */
+	fun onPause() {
+		lock.withLock {
+			resumed = false
+			lockCondition.signalAll()
+		}
+	}
+
+	/**
+	 * Invoked when the [android.view.Surface] has been created.
+	 */
+	fun onSurfaceCreated() {
+		// This is a no op because surface creation will always be followed by surfaceChanged()
+		// which provide all the needed information.
+	}
+
+	/**
+	 * Invoked following structural updates to [android.view.Surface].
+	 */
+	fun onSurfaceChanged(width: Int, height: Int) {
+		lock.withLock {
+			hasSurface = true
+			this.width = width
+			this.height = height
+			lockCondition.signalAll()
+		}
+	}
+
+	/**
+	 * Invoked when the [android.view.Surface] is no longer available.
+	 */
+	fun onSurfaceDestroyed() {
+		lock.withLock {
+			hasSurface = false
+			lockCondition.signalAll()
+		}
+	}
+
+	/**
+	 * Thread loop modeled after [android.opengl.GLSurfaceView]'s GLThread.
+	 */
+	override fun run() {
+		try {
+			while (true) {
+				var event: Runnable? = null
+				lock.withLock {
+					while (true) {
+						// Code path for exiting the thread loop.
+						if (shouldExit) {
+							vkRenderer.onVkDestroy()
+							return
+						}
+
+						// Check for events and execute them outside of the loop if found to avoid
+						// blocking the thread lifecycle by holding onto the lock.
+						if (eventQueue.isNotEmpty()) {
+							event = eventQueue.removeAt(0)
+							break;
+						}
+
+						if (readyToDraw) {
+							if (!rendererResumed) {
+								rendererResumed = true
+								vkRenderer.onVkResume()
+
+								if (!rendererInitialized) {
+									rendererInitialized = true
+									vkRenderer.onVkSurfaceCreated(vkSurfaceView.holder.surface)
+								}
+
+								vkRenderer.onVkSurfaceChanged(vkSurfaceView.holder.surface, width, height)
+							}
+
+							// Break out of the loop so drawing can occur without holding onto the lock.
+							break;
+						} else if (rendererResumed) {
+							// If we aren't ready to draw but are resumed, that means we either lost a surface
+							// or the app was paused.
+							rendererResumed = false
+							vkRenderer.onVkPause()
+						}
+						// We only reach this state if we are not ready to draw and have no queued events, so
+						// we wait.
+						// On state change, the thread will be awoken using the [lock] and [lockCondition], and
+						// we will resume execution.
+						lockCondition.await()
+					}
+				}
+
+				// Run queued event.
+				if (event != null) {
+					event?.run()
+					continue
+				}
+
+				// Draw only when there no more queued events.
+				vkRenderer.onVkDrawFrame()
+			}
+		} catch (ex: InterruptedException) {
+			Log.i(TAG, ex.message)
+		} catch (ex: IllegalStateException) {
+			Log.i(TAG, ex.message)
+		} finally {
+			threadExiting()
+		}
+	}
+
+}