Replace async awaitRedraw by sync window.paint(window.graphics), refactor...

Replace async awaitRedraw by sync window.paint(window.graphics), refactor Direct 3D and Metal redrawers (#146)

* Refactor Direct3DContextHandle - move `device` to Direct3DRedrawer.kt

* Refactor finishFrame: split into Direct3DContextHandler.flush and Direct3DRedrawer.swap

* DirectX: redraw immediately

* Metal: redraw immediately

* Remove awaitRedraw

* Fix screenshot tests on macOs

* Discussions

samples/SkiaJvmSample/src/main/kotlin/SkijaInjectSample/App.kt

@@ -25,7 +25,7 @@ fun main() {
     }
 }
 
-fun createWindow(title: String, exitOnClose: Boolean) = runBlocking(Dispatchers.Swing) {
+fun createWindow(title: String, exitOnClose: Boolean) = SwingUtilities.invokeLater {
     var mouseX = 0
     var mouseY = 0
 
@@ -113,7 +113,7 @@ fun createWindow(title: String, exitOnClose: Boolean) = runBlocking(Dispatchers.
     // MANDATORY: set window preferred size before calling pack()
     window.preferredSize = Dimension(800, 600)
     window.pack()
-    window.layer.awaitRedraw()
+    window.layer.paint(window.graphics)
     window.isVisible = true
 }
 

skiko/src/jvmMain/cpp/windows/direct3DContext.cc

+#ifdef SK_DIRECT3D
+#include <stdexcept>
+#include <locale>
+#include <Windows.h>
+#include <jawt_md.h>
+#include "jni_helpers.h"
+
+#include "GrBackendSurface.h"
+#include "GrDirectContext.h"
+#include "SkSurface.h"
+
+extern "C"
+{
+    JNIEXPORT void JNICALL Java_org_jetbrains_skiko_context_Direct3DContextHandler_flush(
+        JNIEnv *env, jobject redrawer, jlong contextPtr, jlong surfacePtr)
+    {
+        SkSurface *surface = fromJavaPointer<SkSurface *>(surfacePtr);
+        GrDirectContext *context = fromJavaPointer<GrDirectContext *>(contextPtr);
+
+        surface->flushAndSubmit(true);
+        surface->flush(SkSurface::BackendSurfaceAccess::kPresent, GrFlushInfo());
+        context->flush({});
+        context->submit(true);
+    }
+}
+
+#endif

skiko/src/jvmMain/cpp/windows/directXRedrawer.cc

@@ -418,17 +418,10 @@ extern "C"
         GR_D3D_CALL_ERRCHECK(d3dDevice->swapChain->ResizeBuffers(BuffersCount, width, height, DXGI_FORMAT_R8G8B8A8_UNORM, 0));
     }
 
-    JNIEXPORT void JNICALL Java_org_jetbrains_skiko_redrawer_Direct3DRedrawer_finishFrame(
-        JNIEnv *env, jobject redrawer, jlong devicePtr, jlong contextPtr, jlong surfacePtr, jboolean isVsyncEnabled)
+    JNIEXPORT void JNICALL Java_org_jetbrains_skiko_redrawer_Direct3DRedrawer_swap(
+        JNIEnv *env, jobject redrawer, jlong devicePtr, jboolean isVsyncEnabled)
     {
         DirectXDevice *d3dDevice = fromJavaPointer<DirectXDevice *>(devicePtr);
-        SkSurface *surface = fromJavaPointer<SkSurface *>(surfacePtr);
-        GrDirectContext *context = fromJavaPointer<GrDirectContext *>(contextPtr);
-
-        surface->flushAndSubmit(true);
-        surface->flush(SkSurface::BackendSurfaceAccess::kPresent, GrFlushInfo());
-        context->flush({});
-        context->submit(true);
 
         // 1 value in [Present(1, 0)] enables vblank wait so this is how vertical sync works in DirectX.
         const UINT64 fenceValue = d3dDevice->fenceValues[d3dDevice->bufferIndex];

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/FrameDispatcher.kt

@@ -3,11 +3,8 @@ package org.jetbrains.skiko
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.launch
-import kotlinx.coroutines.suspendCancellableCoroutine
 import kotlinx.coroutines.yield
-import kotlin.coroutines.Continuation
 import kotlin.coroutines.CoroutineContext
-import kotlin.coroutines.resume
 
 /**
  * Dispatch frame after call of [scheduleFrame].
@@ -34,7 +31,6 @@ class FrameDispatcher(
             frameChannel.receive()
             frameScheduled = false
             onFrame()
-            resumeFrameAwaiters(isActive = true)
             // As per `yield()` documentation:
             //
             // For other dispatchers (not == Unconfined) , this function calls [CoroutineDispatcher.dispatch] and
@@ -45,12 +41,6 @@ class FrameDispatcher(
         }
     }
 
-    init {
-        job.invokeOnCompletion {
-            resumeFrameAwaiters(isActive = false)
-        }
-    }
-
     fun cancel() {
         job.cancel()
     }
@@ -69,35 +59,4 @@ class FrameDispatcher(
             frameChannel.offer(Unit)
         }
     }
-
-    private val frameAwaiters = mutableListOf<Continuation<Boolean>>()
-
-    /**
-     * Schedule next frame to render in the frame loop, and wait it to finish.
-     *
-     * If frame loop was completed (cancelled or there was an exception inside it) then don't wait and immediately continue execution.
-     *
-     * @return true if frame loop is active, false if it was completed.
-     */
-    suspend fun awaitFrame(): Boolean {
-        return if (job.isActive) {
-            suspendCancellableCoroutine { continuation ->
-                synchronized(frameAwaiters) {
-                    frameAwaiters.add(continuation)
-                }
-                scheduleFrame()
-            }
-        } else {
-            false
-        }
-    }
-
-    private fun resumeFrameAwaiters(isActive: Boolean) {
-        synchronized(frameAwaiters) {
-            for (frameAwaiter in frameAwaiters) {
-                frameAwaiter.resume(isActive)
-            }
-            frameAwaiters.clear()
-        }
-    }
 }
\ No newline at end of file

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/SkiaLayer.kt

 package org.jetbrains.skiko
 
-import kotlinx.coroutines.CompletableDeferred
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.swing.Swing
-import kotlinx.coroutines.withContext
 import org.jetbrains.skia.*
 import org.jetbrains.skiko.context.ContextHandler
 import org.jetbrains.skiko.context.createContextHandler
@@ -67,8 +63,7 @@ open class SkiaLayer(
         }
     }
 
-    private val onInit = CompletableDeferred<Unit>()
-    private val isInited get() = onInit.isCompleted
+    private var isInited = false
     private var isRendering = false
 
     private fun checkInit() {
@@ -138,7 +133,7 @@ open class SkiaLayer(
     open fun init() {
         backedLayer.init()
         findNextWorkingRenderApi(false)
-        onInit.complete(Unit)
+        isInited = true
     }
 
     private val stateHandlers =
@@ -281,20 +276,6 @@ open class SkiaLayer(
         redrawer?.needRedraw()
     }
 
-    /**
-     * Redraw on the next animation Frame (on vsync signal if vsync is enabled),
-     * and wait the frame to finish.
-     *
-     * @return true if frame was rendered, false if rendering loop was completed (cancelled or there was an exception inside it)
-     */
-    suspend fun awaitRedraw(): Boolean {
-        return withContext(Dispatchers.Swing) {
-            check(!isDisposed) { "SkiaLayer is disposed" }
-            onInit.await()
-            redrawer?.awaitRedraw() != false
-        }
-    }
-
     @Suppress("LeakingThis")
     private val fpsCounter = defaultFPSCounter(this)
 

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/context/Direct3DContextHandler.kt

@@ -10,18 +10,13 @@ internal class Direct3DContextHandler(layer: SkiaLayer) : ContextHandler(layer)
     private val bufferCount = 2
     private var surfaces: Array<Surface?> = arrayOfNulls(bufferCount)
 
-    val directXRedrawer: Direct3DRedrawer
+    private val directXRedrawer: Direct3DRedrawer
         get() = layer.redrawer!! as Direct3DRedrawer
 
-    var device: Long = 0
     override fun initContext(): Boolean {
         try {
             if (context == null) {
-                device = directXRedrawer.createDevice()
-                if (device == 0L) {
-                    throw Exception("Failed to create DirectX12 device.")
-                }
-                context = directXRedrawer.makeContext(device)
+                context = directXRedrawer.makeContext()
                 if (System.getProperty("skiko.hardwareInfo.enabled") == "true") {
                     println(rendererInfo())
                 }
@@ -55,14 +50,14 @@ internal class Direct3DContextHandler(layer: SkiaLayer) : ContextHandler(layer)
             context?.flush()
             
             if (!isD3DInited) {
-                directXRedrawer.initSwapChain(device)
+                directXRedrawer.initSwapChain()
             } else {
-                directXRedrawer.resizeBuffers(device, w, h)
+                directXRedrawer.resizeBuffers(w, h)
             }
             
             try {
                 for (bufferIndex in 0..bufferCount - 1) {
-                    surfaces[bufferIndex] = directXRedrawer.makeSurface(device, Native.getPtr(context!!), w, h, bufferIndex)
+                    surfaces[bufferIndex] = directXRedrawer.makeSurface(Native.getPtr(context!!), w, h, bufferIndex)
                 }
             } finally {
                 Reference.reachabilityFence(context!!)
@@ -70,17 +65,16 @@ internal class Direct3DContextHandler(layer: SkiaLayer) : ContextHandler(layer)
 
             if (!isD3DInited) {
                 isD3DInited = true
-                directXRedrawer.initFence(device)
+                directXRedrawer.initFence()
             }
         }
-        surface = surfaces[directXRedrawer.getBufferIndex(device)]
+        surface = surfaces[directXRedrawer.getBufferIndex()]
         canvas = surface!!.canvas
     }
 
     override fun flush() {
         try {
-            directXRedrawer.finishFrame(
-                device,
+            flush(
                 Native.getPtr(context!!),
                 Native.getPtr(surface!!)
             )
@@ -91,19 +85,20 @@ internal class Direct3DContextHandler(layer: SkiaLayer) : ContextHandler(layer)
     }
 
     override fun destroyContext() {
-        directXRedrawer.disposeDevice(device)
         context?.close()
     }
 
     override fun disposeCanvas() {
-        for (bufferIndex in 0..bufferCount - 1) {
+        for (bufferIndex in 0 until bufferCount) {
             surfaces[bufferIndex]?.close()
         }
     }
 
     override fun rendererInfo(): String {
         return super.rendererInfo() +
-            "Video card: ${directXRedrawer.getAdapterName(device)}\n" +
-            "Total VRAM: ${directXRedrawer.getAdapterMemorySize(device) / 1024 / 1024} MB\n"
+            "Video card: ${directXRedrawer.adapterName}\n" +
+            "Total VRAM: ${directXRedrawer.adapterMemorySize / 1024 / 1024} MB\n"
     }
+
+    private external fun flush(context: Long, surface: Long)
 }

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/redrawer/AngleRedrawer.kt

@@ -32,10 +32,6 @@ internal class AngleRedrawer(
         frameDispatcher.scheduleFrame()
     }
 
-    override suspend fun awaitRedraw(): Boolean {
-        return frameDispatcher.awaitFrame()
-    }
-
     override fun redrawImmediately() {
         check(!isDisposed) { "AngleRedrawer is disposed" }
         update(System.nanoTime())

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/redrawer/Direct3DRedrawer.kt

@@ -16,14 +16,21 @@ internal class Direct3DRedrawer(
 ) : Redrawer {
 
     private var isDisposed = false
-    private var disposeLock = Any()
+    private var drawLock = Any()
+
+    private val device = createDirectXDevice(getAdapterPriority(), layer.contentHandle).also {
+        if (it == 0L) {
+            throw Exception("Failed to create DirectX12 device.")
+        }
+    }
 
     private val frameDispatcher = FrameDispatcher(Dispatchers.Swing) {
         update(System.nanoTime())
         draw()
     }
 
-    override fun dispose() = synchronized(disposeLock) {
+    override fun dispose() = synchronized(drawLock) {
+        disposeDevice(device)
         frameDispatcher.cancel()
         isDisposed = true
     }
@@ -33,16 +40,12 @@ internal class Direct3DRedrawer(
         frameDispatcher.scheduleFrame()
     }
 
-    override suspend fun awaitRedraw(): Boolean {
-        return frameDispatcher.awaitFrame()
-    }
-
     override fun redrawImmediately() {
         check(!isDisposed) { "Direct3DRedrawer is disposed" }
-        // TODO now we wait until previous layer.draw is finished. it ends only on the next vsync.
-        //  because of that we lose one frame on resize and can theoretically see very small white bars on the sides of the window
-        //  to avoid this we should be able to draw in two modes: with vsync and without.
-        frameDispatcher.scheduleFrame()
+        layer.update(System.nanoTime())
+        if (prepareDrawContext()) {
+            drawAndSwap(withVsync = false)
+        }
     }
 
     private fun update(nanoTime: Long) {
@@ -50,32 +53,33 @@ internal class Direct3DRedrawer(
     }
 
     private suspend fun draw() {
-        if (layer.prepareDrawContext()) {
+        if (prepareDrawContext()) {
             withContext(Dispatchers.IO) {
-                synchronized(disposeLock) {
-                    if (!isDisposed) {
-                        layer.draw()
+                drawAndSwap(withVsync = properties.isVsyncEnabled)
             }
         }
     }
+
+    private fun prepareDrawContext() = synchronized(drawLock) {
+        layer.prepareDrawContext()
+    }
+
+    private fun drawAndSwap(withVsync: Boolean) = synchronized(drawLock) {
+        if (!isDisposed) {
+            layer.draw()
+            swap(device, withVsync)
         }
     }
 
-    fun makeContext(device: Long) = DirectContext(
+    fun makeContext() = DirectContext(
         makeDirectXContext(device)
     )
 
-    fun makeSurface(device: Long, context: Long, width: Int, height: Int, index: Int) = Surface(
+    fun makeSurface(context: Long, width: Int, height: Int, index: Int) = Surface(
         makeDirectXSurface(device, context, width, height, index)
     )
 
-    fun createDevice(): Long = createDirectXDevice(getAdapterPriority(), layer.contentHandle)
-
-    fun finishFrame(device: Long, context: Long, surface: Long) {
-        finishFrame(device, context, surface, properties.isVsyncEnabled)
-    }
-
-    fun getAdapterPriority(): Int {
+    private fun getAdapterPriority(): Int {
         val adapterPriority = GpuPriority.parse(System.getProperty("skiko.directx.gpu.priority"))
         return when (adapterPriority) {
             GpuPriority.Auto -> 0
@@ -85,15 +89,23 @@ internal class Direct3DRedrawer(
         }
     }
 
-    external fun createDirectXDevice(adapterPriority: Int, contentHandle: Long): Long
-    external fun makeDirectXContext(device: Long): Long
-    external fun makeDirectXSurface(device: Long, context: Long, width: Int, height: Int, index: Int): Long
-    external fun resizeBuffers(device: Long, width: Int, height: Int)
-    private external fun finishFrame(device: Long, context: Long, surface: Long, isVsyncEnabled: Boolean)
-    external fun disposeDevice(device: Long)
-    external fun getBufferIndex(device: Long): Int
-    external fun initSwapChain(device: Long)
-    external fun initFence(device: Long)
-    external fun getAdapterName(device: Long): String
-    external fun getAdapterMemorySize(device: Long): Long
+    fun resizeBuffers(width: Int, height: Int) = resizeBuffers(device, width, height)
+
+    fun getBufferIndex() = getBufferIndex(device)
+    fun initSwapChain() = initSwapChain(device)
+    fun initFence() = initFence(device)
+    val adapterName get() = getAdapterName(device)
+    val adapterMemorySize get() = getAdapterMemorySize(device)
+
+    private external fun createDirectXDevice(adapterPriority: Int, contentHandle: Long): Long
+    private external fun makeDirectXContext(device: Long): Long
+    private external fun makeDirectXSurface(device: Long, context: Long, width: Int, height: Int, index: Int): Long
+    private external fun resizeBuffers(device: Long, width: Int, height: Int)
+    private external fun swap(device: Long, isVsyncEnabled: Boolean)
+    private external fun disposeDevice(device: Long)
+    private external fun getBufferIndex(device: Long): Int
+    private external fun initSwapChain(device: Long)
+    private external fun initFence(device: Long)
+    private external fun getAdapterName(device: Long): String
+    private external fun getAdapterMemorySize(device: Long): Long
 }

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/redrawer/LinuxOpenGLRedrawer.kt

@@ -59,10 +59,6 @@ internal class LinuxOpenGLRedrawer(
         frameDispatcher.scheduleFrame()
     }
 
-    override suspend fun awaitRedraw(): Boolean {
-        return frameDispatcher.awaitFrame()
-    }
-
     override fun redrawImmediately() = layer.backedLayer.lockLinuxDrawingSurface {
         check(!isDisposed) { "LinuxOpenGLRedrawer is disposed" }
         update(System.nanoTime())

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/redrawer/MacOsOpenGLRedrawer.kt

@@ -2,12 +2,7 @@ package org.jetbrains.skiko.redrawer
 
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.swing.Swing
-import org.jetbrains.skiko.FrameDispatcher
-import org.jetbrains.skiko.OpenGLApi
-import org.jetbrains.skiko.SkiaLayer
-import org.jetbrains.skiko.SkiaLayerProperties
-import org.jetbrains.skiko.Task
-import org.jetbrains.skiko.useDrawingSurfacePlatformInfo
+import org.jetbrains.skiko.*
 import javax.swing.SwingUtilities.convertPoint
 import javax.swing.SwingUtilities.getRootPane
 
@@ -121,10 +116,6 @@ internal class MacOsOpenGLRedrawer(
         frameDispatcher.scheduleFrame()
     }
 
-    override suspend fun awaitRedraw(): Boolean {
-        return frameDispatcher.awaitFrame()
-    }
-
     override fun redrawImmediately() {
         layer.update(System.nanoTime())
 

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/redrawer/MetalRedrawer.kt

@@ -7,13 +7,13 @@ import kotlinx.coroutines.withContext
 import org.jetbrains.skia.BackendRenderTarget
 import org.jetbrains.skia.DirectContext
 import org.jetbrains.skiko.*
-import org.jetbrains.skiko.useDrawingSurfacePlatformInfo
 import javax.swing.SwingUtilities.convertPoint
 import javax.swing.SwingUtilities.getRootPane
+import kotlin.time.ExperimentalTime
 
 internal class MetalRedrawer(
     private val layer: SkiaLayer,
-    properties: SkiaLayerProperties
+    private val properties: SkiaLayerProperties
 ) : Redrawer {
     companion object {
         init {
@@ -21,18 +21,22 @@ internal class MetalRedrawer(
         }
     }
     private var isDisposed = false
-    private var disposeLock = Any()
+    private var drawLock = Any()
     private val device = layer.backedLayer.useDrawingSurfacePlatformInfo {
         createMetalDevice(getAdapterPriority(), it)
     }
     private val windowHandle = layer.windowHandle
 
+    init {
+        setVSyncEnabled(device, properties.isVsyncEnabled)
+    }
+
     private val frameDispatcher = FrameDispatcher(Dispatchers.Swing) {
         update(System.nanoTime())
         draw()
     }
 
-    override fun dispose() = synchronized(disposeLock) {
+    override fun dispose() = synchronized(drawLock) {
         frameDispatcher.cancel()
         disposeDevice(device)
         isDisposed = true
@@ -43,16 +47,12 @@ internal class MetalRedrawer(
         frameDispatcher.scheduleFrame()
     }
 
-    override suspend fun awaitRedraw(): Boolean {
-        return frameDispatcher.awaitFrame()
-    }
-
     override fun redrawImmediately() {
         check(!isDisposed) { "MetalRedrawer is disposed" }
-        // TODO: now we wait until previous `layer.draw` is finished. it ends only on the next vsync.
-        //  Because of that we lose one frame on resize and can theoretically see very small white bars on the sides
-        //  of the window to avoid this we should be able to draw in two modes: with vsync and without.
-        frameDispatcher.scheduleFrame()
+        setVSyncEnabled(device, enabled = false)
+        update(System.nanoTime())
+        performDraw()
+        setVSyncEnabled(device, properties.isVsyncEnabled)
     }
 
     private fun update(nanoTime: Long) {
@@ -60,11 +60,6 @@ internal class MetalRedrawer(
     }
 
     private suspend fun draw() {
-        withContext(Dispatchers.IO) {
-            val handle = startRendering()
-            synchronized(disposeLock) {
-                if (!isDisposed)
-                    if (layer.prepareDrawContext()) {
         // 2,3 GHz 8-Core Intel Core i9
         //
         // Test1. 8 windows, multiple clocks, 800x600
@@ -76,9 +71,9 @@ internal class MetalRedrawer(
         //
         // Executors.newSingleThreadExecutor().asCoroutineDispatcher(): 50 FPS, 150% CPU
         // Dispatchers.IO: 50 FPS, 200% CPU
-                        layer.draw()
-                    }
-            }
+        withContext(Dispatchers.IO) {
+            val handle = startRendering()
+            performDraw()
             endRendering(handle)
         }
         // When window is not visible - it doesn't make sense to redraw fast to avoid battery drain.
@@ -88,6 +83,14 @@ internal class MetalRedrawer(
             delay(300)
     }
 
+    private fun performDraw() = synchronized(drawLock) {
+        if (!isDisposed) {
+            if (layer.prepareDrawContext()) {
+                layer.draw()
+            }
+        }
+    }
+
     override fun syncSize() {
         val rootPane = getRootPane(layer)
         val globalPosition = convertPoint(layer, layer.x, layer.y, rootPane)
@@ -131,6 +134,7 @@ internal class MetalRedrawer(
     private external fun finishFrame(device: Long)
     private external fun resizeLayers(device: Long, x: Int, y: Int, width: Int, height: Int)
     private external fun setContentScale(device: Long, contentScale: Float)
+    private external fun setVSyncEnabled(device: Long, enabled: Boolean)
     private external fun isOccluded(window: Long): Boolean
     private external fun getAdapterName(device: Long): String
     private external fun getAdapterMemorySize(device: Long): Long

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/redrawer/Redrawer.kt

 package org.jetbrains.skiko.redrawer
 
-interface Redrawer {
+internal interface Redrawer {
     fun dispose()
     fun needRedraw()
     fun redrawImmediately()
-    suspend fun awaitRedraw(): Boolean
     fun syncSize() = Unit
 }
\ No newline at end of file

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/redrawer/SoftwareRedrawer.kt

@@ -36,10 +36,6 @@ internal class SoftwareRedrawer(
         frameDispatcher.scheduleFrame()
     }
 
-    override suspend fun awaitRedraw(): Boolean {
-        return frameDispatcher.awaitFrame()
-    }
-
     override fun redrawImmediately() {
         layer.update(System.nanoTime())
         if (layer.prepareDrawContext()) {

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/redrawer/WindowsOpenGLRedrawer.kt

@@ -4,12 +4,7 @@ import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.swing.Swing
 import kotlinx.coroutines.withContext
-import org.jetbrains.skiko.FrameDispatcher
-import org.jetbrains.skiko.isVideoCardSupported
-import org.jetbrains.skiko.OpenGLApi
-import org.jetbrains.skiko.SkiaLayer
-import org.jetbrains.skiko.SkiaLayerProperties
-import org.jetbrains.skiko.useDrawingSurfacePlatformInfo
+import org.jetbrains.skiko.*
 
 internal class WindowsOpenGLRedrawer(
     private val layer: SkiaLayer,
@@ -45,10 +40,6 @@ internal class WindowsOpenGLRedrawer(
         frameDispatcher.scheduleFrame()
     }
 
-    override suspend fun awaitRedraw(): Boolean {
-        return frameDispatcher.awaitFrame()
-    }
-
     override fun redrawImmediately() {
         check(!isDisposed) { "WindowsOpenGLRedrawer is disposed" }
         update(System.nanoTime())

skiko/src/jvmMain/objectiveC/macos/MetalRedrawer.mm

@@ -247,6 +247,12 @@ JNIEXPORT void JNICALL Java_org_jetbrains_skiko_redrawer_MetalRedrawer_setConten
     [CATransaction flush];
 }
 
+JNIEXPORT void JNICALL Java_org_jetbrains_skiko_redrawer_MetalRedrawer_setVSyncEnabled(JNIEnv *env, jobject obj, jlong devicePtr, jboolean enabled)
+{
+    MetalDevice *device = (MetalDevice *) devicePtr;
+    device.layer.displaySyncEnabled = enabled;
+}
+
 JNIEXPORT void JNICALL Java_org_jetbrains_skiko_redrawer_MetalRedrawer_finishFrame(
     JNIEnv *env, jobject redrawer, jlong devicePtr)
 {

skiko/src/jvmTest/kotlin/org/jetbrains/skiko/FrameDispatcherTest.kt

 package org.jetbrains.skiko
 
-import kotlinx.coroutines.CoroutineExceptionHandler
-import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.ExperimentalCoroutinesApi
-import kotlinx.coroutines.Job
-import kotlinx.coroutines.asCoroutineDispatcher
-import kotlinx.coroutines.cancel
-import kotlinx.coroutines.launch
-import kotlinx.coroutines.runBlocking
+import kotlinx.coroutines.*
 import kotlinx.coroutines.test.TestCoroutineScope
 import kotlinx.coroutines.test.runBlockingTest
-import kotlinx.coroutines.yield
 import org.junit.Assert.assertEquals
 import org.junit.Test
 import java.util.concurrent.Executors
-import kotlin.coroutines.AbstractCoroutineContextElement
-import kotlin.coroutines.CoroutineContext
-import kotlin.test.assertFalse
-import kotlin.test.assertTrue
 
 @OptIn(ExperimentalCoroutinesApi::class)
 class FrameDispatcherTest {
@@ -197,75 +185,6 @@ class FrameDispatcherTest {
         assertEquals(listOf("frame0", "task", "frame1"), history)
     }
 
-    @Test
-    fun `await frame`() = test {
-        val scope = CoroutineScope(coroutineContext)
-        val frameDispatcher = FrameDispatcher(scope = scope) {
-            frameCount++
-        }
-
-        frameDispatcher.awaitFrame()
-        assertEquals(1, frameCount)
-
-        frameDispatcher.awaitFrame()
-        assertEquals(2, frameCount)
-
-        frameDispatcher.awaitFrame()
-        assertEquals(3, frameCount)
-
-        repeat(100) {
-            yield()
-        }
-        assertEquals(3, frameCount)
-    }
-
-    @Test
-    fun `await active frame`() = test {
-        val scope = CoroutineScope(coroutineContext)
-        val frameDispatcher = FrameDispatcher(scope = scope) {}
-
-        val isActive = frameDispatcher.awaitFrame()
-        assertTrue(isActive)
-    }
-
-    @Test
-    fun `await failed frame`() = test {
-        val ignoreExceptionHandler = object :
-            AbstractCoroutineContextElement(CoroutineExceptionHandler),
-            CoroutineExceptionHandler {
-            override fun handleException(context: CoroutineContext, exception: Throwable) = Unit
-        }
-
-        val scope = CoroutineScope(coroutineContext + ignoreExceptionHandler)
-
-        val frameDispatcher = FrameDispatcher(scope = scope) {
-            throw RuntimeException()
-        }
-
-        val isActive = frameDispatcher.awaitFrame()
-        assertFalse(isActive)
-    }
-
-    @Test
-    fun `cancel dispatcher before awaitFrame`() = test {
-        val scope = CoroutineScope(coroutineContext)
-        val frameDispatcher = FrameDispatcher(scope = scope) {}
-        frameDispatcher.cancel()
-
-        val isActive = frameDispatcher.awaitFrame()
-        assertFalse(isActive)
-    }
-
-    @Test
-    fun `cancel scope before awaitFrame`() = test {
-        val scope = CoroutineScope(coroutineContext)
-        val frameDispatcher = FrameDispatcher(scope = scope) {}
-        scope.cancel()
-
-        val isActive = frameDispatcher.awaitFrame()
-        assertFalse(isActive)
-    }
-
     private fun test(
         block: suspend TestCoroutineScope.() -> Unit
     ) = runBlockingTest {

skiko/src/jvmTest/kotlin/org/jetbrains/skiko/SkiaWindowTest.kt

@@ -79,7 +79,7 @@ class SkiaWindowTest {
             window.layer.renderer = renderer
             window.isUndecorated = true
             window.pack()
-            window.layer.awaitRedraw()
+            window.paint(window.graphics)
             window.isVisible = true
 
             delay(1000)

skiko/src/jvmTest/kotlin/org/jetbrains/skiko/util/Images.kt

 package org.jetbrains.skiko.util
 
+import java.awt.Color
 import java.awt.image.BufferedImage
+import kotlin.math.abs
 
-fun isContentSame(img1: BufferedImage, img2: BufferedImage): Boolean {
+fun isContentSame(img1: BufferedImage, img2: BufferedImage, sensitivity: Double): Boolean {
+    require(sensitivity in 0.0..1.0)
+    val sensitivity255 = (sensitivity * 255).toInt()
     if (img1.width == img2.width && img1.height == img2.height) {
         for (x in 0 until img1.width) {
             for (y in 0 until img1.height) {
-                if (img1.getRGB(x, y) != img2.getRGB(x, y)) {
+                val color1 = Color(img1.getRGB(x, y))
+                val color2 = Color(img2.getRGB(x, y))
+                if (abs(color1.red - color2.red) > sensitivity255) {
+                    return false
+                }
+                if (abs(color1.green - color2.green) > sensitivity255) {
+                    return false
+                }
+                if (abs(color1.blue - color2.blue) > sensitivity255) {
+                    return false
+                }
+                if (abs(color1.alpha - color2.alpha) > sensitivity255) {
                     return false
                 }
             }

skiko/src/jvmTest/kotlin/org/jetbrains/skiko/util/ScreenshotTestRule.kt

@@ -49,7 +49,8 @@ class ScreenshotTestRule : TestRule {
         }
         if (expectedFile.exists()) {
             val expected = ImageIO.read(expectedFile)
-            if (!isContentSame(expected, actual)) {
+            // macOs screenshots can have different color on different configurations
+            if (!isContentSame(expected, actual, sensitivity = 0.25)) {
                 ImageIO.write(actual, "png", actualFile)
                 throw AssertionError(
                     "Image mismatch! Expected image ${expectedFile.absolutePath}, actual: ${actualFile.absolutePath}"