Ability to disable vsync

.run/SkijaInjectSample (without vsync).run.xml

+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="SkijaInjectSample (without vsync)" type="GradleRunConfiguration" factoryName="Gradle">
+    <ExternalSystemSettings>
+      <option name="executionName" />
+      <option name="externalProjectPath" value="$PROJECT_DIR$/samples/SkijaInjectSample" />
+      <option name="externalSystemIdString" value="GRADLE" />
+      <option name="scriptParameters" value="-Dskiko.vsync.enabled=false" />
+      <option name="taskDescriptions">
+        <list />
+      </option>
+      <option name="taskNames">
+        <list>
+          <option value="run" />
+        </list>
+      </option>
+      <option name="vmOptions" value="" />
+    </ExternalSystemSettings>
+    <ExternalSystemDebugServerProcess>true</ExternalSystemDebugServerProcess>
+    <ExternalSystemReattachDebugProcess>true</ExternalSystemReattachDebugProcess>
+    <DebugAllEnabled>false</DebugAllEnabled>
+    <method v="2" />
+  </configuration>
+</component>
\ No newline at end of file

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

@@ -2,6 +2,8 @@ package org.jetbrains.skiko
 
 @Suppress("SameParameterValue")
 internal object SkikoProperties {
+    val vsyncEnabled: Boolean by property("skiko.vsync.enabled", default = true)
+
     val fpsEnabled: Boolean by property("skiko.fps.enabled", default = false)
     val fpsCount: Int by property("skiko.fps.count", default = 300)
     val fpsProbability: Double by property("skiko.fps.probability", default = 0.97)

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

@@ -8,6 +8,7 @@ import kotlinx.coroutines.withContext
 import org.jetbrains.skiko.FrameDispatcher
 import org.jetbrains.skiko.HardwareLayer
 import org.jetbrains.skiko.OpenGLApi
+import org.jetbrains.skiko.SkikoProperties
 
 internal class LinuxRedrawer(
     private val layer: HardwareLayer
@@ -15,7 +16,7 @@ internal class LinuxRedrawer(
     private val context = layer.lockDrawingSurface {
         val context = it.createContext()
         it.makeCurrent(context)
-        it.setSwapInterval(1)
+        it.setSwapInterval(if (SkikoProperties.vsyncEnabled) 1 else 0)
         context
     }
     private var isDisposed = false

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

@@ -6,6 +6,7 @@ import kotlinx.coroutines.swing.Swing
 import org.jetbrains.skiko.FrameDispatcher
 import org.jetbrains.skiko.HardwareLayer
 import org.jetbrains.skiko.OpenGLApi
+import org.jetbrains.skiko.SkikoProperties
 import javax.swing.SwingUtilities.convertPoint
 import javax.swing.SwingUtilities.getRootPane
 
@@ -76,8 +77,10 @@ internal class MacOsRedrawer(
     private val frameDispatcher = FrameDispatcher(Dispatchers.Swing) {
         layer.update(System.nanoTime())
         drawLayer.setNeedsDisplay()
+        if (SkikoProperties.vsyncEnabled) {
             vsyncLayer.sync()
         }
+    }
 
     override fun dispose() = synchronized(drawLock) {
         frameDispatcher.cancel()

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

@@ -8,6 +8,7 @@ import kotlinx.coroutines.withContext
 import org.jetbrains.skiko.FrameDispatcher
 import org.jetbrains.skiko.HardwareLayer
 import org.jetbrains.skiko.OpenGLApi
+import org.jetbrains.skiko.SkikoProperties
 
 internal class WindowsRedrawer(
     private val layer: HardwareLayer
@@ -86,11 +87,13 @@ internal class WindowsRedrawer(
                 OpenGLApi.instance.glFinish()
             }
 
+            if (SkikoProperties.vsyncEnabled) {
                 withContext(Dispatchers.IO) {
                     dwmFlush() // wait for vsync
                 }
             }
         }
+    }
 }
 
 private external fun makeCurrent(device: Long, context: Long)