Added Metal renderer for macos-native. (#307)

* Added Metal renderer for macos-native.

samples/SkiaMultiplatformSample/src/commonMain/kotlin/org/jetbrains/skiko/sample/Clocks.kt

@@ -5,6 +5,8 @@ import org.jetbrains.skia.paragraph.FontCollection
 import org.jetbrains.skia.paragraph.ParagraphBuilder
 import org.jetbrains.skia.paragraph.ParagraphStyle
 import org.jetbrains.skia.paragraph.TextStyle
+import org.jetbrains.skiko.currentSystemTheme
+import org.jetbrains.skiko.SkiaLayer
 import org.jetbrains.skiko.SkikoView
 import org.jetbrains.skiko.SkikoPointerEvent
 import org.jetbrains.skiko.SkikoGestureEvent
@@ -16,7 +18,7 @@ import kotlin.math.sin
 import kotlin.math.PI
 import kotlin.math.pow
 
-class Clocks: SkikoView {
+class Clocks(private val layer: SkiaLayer): SkikoView {
     private var frame = 0
     private var xpos = 0.0
     private var ypos = 0.0
@@ -84,6 +86,13 @@ class Clocks: SkikoView {
         }
 
         val style = ParagraphStyle()
+        val renderInfo = ParagraphBuilder(style, fontCollection)
+            .pushStyle(TextStyle().setColor(0xFF000000.toInt()))
+            .addText("Graphics API: ${layer.renderApi} ✿ﾟ ${currentSystemTheme}")
+            .popStyle()
+            .build()
+        renderInfo.layout(Float.POSITIVE_INFINITY)
+        renderInfo.paint(canvas, 5f, 5f)
         val frames = ParagraphBuilder(style, fontCollection)
             .pushStyle(TextStyle().setColor(0xff9BC730L.toInt()).setFontSize(20f))
             .addText("Frames: ${frame++}\nAngle: $rotate")

samples/SkiaMultiplatformSample/src/iosMain/kotlin/org/jetbrains/skiko/sample/App.ios.kt

@@ -3,12 +3,13 @@ package org.jetbrains.skiko.sample
 
 import kotlinx.cinterop.*
 import org.jetbrains.skiko.GenericSkikoView
+import org.jetbrains.skiko.SkiaLayer
 import org.jetbrains.skiko.SkikoView
 import org.jetbrains.skiko.SkikoViewController
 import platform.UIKit.*
 import platform.Foundation.*
 
-fun makeApp(): SkikoView = Clocks()
+fun makeApp(skiaLayer: SkiaLayer) = Clocks(skiaLayer)
 
 fun main() {
     val args = emptyArray<String>()
@@ -37,7 +38,7 @@ class SkikoAppDelegate : UIResponder, UIApplicationDelegateProtocol {
         window = UIWindow(frame = UIScreen.mainScreen.bounds)
         window!!.rootViewController = SkikoViewController().apply {
             setAppFactory { layer ->
-                GenericSkikoView(layer, makeApp()).also {
+                GenericSkikoView(layer, makeApp(layer)).also {
                     layer.skikoView = it
                 }
             }

samples/SkiaMultiplatformSample/src/jvmMain/kotlin/org/jetbrains/skiko/sample/App.jvm.kt

@@ -7,7 +7,7 @@ import javax.swing.*
 
 fun main() {
     val skiaLayer = SkiaLayer()
-    skiaLayer.addView( GenericSkikoView(skiaLayer, Clocks()))
+    skiaLayer.addView( GenericSkikoView(skiaLayer, Clocks(skiaLayer)))
     SwingUtilities.invokeLater {
         val window = JFrame("Skiko example").apply {
             defaultCloseOperation = WindowConstants.EXIT_ON_CLOSE

samples/SkiaMultiplatformSample/src/macosMain/kotlin/org/jetbrains/skiko/sample/App.macos.kt

@@ -8,7 +8,7 @@ import kotlinx.cinterop.*
 import platform.Foundation.NSMakeRect
 import platform.darwin.NSObject
 
-fun makeApp() = Clocks()
+fun makeApp(skiaLayer: SkiaLayer) = Clocks(skiaLayer)
 
 fun main() {
     val app = NSApplication.sharedApplication()
@@ -27,7 +27,7 @@ fun main() {
         backing = NSBackingStoreBuffered,
         defer = true)
     val skiaLayer = SkiaLayer()
-    skiaLayer.skikoView = GenericSkikoView(skiaLayer, makeApp())
+    skiaLayer.skikoView = GenericSkikoView(skiaLayer, makeApp(skiaLayer))
     skiaLayer.attachTo(window)
     window.orderFrontRegardless()
     app.run()

skiko/src/jsMain/kotlin/org/jetbrains/skiko/SystemTheme.js.kt

+package org.jetbrains.skiko
+
+val currentSystemTheme: SystemTheme
+    // TODO: getting actual OS system theme
+    get() = SystemTheme.LIGHT
\ No newline at end of file

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

@@ -9,7 +9,6 @@ import org.jetbrains.skia.BackendRenderTarget
 import org.jetbrains.skia.DirectContext
 import org.jetbrains.skiko.*
 import org.jetbrains.skiko.context.MetalContextHandler
-import org.jetbrains.skiko.context.OpenGLContextHandler
 import javax.swing.SwingUtilities.*
 
 internal class MetalRedrawer(

skiko/src/macosMain/kotlin/org/jetbrains/skiko/RenderFactory.macos.kt

+package org.jetbrains.skiko
+
+import org.jetbrains.skiko.context.ContextHandler
+import org.jetbrains.skiko.redrawer.MacOsOpenGLRedrawer
+import org.jetbrains.skiko.redrawer.MacOsMetalRedrawer
+import org.jetbrains.skiko.redrawer.Redrawer
+
+internal fun createNativeRedrawer(
+    layer: SkiaLayer,
+    renderApi: GraphicsApi
+): Redrawer = when (renderApi) {
+    GraphicsApi.OPENGL -> MacOsOpenGLRedrawer(layer)
+    GraphicsApi.METAL -> MacOsMetalRedrawer(layer)
+    else -> throw IllegalArgumentException("Unsupported API $renderApi")
+}
\ No newline at end of file

skiko/src/macosMain/kotlin/org/jetbrains/skiko/SkiaLayer.macos.kt

@@ -2,7 +2,6 @@ package org.jetbrains.skiko
 
 import kotlinx.cinterop.ObjCAction
 import kotlinx.cinterop.useContents
-import org.jetbrains.skiko.context.*
 import org.jetbrains.skia.*
 import org.jetbrains.skiko.redrawer.MacOsOpenGLRedrawer
 import org.jetbrains.skiko.redrawer.Redrawer
@@ -15,7 +14,11 @@ import platform.Foundation.addObserver
 import platform.darwin.NSObject
 import platform.CoreGraphics.CGRectMake
 
-actual open class SkiaLayer {
+actual open class SkiaLayer() {
+    fun isShowing(): Boolean {
+        return true
+    }
+
     actual var renderApi: GraphicsApi = GraphicsApi.OPENGL
     actual val contentScale: Float
         get() = if (this::nsView.isInitialized) nsView.window!!.backingScaleFactor.toFloat() else 1.0f
@@ -36,7 +39,7 @@ actual open class SkiaLayer {
 
     actual var skikoView: SkikoView? = null
 
-    private var redrawer: Redrawer? = null
+    internal var redrawer: Redrawer? = null
 
     private var picture: PictureHolder? = null
     private val pictureRecorder = PictureRecorder()
@@ -137,7 +140,7 @@ actual open class SkiaLayer {
             }
         }
         window.contentView!!.addSubview(nsView)
-        redrawer = MacOsOpenGLRedrawer(this).apply {
+        redrawer = createNativeRedrawer(this, renderApi).apply {
             syncSize()
             needRedraw()
         }

skiko/src/macosMain/kotlin/org/jetbrains/skiko/SystemTheme.macos.kt

+package org.jetbrains.skiko
+
+import platform.Foundation.NSUserDefaults
+
+val currentSystemTheme: SystemTheme
+    get() = when (NSUserDefaults.standardUserDefaults.stringForKey("AppleInterfaceStyle")) {
+        "Dark" -> SystemTheme.DARK
+        else -> SystemTheme.LIGHT
+    }
\ No newline at end of file

skiko/src/macosMain/kotlin/org/jetbrains/skiko/context/MetalContextHandler.macos.kt

+package org.jetbrains.skiko.context
+
+import kotlinx.cinterop.useContents
+import org.jetbrains.skia.ColorSpace
+import org.jetbrains.skia.Surface
+import org.jetbrains.skia.SurfaceColorFormat
+import org.jetbrains.skia.SurfaceOrigin
+import org.jetbrains.skiko.SkiaLayer
+import org.jetbrains.skiko.redrawer.MacOsMetalRedrawer
+
+internal class MacOsMetalContextHandler(layer: SkiaLayer) : ContextHandler(layer, layer::draw) {
+    val metalRedrawer: MacOsMetalRedrawer
+        get() = layer.redrawer!! as MacOsMetalRedrawer
+
+    override fun initContext(): Boolean {
+        try {
+            if (context == null) {
+                context = metalRedrawer.makeContext()
+            }
+        } catch (e: Exception) {
+            println("${e.message}\nFailed to create Skia Metal context!")
+            return false
+        }
+        return true
+    }
+
+    override fun initCanvas() {
+        val scale = layer.contentScale
+        val w = (layer.nsView.frame.useContents { size.width } * scale).toInt().coerceAtLeast(0)
+        val h = (layer.nsView.frame.useContents { size.height } * scale).toInt().coerceAtLeast(0)
+
+        renderTarget = metalRedrawer.makeRenderTarget(w, h)
+
+        surface = Surface.makeFromBackendRenderTarget(
+            context!!,
+            renderTarget!!,
+            SurfaceOrigin.TOP_LEFT,
+            SurfaceColorFormat.BGRA_8888,
+            ColorSpace.sRGB
+        )
+
+        canvas = surface!!.canvas
+    }
+
+    override fun flush() {
+        // TODO: maybe make flush async as in JVM version.
+        super.flush()
+        surface!!.flushAndSubmit()
+        metalRedrawer.finishFrame()
+    }
+
+   override fun rendererInfo(): String {
+        return "Native Metal: device ${metalRedrawer.device.name}"
+    }
+}
+

skiko/src/macosMain/kotlin/org/jetbrains/skiko/context/OpenGLContextHandler.macos.kt

@@ -31,14 +31,22 @@ internal class MacOSOpenGLContextHandler(layer: SkiaLayer) : ContextHandler(laye
         return result
     }
 
-    var initedCanvas = false
+    private var currentWidth = 0
+    private var currentHeight = 0
+    private fun isSizeChanged(width: Int, height: Int): Boolean {
+        if (width != currentWidth || height != currentHeight) {
+            currentWidth = width
+            currentHeight = height
+            return true
+        }
+        return false
+    }
 
     override fun initCanvas() {
-        if (!initedCanvas) {
         val scale = layer.contentScale
         val w = (layer.nsView.frame.useContents { size.width } * scale).toInt().coerceAtLeast(0)
         val h = (layer.nsView.frame.useContents { size.height } * scale).toInt().coerceAtLeast(0)
-
+        if (isSizeChanged(w, h)) {
             val fbId = openglGetIntegerv(GL_DRAW_FRAMEBUFFER_BINDING.toUInt())
             renderTarget = BackendRenderTarget.makeGL(
                     w,
@@ -58,8 +66,6 @@ internal class MacOSOpenGLContextHandler(layer: SkiaLayer) : ContextHandler(laye
 
             canvas = surface?.canvas
                 ?: error("Could not obtain Canvas from Surface")
-
-            initedCanvas = true
         }
     }
 }

skiko/src/macosMain/kotlin/org/jetbrains/skiko/redrawer/MetalRedrawer.macos.kt

+package org.jetbrains.skiko.redrawer
+
+import kotlinx.cinterop.addressOf
+import kotlinx.cinterop.autoreleasepool
+import kotlinx.cinterop.objcPtr
+import kotlinx.cinterop.usePinned
+import kotlinx.cinterop.useContents
+import org.jetbrains.skia.BackendRenderTarget
+import org.jetbrains.skia.DirectContext
+import org.jetbrains.skiko.FrameDispatcher
+import org.jetbrains.skiko.SkikoDispatchers
+import org.jetbrains.skiko.SkiaLayer
+import org.jetbrains.skiko.context.ContextHandler
+import org.jetbrains.skiko.context.MacOsMetalContextHandler
+import platform.CoreGraphics.CGColorCreate
+import platform.CoreGraphics.CGColorSpaceCreateDeviceRGB
+import platform.CoreGraphics.CGContextRef
+import platform.Metal.MTLCreateSystemDefaultDevice
+import platform.Metal.MTLDeviceProtocol
+import platform.Metal.MTLPixelFormatBGRA8Unorm
+import platform.QuartzCore.CAMetalDrawableProtocol
+import platform.QuartzCore.CAMetalLayer
+import platform.QuartzCore.CATransaction
+import platform.QuartzCore.kCAGravityTopLeft
+import platform.QuartzCore.kCALayerHeightSizable
+import platform.QuartzCore.kCALayerWidthSizable
+import kotlin.system.getTimeNanos
+import platform.CoreGraphics.CGSizeMake
+
+internal class MacOsMetalRedrawer(
+    private val skiaLayer: SkiaLayer
+) : Redrawer {
+    private val contextHandler = MacOsMetalContextHandler(skiaLayer)
+    override val renderInfo: String get() = contextHandler.rendererInfo()
+
+    private var isDisposed = false
+    internal val device = MTLCreateSystemDefaultDevice()!!
+    private val queue = device.newCommandQueue()!!
+    private var currentDrawable: CAMetalDrawableProtocol? = null
+    private val metalLayer = MetalLayer()
+
+    init {
+        metalLayer.init(skiaLayer, contextHandler, device)
+    }
+
+    private val frameDispatcher = FrameDispatcher(SkikoDispatchers.Main) {
+        if (skiaLayer.isShowing()) {
+            draw()
+        }
+    }
+
+    fun makeContext() = DirectContext.makeMetal(device.objcPtr(), queue.objcPtr())
+
+    fun makeRenderTarget(width: Int, height: Int): BackendRenderTarget {
+        currentDrawable = metalLayer.nextDrawable()!!
+        return BackendRenderTarget.makeMetal(width, height, currentDrawable!!.texture.objcPtr())
+    }
+
+    override fun dispose() {
+        if (!isDisposed) {
+            metalLayer.dispose()
+            isDisposed = true
+        }
+    }
+
+    override fun syncSize() {
+        syncContentScale()
+        val osView = skiaLayer.nsView!!
+        val (w, h) = osView.frame.useContents {
+            size.width to size.height
+        }
+        CATransaction.begin()
+        CATransaction.setDisableActions(true)
+        metalLayer.frame = osView.frame
+        metalLayer.init(skiaLayer, contextHandler, device)
+        metalLayer.drawableSize = CGSizeMake(w * metalLayer.contentsScale, h * metalLayer.contentsScale)
+        CATransaction.commit()
+        CATransaction.flush()
+    }
+
+    private fun syncContentScale() {
+        CATransaction.begin()
+        CATransaction.setDisableActions(true)
+        metalLayer.contentsScale = skiaLayer.nsView.window!!.backingScaleFactor
+        CATransaction.commit()
+        CATransaction.flush()
+    }
+
+    override fun needRedraw() {
+        check(!isDisposed) { "MetalRedrawer is disposed" }
+        frameDispatcher.scheduleFrame()
+    }
+
+    override fun redrawImmediately() {
+        check(!isDisposed) { "MetalRedrawer is disposed" }
+        draw()
+    }
+
+    private fun draw() {
+        // TODO: maybe make flush async as in JVM version.
+        autoreleasepool {
+            if (!isDisposed) {
+                skiaLayer.update(getTimeNanos())
+                contextHandler.draw()
+            }
+        }
+    }
+
+    fun finishFrame() {
+        autoreleasepool {
+            currentDrawable?.let {
+                val commandBuffer = queue.commandBuffer()!!
+                commandBuffer.label = "Present"
+                commandBuffer.presentDrawable(it)
+                commandBuffer.commit()
+                currentDrawable = null
+            }
+        }
+    }
+}
+
+internal class MetalLayer : CAMetalLayer {
+    private lateinit var skiaLayer: SkiaLayer
+    private lateinit var contextHandler: ContextHandler
+
+    @OverrideInit
+    constructor(): super()
+    @OverrideInit
+    constructor(layer: Any): super(layer)
+
+    fun init(
+        layer: SkiaLayer,
+        contextHandler: ContextHandler,
+        theDevice: MTLDeviceProtocol
+    ) {
+        this.skiaLayer = layer
+        this.contextHandler = contextHandler
+        this.setNeedsDisplayOnBoundsChange(true)
+        this.removeAllAnimations()
+        this.setAutoresizingMask(kCALayerWidthSizable or kCALayerHeightSizable )
+        this.device = theDevice as objcnames.protocols.MTLDeviceProtocol?
+        this.pixelFormat = MTLPixelFormatBGRA8Unorm
+        this.opaque = false
+        doubleArrayOf(0.0, 0.0, 0.0, 0.0).usePinned {
+            this.backgroundColor =
+                CGColorCreate(CGColorSpaceCreateDeviceRGB(), it.addressOf(0))
+        }
+        this.displaySyncEnabled = false
+        skiaLayer.nsView.layer = this
+        skiaLayer.nsView.wantsLayer = true
+        this.contentsGravity = kCAGravityTopLeft;
+    }
+
+    fun dispose() {
+        this.removeFromSuperlayer()
+    }
+
+    override fun drawInContext(ctx: CGContextRef?) {
+        skiaLayer.update(getTimeNanos())
+        contextHandler.draw()
+        super.drawInContext(ctx)
+    }
+}

skiko/src/macosMain/kotlin/org/jetbrains/skiko/redrawer/OpenGLRedrawer.macos.kt

@@ -48,7 +48,6 @@ internal class MacOsOpenGLRedrawer(
                 size.height.toInt().coerceAtLeast(0)
             )
         }
-        contextHandler.initedCanvas = false
     }
 
     private fun syncContentScale() {
@@ -70,21 +69,22 @@ internal class MacOsOpenGLRedrawer(
 }
 
 internal class MacosGLLayer : CAOpenGLLayer {
-    private lateinit var layer: SkiaLayer
+    private lateinit var skiaLayer: SkiaLayer
     private lateinit var contextHandler: ContextHandler
+
     @OverrideInit
     constructor(): super()
     @OverrideInit
     constructor(layer: Any): super(layer)
 
     fun init(layer: SkiaLayer, contextHandler: ContextHandler) {
-        this.layer = layer
+        skiaLayer = layer
         this.contextHandler = contextHandler
         this.setNeedsDisplayOnBoundsChange(true)
         this.removeAllAnimations()
         this.setAutoresizingMask(kCALayerWidthSizable or kCALayerHeightSizable )
-        layer.nsView.layer = this
-        layer.nsView.wantsLayer = true
+        skiaLayer.nsView.layer = this
+        skiaLayer.nsView.wantsLayer = true
         this.contentsGravity = kCAGravityTopLeft;
     }
 
@@ -118,7 +118,7 @@ internal class MacosGLLayer : CAOpenGLLayer {
     ) {
         CGLSetCurrentContext(ctx);
         try {
-            layer.update(getTimeNanos())
+            skiaLayer.update(getTimeNanos())
             contextHandler.draw()
         } catch (e: Throwable) {
             e.printStackTrace()