Software rendering support.

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

@@ -15,8 +15,10 @@ import kotlin.math.cos
 import kotlin.math.sin
 
 fun main(args: Array<String>) {
+    System.setProperty("skiko.renderApi", "RASTER")
     repeat(1) {
-        createWindow("window $it")
+        // createWindow("window $it")
+        SwingSkia()
     }
 }
 

samples/SkijaInjectSample/src/main/kotlin/SkijaInjectSample/SkiaPanel.kt

@@ -34,5 +34,6 @@ open class SkiaPanel: JLayeredPane {
 
      override fun removeNotify() {
         super.removeNotify()
+        layer.dispose()
      }
 }

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

 package org.jetbrains.skiko
 
 enum class GraphicsApi {
-    UNKNOWN, OPENGL, VULKAN, METAL
+    UNKNOWN, RASTER, OPENGL, D3D, VULKAN, METAL
 }
\ No newline at end of file

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

 package org.jetbrains.skiko
 
+import org.jetbrains.skiko.GraphicsApi
+import org.jetbrains.skiko.context.renderApi
 import org.jetbrains.skiko.redrawer.LinuxRedrawer
 import org.jetbrains.skiko.redrawer.MacOsRedrawer
+import org.jetbrains.skiko.redrawer.RasterRedrawer
 import org.jetbrains.skiko.redrawer.Redrawer
 import org.jetbrains.skiko.redrawer.WindowsRedrawer
 import java.awt.Component
@@ -30,7 +33,10 @@ internal val platformOperations: PlatformOperations by lazy {
                     return component.graphicsConfiguration.defaultTransform.scaleX.toFloat()
                 }
 
-                override fun createHardwareRedrawer(layer: HardwareLayer) = MacOsRedrawer(layer)
+                override fun createHardwareRedrawer(layer: HardwareLayer) = when(renderApi) {
+                    GraphicsApi.RASTER -> RasterRedrawer(layer)
+                    else -> MacOsRedrawer(layer)
+                }
         }
         OS.Windows -> {
             object: PlatformOperations {
@@ -50,7 +56,10 @@ internal val platformOperations: PlatformOperations by lazy {
                     return component.graphicsConfiguration.defaultTransform.scaleX.toFloat()
                 }
 
-                override fun createHardwareRedrawer(layer: HardwareLayer) = WindowsRedrawer(layer)
+                override fun createHardwareRedrawer(layer: HardwareLayer) = when(renderApi) {
+                    GraphicsApi.RASTER -> RasterRedrawer(layer)
+                    else -> WindowsRedrawer(layer)
+                }
             }
         }
         OS.Linux -> {
@@ -83,7 +92,10 @@ internal val platformOperations: PlatformOperations by lazy {
                     // return linuxGetDpiScaleNative(component)
                 }
 
-                override fun createHardwareRedrawer(layer: HardwareLayer) = LinuxRedrawer(layer)
+                override fun createHardwareRedrawer(layer: HardwareLayer) = when(renderApi) {
+                    GraphicsApi.RASTER -> RasterRedrawer(layer)
+                    else -> LinuxRedrawer(layer)
+                }
             }
         }
     }

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

@@ -2,22 +2,10 @@ package org.jetbrains.skiko
 
 import org.jetbrains.skija.*
 import org.jetbrains.skiko.redrawer.Redrawer
+import org.jetbrains.skiko.context.createContextHandler
 import java.awt.Graphics
 import javax.swing.SwingUtilities.isEventDispatchThread
 
-private class SkijaState {
-    val bleachConstant = if (hostOs == OS.MacOS) 0 else -1
-    var context: DirectContext? = null
-    var renderTarget: BackendRenderTarget? = null
-    var surface: Surface? = null
-    var canvas: Canvas? = null
-
-    fun clear() {
-        surface?.close()
-        renderTarget?.close()
-    }
-}
-
 interface SkiaRenderer {
     suspend fun onRender(canvas: Canvas, width: Int, height: Int, nanoTime: Long)
 }
@@ -25,12 +13,10 @@ interface SkiaRenderer {
 private class PictureHolder(val instance: Picture, val width: Int, val height: Int)
 
 open class SkiaLayer : HardwareLayer() {
-    open val api: GraphicsApi = GraphicsApi.OPENGL
-
     var renderer: SkiaRenderer? = null
     val clipComponents = mutableListOf<ClipRectangle>()
 
-    private val skijaState = SkijaState()
+    private val skijaState = createContextHandler(this)
 
     @Volatile
     private var isDisposed = false
@@ -114,26 +100,17 @@ open class SkiaLayer : HardwareLayer() {
 
     override fun draw() {
         check(!isDisposed)
-
-        if (skijaState.context == null) {
-            skijaState.context = when (api) {
-                GraphicsApi.OPENGL -> makeGLContext()
-                GraphicsApi.METAL -> makeMetalContext()
-                else -> TODO("Unsupported yet")
-            }
-        }
-
-        initSkija()
-
         skijaState.apply {
-            canvas!!.clear(bleachConstant)
+            initContext()
+            initCanvas()
+            clearCanvas()
             synchronized(pictureLock) {
                 val picture = picture
                 if (picture != null) {
-                    canvas!!.drawPicture(picture.instance)
+                    drawOnCanvas(picture.instance)
                 }
             }
-            context!!.flush()
+            flush()
         }
     }
 
@@ -150,51 +127,4 @@ open class SkiaLayer : HardwareLayer() {
             true
         )
     }
-
-    private fun initSkija() {
-        initRenderTarget()
-        initSurface()
-    }
-
-    private fun initRenderTarget() {
-        skijaState.apply {
-            clear()
-            val dpi = contentScale
-            val width = (width * dpi).toInt().coerceAtLeast(0)
-            val height = (height * dpi).toInt().coerceAtLeast(0)
-            renderTarget = when (api) {
-                GraphicsApi.OPENGL -> {
-                    val gl = OpenGLApi.instance
-                    val fbId = gl.glGetIntegerv(gl.GL_DRAW_FRAMEBUFFER_BINDING)
-                    makeGLRenderTarget(
-                        width,
-                        height,
-                        0,
-                        8,
-                        fbId,
-                        FramebufferFormat.GR_GL_RGBA8
-                    )
-                }
-                GraphicsApi.METAL -> makeMetalRenderTarget(
-                    width,
-                    height,
-                    0
-                )
-                else -> TODO("Unsupported yet")
-            }
-        }
-    }
-
-    private fun initSurface() {
-        skijaState.apply {
-            surface = Surface.makeFromBackendRenderTarget(
-                context!!,
-                renderTarget!!,
-                SurfaceOrigin.BOTTOM_LEFT,
-                SurfaceColorFormat.RGBA_8888,
-                ColorSpace.getSRGB()
-            )
-            canvas = surface!!.canvas
-        }
-    }
 }

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

+package org.jetbrains.skiko.context
+
+import org.jetbrains.skija.BackendRenderTarget
+import org.jetbrains.skija.Canvas
+import org.jetbrains.skija.DirectContext
+import org.jetbrains.skija.Picture
+import org.jetbrains.skija.Surface
+import org.jetbrains.skiko.GraphicsApi
+import org.jetbrains.skiko.HardwareLayer
+import org.jetbrains.skiko.hostOs
+import org.jetbrains.skiko.OS
+
+internal val renderApi: GraphicsApi by lazy {
+    val environment = System.getenv("SKIKO_RENDER_API")
+    val property = System.getProperty("skiko.renderApi")
+    if (environment != null) {
+        parseRenderApi(environment)
+    } else {
+        parseRenderApi(property)
+    }
+}
+
+private fun parseRenderApi(text: String?): GraphicsApi {
+    when(text) {
+        "RASTER" -> return GraphicsApi.RASTER
+        "OPENGL" -> return GraphicsApi.OPENGL
+        "VULKAN" -> return GraphicsApi.VULKAN
+        "METAL" -> return GraphicsApi.METAL
+        else -> return GraphicsApi.OPENGL
+    }
+}
+
+internal fun createContextHandler(layer: HardwareLayer): ContextHandler {
+    return when (renderApi) {
+        GraphicsApi.RASTER -> RasterContextHandler(layer)
+        GraphicsApi.OPENGL -> OpenGLContextHandler(layer)
+        GraphicsApi.METAL -> MetalContextHandler(layer)
+        else -> TODO("Unsupported yet")
+    }
+}
+
+internal abstract class ContextHandler(val layer: HardwareLayer) {
+    open val bleachConstant = if (hostOs == OS.MacOS) 0 else -1
+    var context: DirectContext? = null
+    var renderTarget: BackendRenderTarget? = null
+    var surface: Surface? = null
+    var canvas: Canvas? = null
+
+    abstract fun initContext()
+
+    abstract fun initCanvas()
+
+    fun clearCanvas() {
+        canvas?.clear(bleachConstant)
+    }
+
+    open fun drawOnCanvas(picture: Picture) {
+        canvas?.drawPicture(picture)
+    }
+
+    open fun flush() {
+        context?.flush()
+    }
+
+    fun dispose() {
+        surface?.close()
+        renderTarget?.close()
+    }
+}
\ No newline at end of file

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

+package org.jetbrains.skiko.context
+
+import org.jetbrains.skija.ColorSpace
+import org.jetbrains.skija.Surface
+import org.jetbrains.skija.SurfaceColorFormat
+import org.jetbrains.skija.SurfaceOrigin
+import org.jetbrains.skiko.GraphicsApi
+import org.jetbrains.skiko.HardwareLayer
+import org.jetbrains.skiko.makeMetalContext
+import org.jetbrains.skiko.makeMetalRenderTarget
+
+internal class MetalContextHandler(layer: HardwareLayer) : ContextHandler(layer) {
+    override fun initContext() {
+        if (context == null) {
+            context = makeMetalContext()
+        }
+    }
+
+    override fun initCanvas() {
+        dispose()
+
+        val scale = layer.contentScale
+        val w = (layer.width * scale).toInt().coerceAtLeast(0)
+        val h = (layer.height * scale).toInt().coerceAtLeast(0)
+
+        renderTarget = makeMetalRenderTarget(w, h, 0)
+
+        surface = Surface.makeFromBackendRenderTarget(
+            context!!,
+            renderTarget!!,
+            SurfaceOrigin.BOTTOM_LEFT,
+            SurfaceColorFormat.RGBA_8888,
+            ColorSpace.getSRGB()
+        )
+
+        canvas = surface!!.canvas
+    }
+}

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

+package org.jetbrains.skiko.context
+
+import org.jetbrains.skija.ColorSpace
+import org.jetbrains.skija.FramebufferFormat
+import org.jetbrains.skija.Picture
+import org.jetbrains.skija.Surface
+import org.jetbrains.skija.SurfaceColorFormat
+import org.jetbrains.skija.SurfaceOrigin
+import org.jetbrains.skiko.HardwareLayer
+import org.jetbrains.skiko.makeGLContext
+import org.jetbrains.skiko.makeGLRenderTarget
+import org.jetbrains.skiko.OpenGLApi
+
+internal class OpenGLContextHandler(layer: HardwareLayer) : ContextHandler(layer) {
+    override fun initContext() {
+        if (context == null) {
+            context = makeGLContext()
+        }
+    }
+
+    override fun initCanvas() {
+        dispose()
+
+        val scale = layer.contentScale
+        val w = (layer.width * scale).toInt().coerceAtLeast(0)
+        val h = (layer.height * scale).toInt().coerceAtLeast(0)
+
+        val gl = OpenGLApi.instance
+        val fbId = gl.glGetIntegerv(gl.GL_DRAW_FRAMEBUFFER_BINDING)
+        renderTarget = makeGLRenderTarget(
+            w,
+            h,
+            0,
+            8,
+            fbId,
+            FramebufferFormat.GR_GL_RGBA8
+        )
+
+        surface = Surface.makeFromBackendRenderTarget(
+            context!!,
+            renderTarget!!,
+            SurfaceOrigin.BOTTOM_LEFT,
+            SurfaceColorFormat.RGBA_8888,
+            ColorSpace.getSRGB()
+        )
+
+        canvas = surface!!.canvas
+    }
+}

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

+package org.jetbrains.skiko.context
+
+import java.awt.AlphaComposite
+import java.awt.color.ColorSpace
+import java.awt.Color
+import java.awt.Graphics2D
+import java.awt.Transparency
+import java.awt.image.ComponentColorModel
+import java.awt.image.BufferedImage
+import java.awt.image.DataBuffer
+import java.awt.image.DataBufferByte
+import java.awt.image.WritableRaster
+import java.awt.image.Raster
+import org.jetbrains.skija.Bitmap
+import org.jetbrains.skija.ColorAlphaType
+import org.jetbrains.skija.Canvas
+import org.jetbrains.skiko.HardwareLayer
+import org.jetbrains.skija.ImageInfo
+import org.jetbrains.skija.Picture
+
+internal class RasterContextHandler(layer: HardwareLayer) : ContextHandler(layer) {
+    override val bleachConstant = -1 // it looks like java.awt.Canvas doesn't support transparency
+
+    val colorModel = ComponentColorModel(
+        ColorSpace.getInstance(ColorSpace.CS_sRGB),
+        true,
+        false,
+        Transparency.TRANSLUCENT,
+        DataBuffer.TYPE_BYTE
+    )
+    val storage = Bitmap()
+    var image: BufferedImage? = null
+    var imageData: ByteArray? = null
+    var raster: WritableRaster? = null
+
+    override fun initContext() {
+        // Raster does not need context
+    }
+
+    override fun initCanvas() {
+        dispose()
+        
+        val scale = layer.contentScale
+        val w = (layer.width * scale).toInt().coerceAtLeast(0)
+        val h = (layer.height * scale).toInt().coerceAtLeast(0)
+        
+        if (storage.getWidth() != w || storage.getHeight() != h) {
+            storage.allocPixelsFlags(ImageInfo.makeS32(w, h, ColorAlphaType.PREMUL), false)
+        }
+
+        canvas = Canvas(storage)
+    }
+
+    override fun drawOnCanvas(picture: Picture) {
+        super.drawOnCanvas(picture)
+
+        val scale = layer.contentScale
+        val w = (layer.width * scale).toInt().coerceAtLeast(0)
+        val h = (layer.height * scale).toInt().coerceAtLeast(0)
+
+
+        val bytes = storage.readPixels(storage.getImageInfo(), (w * 4).toLong(), 0, 0)
+        if (bytes != null) {
+            val buffer = DataBufferByte(bytes, bytes.size)
+            raster = Raster.createInterleavedRaster(
+                buffer,
+                w,
+                h,
+                w * 4, 4,
+                intArrayOf(2, 1, 0, 3), // BGRA order
+                null
+            )
+            image = BufferedImage(colorModel, raster!!, false, null)
+            layer.getGraphics()?.drawImage(image!!, 0, 0, layer.width, layer.height, null)
+        }
+    }
+
+    override fun flush() {
+        // Raster does not need to flush canvas
+    }
+}

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

+package org.jetbrains.skiko.redrawer
+
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.swing.Swing
+import org.jetbrains.skiko.FrameDispatcher
+import org.jetbrains.skiko.HardwareLayer
+
+internal class RasterRedrawer(
+    private val layer: HardwareLayer
+) : Redrawer {
+
+    private val frameDispatcher = FrameDispatcher(Dispatchers.Swing) {
+        layer.update(System.nanoTime())
+        layer.draw()
+    }
+
+    override fun dispose() {
+        frameDispatcher.cancel()
+    }
+
+    override fun needRedraw() {
+        frameDispatcher.scheduleFrame()
+    }
+}
\ No newline at end of file