1.0

.gitignore

@@ -1,4 +1,5 @@
 target/
+.settings/
 pom.xml.tag
 pom.xml.releaseBackup
 pom.xml.versionsBackup
@@ -9,3 +10,6 @@ buildNumber.properties
 .mvn/timing.properties
 # https://github.com/takari/maven-wrapper#usage-without-binary-jar
 .mvn/wrapper/maven-wrapper.jar
+.project
+.classpath
+.checkstyle

README.md

@@ -1,2 +1,56 @@
 # processing-skia
-Wraps Skija (Skia for Java) for easy interoperability with Processing
+
+**Skia** is an open source 2D graphics library which provides common APIs that work across a variety of hardware and software platforms.
+
+**Skija** provides high-quality Java bindings for Skia.
+
+**processing-skia** does the backend work of setting Skija's render target to Processing, so you can easily use any Skija [bindings](https://github.com/JetBrains/skija/blob/master/docs/Getting%20Started.md) to draw into a Processing sketch.
+
+## Requirements
+* Java 11+
+* A Processing sketch using either the `P2D` or `P3D` renderer.
+
+## Download
+Download the processing-skia *jar* from [releases](https://github.com/micycle1/processing-skia/releases/).
+
+## Example
+### Code
+
+```
+import micycle.processingSkia.SkiaCanvas;
+import org.jetbrains.skija.*;
+
+Canvas skiaCanvas;
+
+@Override
+public void settings() {
+	size(800, 800, P2D);
+}
+
+@Override
+public void setup() {
+	skiaCanvas = SkiaCanvas.getSkiaCanvas(this);
+}
+
+@Override
+public void draw() {
+	background(255);
+	
+	Paint fill = new Paint().setShader(Shader.makeLinearGradient(400, 300, 400, 500, new int[] {0xFFFFA500, 0xFF4CA387}));
+	
+	skiaCanvas.drawCircle(400, 400, 200, fill);
+}
+```
+### Result
+<p align="center">
+<img src="resources/result_example.png" alt="Example" width="400"squares_examplesquares_example/></a><br></p>
+
+## Further Work
+Further work would wrap the Skija library itself, creating something like a `PSurfaceSkia` interface leading to a dedicated Skia-based renderer in Processing.
+
+## Another Example
+
+This is the [squares example](https://github.com/JetBrains/skija/blob/master/examples/lwjgl/src/main/java/org/jetbrains/skija/examples/lwjgl/SquaresScene.java) as rendered in a Processing sketch. Here, the gradient fill and square-circle morphing provide features that are not easily attained in vanilla Processing, but are easily attained with the Skia renderer.
+
+<p align="center">
+<img src="resources/squares_example.gif" alt="Example"/></a><br></p>

pom.xml

@@ -0,0 +1,68 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<groupId>micycle</groupId>
+	<artifactId>processing-skia</artifactId>
+	<version>1.0</version>
+
+	<repositories>
+		<repository>
+			<id>space-maven</id>
+			<url>https://packages.jetbrains.team/maven/p/skija/maven</url>
+		</repository>
+	</repositories>
+
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-compiler-plugin</artifactId>
+				<configuration>
+					<source>11</source>
+					<target>11</target>
+				</configuration>
+			</plugin>
+			<plugin>
+				<artifactId>maven-assembly-plugin</artifactId>
+				<executions>
+					<execution>
+						<phase>package</phase>
+						<goals>
+							<goal>single</goal>
+						</goals>
+					</execution>
+				</executions>
+				<configuration>
+					<descriptorRefs>
+						<descriptorRef>jar-with-dependencies</descriptorRef>
+					</descriptorRefs>
+				</configuration>
+			</plugin>
+		</plugins>
+	</build>
+
+	<dependencies>
+		<dependency>
+			<groupId>org.jetbrains.skija</groupId>
+			<artifactId>skija-windows</artifactId> <!--NOTE windows version -->
+			<version>0.6.10</version>
+		</dependency>
+		<dependency>
+			<groupId>org.jogamp.gluegen</groupId>
+			<artifactId>gluegen-rt-main</artifactId>
+			<version>2.3.2</version>
+		</dependency>
+		<dependency>
+			<groupId>org.jogamp.jogl</groupId>
+			<artifactId>jogl-all-main</artifactId>
+			<version>2.3.2</version>
+		</dependency>
+		<dependency>
+			<groupId>org.processing</groupId>
+			<artifactId>core</artifactId>
+			<version>3.3.7</version>
+		</dependency>
+	</dependencies>
+
+</project>

src/main/java/micycle/processingSkia/SkiaCanvas.java

@@ -0,0 +1,119 @@
+package micycle.processingSkia;
+
+import java.nio.IntBuffer;
+
+import org.jetbrains.skija.BackendRenderTarget;
+import org.jetbrains.skija.Canvas;
+import org.jetbrains.skija.ColorSpace;
+import org.jetbrains.skija.DirectContext;
+import org.jetbrains.skija.FramebufferFormat;
+import org.jetbrains.skija.Surface;
+import org.jetbrains.skija.SurfaceColorFormat;
+import org.jetbrains.skija.SurfaceOrigin;
+
+import com.jogamp.newt.event.WindowEvent;
+import com.jogamp.newt.event.WindowListener;
+import com.jogamp.newt.event.WindowUpdateEvent;
+import com.jogamp.newt.opengl.GLWindow;
+import com.jogamp.opengl.GL;
+
+import processing.core.PApplet;
+import processing.opengl.PSurfaceJOGL;
+
+public class SkiaCanvas {
+
+	private static SkiaCanvas wrapper;
+
+	/**
+	 * Call this to get a Skia Canvas whose render target is the sketch provided.
+	 * Calling Skija drawing methods on this canvas will draw the output to your
+	 * Processing sketch.
+	 * 
+	 * @param p Your Processing sketch
+	 * @return
+	 */
+	public static Canvas getSkiaCanvas(PApplet p) {
+		if (!(p.sketchRenderer() == "processing.opengl.PGraphics3D" || p.sketchRenderer() == "processing.opengl.PGraphics2D")) {
+			System.err.println("SkiaRenderer requires processing using P2D or P3D (JOGL) renderer.");
+			return null;
+		}
+
+		if (wrapper == null) { // singleton pattern
+			wrapper = new SkiaCanvas(p);
+		}
+
+		return wrapper.canvas;
+	}
+
+	private Canvas canvas;
+
+	private DirectContext context;
+	private BackendRenderTarget renderTarget;
+	private Surface surface;
+
+	private GL gl;
+
+	private PApplet p;
+
+	private SkiaCanvas(PApplet p) {
+
+		PSurfaceJOGL pSurface = (PSurfaceJOGL) p.getSurface();
+		GLWindow window = (GLWindow) pSurface.getNative();
+		gl = window.getGL();
+
+		final IntBuffer intBuffer = IntBuffer.allocate(1);
+		gl.glGetIntegerv(GL.GL_DRAW_FRAMEBUFFER_BINDING, intBuffer);
+		final int fbId = intBuffer.get(0);
+
+		renderTarget = BackendRenderTarget.makeGL(p.width, p.height, 0, 8, fbId, FramebufferFormat.GR_GL_RGBA8);
+
+		context = DirectContext.makeGL();
+
+		surface = Surface.makeFromBackendRenderTarget(context, renderTarget, SurfaceOrigin.BOTTOM_LEFT, SurfaceColorFormat.RGBA_8888,
+				ColorSpace.getSRGB());
+
+		canvas = surface.getCanvas();
+
+		window.addWindowListener(new WindowListener() {
+
+			@Override
+			public void windowResized(WindowEvent e) {
+				renderTarget = BackendRenderTarget.makeGL(window.getWidth(), window.getHeight(), 0, 8, fbId, FramebufferFormat.GR_GL_RGBA8);
+				surface = Surface.makeFromBackendRenderTarget(context, renderTarget, SurfaceOrigin.BOTTOM_LEFT,
+						SurfaceColorFormat.RGBA_8888, ColorSpace.getSRGB());
+				canvas = surface.getCanvas();
+			}
+
+			// @formatter:off
+			public void windowRepaint(WindowUpdateEvent e) {}
+			public void windowMoved(WindowEvent e) {}
+			public void windowLostFocus(WindowEvent e) {}
+			public void windowGainedFocus(WindowEvent e) {}
+			public void windowDestroyed(WindowEvent e) {}
+			public void windowDestroyNotify(WindowEvent e) {}
+			// @formatter:on
+		});
+
+		this.p = p;
+
+		p.registerMethod("pre", this);
+		p.registerMethod("post", this);
+	}
+
+	/**
+	 * Calling Skija's {@link Canvas#clear(int) canvas.clear()} breaks it for some
+	 * unknown reason; without calling clear() on the PApplet, skia doesn't update
+	 * (again, for some unknown reason...).
+	 */
+	public void pre() {
+		p.clear();
+	}
+
+	/**
+	 * Flushes Skia graphics to the screen.
+	 */
+	public void post() {
+		context.flush();
+	}
+
+}