abstract Image and add support for watching the image as its being rendered

src/main/java/eu/jonahbauer/raytracing/Main.java

@@ -7,6 +7,8 @@ import eu.jonahbauer.raytracing.math.Vec3;
 import eu.jonahbauer.raytracing.render.Camera;
 import eu.jonahbauer.raytracing.render.Color;
 import eu.jonahbauer.raytracing.render.ImageFormat;
+import eu.jonahbauer.raytracing.render.canvas.LiveCanvas;
+import eu.jonahbauer.raytracing.render.canvas.Image;
 import eu.jonahbauer.raytracing.scene.Scene;
 import eu.jonahbauer.raytracing.scene.Sphere;
 
@@ -32,7 +34,10 @@ public class Main {
                 .withBlurAngle(Math.toRadians(10))
                 .build();
 
-        var image = camera.render(scene);
+        var image = new LiveCanvas(new Image(camera.getWidth(), camera.getHeight()));
+        image.preview();
+
+        camera.render(scene, image);
         ImageFormat.PNG.write(image, Path.of("scene-" + System.currentTimeMillis() + ".png"));
     }
 }

src/main/java/eu/jonahbauer/raytracing/render/Camera.java

@@ -3,11 +3,15 @@ package eu.jonahbauer.raytracing.render;
 import eu.jonahbauer.raytracing.math.Range;
 import eu.jonahbauer.raytracing.math.Ray;
 import eu.jonahbauer.raytracing.math.Vec3;
+import eu.jonahbauer.raytracing.render.canvas.Canvas;
+import eu.jonahbauer.raytracing.render.canvas.Image;
 import eu.jonahbauer.raytracing.scene.Scene;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.Objects;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.stream.IntStream;
 
 public final class Camera {
     // image size
@@ -72,8 +76,16 @@ public final class Camera {
 
     public @NotNull Image render(@NotNull Scene scene) {
         var image = new Image(width, height);
+        render(scene, image);
+        return image;
+    }
+
+    public void render(@NotNull Scene scene, @NotNull Canvas canvas) {
+        if (canvas.getWidth() != width || canvas.getHeight() != height) throw new IllegalArgumentException();
 
-        for (int y = 0; y < height; y++) {
+        var lines = new AtomicInteger();
+        IntStream.range(0, height).parallel().forEach(y -> {
+            System.out.println(lines.incrementAndGet());
             for (int x = 0; x < width; x++) {
                 var r = 0d;
                 var g = 0d;
@@ -87,15 +99,13 @@ public final class Camera {
                     b += color.b();
                 }
 
-                image.set(x, y, new Color(
+                canvas.set(x, y, new Color(
                         Math.pow(r / samplesPerPixel, 1 / gamma),
                         Math.pow(g / samplesPerPixel, 1 / gamma),
                         Math.pow(b / samplesPerPixel, 1 / gamma)
                 ));
             }
-        }
-
-        return image;
+        });
     }
 
     private @NotNull Ray getRay(int x, int y) {
@@ -150,6 +160,14 @@ public final class Camera {
         return Color.lerp(Color.WHITE, Color.SKY, alt / Math.PI + 0.5);
     }
 
+    public int getWidth() {
+        return width;
+    }
+
+    public int getHeight() {
+        return height;
+    }
+
     public static class Builder {
         private int imageWidth = 1920;
         private int imageHeight = 1080;

src/main/java/eu/jonahbauer/raytracing/render/ImageFormat.java

@@ -1,5 +1,6 @@
 package eu.jonahbauer.raytracing.render;
 
+import eu.jonahbauer.raytracing.render.canvas.Canvas;
 import org.jetbrains.annotations.NotNull;
 
 import java.io.*;
@@ -13,12 +14,12 @@ import java.util.zip.DeflaterOutputStream;
 public enum ImageFormat {
     PPM {
         @Override
-        public void write(@NotNull Image image, @NotNull OutputStream out) throws IOException {
+        public void write(@NotNull Canvas image, @NotNull OutputStream out) throws IOException {
             try (var writer = new BufferedWriter(new OutputStreamWriter(out, StandardCharsets.US_ASCII))) {
                 writer.write("P3\n");
-                writer.write(String.valueOf(image.width()));
+                writer.write(String.valueOf(image.getWidth()));
                 writer.write(" ");
-                writer.write(String.valueOf(image.height()));
+                writer.write(String.valueOf(image.getHeight()));
                 writer.write("\n255\n");
 
                 var it = image.pixels().iterator();
@@ -42,7 +43,7 @@ public enum ImageFormat {
         private static final int IEND_TYPE = 0x49454E44;
 
         @Override
-        public void write(@NotNull Image image, @NotNull OutputStream out) throws IOException {
+        public void write(@NotNull Canvas image, @NotNull OutputStream out) throws IOException {
             try (var data = new NoCloseDataOutputStream(out); var _ = data.closeable()) {
                 data.write(MAGIC);
 
@@ -52,15 +53,15 @@ public enum ImageFormat {
             }
         }
 
-        private void writeIHDR(@NotNull Image image, @NotNull DataOutputStream data) throws IOException {
+        private void writeIHDR(@NotNull Canvas image, @NotNull DataOutputStream data) throws IOException {
             data.writeInt(IHDR_LENGTH);
             try (
                     var crc = new CheckedOutputStream(data, new CRC32());
                     var ihdr = new DataOutputStream(crc)
             ) {
                 ihdr.writeInt(IHDR_TYPE);
-                ihdr.writeInt(image.width()); // image width
-                ihdr.writeInt(image.height()); // image height
+                ihdr.writeInt(image.getWidth()); // image width
+                ihdr.writeInt(image.getHeight()); // image height
                 ihdr.writeByte(8); // bit depth
                 ihdr.writeByte(2); // color type
                 ihdr.writeByte(0); // compression method
@@ -71,7 +72,7 @@ public enum ImageFormat {
             }
         }
 
-        private void writeIDAT(@NotNull Image image, @NotNull DataOutputStream data) throws IOException {
+        private void writeIDAT(@NotNull Canvas image, @NotNull DataOutputStream data) throws IOException {
             try (
                     var baos = new ByteArrayOutputStream();
                     var crc = new CheckedOutputStream(baos, new CRC32());
@@ -81,7 +82,7 @@ public enum ImageFormat {
 
                 try (var deflate = new DataOutputStream(new DeflaterOutputStream(idat))) {
                     var pixels = image.pixels().iterator();
-                    for (int i = 0; pixels.hasNext(); i = (i + 1) % image.width()) {
+                    for (int i = 0; pixels.hasNext(); i = (i + 1) % image.getWidth()) {
                         if (i == 0) deflate.writeByte(0); // filter type
                         var pixel = pixels.next();
                         deflate.writeByte(pixel.red());
@@ -97,7 +98,7 @@ public enum ImageFormat {
             }
         }
 
-        private void writeIEND(@NotNull Image image, @NotNull DataOutputStream data) throws IOException {
+        private void writeIEND(@NotNull Canvas image, @NotNull DataOutputStream data) throws IOException {
             data.writeInt(0);
             data.writeInt(IEND_TYPE);
             data.writeInt(0);
@@ -120,11 +121,11 @@ public enum ImageFormat {
     },
     ;
 
-    public void write(@NotNull Image image, @NotNull Path path) throws IOException {
+    public void write(@NotNull Canvas image, @NotNull Path path) throws IOException {
         try (var out = Files.newOutputStream(path)) {
             write(image, out);
         }
     }
 
-    public abstract void write(@NotNull Image image, @NotNull OutputStream out) throws IOException;
+    public abstract void write(@NotNull Canvas image, @NotNull OutputStream out) throws IOException;
 }

src/main/java/eu/jonahbauer/raytracing/render/canvas/Canvas.java

@@ -0,0 +1,22 @@
+package eu.jonahbauer.raytracing.render.canvas;
+
+import eu.jonahbauer.raytracing.render.Color;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.function.Function;
+import java.util.stream.IntStream;
+import java.util.stream.Stream;
+
+public interface Canvas {
+    int getWidth();
+    int getHeight();
+
+    void set(int x, int y, @NotNull Color color);
+    @NotNull Color get(int x, int y);
+
+    default @NotNull Stream<Color> pixels() {
+        return IntStream.range(0, getHeight())
+                .mapToObj(y -> IntStream.range(0, getWidth()).mapToObj(x -> get(x, y)))
+                .flatMap(Function.identity());
+    }
+}

src/main/java/eu/jonahbauer/raytracing/render/canvas/Image.java

@@ -1,12 +1,11 @@
-package eu.jonahbauer.raytracing.render;
+package eu.jonahbauer.raytracing.render.canvas;
 
+import eu.jonahbauer.raytracing.render.Color;
 import org.jetbrains.annotations.NotNull;
 
-import java.util.Arrays;
 import java.util.Objects;
-import java.util.stream.Stream;
 
-public final class Image {
+public final class Image implements Canvas {
     private final int width;
     private final int height;
 
@@ -22,35 +21,27 @@ public final class Image {
         this.data = new Color[height][width];
     }
 
-    public int width() {
+    @Override
+    public int getWidth() {
         return width;
     }
 
-    public int height() {
+    @Override
+    public int getHeight() {
         return height;
     }
 
+    @Override
     public @NotNull Color get(int x, int y) {
         Objects.checkIndex(x, width);
         Objects.checkIndex(y, height);
         return Objects.requireNonNullElse(this.data[y][x], Color.BLACK);
     }
 
-    public @NotNull Stream<Color> pixels() {
-        return Arrays.stream(data).flatMap(Arrays::stream).map(c -> Objects.requireNonNullElse(c, Color.BLACK));
-    }
-
+    @Override
     public void set(int x, int y, @NotNull Color color) {
         Objects.checkIndex(x, width);
         Objects.checkIndex(y, height);
         this.data[y][x] = Objects.requireNonNull(color);
     }
-
-    public void set(int x, int y, int red, int green, int blue) {
-        set(x, y, new Color(red, green, blue));
-    }
-
-    public void set(int x, int y, double r, double g, double b) {
-        set(x, y, new Color(r, g, b));
-    }
 }

src/main/java/eu/jonahbauer/raytracing/render/canvas/LiveCanvas.java

@@ -0,0 +1,77 @@
+package eu.jonahbauer.raytracing.render.canvas;
+
+import eu.jonahbauer.raytracing.render.Color;
+import org.jetbrains.annotations.NotNull;
+
+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.WindowAdapter;
+import java.awt.event.WindowEvent;
+import java.awt.image.BufferedImage;
+
+public final class LiveCanvas implements Canvas {
+    private final @NotNull Canvas delegate;
+    private final @NotNull BufferedImage image;
+
+    public LiveCanvas(@NotNull Canvas delegate) {
+        this.delegate = delegate;
+        this.image = new BufferedImage(delegate.getWidth(), delegate.getHeight(), BufferedImage.TYPE_INT_RGB);
+    }
+
+    @Override
+    public int getWidth() {
+        return delegate.getWidth();
+    }
+
+    @Override
+    public int getHeight() {
+        return delegate.getHeight();
+    }
+
+    @Override
+    public void set(int x, int y, @NotNull Color color) {
+        delegate.set(x, y, color);
+        var rgb = color.red() << 16 | color.green() << 8 | color.blue();
+        image.setRGB(x, y, rgb);
+    }
+
+    @Override
+    public @NotNull Color get(int x, int y) {
+        return delegate.get(x, y);
+    }
+
+    public @NotNull Thread preview() {
+        var frame = new JFrame();
+        frame.setSize(getWidth(), getHeight());
+        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
+        frame.setContentPane(new JPanel() {
+            @Override
+            protected void paintComponent(Graphics g) {
+                g.drawImage(image, 0, 0, null);
+            }
+        });
+        frame.setResizable(false);
+        frame.setVisible(true);
+
+        var update = Thread.ofVirtual().start(() -> {
+            while (!Thread.interrupted()) {
+                try {
+                    Thread.sleep(1000);
+                } catch (InterruptedException ex) {
+                    break;
+                }
+                frame.repaint();
+            }
+            frame.dispose();
+        });
+
+        frame.addWindowListener(new WindowAdapter() {
+            @Override
+            public void windowClosing(WindowEvent e) {
+                update.interrupt();
+            }
+        });
+
+        return update;
+    }
+}