refactor Scene

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

@@ -1,23 +1,17 @@
 package eu.jonahbauer.raytracing;
 
-import eu.jonahbauer.raytracing.render.camera.Camera;
-import eu.jonahbauer.raytracing.render.material.DielectricMaterial;
-import eu.jonahbauer.raytracing.render.material.LambertianMaterial;
-import eu.jonahbauer.raytracing.render.material.Material;
-import eu.jonahbauer.raytracing.render.material.MetallicMaterial;
 import eu.jonahbauer.raytracing.math.Vec3;
 import eu.jonahbauer.raytracing.render.Color;
 import eu.jonahbauer.raytracing.render.ImageFormat;
+import eu.jonahbauer.raytracing.render.camera.Camera;
 import eu.jonahbauer.raytracing.render.camera.SimpleCamera;
-import eu.jonahbauer.raytracing.render.canvas.LiveCanvas;
 import eu.jonahbauer.raytracing.render.canvas.Image;
+import eu.jonahbauer.raytracing.render.canvas.LiveCanvas;
+import eu.jonahbauer.raytracing.render.material.*;
 import eu.jonahbauer.raytracing.render.renderer.SimpleRenderer;
-import eu.jonahbauer.raytracing.scene.Hittable;
+import eu.jonahbauer.raytracing.scene.*;
-import eu.jonahbauer.raytracing.scene.flat.Ellipse;
+import eu.jonahbauer.raytracing.scene.hittable2d.Parallelogram;
-import eu.jonahbauer.raytracing.scene.flat.Parallelogram;
+import eu.jonahbauer.raytracing.scene.hittable3d.Sphere;
-import eu.jonahbauer.raytracing.scene.Scene;
-import eu.jonahbauer.raytracing.scene.Sphere;
-import eu.jonahbauer.raytracing.scene.flat.Triangle;
 import org.jetbrains.annotations.NotNull;
 
 import java.io.IOException;
@@ -91,18 +85,19 @@ public class Main {
                 .withBlurAngle(Math.toRadians(0.6))
                 .build();
 
-        return new Example(new Scene(objects), camera);
+        return new Example(new Scene(getSkyBox(), objects), camera);
     }
 
     private static @NotNull Example getSquares() {
         return new Example(
-                new Scene(List.of(
+                new Scene(
+                        getSkyBox(),
                         new Parallelogram(new Vec3(-3, -2, 5), new Vec3(0, 0, -4), new Vec3(0, 4, 0), new LambertianMaterial(new Color(1.0, 0.2, 0.2))),
                         new Parallelogram(new Vec3(-2, -2, 0), new Vec3(4, 0, 0), new Vec3(0, 4, 0), new LambertianMaterial(new Color(0.2, 1.0, 0.2))),
                         new Parallelogram(new Vec3(3, -2, 1), new Vec3(0, 0, 4), new Vec3(0, 4, 0), new LambertianMaterial(new Color(0.2, 0.2, 1.0))),
                         new Parallelogram(new Vec3(-2, 3, 1), new Vec3(4, 0, 0), new Vec3(0, 0, 4), new LambertianMaterial(new Color(1.0, 0.5, 0.0))),
                         new Parallelogram(new Vec3(-2, -3, 5), new Vec3(4, 0, 0), new Vec3(0, 0, -4), new LambertianMaterial(new Color(0.2, 0.8, 0.8)))
-                )),
+                ),
                 SimpleCamera.builder()
                         .withImage(400, 400)
                         .withFieldOfView(Math.toRadians(80))
@@ -113,13 +108,18 @@ public class Main {
     }
 
     private static @NotNull Scene getSimpleScene() {
-        return new Scene(List.of(
+        return new Scene(
+                getSkyBox(),
                 new Sphere(new Vec3(0, -100.5, -1.0), 100.0, new LambertianMaterial(new Color(0.8, 0.8, 0.0))),
                 new Sphere(new Vec3(0, 0, -1.2), 0.5, new LambertianMaterial(new Color(0.1, 0.2, 0.5))),
                 new Sphere(new Vec3(-1.0, 0, -1.2), 0.5, new DielectricMaterial(1.5)),
                 new Sphere(new Vec3(-1.0, 0, -1.2), 0.4, new DielectricMaterial(1 / 1.5)),
                 new Sphere(new Vec3(1.0, 0, -1.2), 0.5, new MetallicMaterial(new Color(0.8, 0.6, 0.2), 0.0))
-        ));
+        );
+    }
+
+    private static @NotNull SkyBox getSkyBox() {
+        return SkyBox.gradient(new Color(0.5, 0.7, 1.0), Color.WHITE);
     }
 
     private record Example(@NotNull Scene scene, @NotNull Camera camera) {}

src/main/java/eu/jonahbauer/raytracing/math/BoundingBox.java

@@ -3,8 +3,18 @@ package eu.jonahbauer.raytracing.math;
 import org.jetbrains.annotations.NotNull;
 
 public record BoundingBox(@NotNull Vec3 min, @NotNull Vec3 max) {
+    public BoundingBox {
+        var a = min;
+        var b = max;
+        min = Vec3.min(a, b);
+        max = Vec3.max(a, b);
+    }
 
     public @NotNull Vec3 center() {
         return Vec3.average(min, max, 2);
     }
+
+    public @NotNull BoundingBox expand(@NotNull BoundingBox box) {
+        return new BoundingBox(Vec3.min(this.min, box.min), Vec3.max(this.max, box.max));
+    }
 }

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

@@ -7,7 +7,6 @@ import java.util.Random;
 public record Color(double r, double g, double b) {
     public static final @NotNull Color BLACK = new Color(0.0, 0.0, 0.0);
     public static final @NotNull Color WHITE = new Color(1.0, 1.0, 1.0);
-    public static final @NotNull Color SKY = new Color(0.5, 0.7, 1.0);
     public static final @NotNull Color RED = new Color(1.0, 0.0, 0.0);
     public static final @NotNull Color GREEN = new Color(0.0, 1.0, 0.0);
     public static final @NotNull Color BLUE = new Color(0.0, 0.0, 1.0);
@@ -65,25 +64,25 @@ public record Color(double r, double g, double b) {
         }
     }
 
-    public Color {
+    public Color {}
-        if (r < 0 || r > 1 || g < 0 || g > 1 || b < 0 || b > 1) {
-            throw new IllegalArgumentException("r, g and b must be in the range 0 to 1");
-        }
-    }
     
     public Color(int red, int green, int blue) {
         this(red / 255f, green / 255f, blue / 255f);
     }
 
     public int red() {
-        return (int) (255.99 * r);
+        return toInt(r);
     }
 
     public int green() {
-        return (int) (255.99 * g);
+        return toInt(g);
     }
 
     public int blue() {
-        return (int) (255.99 * b);
+        return toInt(b);
+    }
+
+    private static int toInt(double value) {
+        return Math.max(0, Math.min(255, (int) (255.99 * value)));
     }
 }

src/main/java/eu/jonahbauer/raytracing/render/renderer/SimpleRenderer.java

@@ -96,7 +96,7 @@ public final class SimpleRenderer implements Renderer {
                     .map(scatter -> Color.multiply(scatter.attenuation(), getColor0(scene, scatter.ray(), depth - 1)))
                     .orElse(Color.BLACK);
         } else {
-            return getSkyboxColor(ray);
+            return scene.getBackgroundColor(ray);
         }
     }
 
@@ -111,19 +111,6 @@ public final class SimpleRenderer implements Renderer {
         return parallel ? stream.parallel() : stream;
     }
 
-    /**
-     * {@return the color of the skybox for a given ray} The skybox color is a linear gradient based on the altitude of
-     * the ray above the horizon with {@link Color#SKY} at the top and {@link Color#WHITE} at the bottom.
-     */
-    private static @NotNull Color getSkyboxColor(@NotNull Ray ray) {
-        // altitude from -pi/2 to pi/2
-        var alt = Math.copySign(
-                Math.acos(ray.direction().withY(0).unit().times(ray.direction().unit())),
-                ray.direction().y()
-        );
-        return Color.lerp(Color.WHITE, Color.SKY, alt / Math.PI + 0.5);
-    }
-
     public static class Builder {
         private int samplesPerPixel = 100;
         private int maxDepth = 10;

src/main/java/eu/jonahbauer/raytracing/scene/Scene.java

@@ -1,85 +1,64 @@
 package eu.jonahbauer.raytracing.scene;
 
-import eu.jonahbauer.raytracing.math.Octree;
-import eu.jonahbauer.raytracing.math.Range;
 import eu.jonahbauer.raytracing.math.Ray;
-import eu.jonahbauer.raytracing.math.Vec3;
+import eu.jonahbauer.raytracing.render.Color;
+import eu.jonahbauer.raytracing.scene.util.HittableCollection;
+import eu.jonahbauer.raytracing.scene.util.HittableList;
+import eu.jonahbauer.raytracing.scene.util.HittableOctree;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.List;
-import java.util.Optional;
 
-public final class Scene implements Hittable {
+public final class Scene extends HittableCollection {
-    private final @NotNull Octree<@NotNull Hittable> octree;
+    private final @NotNull HittableOctree octree;
-    private final @NotNull List<@NotNull Hittable> list;
+    private final @NotNull HittableList list;
+    private final @NotNull SkyBox background;
 
     public Scene(@NotNull List<? extends @NotNull Hittable> objects) {
-        this.octree = newOctree(objects);
+        this(Color.BLACK, objects);
-        this.list = new ArrayList<>();
+    }
 
-        for (Hittable object : objects) {
+    public Scene(@NotNull Color background, @NotNull List<? extends @NotNull Hittable> objects) {
-            var bbox = object.getBoundingBox();
+        this(SkyBox.solid(background), objects);
-            if (bbox.isPresent()) {
+    }
-                octree.add(bbox.get(), object);
+
+    public Scene(@NotNull SkyBox background, @NotNull List<? extends @NotNull Hittable> objects) {
+        var bounded = new ArrayList<Hittable>();
+        var unbounded = new ArrayList<Hittable>();
+
+        objects.forEach(object -> {
+            if (object.getBoundingBox().isPresent()) {
+                bounded.add(object);
             } else {
-                list.add(object);
+                unbounded.add(object);
             }
+        });
+
+        this.octree = new HittableOctree(bounded);
+        this.list = new HittableList(unbounded);
+        this.background = background;
     }
+
+    public Scene(@NotNull Hittable @NotNull... objects) {
+        this(List.of(objects));
+    }
+
+    public Scene(@NotNull Color background, @NotNull Hittable @NotNull... objects) {
+        this(background, List.of(objects));
+    }
+
+    public Scene(@NotNull SkyBox background, @NotNull Hittable @NotNull... objects) {
+        this(background, List.of(objects));
     }
 
     @Override
-    public @NotNull Optional<HitResult> hit(@NotNull Ray ray, @NotNull Range range) {
+    public void hit(@NotNull Ray ray, @NotNull State state) {
-        var state = new State();
+        octree.hit(ray, state);
-        state.range = range;
+        list.hit(ray, state);
-
-        octree.hit(ray, object -> hit(state, ray, object));
-        list.forEach(object -> hit(state, ray, object));
-
-        return Optional.ofNullable(state.result);
     }
 
-    private boolean hit(@NotNull State state, @NotNull Ray ray, @NotNull Hittable object) {
+    public @NotNull Color getBackgroundColor(@NotNull Ray ray) {
-        var r = object.hit(ray, state.range);
+        return background.getColor(ray);
-        if (r.isPresent()) {
-            if (state.range.surrounds(r.get().t())){
-                state.result = r.get();
-                state.range = new Range(state.range.min(), state.result.t());
-            }
-            return true;
-        } else {
-            return false;
-        }
-    }
-
-    private static @NotNull Octree<Hittable> newOctree(@NotNull List<? extends Hittable> objects) {
-        Vec3 center = Vec3.ZERO, max = Vec3.MIN, min = Vec3.MAX;
-
-        int i = 1;
-        for (Hittable object : objects) {
-            var bbox = object.getBoundingBox();
-            if (bbox.isPresent()) {
-                center = Vec3.average(center, bbox.get().center(), i++);
-                max = Vec3.max(max, bbox.get().max());
-                min = Vec3.min(min, bbox.get().min());
-            }
-        }
-
-        var dimension = Arrays.stream(new double[] {
-                Math.abs(max.x() - center.x()),
-                Math.abs(max.y() - center.y()),
-                Math.abs(max.z() - center.z()),
-                Math.abs(min.x() - center.x()),
-                Math.abs(min.y() - center.y()),
-                Math.abs(min.z() - center.z())
-        }).max().orElse(10);
-
-        return new Octree<>(center, dimension);
-    }
-
-    private static class State {
-        HitResult result;
-        Range range;
     }
 }

src/main/java/eu/jonahbauer/raytracing/scene/SkyBox.java

@@ -0,0 +1,25 @@
+package eu.jonahbauer.raytracing.scene;
+
+import eu.jonahbauer.raytracing.math.Ray;
+import eu.jonahbauer.raytracing.render.Color;
+import org.jetbrains.annotations.NotNull;
+
+@FunctionalInterface
+public interface SkyBox {
+    @NotNull Color getColor(@NotNull Ray ray);
+
+    static @NotNull SkyBox gradient(@NotNull Color top, @NotNull Color bottom) {
+        return ray -> {
+            // altitude from -pi/2 to pi/2
+            var alt = Math.copySign(
+                    Math.acos(ray.direction().withY(0).unit().times(ray.direction().unit())),
+                    ray.direction().y()
+            );
+            return Color.lerp(bottom, top, alt / Math.PI + 0.5);
+        };
+    }
+
+    static @NotNull SkyBox solid(@NotNull Color color) {
+        return _ -> color;
+    }
+}

src/main/java/eu/jonahbauer/raytracing/scene/hittable2d/Ellipse.java

@@ -1,4 +1,4 @@
-package eu.jonahbauer.raytracing.scene.flat;
+package eu.jonahbauer.raytracing.scene.hittable2d;
 
 import eu.jonahbauer.raytracing.math.BoundingBox;
 import eu.jonahbauer.raytracing.math.Vec3;

src/main/java/eu/jonahbauer/raytracing/scene/hittable2d/Hittable2D.java

@@ -1,4 +1,4 @@
-package eu.jonahbauer.raytracing.scene.flat;
+package eu.jonahbauer.raytracing.scene.hittable2d;
 
 import eu.jonahbauer.raytracing.math.Range;
 import eu.jonahbauer.raytracing.math.Ray;

src/main/java/eu/jonahbauer/raytracing/scene/hittable2d/Parallelogram.java

@@ -1,4 +1,4 @@
-package eu.jonahbauer.raytracing.scene.flat;
+package eu.jonahbauer.raytracing.scene.hittable2d;
 
 import eu.jonahbauer.raytracing.math.BoundingBox;
 import eu.jonahbauer.raytracing.math.Vec3;

src/main/java/eu/jonahbauer/raytracing/scene/hittable2d/Plane.java

@@ -1,4 +1,4 @@
-package eu.jonahbauer.raytracing.scene.flat;
+package eu.jonahbauer.raytracing.scene.hittable2d;
 
 import eu.jonahbauer.raytracing.math.Vec3;
 import eu.jonahbauer.raytracing.render.material.Material;

src/main/java/eu/jonahbauer/raytracing/scene/hittable2d/Triangle.java

@@ -1,4 +1,4 @@
-package eu.jonahbauer.raytracing.scene.flat;
+package eu.jonahbauer.raytracing.scene.hittable2d;
 
 import eu.jonahbauer.raytracing.math.BoundingBox;
 import eu.jonahbauer.raytracing.math.Vec3;

src/main/java/eu/jonahbauer/raytracing/scene/hittable3d/Sphere.java

@@ -1,10 +1,12 @@
-package eu.jonahbauer.raytracing.scene;
+package eu.jonahbauer.raytracing.scene.hittable3d;
 
 import eu.jonahbauer.raytracing.render.material.Material;
 import eu.jonahbauer.raytracing.math.BoundingBox;
 import eu.jonahbauer.raytracing.math.Range;
 import eu.jonahbauer.raytracing.math.Ray;
 import eu.jonahbauer.raytracing.math.Vec3;
+import eu.jonahbauer.raytracing.scene.HitResult;
+import eu.jonahbauer.raytracing.scene.Hittable;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.Objects;

src/main/java/eu/jonahbauer/raytracing/scene/util/HittableCollection.java

@@ -0,0 +1,65 @@
+package eu.jonahbauer.raytracing.scene.util;
+
+import eu.jonahbauer.raytracing.math.BoundingBox;
+import eu.jonahbauer.raytracing.math.Range;
+import eu.jonahbauer.raytracing.math.Ray;
+import eu.jonahbauer.raytracing.math.Vec3;
+import eu.jonahbauer.raytracing.scene.HitResult;
+import eu.jonahbauer.raytracing.scene.Hittable;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Collection;
+import java.util.Objects;
+import java.util.Optional;
+
+public abstract class HittableCollection implements Hittable {
+
+    @Override
+    public final @NotNull Optional<HitResult> hit(@NotNull Ray ray, @NotNull Range range) {
+        var state = new State(range);
+        hit(ray, state);
+        return state.getResult();
+    }
+
+    public abstract void hit(@NotNull Ray ray, @NotNull State state);
+
+    protected static @NotNull Optional<BoundingBox> getBoundingBox(@NotNull Collection<? extends @NotNull Hittable> objects) {
+        var bbox = new BoundingBox(Vec3.ZERO, Vec3.ZERO);
+        for (var object : objects) {
+            var b = object.getBoundingBox();
+            if (b.isPresent()) {
+                bbox = bbox.expand(b.get());
+            } else {
+                bbox = null;
+                break;
+            }
+        }
+        return Optional.ofNullable(bbox);
+    }
+
+    protected static boolean hit(@NotNull State state, @NotNull Ray ray, @NotNull Hittable object) {
+        var r = object.hit(ray, state.range);
+        if (r.isPresent()) {
+            if (state.range.surrounds(r.get().t())){
+                state.result = r.get();
+                state.range = new Range(state.range.min(), state.result.t());
+            }
+            return true;
+        } else {
+            return false;
+        }
+    }
+
+    public static class State {
+        private @NotNull Range range;
+        private HitResult result;
+
+        private State(@NotNull Range range) {
+            this.range = Objects.requireNonNull(range);
+        }
+
+        private @NotNull Optional<HitResult> getResult() {
+            return Optional.ofNullable(result);
+        }
+    }
+}

src/main/java/eu/jonahbauer/raytracing/scene/util/HittableList.java

@@ -0,0 +1,33 @@
+package eu.jonahbauer.raytracing.scene.util;
+
+import eu.jonahbauer.raytracing.math.BoundingBox;
+import eu.jonahbauer.raytracing.math.Ray;
+import eu.jonahbauer.raytracing.scene.Hittable;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.List;
+import java.util.Optional;
+
+public final class HittableList extends HittableCollection {
+    private final @NotNull List<Hittable> objects;
+    private final @NotNull Optional<BoundingBox> bbox;
+
+    public HittableList(@NotNull List<? extends @NotNull Hittable> objects) {
+        this.objects = List.copyOf(objects);
+        this.bbox = getBoundingBox(this.objects);
+    }
+
+    public HittableList(@NotNull Hittable @NotNull... objects) {
+        this(List.of(objects));
+    }
+
+    @Override
+    public void hit(@NotNull Ray ray, @NotNull State state) {
+        objects.forEach(object -> hit(state, ray, object));
+    }
+
+    @Override
+    public @NotNull Optional<BoundingBox> getBoundingBox() {
+        return bbox;
+    }
+}

src/main/java/eu/jonahbauer/raytracing/scene/util/HittableOctree.java

@@ -0,0 +1,61 @@
+package eu.jonahbauer.raytracing.scene.util;
+
+import eu.jonahbauer.raytracing.math.*;
+import eu.jonahbauer.raytracing.scene.Hittable;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.Optional;
+
+public final class HittableOctree extends HittableCollection {
+    private final @NotNull Octree<Hittable> objects;
+    private final @NotNull Optional<BoundingBox> bbox;
+
+    public HittableOctree(@NotNull List<? extends @NotNull Hittable> objects) {
+        var result = newOctree(objects);
+        this.objects = result.getKey();
+        this.bbox = Optional.of(result.getValue());
+    }
+
+    public HittableOctree(@NotNull Hittable @NotNull... objects) {
+        this(List.of(objects));
+    }
+
+    @Override
+    public void hit(@NotNull Ray ray, @NotNull State state) {
+        objects.hit(ray, object -> hit(state, ray, object));
+    }
+
+    @Override
+    public @NotNull Optional<BoundingBox> getBoundingBox() {
+        return bbox;
+    }
+
+    private static @NotNull Entry<@NotNull Octree<Hittable>, @NotNull BoundingBox> newOctree(@NotNull List<? extends Hittable> objects) {
+        Vec3 center = Vec3.ZERO, max = Vec3.MIN, min = Vec3.MAX;
+
+        int i = 1;
+        for (var object : objects) {
+            var bbox = object.getBoundingBox().orElseThrow();
+            center = Vec3.average(center, bbox.center(), i++);
+            max = Vec3.max(max, bbox.max());
+            min = Vec3.min(min, bbox.min());
+        }
+
+        var dimension = Arrays.stream(new double[] {
+                Math.abs(max.x() - center.x()),
+                Math.abs(max.y() - center.y()),
+                Math.abs(max.z() - center.z()),
+                Math.abs(min.x() - center.x()),
+                Math.abs(min.y() - center.y()),
+                Math.abs(min.z() - center.z())
+        }).max().orElse(10);
+
+        var out = new Octree<Hittable>(center, dimension);
+        objects.forEach(object -> out.add(object.getBoundingBox().get(), object));
+        return Map.entry(out, new BoundingBox(min, max));
+    }
+}