add 2d primitives

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

@@ -1,5 +1,6 @@
 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;
@@ -12,8 +13,11 @@ import eu.jonahbauer.raytracing.render.canvas.LiveCanvas;
 import eu.jonahbauer.raytracing.render.canvas.Image;
 import eu.jonahbauer.raytracing.render.renderer.SimpleRenderer;
 import eu.jonahbauer.raytracing.scene.Hittable;
+import eu.jonahbauer.raytracing.scene.flat.Ellipse;
+import eu.jonahbauer.raytracing.scene.flat.Parallelogram;
 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;
@@ -24,16 +28,9 @@ import java.util.Random;
 
 public class Main {
     public static void main(String[] args) throws IOException {
-        var scene = getScene();
-
-        var camera = SimpleCamera.builder()
-                .withImage(1200, 675)
-                .withPosition(new Vec3(13, 2, 3))
-                .withTarget(new Vec3(0, 0, 0))
-                .withFieldOfView(Math.toRadians(20))
-                .withFocusDistance(10.0)
-                .withBlurAngle(Math.toRadians(0.6))
-                .build();
+        var example = getSquares();
+        var scene = example.scene();
+        var camera = example.camera();
 
         var renderer = SimpleRenderer.builder()
                 .withSamplesPerPixel(500)
@@ -51,7 +48,7 @@ public class Main {
         ImageFormat.PNG.write(image, Path.of("scene-" + System.currentTimeMillis() + ".png"));
     }
 
-    private static @NotNull Scene getScene() {
+    private static @NotNull Example getSpheres() {
         var rng = new Random(1);
         var objects = new ArrayList<Hittable>();
         objects.add(new Sphere(new Vec3(0, -1000, 0), 1000, new LambertianMaterial(new Color(0.5, 0.5, 0.5))));
@@ -85,7 +82,34 @@ public class Main {
         objects.add(new Sphere(new Vec3(-4, 1, 0), 1.0, new LambertianMaterial(new Color(0.4, 0.2, 0.1))));
         objects.add(new Sphere(new Vec3(4, 1, 0), 1.0, new MetallicMaterial(new Color(0.7, 0.6, 0.5))));
 
-        return new Scene(objects);
+        var camera = SimpleCamera.builder()
+                .withImage(1200, 675)
+                .withPosition(new Vec3(13, 2, 3))
+                .withTarget(new Vec3(0, 0, 0))
+                .withFieldOfView(Math.toRadians(20))
+                .withFocusDistance(10.0)
+                .withBlurAngle(Math.toRadians(0.6))
+                .build();
+
+        return new Example(new Scene(objects), camera);
+    }
+
+    private static @NotNull Example getSquares() {
+        return new Example(
+                new Scene(List.of(
+                        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))
+                        .withPosition(new Vec3(0, 0, 9))
+                        .withTarget(new Vec3(0, 0, 0))
+                        .build()
+        );
     }
 
     private static @NotNull Scene getSimpleScene() {
@@ -97,4 +121,6 @@ public class Main {
                 new Sphere(new Vec3(1.0, 0, -1.2), 0.5, new MetallicMaterial(new Color(0.8, 0.6, 0.2), 0.0))
         ));
     }
+
+    private record Example(@NotNull Scene scene, @NotNull Camera camera) {}
 }

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

@@ -0,0 +1,26 @@
+package eu.jonahbauer.raytracing.scene.flat;
+
+import eu.jonahbauer.raytracing.math.BoundingBox;
+import eu.jonahbauer.raytracing.math.Vec3;
+import eu.jonahbauer.raytracing.render.material.Material;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Optional;
+
+public final class Ellipse extends Hittable2D {
+    public Ellipse(@NotNull Vec3 origin, @NotNull Vec3 u, @NotNull Vec3 v, @NotNull Material material) {
+        super(origin, u, v, material);
+    }
+
+    @Override
+    protected boolean isInterior(double alpha, double beta) {
+        return alpha * alpha + beta * beta < 1;
+    }
+
+    @Override
+    public @NotNull Optional<BoundingBox> getBoundingBox() {
+        var a = origin.minus(u).minus(v);
+        var b = origin.plus(u).plus(v);
+        return Optional.of(new BoundingBox(Vec3.min(a, b), Vec3.max(a, b)));
+    }
+}

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

@@ -0,0 +1,64 @@
+package eu.jonahbauer.raytracing.scene.flat;
+
+import eu.jonahbauer.raytracing.math.Range;
+import eu.jonahbauer.raytracing.math.Ray;
+import eu.jonahbauer.raytracing.math.Vec3;
+import eu.jonahbauer.raytracing.render.material.Material;
+import eu.jonahbauer.raytracing.scene.HitResult;
+import eu.jonahbauer.raytracing.scene.Hittable;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Objects;
+import java.util.Optional;
+
+public abstract class Hittable2D implements Hittable {
+    protected final @NotNull Vec3 origin;
+    protected final @NotNull Vec3 u;
+    protected final @NotNull Vec3 v;
+    private final @NotNull Material material;
+
+    // internal
+    private final @NotNull Vec3 normal;
+    private final double d;
+    private final @NotNull Vec3 w;
+
+    protected Hittable2D(@NotNull Vec3 origin, @NotNull Vec3 u, @NotNull Vec3 v, @NotNull Material material) {
+        this.origin = Objects.requireNonNull(origin);
+        this.u = Objects.requireNonNull(u);
+        this.v = Objects.requireNonNull(v);
+        this.material = Objects.requireNonNull(material);
+
+        var n = u.cross(v);
+        if (n.squared() < 1e-8) throw new IllegalArgumentException();
+        this.normal = n.unit();
+        this.d = origin.times(normal);
+        this.w = n.div(n.squared());
+    }
+
+    @Override
+    public @NotNull Optional<HitResult> hit(@NotNull Ray ray, @NotNull Range range) {
+        var denominator = ray.direction().times(normal);
+        if (Math.abs(denominator) < 1e-8) return Optional.empty(); // parallel
+
+        var t = (d - ray.origin().times(normal)) / denominator;
+        if (!range.surrounds(t)) return Optional.empty();
+
+        var position = ray.at(t);
+        var p = position.minus(origin);
+
+        if (!isInterior(p)) return Optional.empty();
+
+        var frontFace = denominator < 0;
+        return Optional.of(new HitResult(t, position, frontFace ? normal : normal.neg(), material, frontFace));
+    }
+
+    protected boolean isInterior(@NotNull Vec3 p) {
+        var alpha = w.times(p.cross(v));
+        var beta = w.times(u.cross(p));
+        return isInterior(alpha, beta);
+    }
+
+    protected boolean isInterior(double alpha, double beta) {
+        return false;
+    }
+}

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

@@ -0,0 +1,27 @@
+package eu.jonahbauer.raytracing.scene.flat;
+
+import eu.jonahbauer.raytracing.math.BoundingBox;
+import eu.jonahbauer.raytracing.math.Vec3;
+import eu.jonahbauer.raytracing.render.material.Material;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Optional;
+
+public final class Parallelogram extends Hittable2D {
+
+    public Parallelogram(@NotNull Vec3 origin, @NotNull Vec3 u, @NotNull Vec3 v, @NotNull Material material) {
+        super(origin, u, v, material);
+    }
+
+    @Override
+    protected boolean isInterior(double alpha, double beta) {
+        return 0 <= alpha && alpha < 1 && 0 <= beta && beta < 1;
+    }
+
+    @Override
+    public @NotNull Optional<BoundingBox> getBoundingBox() {
+        var a = origin;
+        var b = origin.plus(u).plus(v);
+        return Optional.of(new BoundingBox(Vec3.min(a, b), Vec3.max(a, b)));
+    }
+}

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

@@ -0,0 +1,16 @@
+package eu.jonahbauer.raytracing.scene.flat;
+
+import eu.jonahbauer.raytracing.math.Vec3;
+import eu.jonahbauer.raytracing.render.material.Material;
+import org.jetbrains.annotations.NotNull;
+
+public final class Plane extends Hittable2D {
+    public Plane(@NotNull Vec3 origin, @NotNull Vec3 u, @NotNull Vec3 v, @NotNull Material material) {
+        super(origin, u, v, material);
+    }
+
+    @Override
+    protected boolean isInterior(@NotNull Vec3 p) {
+        return true;
+    }
+}

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

@@ -0,0 +1,27 @@
+package eu.jonahbauer.raytracing.scene.flat;
+
+import eu.jonahbauer.raytracing.math.BoundingBox;
+import eu.jonahbauer.raytracing.math.Vec3;
+import eu.jonahbauer.raytracing.render.material.Material;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Optional;
+
+public final class Triangle extends Hittable2D {
+
+    public Triangle(@NotNull Vec3 origin, @NotNull Vec3 u, @NotNull Vec3 v, @NotNull Material material) {
+        super(origin, u, v, material);
+    }
+
+    @Override
+    protected boolean isInterior(double alpha, double beta) {
+        return 0 <= alpha && 0 <= beta && alpha + beta <= 1;
+    }
+
+    @Override
+    public @NotNull Optional<BoundingBox> getBoundingBox() {
+        var a = origin;
+        var b = origin.plus(u).plus(v);
+        return Optional.of(new BoundingBox(Vec3.min(a, b), Vec3.max(a, b)));
+    }
+}