align operators in Vec3, Color, ColorXYZ and SampledSpectrum

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

@@ -82,7 +82,7 @@ public class Examples {
                 var rnd = rng.nextDouble();
                 if (rnd < 0.8) {
                     // diffuse
-                    var albedo = Color.multiply(Color.random(rng), Color.random(rng));
+                    var albedo = Color.random(rng).times(Color.random(rng));
                     material = new LambertianMaterial(albedo);
                 } else if (rnd < 0.95) {
                     // metal

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

@@ -0,0 +1,21 @@
+package eu.jonahbauer.raytracing.math;
+
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * A vector-like object that implements the standard mathematical operations
+ * @param <T> the type
+ */
+public interface IVec<T extends IVec<T>> {
+    double get(int i);
+
+    @NotNull T plus(@NotNull T other);
+    @NotNull T minus(@NotNull T other);
+    @NotNull T times(@NotNull T other);
+    @NotNull T times(double d);
+    default @NotNull T div(double d) {
+        return times(1 / d);
+    }
+
+    double @NotNull[] toArray();
+}

src/main/java/eu/jonahbauer/raytracing/math/IVec3.java

@@ -0,0 +1,36 @@
+package eu.jonahbauer.raytracing.math;
+
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * A vector-like object with three components.
+ * @param <T> the type
+ */
+public interface IVec3<T extends Record & IVec3<T>> extends IVec<T> {
+    default double component1() {
+        return toVec3().x();
+    }
+    default double component2() {
+        return toVec3().y();
+    }
+    default double component3() {
+        return toVec3().z();
+    }
+
+    @Override
+    default double get(int i) {
+        return switch (i) {
+            case 0 -> component1();
+            case 1 -> component2();
+            case 2 -> component3();
+            default -> throw new IndexOutOfBoundsException(i);
+        };
+    }
+
+    @NotNull Vec3 toVec3();
+
+    @Override
+    default double @NotNull [] toArray() {
+        return new double[] {component1(), component2(), component3()};
+    }
+}

src/main/java/eu/jonahbauer/raytracing/math/Vec3.java

@@ -7,10 +7,8 @@ import java.util.random.RandomGenerator;
 
 import static eu.jonahbauer.raytracing.Main.DEBUG;
 
-public record Vec3(double x, double y, double z) {
+public record Vec3(double x, double y, double z) implements IVec3<Vec3> {
     public static final Vec3 ZERO = new Vec3(0, 0, 0);
-    public static final Vec3 MAX = new Vec3(Double.MAX_VALUE, Double.MAX_VALUE, Double.MAX_VALUE);
-    public static final Vec3 MIN = new Vec3(-Double.MAX_VALUE, -Double.MAX_VALUE, -Double.MAX_VALUE);
     public static final Vec3 UNIT_X = new Vec3(1, 0, 0);
     public static final Vec3 UNIT_Y = new Vec3(0, 1, 0);
     public static final Vec3 UNIT_Z = new Vec3(0, 0, 1);
@@ -62,7 +60,7 @@ public record Vec3(double x, double y, double z) {
      * @return the reflected vector
      */
     public static @NotNull Vec3 reflect(@NotNull Vec3 vec, @NotNull Vec3 normal) {
-        var factor = - 2 * normal.times(vec);
+        var factor = - 2 * normal.dot(vec);
         return Vec3.fma(factor, normal, vec);
     }
 
@@ -75,7 +73,7 @@ public record Vec3(double x, double y, double z) {
      */
     public static @NotNull Optional<Vec3> refract(@NotNull Vec3 vec, @NotNull Vec3 normal, double ri) {
         vec = vec.unit();
-        var cosTheta = Math.min(- vec.times(normal), 1.0);
+        var cosTheta = Math.min(- vec.dot(normal), 1.0);
         var sinTheta = Math.sqrt(1 - cosTheta * cosTheta);
         if (ri * sinTheta > 1) return Optional.empty();
 
@@ -166,6 +164,10 @@ public record Vec3(double x, double y, double z) {
         return a.x * b.y * c.z + a.y * b.z * c.x + a.z * b.x * c.y - c.x * b.y * a.z - c.y * b.z * a.x - c.z * b.x * a.y;
     }
 
+    /*
+     * Math
+     */
+
     public @NotNull Vec3 plus(double x, double y, double z) {
         return new Vec3(this.x + x, this.y + y, this.z + z);
     }
@@ -179,6 +181,7 @@ public record Vec3(double x, double y, double z) {
      * @param other a vector
      * @return the sum of this and the other vector
      */
+    @Override
     public @NotNull Vec3 plus(@NotNull Vec3 other) {
         return new Vec3(this.x + other.x, this.y + other.y, this.z + other.z);
     }
@@ -188,49 +191,58 @@ public record Vec3(double x, double y, double z) {
      * @param other a vector
      * @return the difference of this and the other vector
      */
+    @Override
     public @NotNull Vec3 minus(@NotNull Vec3 other) {
         return new Vec3(this.x - other.x, this.y - other.y, this.z - other.z);
     }
 
-    /**
-     * Computes the scalar product of this and another vector
-     * @param other a vector
-     * @return the scalar product
-     */
-    public double times(@NotNull Vec3 other) {
-        return this.x * other.x + this.y * other.y + this.z * other.z;
-    }
-
     /**
      * Multiplies this vector with a scalar
      * @param t a scalar
      * @return the product of this vector and the scalar
      */
+    @Override
     public @NotNull Vec3 times(double t) {
         return new Vec3(this.x * t, this.y * t, this.z * t);
     }
 
     /**
-     * Negates this vector.
-     * {@return the negated vector}
+     * Multiplies this vector with another vector component-wise.
+     * @param other a vector
+     * @return the component-wise product of this vector and the other vector
      */
-    public @NotNull Vec3 neg() {
-        return new Vec3(-x, -y, -z);
+    @Override
+    public @NotNull Vec3 times(@NotNull Vec3 other) {
+        return new Vec3(this.x * other.x, this.y * other.y, this.z * other.z);
     }
 
     /**
-     * Inverts each component of this vector.
-     * @return the inverted vector.
+     * Divides this vector by a scalar
+     * @param t a scalar
+     * @return this vector divided by the scalar
      */
-    public @NotNull Vec3 inv() {
-        return new Vec3(1 / x, 1 / y, 1 / z);
+    @Override
+    public @NotNull Vec3 div(double t) {
+        return times(1 / t);
     }
 
     /**
-     * Computes the cross-product of this and another vector
+     * Computes the scalar product of this and another vector
      * @param other a vector
-     * @return the cross-product
+     * @return the scalar product
      */
+    public double dot(@NotNull Vec3 other) {
+        return this.x * other.x + this.y * other.y + this.z * other.z;
+    }
+
+    public @NotNull Vec3 neg() {
+        return new Vec3(-x, -y, -z);
+    }
+
+    public @NotNull Vec3 inv() {
+        return new Vec3(1 / x, 1 / y, 1 / z);
+    }
+
     public @NotNull Vec3 cross(@NotNull Vec3 other) {
         return new Vec3(
                 Math.fma(this.y, other.z, - other.y * this.z),
@@ -239,15 +251,6 @@ public record Vec3(double x, double y, double z) {
         );
     }
 
-    /**
-     * Divides this vector by a scalar
-     * @param t a scalar
-     * @return this vector divided by the scalar
-     */
-    public @NotNull Vec3 div(double t) {
-        return new Vec3(this.x / t, this.y / t, this.z / t);
-    }
-
     /**
      * {@return the squared length of this vector}
      */
@@ -279,17 +282,28 @@ public record Vec3(double x, double y, double z) {
         return div(Math.sqrt(squared));
     }
 
-    /**
-     * {@return the n-th component of this vector}
-     * @param axis the component index
+    /*
+     * Accessors
      */
-    public double get(int axis) {
-        return switch (axis) {
-            case 0 -> x;
-            case 1 -> y;
-            case 2 -> z;
-            default -> throw new IndexOutOfBoundsException(axis);
-        };
+
+    @Override
+    public double component1() {
+        return x;
+    }
+
+    @Override
+    public double component2() {
+        return y;
+    }
+
+    @Override
+    public double component3() {
+        return z;
+    }
+
+    @Override
+    public @NotNull Vec3 toVec3() {
+        return this;
     }
 
     public @NotNull Vec3 withX(double x) {

src/main/java/eu/jonahbauer/raytracing/render/material/DielectricMaterial.java

@@ -24,7 +24,7 @@ public record DielectricMaterial(double refractionIndex, @NotNull Texture textur
     public @NotNull Optional<ScatterResult> scatter(@NotNull Ray ray, @NotNull HitResult hit, @NotNull RandomGenerator random) {
         var ri = hit.isFrontFace() ? (1 / refractionIndex) : refractionIndex;
 
-        var cosTheta = Math.min(- ray.direction().unit().times(hit.normal()), 1.0);
+        var cosTheta = Math.min(- ray.direction().unit().dot(hit.normal()), 1.0);
         var reflectance = reflectance(cosTheta);
         var reflect = reflectance > random.nextDouble();
 

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

@@ -1,6 +1,5 @@
 package eu.jonahbauer.raytracing.render.renderer;
 
-import eu.jonahbauer.raytracing.math.Range;
 import eu.jonahbauer.raytracing.math.Ray;
 import eu.jonahbauer.raytracing.render.material.Material;
 import eu.jonahbauer.raytracing.render.renderer.pdf.TargetingProbabilityDensityFunction;
@@ -133,7 +132,7 @@ public final class SimpleRenderer implements Renderer {
             var optional = scene.hit(ray);
             if (optional.isEmpty()) {
                 var background = scene.getBackgroundColor(ray);
-                color = Color.add(color, Color.multiply(attenuation, background));
+                color = Color.fma(attenuation, background, color);
                 if (DEBUG) {
                     System.out.println("  Hit background: " + background);
                 }
@@ -151,7 +150,7 @@ public final class SimpleRenderer implements Renderer {
             }
 
             var result = material.scatter(ray, hit, random);
-            color = Color.add(color, Color.multiply(attenuation, emitted));
+            color = Color.fma(attenuation, emitted, color);
 
             if (result.isEmpty()) {
                 if (DEBUG) {
@@ -162,7 +161,7 @@ public final class SimpleRenderer implements Renderer {
 
             switch (result.get()) {
                 case Material.SpecularScatterResult(var a, var scattered) -> {
-                    attenuation = Color.multiply(attenuation, a);
+                    attenuation = attenuation.times(a);
                     ray = scattered;
 
                     if (DEBUG) {
@@ -171,7 +170,7 @@ public final class SimpleRenderer implements Renderer {
                 }
                 case Material.PdfScatterResult(var a, var pdf) -> {
                     if (scene.getTargets() == null) {
-                        attenuation = Color.multiply(attenuation, a);
+                        attenuation = attenuation.times(a);
                         ray = new Ray(hit.position(), pdf.generate(random));
 
                         if (DEBUG) {
@@ -187,7 +186,7 @@ public final class SimpleRenderer implements Renderer {
 
                         var factor =  idealPdf / actualPdf;
 
-                        attenuation = Color.multiply(attenuation, Color.multiply(a, factor));
+                        attenuation = attenuation.times(a.times(factor));
                         ray = new Ray(hit.position(), direction);
 
                         if (DEBUG) {

src/main/java/eu/jonahbauer/raytracing/render/renderer/pdf/CosineProbabilityDensityFunction.java

@@ -15,7 +15,7 @@ public record CosineProbabilityDensityFunction(@NotNull Vec3 normal) implements
 
     @Override
     public double value(@NotNull Vec3 direction) {
-        var cos = normal.times(direction);
+        var cos = normal.dot(direction);
         return Math.max(0, cos / Math.PI);
     }
 

src/main/java/eu/jonahbauer/raytracing/render/spectral/SampledSpectrum.java

@@ -1,12 +1,25 @@
 package eu.jonahbauer.raytracing.render.spectral;
 
+import eu.jonahbauer.raytracing.math.IVec;
 import eu.jonahbauer.raytracing.render.spectral.colors.ColorSpace;
 import eu.jonahbauer.raytracing.render.spectral.colors.ColorXYZ;
 import eu.jonahbauer.raytracing.render.spectral.spectrum.Spectrum;
 import eu.jonahbauer.raytracing.render.texture.Color;
 import org.jetbrains.annotations.NotNull;
 
-public final class SampledSpectrum {
+import java.util.Arrays;
+
+public final class SampledSpectrum implements IVec<SampledSpectrum> {
+    public static final SampledSpectrum BLACK;
+    public static final SampledSpectrum WHITE;
+
+    static {
+        BLACK = new SampledSpectrum(new double[SampledWavelengths.SAMPLES]);
+        var one = new double[SampledWavelengths.SAMPLES];
+        Arrays.fill(one, 1);
+        WHITE = new SampledSpectrum(one);
+    }
+
     private final double @NotNull[] values;
 
     public SampledSpectrum(@NotNull SampledWavelengths lambdas, @NotNull Spectrum spectrum) {
@@ -21,30 +34,74 @@ public final class SampledSpectrum {
         this.values = values;
     }
 
-    public static @NotNull SampledSpectrum multiply(@NotNull SampledSpectrum a, @NotNull SampledSpectrum b) {
+    /*
+     * Math
+     */
+
+    public static @NotNull SampledSpectrum fma(@NotNull SampledSpectrum a, @NotNull SampledSpectrum b, @NotNull SampledSpectrum c) {
         var out = new double[a.values.length];
         for (int i = 0; i < a.values.length; i++) {
-            out[i] = a.values[i] * b.values[i];
+            out[i] = Math.fma(a.values[i], b.values[i], c.values[i]);
         }
         return new SampledSpectrum(out);
     }
 
-    public static @NotNull SampledSpectrum multiply(@NotNull SampledSpectrum a, double b) {
+    public static @NotNull SampledSpectrum lerp(@NotNull SampledSpectrum a, @NotNull SampledSpectrum b, double t) {
+        if (t < 0) return a;
+        if (t > 1) return b;
         var out = new double[a.values.length];
         for (int i = 0; i < a.values.length; i++) {
-            out[i] = a.values[i] * b;
+            out[i] = Math.fma(t, b.values[i] - a.values[i], a.values[i]);
         }
         return new SampledSpectrum(out);
     }
 
-    public static @NotNull SampledSpectrum add(@NotNull SampledSpectrum a, @NotNull SampledSpectrum b) {
-        var out = new double[a.values.length];
-        for (int i = 0; i < a.values.length; i++) {
-            out[i] = a.values[i] + b.values[i];
+    @Override
+    public @NotNull SampledSpectrum plus(@NotNull SampledSpectrum other) {
+        var out = new double[other.values.length];
+        for (int i = 0; i < other.values.length; i++) {
+            out[i] = values[i] + other.values[i];
+        }
+        return new SampledSpectrum(out);
+    }
+
+    @Override
+    public @NotNull SampledSpectrum minus(@NotNull SampledSpectrum other) {
+        var out = new double[other.values.length];
+        for (int i = 0; i < other.values.length; i++) {
+            out[i] = values[i] - other.values[i];
+        }
+        return new SampledSpectrum(out);
+    }
+
+    @Override
+    public @NotNull SampledSpectrum times(@NotNull SampledSpectrum other) {
+        var out = new double[other.values.length];
+        for (int i = 0; i < other.values.length; i++) {
+            out[i] = values[i] * other.values[i];
         }
         return new SampledSpectrum(out);
     }
 
+    @Override
+    public @NotNull SampledSpectrum times(double d) {
+        var out = new double[values.length];
+        for (int i = 0; i < values.length; i++) {
+            out[i] = values[i] * d;
+        }
+        return new SampledSpectrum(out);
+    }
+
+    @Override
+    public double @NotNull [] toArray() {
+        return Arrays.copyOf(values, values.length);
+    }
+
+    /*
+     * Accessors
+     */
+
+    @Override
     public double get(int index) {
         return values[index];
     }
@@ -53,14 +110,29 @@ public final class SampledSpectrum {
         return values.length;
     }
 
-    public double average() {
-        double avg = 0;
-        for (int i = 0; i < values.length; i++) {
-            avg = Math.fma(1d / (i + 1), values[i] - avg, avg);
-        }
-        return avg;
+    /*
+     * Object
+     */
+
+    @Override
+    public boolean equals(Object obj) {
+        return obj instanceof SampledSpectrum o && Arrays.equals(values, o.values);
+    }
+
+    @Override
+    public int hashCode() {
+        return Arrays.hashCode(values);
     }
 
+    @Override
+    public @NotNull String toString() {
+        return "SampledSpectrum[values=" + Arrays.toString(values) + "]";
+    }
+
+    /*
+     * Conversions
+     */
+
     public @NotNull ColorXYZ toXYZ(@NotNull SampledWavelengths lambdas) {
         return lambdas.toXYZ(this);
     }

src/main/java/eu/jonahbauer/raytracing/render/spectral/SampledWavelengths.java

@@ -12,6 +12,7 @@ import java.util.Arrays;
  */
 public final class SampledWavelengths {
     public static final int SAMPLES = 4;
+    public static final SampledWavelengths EMPTY = new SampledWavelengths(new double[0], new double[0]);
 
     private final double @NotNull[] lambdas;
     private final double @NotNull[] pdf;
@@ -57,12 +58,37 @@ public final class SampledWavelengths {
      * Terminates the secondary wavelengths. This method should be called after a wavelength-dependent operation like
      * refraction that makes it incorrect to track multiple wavelengths together.
      */
-    public void terminateSecondary() {
-        if (pdf.length < 2 || pdf[1] == 0) return;
-        Arrays.fill(pdf, 1, pdf.length, 0d);
-        pdf[0] /= pdf.length;
+    public @NotNull SampledWavelengths collapse() {
+        if (pdf.length < 2 || pdf[1] == 0) return this;
+        var newPdf = Arrays.copyOf(pdf, pdf.length);
+        Arrays.fill(newPdf, 1, newPdf.length, 0d);
+        newPdf[0] /= newPdf.length;
+        return new SampledWavelengths(lambdas, newPdf);
     }
 
+    /*
+     * Object
+     */
+
+    @Override
+    public boolean equals(Object obj) {
+        return obj instanceof SampledWavelengths o && Arrays.equals(lambdas, o.lambdas) && Arrays.equals(pdf, o.pdf);
+    }
+
+    @Override
+    public int hashCode() {
+        return 31 * Arrays.hashCode(lambdas) + Arrays.hashCode(pdf);
+    }
+
+    @Override
+    public @NotNull String toString() {
+        return "SampledWavelengths[lambdas=" + Arrays.toString(lambdas) + ", pdf=" + Arrays.toString(pdf) + "]";
+    }
+
+    /*
+     * Conversions
+     */
+
     @NotNull
     ColorXYZ toXYZ(@NotNull SampledSpectrum spectrum) {
         var x = Spectra.X.sample(this);

src/main/java/eu/jonahbauer/raytracing/render/spectral/colors/ColorSpace.java

@@ -62,7 +62,7 @@ public final class ColorSpace {
 
     public @NotNull ColorXYZ toXYZ(@NotNull Color rgb) {
         var out = XYZfromRGB.times(rgb.toVec3());
-        return new ColorXYZ(out);
+        return ColorXYZ.fromVec3(out);
     }
 
     public @NotNull Vec3 toCIELab(@NotNull Color rgb) {

src/main/java/eu/jonahbauer/raytracing/render/spectral/colors/ColorXYZ.java

@@ -1,14 +1,18 @@
 package eu.jonahbauer.raytracing.render.spectral.colors;
 
+import eu.jonahbauer.raytracing.math.IVec3;
 import eu.jonahbauer.raytracing.math.Vec3;
 import org.jetbrains.annotations.NotNull;
 
 /**
  * A CIE XYZ color
  */
-public record ColorXYZ(double x, double y, double z) {
+public record ColorXYZ(double x, double y, double z) implements IVec3<ColorXYZ> {
     public static final double CIE_Y_INTEGRAL = 106.85689500000002;
 
+    public static final @NotNull ColorXYZ BLACK = new ColorXYZ(0, 0, 0);
+    public static final @NotNull ColorXYZ WHITE = new ColorXYZ(0, 1, 0);
+
     public ColorXYZ(@NotNull Chromaticity chromaticity) {
         this(chromaticity, 1);
     }
@@ -21,10 +25,69 @@ public record ColorXYZ(double x, double y, double z) {
         );
     }
 
-    public ColorXYZ(@NotNull Vec3 vec) {
-        this(vec.x(), vec.y(), vec.z());
+    /*
+     * Math
+     */
+
+    public static @NotNull ColorXYZ average(@NotNull ColorXYZ a, @NotNull ColorXYZ b, int index) {
+        return lerp(a, b, 1d / index);
+    }
+
+    public static @NotNull ColorXYZ lerp(@NotNull ColorXYZ a, @NotNull ColorXYZ b, double t) {
+        if (t < 0) return a;
+        if (t > 1) return b;
+        return new ColorXYZ(
+                Math.fma(t, b.x - a.x, a.x),
+                Math.fma(t, b.y - a.y, a.y),
+                Math.fma(t, b.z - a.z, a.z)
+        );
+    }
+
+    public static @NotNull ColorXYZ fma(@NotNull ColorXYZ a, @NotNull ColorXYZ b, @NotNull ColorXYZ c) {
+        return new ColorXYZ(
+                Math.fma(a.x, b.x, c.x),
+                Math.fma(a.y, b.y, c.y),
+                Math.fma(a.z, b.z, c.z)
+        );
+    }
+
+    @Override
+    public @NotNull ColorXYZ plus(@NotNull ColorXYZ other) {
+        return new ColorXYZ(x + other.x, y + other.y, z + other.z);
+    }
+
+    @Override
+    public @NotNull ColorXYZ minus(@NotNull ColorXYZ other) {
+        return new ColorXYZ(x - other.x, y - other.y, z - other.z);
+    }
+
+    @Override
+    public @NotNull ColorXYZ times(@NotNull ColorXYZ other) {
+        return new ColorXYZ(x * other.x, y * other.y, z * other.z);
     }
 
+    @Override
+    public @NotNull ColorXYZ times(double d) {
+        return new ColorXYZ(x * d, y * d, z * d);
+    }
+
+    /*
+     * Vec3
+     */
+
+    @Override
+    public @NotNull Vec3 toVec3() {
+        return new Vec3(x, y, z);
+    }
+
+    public static @NotNull ColorXYZ fromVec3(@NotNull Vec3 vec) {
+        return new ColorXYZ(vec.x(), vec.y(), vec.z());
+    }
+
+    /*
+     * Accessors
+     */
+
     public double average() {
         return (x + y + z) / 3;
     }
@@ -34,19 +97,18 @@ public record ColorXYZ(double x, double y, double z) {
         return new Chromaticity(factor * x, factor * y);
     }
 
-    public @NotNull Vec3 toVec3() {
-        return new Vec3(x, y, z);
-    }
-
-    public static @NotNull ColorXYZ multiply(@NotNull ColorXYZ a, @NotNull ColorXYZ b) {
-        return new ColorXYZ(a.x * b.x, a.y * b.y, a.z * b.z);
+    @Override
+    public double component1() {
+        return x;
     }
 
-    public static @NotNull ColorXYZ multiply(@NotNull ColorXYZ a, double b) {
-        return new ColorXYZ(a.x * b, a.y * b, a.z * b);
+    @Override
+    public double component2() {
+        return y;
     }
 
-    public static @NotNull ColorXYZ add(@NotNull ColorXYZ a, @NotNull ColorXYZ b) {
-        return new ColorXYZ(a.x + b.x, a.y + b.y, a.z + b.z);
+    @Override
+    public double component3() {
+        return z;
     }
 }

src/main/java/eu/jonahbauer/raytracing/render/spectral/colors/SpectrumTable.java

@@ -97,9 +97,9 @@ public final class SpectrumTable {
                 ? (color.r() > color.b() ? 0 : 2)
                 : (color.g() > color.b() ? 1 : 2);
 
-        var z = color.component(max);
-        var x = color.component((max + 1) % 3) * (resolution - 1) / z;
-        var y = color.component((max + 2) % 3) * (resolution - 1) / z;
+        var z = color.get(max);
+        var x = color.get((max + 1) % 3) * (resolution - 1) / z;
+        var y = color.get((max + 2) % 3) * (resolution - 1) / z;
 
         // compute integer indices and offsets for coefficient interpolation
         int xi = Math.min((int) x, resolution - 2);

src/main/java/eu/jonahbauer/raytracing/render/spectral/spectrum/RGBIlluminantSpectrum.java

@@ -20,7 +20,7 @@ public final class RGBIlluminantSpectrum implements Spectrum {
         }
         var max = Math.max(rgb.r(), Math.max(rgb.g(), rgb.b()));
         this.scale = 2 * max;
-        this.polynomial = cs.toSpectrum(scale == 0 ? Color.multiply(rgb, scale) : Color.BLACK);
+        this.polynomial = cs.toSpectrum(scale == 0 ? rgb.div(scale) : Color.BLACK);
         this.illuminant = cs.illuminant();
     }
 

src/main/java/eu/jonahbauer/raytracing/render/spectral/spectrum/RGBUnboundedSpectrum.java

@@ -15,7 +15,7 @@ public final class RGBUnboundedSpectrum implements Spectrum {
         }
         var max = Math.max(rgb.r(), Math.max(rgb.g(), rgb.b()));
         this.scale = 2 * max;
-        this.polynomial = cs.toSpectrum(scale == 0 ? Color.multiply(rgb, scale) : Color.BLACK);
+        this.polynomial = cs.toSpectrum(scale == 0 ? rgb.div(scale) : Color.BLACK);
     }
 
     @Override

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

@@ -1,43 +1,18 @@
 package eu.jonahbauer.raytracing.render.texture;
 
+import eu.jonahbauer.raytracing.math.IVec3;
 import eu.jonahbauer.raytracing.math.Ray;
 import eu.jonahbauer.raytracing.math.Vec3;
 import eu.jonahbauer.raytracing.scene.SkyBox;
 import org.jetbrains.annotations.NotNull;
 
-import java.util.Objects;
 import java.util.Random;
 
 import static eu.jonahbauer.raytracing.Main.DEBUG;
 
-public record Color(double r, double g, double b) implements Texture, SkyBox {
+public record Color(double r, double g, double b) implements Texture, SkyBox, IVec3<Color> {
     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 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);
-
-    public static @NotNull Color lerp(@NotNull Color a, @NotNull Color b, double t) {
-        if (t < 0) return a;
-        if (t > 1) return b;
-        return new Color(
-                Math.fma(t, b.r, Math.fma(-t, a.r, a.r)),
-                Math.fma(t, b.g, Math.fma(-t, a.g, a.g)),
-                Math.fma(t, b.b, Math.fma(-t, a.b, a.b))
-        );
-    }
-
-    public static @NotNull Color multiply(@NotNull Color a, @NotNull Color b) {
-        return new Color(a.r() * b.r(), a.g() * b.g(), a.b() * b.b());
-    }
-
-    public static @NotNull Color multiply(@NotNull Color a, double b) {
-        return new Color(a.r() * b, a.g() * b, a.b() * b);
-    }
-
-    public static @NotNull Color add(@NotNull Color a, @NotNull Color b) {
-        return new Color(a.r() + b.r(), a.g() + b.g(), a.b() + b.b());
-    }
 
     public static @NotNull Color random(@NotNull Random random) {
         return new Color(random.nextDouble(), random.nextDouble(), random.nextDouble());
@@ -52,15 +27,6 @@ public record Color(double r, double g, double b) implements Texture, SkyBox {
         );
     }
 
-    public static @NotNull Color average(@NotNull Color current, @NotNull Color next, int index) {
-        var factor = 1d / index;
-        return new Color(
-                Math.fma(factor, next.r() - current.r(), current.r()),
-                Math.fma(factor, next.g() - current.g(), current.g()),
-                Math.fma(factor, next.b() - current.b(), current.b())
-        );
-    }
-
     public static @NotNull Color gamma(@NotNull Color color, double gamma) {
         if (gamma == 1.0) {
             return color;
@@ -87,21 +53,75 @@ public record Color(double r, double g, double b) implements Texture, SkyBox {
         this(red / 255f, green / 255f, blue / 255f);
     }
 
-    public Color(@NotNull Vec3 vec) {
-        this(vec.x(), vec.y(), vec.z());
-    }
-
     public Color {
-        if (DEBUG) {
-            if (!Double.isFinite(r) || !Double.isFinite(g) || !Double.isFinite(b)) {
-                throw new IllegalArgumentException("r, g and b must be finite");
-            }
-            if (r < 0 || g < 0 || b < 0) {
-                throw new IllegalArgumentException("r, g and b must be non-negative");
-            }
+        if (DEBUG && (!Double.isFinite(r) || !Double.isFinite(g) || !Double.isFinite(b))) {
+            throw new IllegalArgumentException("r, g and b must be finite");
         }
     }
 
+    /*
+     * Math
+     */
+
+    public static @NotNull Color average(@NotNull Color current, @NotNull Color next, int index) {
+        return lerp(current, next, 1d / index);
+    }
+
+    public static @NotNull Color lerp(@NotNull Color a, @NotNull Color b, double t) {
+        if (t < 0) return a;
+        if (t > 1) return b;
+        return new Color(
+                Math.fma(t, b.r - a.r, a.r),
+                Math.fma(t, b.g - a.g, a.g),
+                Math.fma(t, b.b - a.b, a.b)
+        );
+    }
+
+    public static @NotNull Color fma(@NotNull Color a, @NotNull Color b, @NotNull Color c) {
+        return new Color(
+                Math.fma(a.r, b.r, c.r),
+                Math.fma(a.g, b.g, c.g),
+                Math.fma(a.b, b.b, c.b)
+        );
+    }
+
+    @Override
+    public @NotNull Color plus(@NotNull Color other) {
+        return new Color(r + other.r, g + other.g, b + other.b);
+    }
+
+    @Override
+    public @NotNull Color minus(@NotNull Color other) {
+        return new Color(r - other.r, g - other.g, b - other.b);
+    }
+
+    @Override
+    public @NotNull Color times(double d) {
+        return new Color(r * d, g * d, b * d);
+    }
+
+    @Override
+    public @NotNull Color times(@NotNull Color other) {
+        return new Color(r * other.r, g * other.g, b * other.b);
+    }
+
+    /*
+     * Vec3
+     */
+
+    @Override
+    public @NotNull Vec3 toVec3() {
+        return new Vec3(r, g, b);
+    }
+
+    public static @NotNull Color fromVec3(@NotNull Vec3 vec) {
+        return new Color(vec.x(), vec.y(), vec.z());
+    }
+
+    /*
+     * Accessors
+     */
+
     public int red() {
         return toInt(r);
     }
@@ -114,22 +134,31 @@ public record Color(double r, double g, double b) implements Texture, SkyBox {
         return toInt(b);
     }
 
-    public double component(int i) {
-        return switch (i) {
-            case 0 -> r;
-            case 1 -> g;
-            case 2 -> b;
-            default -> throw new IndexOutOfBoundsException(i);
-        };
+    private static int toInt(double value) {
+        return Math.clamp((int) (255.99 * value), 0, 255);
+    }
+
+    @Override
+    public double component1() {
+        return r;
     }
 
     @Override
-    public @NotNull Color get(double u, double v, @NotNull Vec3 p) {
-        return this;
+    public double component2() {
+        return g;
     }
 
     @Override
-    public @NotNull Color getColor(@NotNull Ray ray) {
+    public double component3() {
+        return b;
+    }
+
+    /*
+     * Texture
+     */
+
+    @Override
+    public @NotNull Color get(double u, double v, @NotNull Vec3 p) {
         return this;
     }
 
@@ -138,11 +167,12 @@ public record Color(double r, double g, double b) implements Texture, SkyBox {
         return false;
     }
 
-    public @NotNull Vec3 toVec3() {
-        return new Vec3(r, g, b);
-    }
+    /*
+     * SkyBox
+     */
 
-    private static int toInt(double value) {
-        return Math.clamp((int) (255.99 * value), 0, 255);
+    @Override
+    public @NotNull Color getColor(@NotNull Ray ray) {
+        return this;
     }
 }

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

@@ -12,7 +12,7 @@ public interface SkyBox {
         return ray -> {
             // altitude from -pi/2 to pi/2
             var alt = Math.copySign(
-                    Math.acos(ray.direction().withY(0).unit().times(ray.direction().unit())),
+                    Math.acos(ray.direction().withY(0).unit().dot(ray.direction().unit())),
                     ray.direction().y()
             );
             return Color.lerp(bottom, top, alt / Math.PI + 0.5);

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

@@ -31,23 +31,23 @@ public abstract class Hittable2D implements Hittable {
         var n = u.cross(v);
         if (n.squared() < 1e-8) throw new IllegalArgumentException();
         this.normal = n.unit();
-        this.d = origin.times(normal);
+        this.d = origin.dot(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);
+        var denominator = ray.direction().dot(normal);
         if (Math.abs(denominator) < 1e-8) return Optional.empty(); // parallel
 
-        var t = (d - ray.origin().times(normal)) / denominator;
+        var t = (d - ray.origin().dot(normal)) / denominator;
         if (!range.surrounds(t)) return Optional.empty();
 
         var position = ray.at(t);
         var p = position.minus(origin);
 
-        var alpha = w.times(p.cross(v));
-        var beta = w.times(u.cross(p));
+        var alpha = w.dot(p.cross(v));
+        var beta = w.dot(u.cross(p));
         if (!isInterior(alpha, beta)) return Optional.empty();
 
         var frontFace = denominator < 0;
@@ -58,10 +58,10 @@ public abstract class Hittable2D implements Hittable {
     }
 
     protected double hit0(@NotNull Ray ray, @NotNull Range range) {
-        var denominator = ray.direction().times(normal);
+        var denominator = ray.direction().dot(normal);
         if (Math.abs(denominator) < 1e-8) return Double.NaN; // parallel
 
-        var t = (d - ray.origin().times(normal)) / denominator;
+        var t = (d - ray.origin().dot(normal)) / denominator;
         if (!range.surrounds(t)) return Double.NaN;
 
         var position = ray.at(t);

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

@@ -46,7 +46,7 @@ public final class Sphere implements Hittable, Target {
 
         var position = ray.at(t);
         var normal = Vec3.fma(invRadius, position, normalizedCenter);
-        var frontFace = normal.times(ray.direction()) < 0;
+        var frontFace = normal.dot(ray.direction()) < 0;
 
         double u;
         double v;
@@ -70,7 +70,7 @@ public final class Sphere implements Hittable, Target {
         var oc = ray.origin().minus(center);
 
         var a = ray.direction().squared();
-        var h = ray.direction().times(oc);
+        var h = ray.direction().dot(oc);
         var c = oc.squared() - radius * radius;
 
         var discriminant = h * h - a * c;

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

@@ -13,7 +13,7 @@ public final class PdfUtil {
      * must be unit vectors.
      */
     public static double getSolidAngle(@NotNull Vec3 a, @NotNull Vec3 b, @NotNull Vec3 c) {
-        var angle = 2 * Math.atan(Math.abs(Vec3.tripleProduct(a, b, c)) / (1 + a.times(b) + b.times(c) + c.times(a)));
+        var angle = 2 * Math.atan(Math.abs(Vec3.tripleProduct(a, b, c)) / (1 + a.dot(b) + b.dot(c) + c.dot(a)));
         return angle < 0 ? 2 * Math.PI + angle : angle;
     }
 }

src/test/java/eu/jonahbauer/raytracing/math/Vec3Test.java

@@ -21,10 +21,10 @@ class Vec3Test {
     }
 
     @Test
-    void timesVec() {
+    void dotVec() {
         var a = new Vec3(1, 2, 3);
         var b = new Vec3(-1, 1, -2);
-        assertEquals(-5, a.times(b));
+        assertEquals(-5, a.dot(b));
     }
 
     @Test