add command line argument parser

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

@@ -5,11 +5,14 @@ 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.Canvas;
 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.*;
+import eu.jonahbauer.raytracing.scene.Hittable;
+import eu.jonahbauer.raytracing.scene.Scene;
+import eu.jonahbauer.raytracing.scene.SkyBox;
 import eu.jonahbauer.raytracing.scene.hittable2d.Parallelogram;
 import eu.jonahbauer.raytracing.scene.hittable3d.ConstantMedium;
 import eu.jonahbauer.raytracing.scene.hittable3d.Sphere;
@@ -17,33 +20,140 @@ import eu.jonahbauer.raytracing.scene.util.Hittables;
 import org.jetbrains.annotations.NotNull;
 
 import java.io.IOException;
+import java.nio.file.InvalidPathException;
 import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.Random;
+import java.util.function.IntFunction;
 
 public class Main {
     public static void main(String[] args) throws IOException {
-        var example = getCornellBoxSmoke();
+        var config = Config.parse(args);
+        var example = config.example;
         var scene = example.scene();
         var camera = example.camera();
 
         var renderer = SimpleRenderer.builder()
-                .withSamplesPerPixel(1000)
+                .withSamplesPerPixel(config.samples)
-                .withMaxDepth(50)
+                .withMaxDepth(config.depth)
-                .withIterative(true)
+                .withIterative(config.iterative)
                 .build();
 
+        Canvas canvas;
+        if (config.preview) {
             var image = new LiveCanvas(new Image(camera.getWidth(), camera.getHeight()));
             image.preview();
+            canvas = image;
+        } else {
+            canvas = new Image(camera.getWidth(), camera.getHeight());
+        }
 
         long time = System.nanoTime();
-        renderer.render(camera, scene, image);
+        renderer.render(camera, scene, canvas);
         System.out.printf("rendering finished after %dms", (System.nanoTime() - time) / 1_000_000);
 
-        ImageFormat.PNG.write(image, Path.of("scene-" + System.currentTimeMillis() + ".png"));
+        ImageFormat.PNG.write(canvas, config.path);
+    }
+
+    private record Config(@NotNull Example example, @NotNull Path path, boolean preview, boolean iterative, int samples, int depth) {
+
+        public static @NotNull Config parse(@NotNull String @NotNull[] args) {
+            IntFunction<Example> example = null;
+            Path path = null;
+            boolean preview = true;
+            boolean iterative = false;
+            int samples = 1000;
+            int depth = 50;
+            int height = -1;
+
+            for (int i = 0; i < args.length; i++) {
+                switch (args[i]) {
+                    case "--output" -> {
+                        if (i + 1 == args.length) throw fail("missing value for parameter --output");
+                        try {
+                            path = Path.of(args[++i]);
+                        } catch (InvalidPathException ex) {
+                            throw fail("value " + args[i] + " is not a valid path");
+                        }
+                    }
+                    case "--preview" -> preview = true;
+                    case "--no-preview" -> preview = false;
+                    case "--iterative" -> iterative = true;
+                    case "--no-iterative" -> iterative = false;
+                    case "--samples" -> {
+                        if (i + 1 == args.length) throw fail("missing value for parameter --samples");
+                        try {
+                            samples = Integer.parseInt(args[++i]);
+                            if (samples <= 0) throw fail("samples must be positive");
+                        } catch (NumberFormatException ex) {
+                            throw fail("value " + args[i] + " is not a valid integer");
+                        }
+                    }
+                    case "--depth" -> {
+                        if (i + 1 == args.length) throw fail("missing value for parameter --depth");
+                        try {
+                            depth = Integer.parseInt(args[++i]);
+                            if (depth <= 0) throw fail("depth must be positive");
+                        } catch (NumberFormatException ex) {
+                            throw fail("value " + args[i] + " is not a valid integer");
+                        }
+                    }
+                    case "--height" -> {
+                        if (i + 1 == args.length) throw fail("missing value for parameter --height");
+                        try {
+                            height = Integer.parseInt(args[++i]);
+                            if (height <= 0) throw fail("height must be positive");
+                        } catch (NumberFormatException ex) {
+                            throw fail("value " + args[i] + " is not a valid integer");
+                        }
+                    }
+                    case String str when !str.startsWith("-") -> example = switch (str) {
+                         case "SIMPLE" -> Examples::getSimpleScene;
+                         case "SPHERES" -> Examples::getSpheres;
+                         case "SQUARES" -> Examples::getSquares;
+                         case "LIGHT" -> Examples::getLight;
+                         case "CORNELL" -> Examples::getCornellBox;
+                         case "CORNELL_SMOKE" -> Examples::getCornellBoxSmoke;
+                         default -> throw fail("unknown example " + str + ", expected one of SIMPLE, SPHERES, SQUARES, LIGHT, CORNELL or CORNELL_SMOKE");
+                    };
+                    default -> throw fail("unknown option " + args[i]);
+                }
+            }
+
+            if (example == null) example = Examples::getCornellBoxSmoke;
+            if (path == null) path = Path.of("scene-" + System.currentTimeMillis() + ".png");
+            return new Config(example.apply(height), path, preview, iterative, samples, depth);
+        }
+
+        private static @NotNull RuntimeException fail(@NotNull String message) {
+            System.err.println(message);
+            System.exit(1);
+            return new RuntimeException();
+        }
+
     }
 
-    private static @NotNull Example getSpheres() {
+    private static class Examples {
+        public static @NotNull Example getSimpleScene(int height) {
+            if (height <= 0) height = 675;
+            return new Example(
+                    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))
+                    ),
+                    SimpleCamera.builder()
+                            .withImage(height * 16 / 9, height)
+                            .build()
+            );
+        }
+
+        public static @NotNull Example getSpheres(int height) {
+            if (height <= 0) height = 675;
+
             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))));
@@ -78,7 +188,7 @@ public class Main {
             objects.add(new Sphere(new Vec3(4, 1, 0), 1.0, new MetallicMaterial(new Color(0.7, 0.6, 0.5))));
 
             var camera = SimpleCamera.builder()
-                .withImage(1200, 675)
+                    .withImage(height * 16 / 9, height)
                     .withPosition(new Vec3(13, 2, 3))
                     .withTarget(new Vec3(0, 0, 0))
                     .withFieldOfView(Math.toRadians(20))
@@ -89,7 +199,8 @@ public class Main {
             return new Example(new Scene(getSkyBox(), objects), camera);
         }
 
-    private static @NotNull Example getSquares() {
+        public static @NotNull Example getSquares(int height) {
+            if (height <= 0) height = 600;
             return new Example(
                     new Scene(
                             getSkyBox(),
@@ -100,7 +211,7 @@ public class Main {
                             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)
+                            .withImage(height, height)
                             .withFieldOfView(Math.toRadians(80))
                             .withPosition(new Vec3(0, 0, 9))
                             .withTarget(new Vec3(0, 0, 0))
@@ -108,7 +219,8 @@ public class Main {
             );
         }
 
-    private static @NotNull Example getLight() {
+        public static @NotNull Example getLight(int height) {
+            if (height <= 0) height = 225;
             return new Example(
                     new Scene(
                             new Sphere(new Vec3(0, -1000, 0), 1000, new LambertianMaterial(new Color(0.2, 0.2, 0.2))),
@@ -117,7 +229,7 @@ public class Main {
                             new Sphere(new Vec3(0, 7, 0), 2, new DiffuseLight(new Color(4.0, 4.0, 4.0)))
                     ),
                     SimpleCamera.builder()
-                        .withImage(400, 225)
+                            .withImage(height * 16 / 9, height)
                             .withFieldOfView(Math.toRadians(20))
                             .withPosition(new Vec3(26, 3, 6))
                             .withTarget(new Vec3(0, 2, 0))
@@ -125,7 +237,9 @@ public class Main {
             );
         }
 
-    private static @NotNull Example getCornellBox() {
+        public static @NotNull Example getCornellBox(int height) {
+            if (height <= 0) height = 600;
+
             var red = new LambertianMaterial(new Color(.65, .05, .05));
             var white = new LambertianMaterial(new Color(.73, .73, .73));
             var green = new LambertianMaterial(new Color(.12, .45, .15));
@@ -143,7 +257,7 @@ public class Main {
                             Hittables.box(new Vec3(0, 0, 0), new Vec3(165, 165, 165), white).rotateY(Math.toRadians(-18)).translate(new Vec3(130, 0, 65))
                     ),
                     SimpleCamera.builder()
-                        .withImage(600, 600)
+                            .withImage(height, height)
                             .withFieldOfView(Math.toRadians(40))
                             .withPosition(new Vec3(278, 278, -800))
                             .withTarget(new Vec3(278, 278, 0))
@@ -151,7 +265,8 @@ public class Main {
             );
         }
 
-    private static @NotNull Example getCornellBoxSmoke() {
+        public static @NotNull Example getCornellBoxSmoke(int height) {
+            if (height <= 0) height = 600;
             var red = new LambertianMaterial(new Color(.65, .05, .05));
             var white = new LambertianMaterial(new Color(.73, .73, .73));
             var green = new LambertianMaterial(new Color(.12, .45, .15));
@@ -175,7 +290,7 @@ public class Main {
                             )
                     ),
                     SimpleCamera.builder()
-                        .withImage(600, 600)
+                            .withImage(height, height)
                             .withFieldOfView(Math.toRadians(40))
                             .withPosition(new Vec3(278, 278, -800))
                             .withTarget(new Vec3(278, 278, 0))
@@ -183,20 +298,10 @@ public class Main {
             );
         }
 
-    private static @NotNull Scene getSimpleScene() {
-        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) {}
 }