separate camera from rendering
parent
c17b9aedf5
commit
0c6db707e0
@ -0,0 +1,22 @@
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package eu.jonahbauer.raytracing.render.camera;
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import eu.jonahbauer.raytracing.math.Ray;
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import org.jetbrains.annotations.NotNull;
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public interface Camera {
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/**
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* {@return the width of this camera in pixels}
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*/
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int getWidth();
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/**
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* {@return the height of this camera in pixels}
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*/
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int getHeight();
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/**
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* Casts a ray through the given pixel.
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* @return a new ray
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*/
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@NotNull Ray cast(int x, int y);
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}
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package eu.jonahbauer.raytracing.render.renderer;
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import eu.jonahbauer.raytracing.render.camera.Camera;
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import eu.jonahbauer.raytracing.render.canvas.Canvas;
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import eu.jonahbauer.raytracing.render.canvas.Image;
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import eu.jonahbauer.raytracing.scene.Scene;
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import org.jetbrains.annotations.NotNull;
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public interface Renderer {
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default @NotNull Image render(@NotNull Camera camera, @NotNull Scene scene) {
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var image = new Image(camera.getWidth(), camera.getHeight());
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render(camera, scene, image);
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return image;
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}
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/**
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* Renders the {@code scene} as seen by the {@code camera} to the {@code canvas}.
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*/
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void render(@NotNull Camera camera, @NotNull Scene scene, @NotNull Canvas canvas);
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}
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@ -0,0 +1,126 @@
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package eu.jonahbauer.raytracing.render.renderer;
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import eu.jonahbauer.raytracing.math.Range;
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import eu.jonahbauer.raytracing.math.Ray;
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import eu.jonahbauer.raytracing.render.Color;
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import eu.jonahbauer.raytracing.render.camera.Camera;
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import eu.jonahbauer.raytracing.render.canvas.Canvas;
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import eu.jonahbauer.raytracing.scene.Scene;
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import org.jetbrains.annotations.NotNull;
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import java.util.function.Function;
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import java.util.stream.IntStream;
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import java.util.stream.LongStream;
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public final class SimpleRenderer implements Renderer {
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private final int samplesPerPixel;
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private final int maxDepth;
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private final double gamma;
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public static @NotNull Builder builder() {
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return new Builder();
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}
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public static @NotNull Renderer withDefaults() {
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return new Builder().build();
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}
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private SimpleRenderer(@NotNull Builder builder) {
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this.samplesPerPixel = builder.samplesPerPixel;
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this.maxDepth = builder.maxDepth;
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this.gamma = builder.gamma;
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}
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@Override
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public void render(@NotNull Camera camera, @NotNull Scene scene, @NotNull Canvas canvas) {
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if (canvas.getWidth() != camera.getWidth() || canvas.getHeight() != camera.getHeight()) {
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throw new IllegalArgumentException("sizes of camera and canvas are different");
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}
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getPixelStream(camera.getWidth(), camera.getHeight()).parallel().forEach(pixel -> {
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var y = (int) (pixel >> 32);
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var x = (int) pixel;
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var color = Color.BLACK;
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for (int i = 1; i <= samplesPerPixel; i++) {
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var ray = camera.cast(x, y);
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var c = getColor(scene, ray);
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color = Color.average(color, c, i);
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}
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canvas.set(x, y, Color.gamma(color, gamma));
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});
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}
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/**
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* {@return the color of the given ray in the given scene}
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*/
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private @NotNull Color getColor(@NotNull Scene scene, @NotNull Ray ray) {
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return getColor0(scene, ray, maxDepth);
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}
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private @NotNull Color getColor0(@NotNull Scene scene, @NotNull Ray ray, int depth) {
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if (depth <= 0) return Color.BLACK;
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var optional = scene.hit(ray, new Range(0.001, Double.POSITIVE_INFINITY));
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if (optional.isPresent()) {
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var hit = optional.get();
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var material = hit.material();
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return material.scatter(ray, hit)
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.map(scatter -> Color.multiply(scatter.attenuation(), getColor0(scene, scatter.ray(), depth - 1)))
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.orElse(Color.BLACK);
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} else {
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return getSkyboxColor(ray);
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}
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}
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/**
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* {@return a stream of the pixels in a canvas with the given size} The pixels {@code x} and {@code y} coordinate
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* are encoded in the longs lower and upper 32 bits respectively.
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*/
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private static @NotNull LongStream getPixelStream(int width, int height) {
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return IntStream.range(0, height)
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.mapToObj(y -> IntStream.range(0, width).mapToLong(x -> (long) y << 32 | x))
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.flatMapToLong(Function.identity());
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}
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/**
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* {@return the color of the skybox for a given ray} The skybox color is a linear gradient based on the altitude of
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* the ray above the horizon with {@link Color#SKY} at the top and {@link Color#WHITE} at the bottom.
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*/
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private static @NotNull Color getSkyboxColor(@NotNull Ray ray) {
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// altitude from -pi/2 to pi/2
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var alt = Math.copySign(
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Math.acos(ray.direction().withY(0).unit().times(ray.direction().unit())),
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ray.direction().y()
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);
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return Color.lerp(Color.WHITE, Color.SKY, alt / Math.PI + 0.5);
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}
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public static class Builder {
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private int samplesPerPixel = 100;
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private int maxDepth = 10;
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private double gamma = 2.0;
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public @NotNull Builder withSamplesPerPixel(int samples) {
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if (samples <= 0) throw new IllegalArgumentException("samples must be positive");
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this.samplesPerPixel = samples;
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return this;
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}
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public @NotNull Builder withMaxDepth(int depth) {
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if (depth <= 0) throw new IllegalArgumentException("depth must be positive");
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this.maxDepth = depth;
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return this;
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}
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public @NotNull Builder withGamma(double gamma) {
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if (gamma <= 0 || !Double.isFinite(gamma)) throw new IllegalArgumentException("gamma must be positive");
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this.gamma = gamma;
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return this;
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}
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public @NotNull SimpleRenderer build() {
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return new SimpleRenderer(this);
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}
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}
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}
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