main.cpp

#include "color.h"
#include "rtweekend.h"
#include "sphere.h"
#include "hittable_list.h"
#include "camera.h"
#include "material.h"

#include <iostream>

color ray_color(const ray& r, const hittable& world, int depth) {
    hit_record rec;

    if (depth <= 0)
    {
        return color(0, 0, 0);
    }

    if (world.hit(r, 0.001, infinity, rec)) {
        ray scattered;
        color attenuation;
        if (rec.mat_ptr->scatter(r, rec, attenuation, scattered))
            return attenuation * ray_color(scattered, world, depth - 1);
        return color(0, 0, 0);
    }

    vec3 unit_direction = unit_vector(r.direction());
    auto t = 0.5 * (unit_direction.y() + 1.0);
    return (1.0 - t) * color(1.0, 0.0, 0.4) + t * color(0.8, 0.2, 1.0);
}

int main() {

    const auto aspect_ratio = 16.0 / 9.0;
    const int image_width = 1920;
    const int image_height = static_cast<int>(image_width / aspect_ratio);
    const int samples_per_pixel = 300;
    const int max_depth = 50;

    hittable_list world;

    shared_ptr<material> material_ground = make_shared<lambertian>(color(0.2, 0.8, 0.5));
    shared_ptr<material> material_center = make_shared<lambertian>(color(0.2, 0.3, 1.0));
    shared_ptr<material> material_left = make_shared<metal>(color(0.8, 0.8, 0.8));
    shared_ptr<material> material_right = make_shared<metal>(color(0.8, 0.6, 0.2));

    world.add(make_shared<sphere>(point3(0.0, -100.5, -1.0), 100.0, material_ground));
    world.add(make_shared<sphere>(point3(0.0, 0.0, -1.0), 0.5, material_center));
    world.add(make_shared<sphere>(point3(-1.0, 0.0, -1.0), 0.5, material_left));
    world.add(make_shared<sphere>(point3(1.0, 0.0, -1.0), 0.5, material_right));

    camera cam;

    std::cout << "P3\n" << image_width << ' ' << image_height << "\n255\n";

    for (int j = image_height - 1; j >= 0; --j) {
        std::cerr << "\rScanlines remaining: " << j << ' ' << std::flush;
        for (int i = 0; i < image_width; ++i) {
            color pixel_color(0, 0, 0);
            for (int s = 0; s < samples_per_pixel; ++s) {
                auto u = (i + random_double()) / (image_width - 1);
                auto v = (j + random_double()) / (image_height - 1);
                ray r = cam.get_ray(u, v);
                pixel_color += ray_color(r, world, max_depth);
            }
            write_color(std::cout, pixel_color, samples_per_pixel);
        }
        std::cerr << "\rScanlines remaining: " << j << ' ' << std::flush;
    }
}