toytracer/wtracer.cpp

#include <iostream>

#include "color.h"
#include "vec3.h"
#include "ray.h"
#include "util.h"

#include "hittable_list.h"
#include "sphere.h"
#include "camera.h"

Color ray_color(const Ray& r, const Hittable& world) {
    hit_record rec;
    if (world.hit(r, 0, infinity, rec)) {
        return 0.5 * (rec.normal + Color(1,1,1));
    }
    Vec3 unit_direction = unit_vector(r.direction());
    auto t = 0.5 * (unit_direction.y() + 1.0);
    return (1.0 - t) * Color(1.0, 1.0, 1.0) + t * Color(0.5, 0.7, 1.0);
}

int main() {
    const auto aspect_ratio = 16.0 / 9.0;
    const int image_width = 1280;
    //const int image_width = 384;
    const int image_height = static_cast<int>(image_width / aspect_ratio);
    const int samples_per_pixel = 100;

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

    Hittable_list world;
    world.add(std::make_shared<Sphere>(Point3(0, 0, -1), 0.5));
    world.add(std::make_shared<Sphere>(Point3(0, -100.5, -1), 100));

    Camera cam;

    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 = double(i + random_double()) / (image_width - 1);
                auto v = double(j + random_double()) / (image_height - 1);
                Ray r = cam.get_ray(u, v);
                pixel_color += ray_color(r, world);
            }
            write_color(std::cout, pixel_color, samples_per_pixel);
        }
    }
    std::cerr << "\nDone.\n";
}