135 lines
4.7 KiB
C++
135 lines
4.7 KiB
C++
#include <iostream>
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#include <iomanip>
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#include <memory>
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#define LODEPNG_NO_COMPILE_DECODER
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#include "lodepng.h"
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#include "color.h"
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#include "vec3.h"
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#include "ray.h"
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#include "util.h"
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#include "hittable_list.h"
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#include "sphere.h"
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#include "camera.h"
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Color ray_color(const Ray& r, const Hittable& world, int depth) {
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hit_record rec;
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if (depth <= 0)
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return Color(0, 0, 0);
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if (world.hit(r, 0.001, infinity, rec)) {
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Ray scattered;
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Color attenuation;
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if (rec.mat_ptr->scatter(r, rec, attenuation, scattered))
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return attenuation * ray_color(scattered, world, depth - 1);
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return Color(0, 0, 0);
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}
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Vec3 unit_direction = unit_vector(r.direction());
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auto t = 0.5 * (unit_direction.y() + 1.0);
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return (1.0 - t) * Color(1.0, 1.0, 1.0) + t * Color(0.5, 0.7, 1.0);
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}
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Hittable_list setup_random_scene() {
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Hittable_list world;
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const int sph_i = 3;
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auto ground_material = std::make_shared<Lambertian>(Color(0.5, 0.5, 0.5));
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world.add(std::make_shared<Sphere>(Point3(0, -1000, 0), 1000, ground_material));
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for (int a = -sph_i; a<sph_i; a++) {
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for (int b = -sph_i; b<sph_i; b++) {
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auto choose_mat = random_double();
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Point3 center(a + 0.9 * (11/sph_i) * random_double(), 0.2, b + 0.9 * (11/sph_i) * random_double());
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if ((center - Point3(4, 0.2, 0)).length() > 0.9) {
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std::shared_ptr<Material> sphere_material;
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if (choose_mat < 0.8) {
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// diffuse
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auto albedo = Color::random() * Color::random();
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sphere_material = std::make_shared<Lambertian>(albedo);
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world.add(std::make_shared<Sphere>(center, 0.2, sphere_material));
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} else if (choose_mat < 0.95) {
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// metal
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auto albedo = Color::random(0.5, 1);
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auto fuzz = random_double(0, 0.5);
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sphere_material = std::make_shared<Metal>(albedo, fuzz);
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world.add(std::make_shared<Sphere>(center, 0.2, sphere_material));
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} else {
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// glass
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sphere_material = std::make_shared<Dielectric>(1.45);
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world.add(std::make_shared<Sphere>(center, 0.2, sphere_material));
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}
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}
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}
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}
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auto material1 = std::make_shared<Dielectric>(1.45);
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world.add(std::make_shared<Sphere>(Point3(0, 1, 0), 1.0, material1));
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auto material2 = std::make_shared<Lambertian>(Color(0.4, 0.2, 0.1));
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world.add(std::make_shared<Sphere>(Point3(-4, 1, 0), 1.0, material2));
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auto material3 = std::make_shared<Metal>(Color(0.7, 0.6, 0.5), 0.0);
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world.add(std::make_shared<Sphere>(Point3(4, 1, 0), 1.0, material3));
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return world;
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}
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int main() {
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const auto aspect_ratio = 16.0 / 9.0;
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//const int image_width = 1280;
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const int image_width = 768;
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//const int image_width = 384;
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const int image_height = static_cast<int>(image_width / aspect_ratio);
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//const int samples_per_pixel = 1000;
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const int samples_per_pixel = 400;
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const int max_depth = 50;
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auto world = setup_random_scene();
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Point3 lookfrom(13, 2, 3);
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Point3 lookat(0, 0, 0);
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Vec3 vup(0, 1, 0);
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auto dist_to_focus = (lookfrom - lookat).length();
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auto aperture = 0.1;
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Camera cam(lookfrom, lookat, vup, 20, aspect_ratio, aperture, dist_to_focus);
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std::vector<Color> image(image_width * image_height);
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for (int i = image_height-1; i>=0; --i) {
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std::cerr << "\rScanline remaining: " << std::setw(4) << i << std::flush;
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#pragma omp parallel for
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for (int j = 0; j<image_width; ++j) {
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Color pixel_color(0, 0, 0);
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for (int s = 0; s<samples_per_pixel; ++s) {
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auto u = double(j + random_double(-0.5, 0.5)) / (image_width - 1);
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auto v = double(i + random_double(-0.5, 0.5)) / (image_height - 1);
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Ray r = cam.get_ray(u, v);
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pixel_color += ray_color(r, world, max_depth);
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}
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image.at(i*image_width+j) = pixel_color;
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}
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}
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std::cerr << "\nAssembling image.\n";
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std::vector<unsigned char> img_lode(image_width * image_height * 3);
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for (int i = 0; i<image_height; ++i) {
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for (int j = 0; j<image_width; ++j) {
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write_color_vec(img_lode, i*image_width*3+j*3, image.at((image_height-1-i)*image_width+j), samples_per_pixel);
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}
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}
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std::cerr << "Writing file \"image.png\".\n";
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unsigned error = lodepng::encode("image.png", img_lode, image_width, image_height, LCT_RGB);
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if (error)
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std::cerr << "lodepng encoder error " << error << ": "<< lodepng_error_text(error) << std::endl;
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std::cerr << "Done.\n";
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}
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