main.cpp

#include <iostream>
#include "sphere.hpp"
#include "hitable_list.hpp"
#include <cfloat> 
#include "vec.hpp"
#include "ray.hpp"
#include "materials.hpp"
#include "sphere.hpp"
#include "camera.hpp"
#include "hitable.hpp"
#include <fstream>
#ifndef MAXFLOAT
#define MAXFLOAT FLT_MAX
#endif



hitable *random_scene() {
    int n = 500;
    hitable **list = new hitable*[n+1];
    list[0] = new sphere(vec3(0,-1000,0), 1000, new lambertian(vec3(0.5, 0.5, 0.5)));
    int i = 1;
    for (int a = -11; a < 11; a++) {
        for (int b = -11; b < 11; b++) {
            float choose_mat = drand48();
            vec3 center(a+0.9*drand48(),0.2,b+0.9*drand48());
            if ((center-vec3(4,0.2,0)).length() > 0.9) {
                if (choose_mat < 0.8) { // diffuse
                    list[i++] = new sphere(center, 0.2, new lambertian(vec3(drand48()*drand48(), drand48()*drand48(), drand48()*drand48())));
                }
                else if (choose_mat < 0.95) { // metal
                    list[i++] = new sphere(center, 0.2, 
                        new metal(vec3(0.5*(1 + drand48()), 0.5*(1 + drand48()), 0.5*(1 + drand48())), 0.5*drand48()));
                }
                else { // glass
                    list[i++] = new sphere(center, 0.2, new dielectric(1.5));
                }
            }
        }
    }

    list[i++] = new sphere(vec3(0, 1, 0), 1.0, new dielectric(1.5));
    list[i++] = new sphere(vec3(-4, 1, 0), 1.0, new lambertian(vec3(0.4, 0.2, 0.1)));
    list[i++] = new sphere(vec3(4, 1, 0), 1.0, new metal(vec3(0.7, 0.6, 0.5), 0.0));

    return new hitable_list(list,i);
}


vec3 color(const ray& r, hitable *world, int depth) {
    hit_record rec;
    
    if (world->hit(r, 0.001, MAXFLOAT, rec)) {
        ray scattered;
        vec3 attenuation;
        
        if (depth < 50 && rec.mat_ptr->scatter(r, rec, attenuation, scattered)) {
            return attenuation * color(scattered, world, depth + 1);
            std::cout  << " Current depth of the ray is" << depth;
        } else {
            return vec3(0,0,0); 
        }
    } else {
        // Background (Sky)
        vec3 unit_direction = unit_vector(r.direction());
        float t = 0.5*(unit_direction.y() + 1.0);
        return (1.0-t)*vec3(1.0, 1.0, 1.0) + t*vec3(0.5, 0.7, 1.0);
    }
}


int main() {
    int nx = 600;
    int ny = 600;
    int ns = 10;
    
    std::ofstream outfile("image.ppm");

    outfile << "P3\n" << nx << " " << ny << "\n255\n";
    
    hitable *world = random_scene();

    vec3 lookfrom(13,2,3);
    vec3 lookat(0,0,0);
    float dist_to_focus = 10.0;
    float aperture = 0.1;

    camera cam(lookfrom, lookat, vec3(0,1,0), 20, float(nx)/float(ny), aperture, dist_to_focus);

    for (int j = ny-1; j >= 0; j--) {
        
        std::cout << "Scanlines remaining: " << j << "    \n";
        
        for (int i = 0; i < nx; i++) {
            vec3 col(0, 0, 0);
            for (int s=0; s < ns; s++) {
                float u = float(i + drand48()) / float(nx);
                float v = float(j + drand48()) / float(ny);
                ray r = cam.get_ray(u, v);
                col += color(r, world, 0); 
            }
            col /= float(ns);
            
            col = vec3( sqrt(col[0]), sqrt(col[1]), sqrt(col[2]) );
            
            int ir = int(255.99*col[0]);
            int ig = int(255.99*col[1]);
            int ib = int(255.99*col[2]);

            outfile << ir << " " << ig << " " << ib << "\n";
        }
    }
    
    outfile.close();
    std::cout << "\nDone! Image saved to 'image.ppm'.\n";
}