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2 years ago
#include <fstream>
#include <iostream>
#include "ray.h"
#include "vec3.h"
using namespace std;
//skybox
bool hit_sphere(const vec3& center, float radius, const ray& r) {
float a, b, c;
a = dot(r.D, r.D);
b = 2 * (dot(r.D, (r.O - center)));
c = dot(r.O - center, r.O - center) - radius * radius;
return ((b * b) - (4 * a * c) >= 0);
}
vec3 color(ray& r) {
/*
if (hit_sphere(vec3(0, 0, -1), 0.5, r)) {
return vec3(1, 0, 0);
}
*/
vec3 unit_direction = unit_vector(r.direction());
float t = 0.5 * (unit_direction.y() + 1.0);
return vec3(1, 1, 1) * float(1.0 - t) + float(t) * vec3(0.5, 0.7, 1.0);
}
int main() {
int width = 200;
int height = 100;
fstream file;
file.open("ray.ppm", ios::out);
vec3 lower_left_corner(-2, -1, -1);
vec3 origin(0, 0, 0);
vec3 horizontal(4, 0, 0);
vec3 vertical(0, 2, 0);
file << "P3\n"
<< width << " " << height << "\n255\n";
for (int j = height - 1; j >= 0; j--) {
for (int i = 0; i < width; i++) {
float u = float(i) / float(width);
float v = float(j) / float(height);
ray r = ray(origin, lower_left_corner + u * horizontal + v * vertical);
vec3 color2 = color(r);
file << int(color2.r() * 255) << " " << int(color2.g() * 255) << " " << int(color2.b() * 255) << "\n";
}
}
file.close();
}