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55 lines
1.5 KiB
55 lines
1.5 KiB
2 years ago
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#include <iostream>
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#include <fstream>
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#include <cmath>
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#include "vec3.h"
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#include "ray.h"
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using namespace std;
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//skybox
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float hit_sphere(const vec3 ¢er, float radius, const ray& r) {
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float a, b, c;
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a = dot(r.D, r.D);
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b = 2 * (dot(r.D, (r.O - center)));
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c = dot(r.O - center, r.O - center) - radius * radius;
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return (((-b) + sqrt((b * b) - (4 * a * c))) / (2 * a));
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}
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vec3 color(ray& r){
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vec3 center = vec3(0, 0, -1);
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float t = hit_sphere(center, 0.5, r);
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if (t > 0.0) {
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vec3 N = unit_vector(r.point_at_parameter(t) - center);
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return 0.5 * vec3(N.x()+1, N.y()+1, N.z()+1);
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}
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vec3 unit_direction = unit_vector(r.direction());
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t = 0.5 * (unit_direction.y() + 1.0);
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return (1.0-t)* vec3(1, 1, 1) + t* vec3(0.5, 0.7, 1.0);
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}
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int main(){
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int width = 200;
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int height = 100;
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fstream file;
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file.open("ray.ppm", ios::out);
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vec3 lower_left_corner(-2, -1, -1);
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vec3 origin(0, 0, 0);
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vec3 horizontal(4, 0, 0);
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vec3 vertical(0, 2, 0);
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file << "P3\n" << width << " " << height << "\n255\n";
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for (int j = height - 1; j >= 0; j--) {
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for (int i = 0; i < width; i++) {
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float u = float(i) / float(width);
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float v = float(j) / float(height);
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ray r = ray(origin, lower_left_corner + u*horizontal + v*vertical);
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vec3 color2 = color(r);
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file << int(color2.r() * 255) << " " << int(color2.g() * 255) << " " << int(color2.b() * 255) << "\n";
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}
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}
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file.close();
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}
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