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77 lines
2.8 KiB
77 lines
2.8 KiB
#include <cmath>
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#include <fstream>
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#include <iostream>
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#include "ray.h"
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#include "vec3.h"
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using namespace std;
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//skybox
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float hit_sphere(const vec3& center, float radius, const ray& r) {
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float a, b, c, t;
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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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t = (((-b) - sqrt((b * b) - (4 * a * c))) / (2 * a));
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//cout << a << " " << b << " " << c;
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return t >= 0 ? t : 0;
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}
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vec3 color(ray& r) {
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vec3 center(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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vec3 L = unit_vector(vec3(1, 1, 0) - r.point_at_parameter(t));
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vec3 I = vec3(1, 1, 1); //intensity of lightsource
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return (dot(N, L) > 0 ? dot(N, L) : 0) * I;
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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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int anti_aliasing_scale = 5;
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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"
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<< width << " " << height << "\n255\n";
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vec3** colors = new vec3*[height * anti_aliasing_scale];
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for (int i = 0; i < height * anti_aliasing_scale; i++) {
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colors[i] = new vec3[width * anti_aliasing_scale];
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}
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for (int j = (height * anti_aliasing_scale) - 1; j >= 0; j--) {
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for (int i = 0; i < (width * anti_aliasing_scale); i++) {
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float u = float(i) / float(width * anti_aliasing_scale);
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float v = float(j) / float(height * anti_aliasing_scale);
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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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colors[j][i] = color2 * 255;
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}
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}
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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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vec3 color3 = vec3(0, 0, 0);
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for (int a = 0; a < anti_aliasing_scale; a++) {
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for (int b = 0; b < anti_aliasing_scale; b++) {
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color3 = vec3(color3.r() + colors[j * anti_aliasing_scale + a][i * anti_aliasing_scale + b].r(), color3.g() + colors[j * anti_aliasing_scale + a][i * anti_aliasing_scale + b].g(), color3.b() + colors[j * anti_aliasing_scale + a][i * anti_aliasing_scale + b].b());
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}
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}
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color3 = vec3(color3.r() / (anti_aliasing_scale * anti_aliasing_scale), color3.g() / (anti_aliasing_scale * anti_aliasing_scale), color3.b() / (anti_aliasing_scale * anti_aliasing_scale));
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file << int(color3.r()) << " " << int(color3.g()) << " " << int(color3.b()) << "\n";
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}
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}
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file.close();
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} |