Files
dorayme/source/shapes/sphere.cpp
2020-02-28 09:29:09 +00:00

53 lines
1.2 KiB
C++

/*
* DoRayMe - a quick and dirty Raytracer
* Sphere implementation
*
* Created by Manoël Trapier
* Copyright (c) 2020 986-Studio.
*
*/
#include <math.h>
#include <sphere.h>
#include <ray.h>
#include <tuple.h>
#include <intersect.h>
Intersect Sphere::localIntersect(Ray r)
{
Intersect ret;
double a, b, c, discriminant;
Tuple sphere_to_ray = r.origin - Point(0, 0, 0);
a = r.direction.dot(r.direction);
b = 2 * r.direction.dot(sphere_to_ray);
c = sphere_to_ray.dot(sphere_to_ray) - 1;
discriminant = b * b - 4 * a * c;
if (discriminant >= 0)
{
ret.add(Intersection((-b - sqrt(discriminant)) / (2 * a), this));
ret.add(Intersection((-b + sqrt(discriminant)) / (2 * a), this));
}
return ret;
}
Tuple Sphere::localNormalAt(Tuple point)
{
return (point - Point(0, 0, 0)).normalise();
}
void Sphere::dumpMe(FILE *fp)
{
fprintf(fp, "\"Type\": \"Sphere\",\n");
Tuple t = this->transformMatrix * Point(0, 0, 0);
fprintf(fp, "\"center\": { \"x\": %f, \"y\": %f, \"z\": %f}, \n",
t.x, t.y, t.z);
t = this->transformMatrix * Point(1, 1, 1);
fprintf(fp, "\"radius\": { \"x\": %f, \"y\": %f, \"z\": %f}, \n",
t.x, t.y, t.z);
Shape::dumpMe(fp);
}