#include "../include/objects.hpp"

/* Plane */

Plane::Plane(const v3& n, choice_t offset, const Material& specs, int surface_type)
    : Renderable(specs), n(n), offset(offset), surface_type(surface_type) {}
Plane::Plane(const v3& n, choice_t offset, const Material& specs) : Plane(n, offset, specs, 2) {}

int Plane::intersect(const v3& eye, const v3& dir, choice_t& hit_dist, v3& hit_loc, v3& hit_normal)
{
    const choice_t d = dir ^ n;
    if(d <= 0) return 0;

    const choice_t k = -((eye ^ n) + offset) / d;

    hit_loc = eye + dir * k;
    hit_normal = n;
    hit_dist = (hit_loc - eye).len();
    return surface_type;
}

/* Sphere */

Sphere::Sphere(const v3& origin, choice_t r, const Material& specs, int surface_type)
    : Renderable(specs), o(origin), r(r), surface_type(surface_type) {}
Sphere::Sphere(const v3& origin, choice_t r) : Sphere(origin, r, Material(), 1) {}

template<int K = 1>
static inline int _sphere_intersect(Sphere& self, const v3& eye, const v3& dir, choice_t& hit_dist, v3& hit_loc, v3& hit_normal)
{
    const v3 d = self.o - eye;
    const choice_t dist_above_o = dir ^ d;

    // We're facing directly away from the sphere
    if(dist_above_o < 0) { return -1; }

    // The ray is pointing directly at the center of the sphere
    // if(fabs(dist_above_o - d.len()) < 1e-5) {
    // 	hit_loc = eye + d.norm() * (d.len() - self.r);
    // 	hit_normal = self.normal(hit_loc);
    // 	hit_dist = (hit_loc - eye).len();
    // 	return self.surface_type;
    // }

    const choice_t rejection = sqrtf(d.len() * d.len() - dist_above_o * dist_above_o);
    // The ray is tangent/missing the sphere
    if(rejection >= self.r) return -1;

    choice_t inside = sqrt(self.r*self.r - rejection*rejection) * K;

    hit_dist = dist_above_o - inside;
    hit_loc = eye + dir * hit_dist;
    hit_normal = self.normal(hit_loc);
    return self.surface_type;
}

int Sphere::intersect(const v3& eye, const v3& dir, choice_t& hit_dist, v3& hit_loc, v3& hit_normal)
{ return _sphere_intersect(*this, eye, dir, hit_dist, hit_loc, hit_normal); }

int Sphere::transmit(const v3& eye, const v3& dir, choice_t& hit_dist, v3& hit_loc, v3& hit_normal)
{ return _sphere_intersect<-1>(*this, eye, dir, hit_dist, hit_loc, hit_normal); }


/* Light */

Light::Light(const v3& origin, choice_t r, const v3& colour) : Light(origin, r,
								   Material{ .specular = 0,
									     .roughness = 1,
									     .colour = colour }) {}
Light::Light(const v3& origin, choice_t r, const Material& specs) : Sphere(origin, r, specs, 0) {}