Files
dorayme/source/shapes/triangle.cpp
2020-02-26 02:17:57 +00:00

71 lines
1.4 KiB
C++

/*
* DoRayMe - a quick and dirty Raytracer
* Cone implementation
*
* Created by Manoël Trapier
* Copyright (c) 2020 986-Studio.
*
*/
#include <ray.h>
#include <shape.h>
#include <triangle.h>
#include <math_helper.h>
Triangle::Triangle(Point p1, Point p2, Point p3) : Shape(SHAPE_TRIANGLE), p1(p1), p2(p2), p3(p3)
{
this->e1 = p2 - p1;
this->e2 = p3 - p1;
this->normal = e2.cross(e1).normalise();
}
Intersect Triangle::localIntersect(Ray r)
{
Intersect ret;
Tuple dirCrossE2 = r.direction.cross(this->e2);
double determinant = this->e1.dot(dirCrossE2);
if (fabs(determinant) < getEpsilon())
{
return ret;
}
double f = 1.0 / determinant;
Tuple p1ToOrigin = r.origin - this->p1;
Tuple originCrossE1 = p1ToOrigin.cross(this->e1);
double u = f * p1ToOrigin.dot(dirCrossE2);
double v = f * r.direction.dot(originCrossE1);
if ((u < 0) || (u > 1))
{
return ret;
}
if ((v < 0) || ((u + v) > 1))
{
return ret;
}
double t = f * this->e2.dot(originCrossE1);
ret.add(Intersection(t, this));
return ret;
}
Tuple Triangle::localNormalAt(Tuple point)
{
return this->normal;
}
BoundingBox Triangle::getBounds()
{
BoundingBox ret;
ret | p1;
ret | p2;
ret | p3;
ret.min = this->objectToWorld(ret.min);
ret.max = this->objectToWorld(ret.max);
return ret;
}