Raytracer/ray.cpp at main · AnanasikDev/Raytracer · GitHub

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// This is a personal academic project. Dear PVS-Studio, please check it.

// PVS-Studio Static Code Analyzer for C, C++, C#, and Java: https://pvs-studio.com


#include "template.h"
#include "Sphere.h"

Ray::Ray( const float3 origin, const float3 direction, const float rayLength )
	: m_origin( origin ), m_direction( normalize( direction ) ), m_normal(0), m_length( rayLength )
{
}

float3 Ray::GetNormal() const
{
	if (m_axis == AXIS_ARBITRARY_AXIS) // return the voxel normal at the nearest intersection
	{
		return m_normal;
	}

	const float xsign = (*(uint*)&m_direction.x >> 31 == 0) ? -1.f : 1.f;
	const float ysign = (*(uint*)&m_direction.y >> 31 == 0) ? -1.f : 1.f;
	const float zsign = (*(uint*)&m_direction.z >> 31 == 0) ? -1.f : 1.f;
	return float3( m_axis == 0 ? xsign : 0.f, m_axis == 1 ? ysign : 0.f, m_axis == 2 ? zsign : 0.f );
}

Ray::SphereIntersection Ray::TrySphere(const Sphere& sphere) const
{
	SphereIntersection result;
	result.exists = false;

	const float3 c = sphere.m_center - m_origin;
	const float t = dot(c, m_direction);
	const float3 q = c - t * m_direction;
	const float sqrq = dot(q, q);
	const float sqrr = sphere.m_radius * sphere.m_radius;
	if (sqrq > sqrr)
	{
		return result;
	}

	const float thc = sqrt(sqrr - sqrq);
	const float t0 = t - thc;
	const float t1 = t + thc;
	float tHit = t0;
	if (tHit <= 0.0f)
	{
		tHit = t1;
		if (tHit <= 0.0f)
			return result;
	}

	result.exists = true;
	result.distance = tHit;
	result.material = sphere.m_material;
	result.closest = m_origin + m_direction * tHit;
	result.normal = (result.closest - sphere.m_center) / sphere.m_radius;
	if (t0 <= 0.0f)
	{
		result.normal *= -1.0f;
	}

	return result;
}