GeometryNode.cpp

// Termm--Fall 2020

#include "GeometryNode.hpp"

//---------------------------------------------------------------------------------------
GeometryNode::GeometryNode(
	const std::string & name, Primitive *prim, Material *mat )
	: SceneNode( name )
	, m_material( mat )
	, m_primitive( prim )
{
	m_nodeType = NodeType::GeometryNode;
}

void GeometryNode::setMaterial( Material *mat )
{
	// Obviously, there's a potential memory leak here.  A good solution
	// would be to use some kind of reference counting, as in the 
	// C++ shared_ptr.  But I'm going to punt on that problem here.
	// Why?  Two reasons:
	// (a) In practice we expect the scene to be constructed exactly
	//     once.  There's no reason to believe that materials will be
	//     repeatedly overwritten in a GeometryNode.
	// (b) A ray tracer is a program in which you compute once, and 
	//     throw away all your data.  A memory leak won't build up and
	//     crash the program.

	m_material = mat;
}

bool GeometryNode::intersect(const Ray &ray, double tMin, double tMax, HitInfo &hit)
{
	if (ray.opaqueOnly && m_material->transparency > 0.0)
	{
		return false;
	}

	Ray tRay = transformRay(ray);

	bool hitFound = m_primitive->intersect(tRay, tMin, tMax, hit);

	if (hitFound)
	{
		hit = transformHitInfo(hit);
		hit.hitObject = this;
	}
	return hitFound;
}