#include <vrmath/vrPlane2.h>

void vrPlane2::makePts(const vrVector3f& p1, const vrVector3f& p2, const vrVector3f& p3) {

	normal.cross(p2 - p1, p3 - p1);
	normal.normalize();

	point = p1;
	
}

void vrPlane2::makeNormalPt(const vrVector3f& norm, const vrVector3f& pos) {
	normal = norm;
	point = pos;
}

bool vrPlane2::intersect(const vrLineSegment &seg, float &d) const 
{
	// STEVE
	// 2005-09-07
	
	float tu, td;

	tu = normal.x * (point.x - seg.pos.x) + normal.y * (point.y - seg.pos.y) 
			+ normal.z * (point.z - seg.pos.z);

	td = normal.x * seg.dir.x + normal.y * seg.dir.y + normal.z * seg.dir.z;

	if ( td == 0.0f ) return false;

	d = tu / td;
	
	return true;
}

float vrPlane2::distance(const vrVector3f& pos) const 
{

	vrVector3f plane_point = crossPoint( pos );

	return pos.distance( plane_point );
}

vrVector3f vrPlane2::crossPoint(const vrVector3f& pos) const {

	vrLineSegment seg;

	seg.pos = pos;
	seg.dir = normal;

	float t = 0;
	intersect(seg, t);

	return seg.getPoint(t);
}