// octreeFace.cpp: implementation of the octreeFace class.
//
//////////////////////////////////////////////////////////////////////

#include "octreeFace.h"

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

octreeFace::octreeFace()
{

}

octreeFace::~octreeFace()
{

}

float octreeFace::evaluateFace(float x, float y){
	float ret = m_c[0]*x*x*y*y + m_c[1]*x*x*y+ m_c[2]*x*y*y + m_c[3]*x*y+ m_c[4]*x*x+ m_c[5]*y*y+
		m_c[6]*x+ m_c[7]*y + m_c[8];
	return ret;
}

void octreeFace::computeABCFromSamples(float d0, float d1, float d2, float d3, float d4, float d5, float d6, float d7, float d8)//compute a,b and c from sample points on the edge
{
	m_c[0]=  4*d0  - 8*d3  + 4*d6 - 8*d1  + 4*d2 - 8*d5 + 16*d4 - 8*d7 + 4*d8;
	m_c[1]=	 -6*d0 + 8*d3  - 2*d6 + 12*d1 - 6*d2 + 8*d5 - 16*d4 + 4*d7 - 2*d8;
	m_c[2]=	 -6*d0 + 12*d3 - 6*d6 + 8*d1  - 2*d2 + 4*d5 - 16*d4 + 8*d7 - 2*d8;
	m_c[3]=  9*d0  - 12*d3 + 3*d6 - 12*d1 + 3*d2 - 4*d5 + 16*d4 - 4*d7 + d8;
	m_c[4]=	 2*d0 - 4*d1 + 2*d2; 
	m_c[5]=  2*d0 - 4*d3 + 2*d6;
	m_c[6]=  -3*d0 + 4*d1 - d2;
	m_c[7]=  -3*d0 + 4*d3 - d6; 
	m_c[8]=  d0;  	
}

void octreeFace::decompose(int quadrant, octreeFace& bigFace, octreeFace& smallFace){
	float a[9];
	a[0] = bigFace.getC(0); a[1] = bigFace.getC(1); a[2] = bigFace.getC(2); 
	a[3] = bigFace.getC(3); a[4] = bigFace.getC(4); a[5] = bigFace.getC(5); 
	a[6] = bigFace.getC(6); a[7] = bigFace.getC(7); a[8] = bigFace.getC(8);
		
	switch(quadrant){
	case 0: //LD quadrant
		
		smallFace.setC(0,a[0]/16.0);
		smallFace.setC(1,a[1]/8.0);
		smallFace.setC(2,a[2]/8.0);
		smallFace.setC(3,a[3]/4.0);
		smallFace.setC(4,a[4]/4.0);
		smallFace.setC(5,a[5]/4.0);
		smallFace.setC(6,a[6]/2.0);
		smallFace.setC(7,a[7]/2.0);
		smallFace.setC(8,a[8]);
		break;
	case 1: //RD quadrant
		
		smallFace.setC(0, a[0]/16.0);
		smallFace.setC(1, a[1]/8.0);
		smallFace.setC(2, a[0]/8.0 + a[2]/8.0);
		smallFace.setC(3, a[1]/4.0 + a[3]/4.0);
		smallFace.setC(4, a[4]/4.0 );
		smallFace.setC(5, a[5]/4.0 + a[2]/8.0 + a[0]/16.0);
		smallFace.setC(6, a[4]/2.0 + a[6]/2.0);
		smallFace.setC(7, a[7]/2.0 + a[3]/4.0 + a[1]/8.0);
		smallFace.setC(8, a[4]/4.0 + a[6]/2.0 + a[8]);
		break;
	case 2: //LU quadrant
		
		smallFace.setC(0, a[0]/16.0);
		smallFace.setC(1, a[0]/8.0 + a[1]/8.0);
		smallFace.setC(2, a[2]/8.0);
		smallFace.setC(3, a[2]/4.0 + a[3]/4.0);
		smallFace.setC(4, a[4]/4.0 + a[1]/8.0 + a[0]/16.0);
		smallFace.setC(5, a[5]/4.0);
		smallFace.setC(6, a[6]/2.0 + a[3]/4.0 + a[2]/8.0);
		smallFace.setC(7, a[5]/2.0 + a[7]/2.0);
		smallFace.setC(8, a[5]/4.0 + a[7]/2.0 + a[8]);

		break;
	case 3: //RU quadrant
		
		smallFace.setC(0, a[0]/16.0);
		smallFace.setC(1, a[0]/8.0 + a[1]/8.0);
		smallFace.setC(2, a[0]/8.0 + a[2]/8.0);
		smallFace.setC(3, a[0]/4.0 + a[1]/4.0 + a[2]/4.0 + a[3]/4.0 );
		smallFace.setC(4, (a[0] + 2*a[1] +4*a[4])/16.0);
		smallFace.setC(5, (a[0] + 2*a[2] +4*a[5])/16.0);
		smallFace.setC(6,(a[0] +2*a[1] + a[2]+ 2*a[3] + 4*a[4] +4*a[6])/8.0);
		smallFace.setC(7,(a[0] +a[1] +2*a[2]+ 2*a[3] +  4*a[5] +4*a[7])/8.0);
		smallFace.setC(8,(a[0]+2*a[1] +2*a[2]+4*a[3]+4*a[4]+4*a[5]+8*a[6]+8*a[7]+16*a[8])/16.0);
		break;
	default: 
		break;

	}
}