#/*############################################################################
# Marching Cubes Example Program
# by Cory Bloyd (corysama@yahoo.com)
#
# A simple, portable and complete implementation of the Marching Cubes
# in a single source file.
# There are many ways that this code could be made faster, but the
# intent is for the code to be easy to understand.
#
# For a description of the algorithm go to
# http://astronomy.swin.edu.au/pbourke/modelling/polygonise/
#
# Originally this code is public domain. The MIT license has been added
# by V.A Sole (sole@esrf.fr) to provide a disclaimer. V.A. Sole does not
# claim authorship of this code developed by Cory Bloyd.
#
#
# Copyright (c) 2004-2015 Cory Bloyd (corysama@yahoo.com)
#
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
#
#############################################################################*/
#include "stdio.h"
#include "math.h"
#ifdef WIN32
#include <windows.h>
#endif
#ifdef __APPLE__
#include <OpenGL/gl.h>
#else
#include <GL/gl.h>
#endif
#ifndef GLfloat
#define GLfloat float
#endif

#ifndef GLint
#define GLint int
#endif

#ifndef GLboolean
#define GLboolean bool
#endif

typedef struct
{
        GLfloat fX;
        GLfloat fY;
        GLfloat fZ;
} GLvector;


//These tables are used so that everything can be done in little loops that you can look at all at once
// rather than in pages and pages of unrolled code.

//a2fVertexOffset lists the positions, relative to vertex0, of each of the 8 vertices of a cube
/*static const GLfloat a2fVertexOffset[8][3] =
{
        {0.0, 0.0, 0.0},{1.0, 0.0, 0.0},{1.0, 1.0, 0.0},{0.0, 1.0, 0.0},
        {0.0, 0.0, 1.0},{1.0, 0.0, 1.0},{1.0, 1.0, 1.0},{0.0, 1.0, 1.0}
};
*/

static const int a2fVertexOffset[8][3] =
{
        {0, 0, 0},{1, 0, 0},{1, 1, 0},{0, 1, 0},
        {0, 0, 1},{1, 0, 1},{1, 1, 1},{0, 1, 1}
};

//a2iEdgeConnection lists the index of the endpoint vertices for each of the 12 edges of the cube
static const GLint a2iEdgeConnection[12][2] =
{
        {0,1}, {1,2}, {2,3}, {3,0},
        {4,5}, {5,6}, {6,7}, {7,4},
        {0,4}, {1,5}, {2,6}, {3,7}
};

//a2fEdgeDirection lists the direction vector (vertex1-vertex0) for each edge in the cube
static const GLfloat a2fEdgeDirection[12][3] =
{
        {1.0, 0.0, 0.0},{0.0, 1.0, 0.0},{-1.0, 0.0, 0.0},{0.0, -1.0, 0.0},
        {1.0, 0.0, 0.0},{0.0, 1.0, 0.0},{-1.0, 0.0, 0.0},{0.0, -1.0, 0.0},
        {0.0, 0.0, 1.0},{0.0, 0.0, 1.0},{ 0.0, 0.0, 1.0},{0.0,  0.0, 1.0}
};


int     iXDataSetSize = 0;
int     iYDataSetSize = 0;
int     iZDataSetSize = 0;
GLfloat fIsoColor[4];
int     iXStep = 1;
int     iYStep = 1;
int     iZStep = 1;
int		iNTotalTriangles;
int		iUseGridPointers = 0;
float   fTargetValue = 0.0;

GLfloat fSample(int iX, int iY, int iZ);

void vMarchingCubes(void);
void vMarchCube(int iX, int iY, int iZ);
GLvector *fSourceDataVerticesPointer = NULL;
float *fSourceXPointer = NULL;
float *fSourceYPointer = NULL;
float *fSourceZPointer = NULL;
float *fSourceDataValuesPointer = NULL;

void vSetGridPointers(float *xPointer, float *yPointer, float *zPointer);
void vSetVerticesPointer(float *);
void vSetValuesPointer(float *);
void vSetDataSizes(int xSize, int ySize, int zSize);
void vSetIsoValue(float);
void vSetColor(float, float, float, float);
void vSetStepIncrements(int, int, int);


void vSetVerticesPointer(float *verticesPointer)
{
	fSourceDataVerticesPointer = (GLvector *) verticesPointer;
	iUseGridPointers = 0;
	fSourceXPointer = NULL;
	fSourceYPointer = NULL;
	fSourceZPointer = NULL;
}

void vSetGridPointers(float *xPointer, float *yPointer, float *zPointer)
{
	fSourceDataVerticesPointer = NULL;
	iUseGridPointers = 1;
	fSourceXPointer = xPointer;
	fSourceYPointer = yPointer;
	fSourceZPointer = zPointer;
}

void vSetValuesPointer(float *valuesPointer)
{
	fSourceDataValuesPointer = valuesPointer;
}

void vSetDataSizes(int xSize, int ySize, int zSize)
{
	iXDataSetSize = xSize;
	iYDataSetSize = ySize;
	iZDataSetSize = zSize;
}

void vSetIsoValue(float value)
{
	fTargetValue = value;
}

void vSetColor(float r, float g, float b, float a)
{
	fIsoColor[0] = r;
	fIsoColor[1] = g;
	fIsoColor[2] = b;
	fIsoColor[3] = a;
}
void vSetStepIncrements(int iX, int iY, int iZ)
{
	iXStep = iX;
	iYStep = iY;
	iZStep = iZ;
}


//fGetOffset finds the approximate point of intersection of the surface
// between two points with the values fValue1 and fValue2
GLfloat fGetOffset(GLfloat fValue1, GLfloat fValue2, GLfloat fValueDesired)
{
        GLfloat fDelta = fValue2 - fValue1;

        if(fDelta == 0.0)
        {
                return 0.5;
        }
        return (fValueDesired - fValue1)/fDelta;
}


//vGetColor generates a color from a given position and normal of a point
GLvoid vGetColor(GLvector *rfColor, GLvector rfPosition, GLvector rfNormal)
{
        GLfloat fX = rfNormal.fX;
        GLfloat fY = rfNormal.fY;
        GLfloat fZ = rfNormal.fZ;

        rfColor->fX = (GLfloat) ((fX > 0.0 ? fX : 0.0) + (fY < 0.0 ? -0.5*fY : 0.0) + (fZ < 0.0 ? -0.5*fZ : 0.0));
        rfColor->fY = (GLfloat) ((fY > 0.0 ? fY : 0.0) + (fZ < 0.0 ? -0.5*fZ : 0.0) + (fX < 0.0 ? -0.5*fX : 0.0));
        rfColor->fZ = (GLfloat) ((fZ > 0.0 ? fZ : 0.0) + (fX < 0.0 ? -0.5*fX : 0.0) + (fY < 0.0 ? -0.5*fY : 0.0));

}

GLvoid vNormalizeVector(GLvector *rfVectorResult, GLvector rfVectorSource)
{
        GLfloat fOldLength;
        GLfloat fScale;

        fOldLength = sqrt(  (rfVectorSource.fX * rfVectorSource.fX) +
                            (rfVectorSource.fY * rfVectorSource.fY) +
                            (rfVectorSource.fZ * rfVectorSource.fZ) );

        if(fOldLength == 0.0)
        {
                rfVectorResult->fX = rfVectorSource.fX;
                rfVectorResult->fY = rfVectorSource.fY;
                rfVectorResult->fZ = rfVectorSource.fZ;
        }
        else
        {
                fScale = (GLfloat) 1.0/fOldLength;
                rfVectorResult->fX = rfVectorSource.fX*fScale;
                rfVectorResult->fY = rfVectorSource.fY*fScale;
                rfVectorResult->fZ = rfVectorSource.fZ*fScale;
        }
}


//fSample returns the value of the vertex without interpolation
GLfloat fSample(int iX, int iY, int iZ)
{
        GLfloat fResult = 0.0;
		int iValueIndex;

		// No interpolation needed (integer indices)
		if (iX >= iXDataSetSize)
		{
			iX = iXDataSetSize-1;
		}
		if (iY >= iYDataSetSize)
		{
			iY = iYDataSetSize-1;
		}
		if (iZ >= iZDataSetSize)
		{
			iZ = iZDataSetSize-1;
		}
		/* I could start the loop at iX, iY and iZ equal to 1 to avoid this check
		   because in any case the normals will not be correct. */
		if (iX < 0)
		{
			iX = 0;
		}
		if (iY < 0)
		{
			iY = 0;
		}
		if (iZ < 0)
		{
			iZ = 0;
		}
		iValueIndex = iX * (iYDataSetSize * iZDataSetSize) + \
					  iY * (iZDataSetSize) + iZ;

		fResult = fSourceDataValuesPointer[iValueIndex];

        return fResult;
}


//vGetNormal() finds the gradient of the scalar field at a point
//This gradient can be used as a very accurate vertx normal for lighting calculations
GLvoid vGetNormal(GLvector *rfNormal, GLfloat fX, GLfloat fY, GLfloat fZ)
{
		rfNormal->fX = fSample(fX-0.01, fY, fZ) - fSample(fX+0.01, fY, fZ);
		rfNormal->fY = fSample(fX, fY-0.01, fZ) - fSample(fX, fY+0.01, fZ);
		rfNormal->fZ = fSample(fX, fY, fZ-0.01) - fSample(fX, fY, fZ+0.01);
        vNormalizeVector(rfNormal, *rfNormal);
}


//vMarchCube performs the Marching Cubes algorithm on a single cube
void vMarchCube(int iX, int iY, int iZ)
{
        extern GLint aiCubeEdgeFlags[256];
        extern GLint a2iTriangleConnectionTable[256][16];

		int iValueIndex;
		GLfloat    fX, fY, fZ;
		GLfloat    fXScale, fYScale, fZScale;
		GLfloat	   fCentralPoint = 0.0;
		GLfloat	   fDeltaValue, fDeltaX, fDeltaY, fDeltaZ;

		GLint iCorner, iVertex, iVertexTest, iEdge, iTriangle, iFlagIndex, iEdgeFlags;
        GLfloat fOffset;
        GLvector sColor;
        GLfloat afCubeValue[8];
        GLvector asEdgeVertex[12];
		GLvector asEdgeNorm[12];

		int iX0, iY0, iZ0;
		int iX1, iY1, iZ1;
		GLfloat fValue0, fValue1;

        //Make a local copy of the values at the cube's corners

		for(iVertex = 0; iVertex < 8; iVertex++)
        {
			afCubeValue[iVertex] = fSample(iX + a2fVertexOffset[iVertex][0]*iXStep,
                                           iY + a2fVertexOffset[iVertex][1]*iYStep,
                                           iZ + a2fVertexOffset[iVertex][2]*iZStep);

			fCentralPoint += afCubeValue[iVertex];
        }

		if (iUseGridPointers)
		{
			fX = fSourceXPointer[iX];
			fY = fSourceYPointer[iY];
			fZ = fSourceZPointer[iZ];
			/* this can be calculated beforehand ... */
			if ((iX+iXStep) < iXDataSetSize)
			{
				fXScale = fSourceXPointer[iX+iXStep] - fX;
			}else{
				fXScale = 0.0;
			}
			if ((iY+iYStep) < iYDataSetSize)
			{
				fYScale = fSourceYPointer[iY+iYStep] - fY;
			}else{
				fYScale = 0.0;
			}
			if ((iZ+iZStep) < iZDataSetSize)
			{
				fZScale = fSourceZPointer[iZ+iZStep] - fZ;
			}else{
				fZScale = 0.0;
			}
		}
		else
		{
			iValueIndex = iX * (iYDataSetSize * iZDataSetSize) + \
							iY * (iZDataSetSize) + iZ;
			fX = fSourceDataVerticesPointer[iValueIndex].fX;
			fY = fSourceDataVerticesPointer[iValueIndex].fY;
			fZ = fSourceDataVerticesPointer[iValueIndex].fZ;
			iValueIndex = (iX+iXStep) * (iYDataSetSize * iZDataSetSize) + \
					  (iY +iYStep) * (iZDataSetSize) + (iZ+iZStep);
			fXScale = fSourceDataVerticesPointer[iValueIndex].fX - fX;
			fYScale = fSourceDataVerticesPointer[iValueIndex].fY - fY;
			fZScale = fSourceDataVerticesPointer[iValueIndex].fZ - fZ;
		}

		/* Normal calucation */
		/* Store the value of the scalar field at the center of the cube */
		fCentralPoint *= 0.125;

		/* The central point has coordinates
		fCentralPointX = fX + 0.5 * fXScale
		fCentralPointY = fY + 0.5 * fYScale
		fCentralPointZ = fZ + 0.5 * fZScale
		*/


        //Find which vertices are inside of the surface and which are outside
        iFlagIndex = 0;
        for(iVertexTest = 0; iVertexTest < 8; iVertexTest++)
        {
                if(afCubeValue[iVertexTest] <= fTargetValue)
                        iFlagIndex |= 1<<iVertexTest;
        }

        //Find which edges are intersected by the surface
        iEdgeFlags = aiCubeEdgeFlags[iFlagIndex];

        //If the cube is entirely inside or outside of the surface, then there will be no intersections
        if((iEdgeFlags == 0) || (iEdgeFlags == 255))
        {
                return;
        }

        //Find the point of intersection of the surface with each edge
        //Then find the normal to the surface at those points

		for(iEdge = 0; iEdge < 12; iEdge++)
        {
                //if there is an intersection on this edge
                if(iEdgeFlags & (1<<iEdge))
                {
                        fOffset = fGetOffset(afCubeValue[ a2iEdgeConnection[iEdge][0] ],
                                             afCubeValue[ a2iEdgeConnection[iEdge][1] ], fTargetValue);

						//The vertex value in actual coordenates
                        asEdgeVertex[iEdge].fX = fX + fXScale * (a2fVertexOffset[ a2iEdgeConnection[iEdge][0] ][0]  +  fOffset * a2fEdgeDirection[iEdge][0]);
                        asEdgeVertex[iEdge].fY = fY + fYScale * (a2fVertexOffset[ a2iEdgeConnection[iEdge][0] ][1]  +  fOffset * a2fEdgeDirection[iEdge][1]);
                        asEdgeVertex[iEdge].fZ = fZ + fZScale * (a2fVertexOffset[ a2iEdgeConnection[iEdge][0] ][2]  +  fOffset * a2fEdgeDirection[iEdge][2]);

						if (0)
						{
							//This would be for the interpolating case:
							vGetNormal(&asEdgeNorm[iEdge], asEdgeVertex[iEdge].fX, asEdgeVertex[iEdge].fY, asEdgeVertex[iEdge].fZ);
						}
						else
						{
							/* This is for the "regular" grid */
							if (1){
								/* the correct way ... (hopefully) */
								/* calculate the indices of the two vertices */
								iX0 = a2fVertexOffset[ a2iEdgeConnection[iEdge][0] ][0];
								iY0 = a2fVertexOffset[ a2iEdgeConnection[iEdge][0] ][1];
								iZ0 = a2fVertexOffset[ a2iEdgeConnection[iEdge][0] ][2];

								iX1 = a2fVertexOffset[ a2iEdgeConnection[iEdge][1] ][0];
								iY1 = a2fVertexOffset[ a2iEdgeConnection[iEdge][1] ][1];
								iZ1 = a2fVertexOffset[ a2iEdgeConnection[iEdge][1] ][2];

								/* I have the indices */
								/* The derivative in the first vertex respect to X*/
								if (fXScale != 0){
									fValue0 = fSample(iX + (iX0 + 1) * iXStep, iY + iY0 * iYStep, iZ + iZ0 * iZStep) -\
									          fSample(iX + (iX0 - 1) * iXStep, iY + iY0 * iYStep, iZ + iZ0 * iZStep);
									fValue1 = fSample(iX + (iX1 + 1) * iXStep, iY + iY1 * iYStep, iZ + iZ1 * iZStep) -\
									          fSample(iX + (iX1 - 1) * iXStep, iY + iY1 * iYStep, iZ + iZ1 * iZStep);
									asEdgeNorm[iEdge].fX = 0.5 * (fValue1 - fValue0) / fXScale;
								}else{
									asEdgeNorm[iEdge].fX = 0.0;
								}
								/* The derivative in the first vertex respect to X */
								if (fXScale != 0){
									fValue0 = fSample(iX + (iX0 + 1) * iXStep, iY + iY0 * iYStep, iZ + iZ0 * iZStep) -\
									          fSample(iX + (iX0 - 1) * iXStep, iY + iY0 * iYStep, iZ + iZ0 * iZStep);
									fValue1 = fSample(iX + (iX1 + 1) * iXStep, iY + iY1 * iYStep, iZ + iZ1 * iZStep) -\
									          fSample(iX + (iX1 - 1) * iXStep, iY + iY1 * iYStep, iZ + iZ1 * iZStep);
									asEdgeNorm[iEdge].fX = 0.5 * (fValue0 + fOffset * fValue1) / fXScale;
								}else{
									asEdgeNorm[iEdge].fX = 0.0;
								}
								/* The derivative in the first vertex respect to Y */
								if (fYScale != 0){
									fValue0 = fSample(iX * iXStep, iY + (iY0 + 1) * iYStep, iZ + iZ0 * iZStep) -\
									          fSample(iX * iXStep, iY + (iY0 - 1) * iYStep, iZ + iZ0 * iZStep);
									fValue1 = fSample(iX + iX1 * iXStep, iY + (iY1 + 1) * iYStep, iZ + iZ1 * iZStep) -\
									          fSample(iX + iX1 * iXStep, iY + (iY1 - 1) * iYStep, iZ + iZ1 * iZStep);
									asEdgeNorm[iEdge].fY = 0.5 * (fValue0 + fOffset * fValue1) / fYScale;
								}else{
									asEdgeNorm[iEdge].fY = 0.0;
								}
								/* The derivative in the first vertex respect to Z */
								if (fYScale != 0){
									fValue0 = fSample(iX * iXStep, iY + iY0 * iYStep, iZ + (iZ0 + 1) * iZStep) -\
									          fSample(iX * iXStep, iY + iY0 * iYStep, iZ + (iZ0 - 1) * iZStep);
									fValue1 = fSample(iX + iX1 * iXStep, iY + iY1 * iYStep, iZ + (iZ1 + 1) * iZStep) -\
									          fSample(iX + iX1 * iXStep, iY + iY1 * iYStep, iZ + (iZ1 - 1) * iZStep);
									asEdgeNorm[iEdge].fZ = 0.5 * (fValue0 + fOffset * fValue1) / fZScale;
								}else{
									asEdgeNorm[iEdge].fZ = 0.0;
								}
							}else {
								/* calculate all respect to the center */
								fDeltaValue = fTargetValue - fCentralPoint;
								fDeltaX = asEdgeVertex[iEdge].fX - fX - 0.5 * fXScale;
								fDeltaY = asEdgeVertex[iEdge].fY - fY - 0.5 * fYScale;
								fDeltaZ = asEdgeVertex[iEdge].fZ - fZ - 0.5 * fZScale;
								if (fDeltaX > 0)
								{
									asEdgeNorm[iEdge].fX = fDeltaValue/fDeltaX;
								}else{
									asEdgeNorm[iEdge].fX = 0.0;
								}
								if (fDeltaY > 0)
								{
									asEdgeNorm[iEdge].fY = fDeltaValue/fDeltaY;
								}else{
									asEdgeNorm[iEdge].fY = 0.0;
								}
								if (fDeltaZ > 0)
								{
									asEdgeNorm[iEdge].fZ = fDeltaValue/fDeltaZ;
								}else{
									asEdgeNorm[iEdge].fZ = 0.0;
								}
							}
							vNormalizeVector(&asEdgeNorm[iEdge], asEdgeNorm[iEdge]);
						}
                }
        }

        //Draw the triangles that were found.  There can be up to five per cube
        for(iTriangle = 0; iTriangle < 5; iTriangle++)
        {
                if(a2iTriangleConnectionTable[iFlagIndex][3*iTriangle] < 0)
                        break;

                for(iCorner = 0; iCorner < 3; iCorner++)
                {
                        iVertex = a2iTriangleConnectionTable[iFlagIndex][3*iTriangle+iCorner];

						if ((fIsoColor[0] < 0) || (fIsoColor[2] < 0) || (fIsoColor[3] < 0))
						{
							vGetColor(&sColor, asEdgeVertex[iVertex], asEdgeNorm[iVertex]);
							glColor3f(sColor.fX, sColor.fY, sColor.fZ);
						}
						else
						{
							//glColor4f(fIsoColor[0], fIsoColor[1], fIsoColor[2], fIsoColor[3]);
						}
                        glNormal3f(asEdgeNorm[iVertex].fX,   asEdgeNorm[iVertex].fY,   asEdgeNorm[iVertex].fZ);
                        glVertex3f(asEdgeVertex[iVertex].fX, asEdgeVertex[iVertex].fY, asEdgeVertex[iVertex].fZ);
						/*
						if ((asEdgeVertex[iVertex].fZ > 1.93) || (asEdgeVertex[iVertex].fZ < 1.8))
						{
							printf("iVertex = %d Z = %f\n", iVertex, asEdgeVertex[iVertex].fZ);
							printf("iX = %d iY = %d iZ = %d\n", iX, iY, iZ);
							printf("fx = %f, fy = %f, fz = %f\n", fX, fY, fZ);
							printf("scalex = %f, scaley = %f, scalez = %f\n", fXScale , fYScale , fZScale );
							exit(1);
						}
						*/
                }
				iNTotalTriangles++;
				/* This was for some tests */
				if (0)
				{
					if (iNTotalTriangles < 2)
					{
						printf("Triangle %d\n", iNTotalTriangles);
						printf("Target value =%f\n", fTargetValue);
						printf("Indices = %d, %d, %d\n", iX, iY, iZ);
						iValueIndex = iX * (iYDataSetSize * iZDataSetSize) + \
									  iY * (iZDataSetSize) + iZ;
						printf("Value index = %d,  value =%f, vertex = %f, %f, %f\n", iValueIndex, *fSourceDataValuesPointer, fX, fY, fZ);
						printf("iFlagIndex=%d\n", iFlagIndex);
						printf("Edge flags =%d\n", iEdgeFlags);
						printf("Cube limits\n");
						for(iVertex = 0; iVertex < 8; iVertex++)
						{
							printf("vertex = %d, value = %f\n", iVertex, afCubeValue[iVertex]);
						}
					}
				}
        }
}


//vMarchingCubes iterates over the entire dataset, calling vMarchCube on each cube
void vMarchingCubes()
{
        int iX, iY, iZ;

		iNTotalTriangles = 0;

		/* printf("Entered here\n"); */
		if (iUseGridPointers)
		{
			/* printf("Using grid pointers\n"); */
			if ((fSourceXPointer == NULL) || (fSourceYPointer == NULL) || (fSourceZPointer == NULL))
			{
				printf("Grid pointers not initialized\n");
				return;
			}
		}
		else
		{
			/* printf("Not using grid pointers\n"); */
			if (fSourceDataVerticesPointer == NULL)
			{
				printf("Data vertices not initialized\n");
				return;
			}
		}

		/* printf("Going to start loop\n"); */

		for(iX = 0; iX < iXDataSetSize; iX+=iXStep)
        for(iY = 0; iY < iYDataSetSize; iY+=iYStep)
        for(iZ = 0; iZ < iZDataSetSize; iZ+=iZStep)
        {
			/* Here I have to check if the point or any of its neighbours
			   is above the isosurface value */
			vMarchCube(iX, iY, iZ);
        }

		printf("Total triangles = %d", iNTotalTriangles);
}


// For any edge, if one vertex is inside of the surface and the other is outside of the surface
//  then the edge intersects the surface
// For each of the 4 vertices of the tetrahedron can be two possible states : either inside or outside of the surface
// For any tetrahedron the are 2^4=16 possible sets of vertex states
// This table lists the edges intersected by the surface for all 16 possible vertex states
// There are 6 edges.  For each entry in the table, if edge #n is intersected, then bit #n is set to 1

GLint aiTetrahedronEdgeFlags[16]=
{
        0x00, 0x0d, 0x13, 0x1e, 0x26, 0x2b, 0x35, 0x38, 0x38, 0x35, 0x2b, 0x26, 0x1e, 0x13, 0x0d, 0x00,
};


// For any edge, if one vertex is inside of the surface and the other is outside of the surface
//  then the edge intersects the surface
// For each of the 8 vertices of the cube can be two possible states : either inside or outside of the surface
// For any cube the are 2^8=256 possible sets of vertex states
// This table lists the edges intersected by the surface for all 256 possible vertex states
// There are 12 edges.  For each entry in the table, if edge #n is intersected, then bit #n is set to 1

GLint aiCubeEdgeFlags[256]=
{
        0x000, 0x109, 0x203, 0x30a, 0x406, 0x50f, 0x605, 0x70c, 0x80c, 0x905, 0xa0f, 0xb06, 0xc0a, 0xd03, 0xe09, 0xf00,
        0x190, 0x099, 0x393, 0x29a, 0x596, 0x49f, 0x795, 0x69c, 0x99c, 0x895, 0xb9f, 0xa96, 0xd9a, 0xc93, 0xf99, 0xe90,
        0x230, 0x339, 0x033, 0x13a, 0x636, 0x73f, 0x435, 0x53c, 0xa3c, 0xb35, 0x83f, 0x936, 0xe3a, 0xf33, 0xc39, 0xd30,
        0x3a0, 0x2a9, 0x1a3, 0x0aa, 0x7a6, 0x6af, 0x5a5, 0x4ac, 0xbac, 0xaa5, 0x9af, 0x8a6, 0xfaa, 0xea3, 0xda9, 0xca0,
        0x460, 0x569, 0x663, 0x76a, 0x066, 0x16f, 0x265, 0x36c, 0xc6c, 0xd65, 0xe6f, 0xf66, 0x86a, 0x963, 0xa69, 0xb60,
        0x5f0, 0x4f9, 0x7f3, 0x6fa, 0x1f6, 0x0ff, 0x3f5, 0x2fc, 0xdfc, 0xcf5, 0xfff, 0xef6, 0x9fa, 0x8f3, 0xbf9, 0xaf0,
        0x650, 0x759, 0x453, 0x55a, 0x256, 0x35f, 0x055, 0x15c, 0xe5c, 0xf55, 0xc5f, 0xd56, 0xa5a, 0xb53, 0x859, 0x950,
        0x7c0, 0x6c9, 0x5c3, 0x4ca, 0x3c6, 0x2cf, 0x1c5, 0x0cc, 0xfcc, 0xec5, 0xdcf, 0xcc6, 0xbca, 0xac3, 0x9c9, 0x8c0,
        0x8c0, 0x9c9, 0xac3, 0xbca, 0xcc6, 0xdcf, 0xec5, 0xfcc, 0x0cc, 0x1c5, 0x2cf, 0x3c6, 0x4ca, 0x5c3, 0x6c9, 0x7c0,
        0x950, 0x859, 0xb53, 0xa5a, 0xd56, 0xc5f, 0xf55, 0xe5c, 0x15c, 0x055, 0x35f, 0x256, 0x55a, 0x453, 0x759, 0x650,
        0xaf0, 0xbf9, 0x8f3, 0x9fa, 0xef6, 0xfff, 0xcf5, 0xdfc, 0x2fc, 0x3f5, 0x0ff, 0x1f6, 0x6fa, 0x7f3, 0x4f9, 0x5f0,
        0xb60, 0xa69, 0x963, 0x86a, 0xf66, 0xe6f, 0xd65, 0xc6c, 0x36c, 0x265, 0x16f, 0x066, 0x76a, 0x663, 0x569, 0x460,
        0xca0, 0xda9, 0xea3, 0xfaa, 0x8a6, 0x9af, 0xaa5, 0xbac, 0x4ac, 0x5a5, 0x6af, 0x7a6, 0x0aa, 0x1a3, 0x2a9, 0x3a0,
        0xd30, 0xc39, 0xf33, 0xe3a, 0x936, 0x83f, 0xb35, 0xa3c, 0x53c, 0x435, 0x73f, 0x636, 0x13a, 0x033, 0x339, 0x230,
        0xe90, 0xf99, 0xc93, 0xd9a, 0xa96, 0xb9f, 0x895, 0x99c, 0x69c, 0x795, 0x49f, 0x596, 0x29a, 0x393, 0x099, 0x190,
        0xf00, 0xe09, 0xd03, 0xc0a, 0xb06, 0xa0f, 0x905, 0x80c, 0x70c, 0x605, 0x50f, 0x406, 0x30a, 0x203, 0x109, 0x000
};

//  For each of the possible vertex states listed in aiCubeEdgeFlags there is a specific triangulation
//  of the edge intersection points.  a2iTriangleConnectionTable lists all of them in the form of
//  0-5 edge triples with the list terminated by the invalid value -1.
//  For example: a2iTriangleConnectionTable[3] list the 2 triangles formed when corner[0]
//  and corner[1] are inside of the surface, but the rest of the cube is not.
//
//  I found this table in an example program someone wrote long ago.  It was probably generated by hand

GLint a2iTriangleConnectionTable[256][16] =
{
        {-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {0, 8, 3, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {0, 1, 9, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {1, 8, 3, 9, 8, 1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {1, 2, 10, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {0, 8, 3, 1, 2, 10, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {9, 2, 10, 0, 2, 9, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {2, 8, 3, 2, 10, 8, 10, 9, 8, -1, -1, -1, -1, -1, -1, -1},
        {3, 11, 2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {0, 11, 2, 8, 11, 0, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {1, 9, 0, 2, 3, 11, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {1, 11, 2, 1, 9, 11, 9, 8, 11, -1, -1, -1, -1, -1, -1, -1},
        {3, 10, 1, 11, 10, 3, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {0, 10, 1, 0, 8, 10, 8, 11, 10, -1, -1, -1, -1, -1, -1, -1},
        {3, 9, 0, 3, 11, 9, 11, 10, 9, -1, -1, -1, -1, -1, -1, -1},
        {9, 8, 10, 10, 8, 11, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {4, 7, 8, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {4, 3, 0, 7, 3, 4, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {0, 1, 9, 8, 4, 7, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {4, 1, 9, 4, 7, 1, 7, 3, 1, -1, -1, -1, -1, -1, -1, -1},
        {1, 2, 10, 8, 4, 7, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {3, 4, 7, 3, 0, 4, 1, 2, 10, -1, -1, -1, -1, -1, -1, -1},
        {9, 2, 10, 9, 0, 2, 8, 4, 7, -1, -1, -1, -1, -1, -1, -1},
        {2, 10, 9, 2, 9, 7, 2, 7, 3, 7, 9, 4, -1, -1, -1, -1},
        {8, 4, 7, 3, 11, 2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {11, 4, 7, 11, 2, 4, 2, 0, 4, -1, -1, -1, -1, -1, -1, -1},
        {9, 0, 1, 8, 4, 7, 2, 3, 11, -1, -1, -1, -1, -1, -1, -1},
        {4, 7, 11, 9, 4, 11, 9, 11, 2, 9, 2, 1, -1, -1, -1, -1},
        {3, 10, 1, 3, 11, 10, 7, 8, 4, -1, -1, -1, -1, -1, -1, -1},
        {1, 11, 10, 1, 4, 11, 1, 0, 4, 7, 11, 4, -1, -1, -1, -1},
        {4, 7, 8, 9, 0, 11, 9, 11, 10, 11, 0, 3, -1, -1, -1, -1},
        {4, 7, 11, 4, 11, 9, 9, 11, 10, -1, -1, -1, -1, -1, -1, -1},
        {9, 5, 4, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {9, 5, 4, 0, 8, 3, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {0, 5, 4, 1, 5, 0, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {8, 5, 4, 8, 3, 5, 3, 1, 5, -1, -1, -1, -1, -1, -1, -1},
        {1, 2, 10, 9, 5, 4, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {3, 0, 8, 1, 2, 10, 4, 9, 5, -1, -1, -1, -1, -1, -1, -1},
        {5, 2, 10, 5, 4, 2, 4, 0, 2, -1, -1, -1, -1, -1, -1, -1},
        {2, 10, 5, 3, 2, 5, 3, 5, 4, 3, 4, 8, -1, -1, -1, -1},
        {9, 5, 4, 2, 3, 11, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {0, 11, 2, 0, 8, 11, 4, 9, 5, -1, -1, -1, -1, -1, -1, -1},
        {0, 5, 4, 0, 1, 5, 2, 3, 11, -1, -1, -1, -1, -1, -1, -1},
        {2, 1, 5, 2, 5, 8, 2, 8, 11, 4, 8, 5, -1, -1, -1, -1},
        {10, 3, 11, 10, 1, 3, 9, 5, 4, -1, -1, -1, -1, -1, -1, -1},
        {4, 9, 5, 0, 8, 1, 8, 10, 1, 8, 11, 10, -1, -1, -1, -1},
        {5, 4, 0, 5, 0, 11, 5, 11, 10, 11, 0, 3, -1, -1, -1, -1},
        {5, 4, 8, 5, 8, 10, 10, 8, 11, -1, -1, -1, -1, -1, -1, -1},
        {9, 7, 8, 5, 7, 9, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {9, 3, 0, 9, 5, 3, 5, 7, 3, -1, -1, -1, -1, -1, -1, -1},
        {0, 7, 8, 0, 1, 7, 1, 5, 7, -1, -1, -1, -1, -1, -1, -1},
        {1, 5, 3, 3, 5, 7, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {9, 7, 8, 9, 5, 7, 10, 1, 2, -1, -1, -1, -1, -1, -1, -1},
        {10, 1, 2, 9, 5, 0, 5, 3, 0, 5, 7, 3, -1, -1, -1, -1},
        {8, 0, 2, 8, 2, 5, 8, 5, 7, 10, 5, 2, -1, -1, -1, -1},
        {2, 10, 5, 2, 5, 3, 3, 5, 7, -1, -1, -1, -1, -1, -1, -1},
        {7, 9, 5, 7, 8, 9, 3, 11, 2, -1, -1, -1, -1, -1, -1, -1},
        {9, 5, 7, 9, 7, 2, 9, 2, 0, 2, 7, 11, -1, -1, -1, -1},
        {2, 3, 11, 0, 1, 8, 1, 7, 8, 1, 5, 7, -1, -1, -1, -1},
        {11, 2, 1, 11, 1, 7, 7, 1, 5, -1, -1, -1, -1, -1, -1, -1},
        {9, 5, 8, 8, 5, 7, 10, 1, 3, 10, 3, 11, -1, -1, -1, -1},
        {5, 7, 0, 5, 0, 9, 7, 11, 0, 1, 0, 10, 11, 10, 0, -1},
        {11, 10, 0, 11, 0, 3, 10, 5, 0, 8, 0, 7, 5, 7, 0, -1},
        {11, 10, 5, 7, 11, 5, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {10, 6, 5, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {0, 8, 3, 5, 10, 6, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {9, 0, 1, 5, 10, 6, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {1, 8, 3, 1, 9, 8, 5, 10, 6, -1, -1, -1, -1, -1, -1, -1},
        {1, 6, 5, 2, 6, 1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {1, 6, 5, 1, 2, 6, 3, 0, 8, -1, -1, -1, -1, -1, -1, -1},
        {9, 6, 5, 9, 0, 6, 0, 2, 6, -1, -1, -1, -1, -1, -1, -1},
        {5, 9, 8, 5, 8, 2, 5, 2, 6, 3, 2, 8, -1, -1, -1, -1},
        {2, 3, 11, 10, 6, 5, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {11, 0, 8, 11, 2, 0, 10, 6, 5, -1, -1, -1, -1, -1, -1, -1},
        {0, 1, 9, 2, 3, 11, 5, 10, 6, -1, -1, -1, -1, -1, -1, -1},
        {5, 10, 6, 1, 9, 2, 9, 11, 2, 9, 8, 11, -1, -1, -1, -1},
        {6, 3, 11, 6, 5, 3, 5, 1, 3, -1, -1, -1, -1, -1, -1, -1},
        {0, 8, 11, 0, 11, 5, 0, 5, 1, 5, 11, 6, -1, -1, -1, -1},
        {3, 11, 6, 0, 3, 6, 0, 6, 5, 0, 5, 9, -1, -1, -1, -1},
        {6, 5, 9, 6, 9, 11, 11, 9, 8, -1, -1, -1, -1, -1, -1, -1},
        {5, 10, 6, 4, 7, 8, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {4, 3, 0, 4, 7, 3, 6, 5, 10, -1, -1, -1, -1, -1, -1, -1},
        {1, 9, 0, 5, 10, 6, 8, 4, 7, -1, -1, -1, -1, -1, -1, -1},
        {10, 6, 5, 1, 9, 7, 1, 7, 3, 7, 9, 4, -1, -1, -1, -1},
        {6, 1, 2, 6, 5, 1, 4, 7, 8, -1, -1, -1, -1, -1, -1, -1},
        {1, 2, 5, 5, 2, 6, 3, 0, 4, 3, 4, 7, -1, -1, -1, -1},
        {8, 4, 7, 9, 0, 5, 0, 6, 5, 0, 2, 6, -1, -1, -1, -1},
        {7, 3, 9, 7, 9, 4, 3, 2, 9, 5, 9, 6, 2, 6, 9, -1},
        {3, 11, 2, 7, 8, 4, 10, 6, 5, -1, -1, -1, -1, -1, -1, -1},
        {5, 10, 6, 4, 7, 2, 4, 2, 0, 2, 7, 11, -1, -1, -1, -1},
        {0, 1, 9, 4, 7, 8, 2, 3, 11, 5, 10, 6, -1, -1, -1, -1},
        {9, 2, 1, 9, 11, 2, 9, 4, 11, 7, 11, 4, 5, 10, 6, -1},
        {8, 4, 7, 3, 11, 5, 3, 5, 1, 5, 11, 6, -1, -1, -1, -1},
        {5, 1, 11, 5, 11, 6, 1, 0, 11, 7, 11, 4, 0, 4, 11, -1},
        {0, 5, 9, 0, 6, 5, 0, 3, 6, 11, 6, 3, 8, 4, 7, -1},
        {6, 5, 9, 6, 9, 11, 4, 7, 9, 7, 11, 9, -1, -1, -1, -1},
        {10, 4, 9, 6, 4, 10, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {4, 10, 6, 4, 9, 10, 0, 8, 3, -1, -1, -1, -1, -1, -1, -1},
        {10, 0, 1, 10, 6, 0, 6, 4, 0, -1, -1, -1, -1, -1, -1, -1},
        {8, 3, 1, 8, 1, 6, 8, 6, 4, 6, 1, 10, -1, -1, -1, -1},
        {1, 4, 9, 1, 2, 4, 2, 6, 4, -1, -1, -1, -1, -1, -1, -1},
        {3, 0, 8, 1, 2, 9, 2, 4, 9, 2, 6, 4, -1, -1, -1, -1},
        {0, 2, 4, 4, 2, 6, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {8, 3, 2, 8, 2, 4, 4, 2, 6, -1, -1, -1, -1, -1, -1, -1},
        {10, 4, 9, 10, 6, 4, 11, 2, 3, -1, -1, -1, -1, -1, -1, -1},
        {0, 8, 2, 2, 8, 11, 4, 9, 10, 4, 10, 6, -1, -1, -1, -1},
        {3, 11, 2, 0, 1, 6, 0, 6, 4, 6, 1, 10, -1, -1, -1, -1},
        {6, 4, 1, 6, 1, 10, 4, 8, 1, 2, 1, 11, 8, 11, 1, -1},
        {9, 6, 4, 9, 3, 6, 9, 1, 3, 11, 6, 3, -1, -1, -1, -1},
        {8, 11, 1, 8, 1, 0, 11, 6, 1, 9, 1, 4, 6, 4, 1, -1},
        {3, 11, 6, 3, 6, 0, 0, 6, 4, -1, -1, -1, -1, -1, -1, -1},
        {6, 4, 8, 11, 6, 8, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {7, 10, 6, 7, 8, 10, 8, 9, 10, -1, -1, -1, -1, -1, -1, -1},
        {0, 7, 3, 0, 10, 7, 0, 9, 10, 6, 7, 10, -1, -1, -1, -1},
        {10, 6, 7, 1, 10, 7, 1, 7, 8, 1, 8, 0, -1, -1, -1, -1},
        {10, 6, 7, 10, 7, 1, 1, 7, 3, -1, -1, -1, -1, -1, -1, -1},
        {1, 2, 6, 1, 6, 8, 1, 8, 9, 8, 6, 7, -1, -1, -1, -1},
        {2, 6, 9, 2, 9, 1, 6, 7, 9, 0, 9, 3, 7, 3, 9, -1},
        {7, 8, 0, 7, 0, 6, 6, 0, 2, -1, -1, -1, -1, -1, -1, -1},
        {7, 3, 2, 6, 7, 2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {2, 3, 11, 10, 6, 8, 10, 8, 9, 8, 6, 7, -1, -1, -1, -1},
        {2, 0, 7, 2, 7, 11, 0, 9, 7, 6, 7, 10, 9, 10, 7, -1},
        {1, 8, 0, 1, 7, 8, 1, 10, 7, 6, 7, 10, 2, 3, 11, -1},
        {11, 2, 1, 11, 1, 7, 10, 6, 1, 6, 7, 1, -1, -1, -1, -1},
        {8, 9, 6, 8, 6, 7, 9, 1, 6, 11, 6, 3, 1, 3, 6, -1},
        {0, 9, 1, 11, 6, 7, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {7, 8, 0, 7, 0, 6, 3, 11, 0, 11, 6, 0, -1, -1, -1, -1},
        {7, 11, 6, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {7, 6, 11, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {3, 0, 8, 11, 7, 6, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {0, 1, 9, 11, 7, 6, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {8, 1, 9, 8, 3, 1, 11, 7, 6, -1, -1, -1, -1, -1, -1, -1},
        {10, 1, 2, 6, 11, 7, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {1, 2, 10, 3, 0, 8, 6, 11, 7, -1, -1, -1, -1, -1, -1, -1},
        {2, 9, 0, 2, 10, 9, 6, 11, 7, -1, -1, -1, -1, -1, -1, -1},
        {6, 11, 7, 2, 10, 3, 10, 8, 3, 10, 9, 8, -1, -1, -1, -1},
        {7, 2, 3, 6, 2, 7, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {7, 0, 8, 7, 6, 0, 6, 2, 0, -1, -1, -1, -1, -1, -1, -1},
        {2, 7, 6, 2, 3, 7, 0, 1, 9, -1, -1, -1, -1, -1, -1, -1},
        {1, 6, 2, 1, 8, 6, 1, 9, 8, 8, 7, 6, -1, -1, -1, -1},
        {10, 7, 6, 10, 1, 7, 1, 3, 7, -1, -1, -1, -1, -1, -1, -1},
        {10, 7, 6, 1, 7, 10, 1, 8, 7, 1, 0, 8, -1, -1, -1, -1},
        {0, 3, 7, 0, 7, 10, 0, 10, 9, 6, 10, 7, -1, -1, -1, -1},
        {7, 6, 10, 7, 10, 8, 8, 10, 9, -1, -1, -1, -1, -1, -1, -1},
        {6, 8, 4, 11, 8, 6, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {3, 6, 11, 3, 0, 6, 0, 4, 6, -1, -1, -1, -1, -1, -1, -1},
        {8, 6, 11, 8, 4, 6, 9, 0, 1, -1, -1, -1, -1, -1, -1, -1},
        {9, 4, 6, 9, 6, 3, 9, 3, 1, 11, 3, 6, -1, -1, -1, -1},
        {6, 8, 4, 6, 11, 8, 2, 10, 1, -1, -1, -1, -1, -1, -1, -1},
        {1, 2, 10, 3, 0, 11, 0, 6, 11, 0, 4, 6, -1, -1, -1, -1},
        {4, 11, 8, 4, 6, 11, 0, 2, 9, 2, 10, 9, -1, -1, -1, -1},
        {10, 9, 3, 10, 3, 2, 9, 4, 3, 11, 3, 6, 4, 6, 3, -1},
        {8, 2, 3, 8, 4, 2, 4, 6, 2, -1, -1, -1, -1, -1, -1, -1},
        {0, 4, 2, 4, 6, 2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {1, 9, 0, 2, 3, 4, 2, 4, 6, 4, 3, 8, -1, -1, -1, -1},
        {1, 9, 4, 1, 4, 2, 2, 4, 6, -1, -1, -1, -1, -1, -1, -1},
        {8, 1, 3, 8, 6, 1, 8, 4, 6, 6, 10, 1, -1, -1, -1, -1},
        {10, 1, 0, 10, 0, 6, 6, 0, 4, -1, -1, -1, -1, -1, -1, -1},
        {4, 6, 3, 4, 3, 8, 6, 10, 3, 0, 3, 9, 10, 9, 3, -1},
        {10, 9, 4, 6, 10, 4, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {4, 9, 5, 7, 6, 11, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {0, 8, 3, 4, 9, 5, 11, 7, 6, -1, -1, -1, -1, -1, -1, -1},
        {5, 0, 1, 5, 4, 0, 7, 6, 11, -1, -1, -1, -1, -1, -1, -1},
        {11, 7, 6, 8, 3, 4, 3, 5, 4, 3, 1, 5, -1, -1, -1, -1},
        {9, 5, 4, 10, 1, 2, 7, 6, 11, -1, -1, -1, -1, -1, -1, -1},
        {6, 11, 7, 1, 2, 10, 0, 8, 3, 4, 9, 5, -1, -1, -1, -1},
        {7, 6, 11, 5, 4, 10, 4, 2, 10, 4, 0, 2, -1, -1, -1, -1},
        {3, 4, 8, 3, 5, 4, 3, 2, 5, 10, 5, 2, 11, 7, 6, -1},
        {7, 2, 3, 7, 6, 2, 5, 4, 9, -1, -1, -1, -1, -1, -1, -1},
        {9, 5, 4, 0, 8, 6, 0, 6, 2, 6, 8, 7, -1, -1, -1, -1},
        {3, 6, 2, 3, 7, 6, 1, 5, 0, 5, 4, 0, -1, -1, -1, -1},
        {6, 2, 8, 6, 8, 7, 2, 1, 8, 4, 8, 5, 1, 5, 8, -1},
        {9, 5, 4, 10, 1, 6, 1, 7, 6, 1, 3, 7, -1, -1, -1, -1},
        {1, 6, 10, 1, 7, 6, 1, 0, 7, 8, 7, 0, 9, 5, 4, -1},
        {4, 0, 10, 4, 10, 5, 0, 3, 10, 6, 10, 7, 3, 7, 10, -1},
        {7, 6, 10, 7, 10, 8, 5, 4, 10, 4, 8, 10, -1, -1, -1, -1},
        {6, 9, 5, 6, 11, 9, 11, 8, 9, -1, -1, -1, -1, -1, -1, -1},
        {3, 6, 11, 0, 6, 3, 0, 5, 6, 0, 9, 5, -1, -1, -1, -1},
        {0, 11, 8, 0, 5, 11, 0, 1, 5, 5, 6, 11, -1, -1, -1, -1},
        {6, 11, 3, 6, 3, 5, 5, 3, 1, -1, -1, -1, -1, -1, -1, -1},
        {1, 2, 10, 9, 5, 11, 9, 11, 8, 11, 5, 6, -1, -1, -1, -1},
        {0, 11, 3, 0, 6, 11, 0, 9, 6, 5, 6, 9, 1, 2, 10, -1},
        {11, 8, 5, 11, 5, 6, 8, 0, 5, 10, 5, 2, 0, 2, 5, -1},
        {6, 11, 3, 6, 3, 5, 2, 10, 3, 10, 5, 3, -1, -1, -1, -1},
        {5, 8, 9, 5, 2, 8, 5, 6, 2, 3, 8, 2, -1, -1, -1, -1},
        {9, 5, 6, 9, 6, 0, 0, 6, 2, -1, -1, -1, -1, -1, -1, -1},
        {1, 5, 8, 1, 8, 0, 5, 6, 8, 3, 8, 2, 6, 2, 8, -1},
        {1, 5, 6, 2, 1, 6, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {1, 3, 6, 1, 6, 10, 3, 8, 6, 5, 6, 9, 8, 9, 6, -1},
        {10, 1, 0, 10, 0, 6, 9, 5, 0, 5, 6, 0, -1, -1, -1, -1},
        {0, 3, 8, 5, 6, 10, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {10, 5, 6, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {11, 5, 10, 7, 5, 11, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {11, 5, 10, 11, 7, 5, 8, 3, 0, -1, -1, -1, -1, -1, -1, -1},
        {5, 11, 7, 5, 10, 11, 1, 9, 0, -1, -1, -1, -1, -1, -1, -1},
        {10, 7, 5, 10, 11, 7, 9, 8, 1, 8, 3, 1, -1, -1, -1, -1},
        {11, 1, 2, 11, 7, 1, 7, 5, 1, -1, -1, -1, -1, -1, -1, -1},
        {0, 8, 3, 1, 2, 7, 1, 7, 5, 7, 2, 11, -1, -1, -1, -1},
        {9, 7, 5, 9, 2, 7, 9, 0, 2, 2, 11, 7, -1, -1, -1, -1},
        {7, 5, 2, 7, 2, 11, 5, 9, 2, 3, 2, 8, 9, 8, 2, -1},
        {2, 5, 10, 2, 3, 5, 3, 7, 5, -1, -1, -1, -1, -1, -1, -1},
        {8, 2, 0, 8, 5, 2, 8, 7, 5, 10, 2, 5, -1, -1, -1, -1},
        {9, 0, 1, 5, 10, 3, 5, 3, 7, 3, 10, 2, -1, -1, -1, -1},
        {9, 8, 2, 9, 2, 1, 8, 7, 2, 10, 2, 5, 7, 5, 2, -1},
        {1, 3, 5, 3, 7, 5, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {0, 8, 7, 0, 7, 1, 1, 7, 5, -1, -1, -1, -1, -1, -1, -1},
        {9, 0, 3, 9, 3, 5, 5, 3, 7, -1, -1, -1, -1, -1, -1, -1},
        {9, 8, 7, 5, 9, 7, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {5, 8, 4, 5, 10, 8, 10, 11, 8, -1, -1, -1, -1, -1, -1, -1},
        {5, 0, 4, 5, 11, 0, 5, 10, 11, 11, 3, 0, -1, -1, -1, -1},
        {0, 1, 9, 8, 4, 10, 8, 10, 11, 10, 4, 5, -1, -1, -1, -1},
        {10, 11, 4, 10, 4, 5, 11, 3, 4, 9, 4, 1, 3, 1, 4, -1},
        {2, 5, 1, 2, 8, 5, 2, 11, 8, 4, 5, 8, -1, -1, -1, -1},
        {0, 4, 11, 0, 11, 3, 4, 5, 11, 2, 11, 1, 5, 1, 11, -1},
        {0, 2, 5, 0, 5, 9, 2, 11, 5, 4, 5, 8, 11, 8, 5, -1},
        {9, 4, 5, 2, 11, 3, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {2, 5, 10, 3, 5, 2, 3, 4, 5, 3, 8, 4, -1, -1, -1, -1},
        {5, 10, 2, 5, 2, 4, 4, 2, 0, -1, -1, -1, -1, -1, -1, -1},
        {3, 10, 2, 3, 5, 10, 3, 8, 5, 4, 5, 8, 0, 1, 9, -1},
        {5, 10, 2, 5, 2, 4, 1, 9, 2, 9, 4, 2, -1, -1, -1, -1},
        {8, 4, 5, 8, 5, 3, 3, 5, 1, -1, -1, -1, -1, -1, -1, -1},
        {0, 4, 5, 1, 0, 5, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {8, 4, 5, 8, 5, 3, 9, 0, 5, 0, 3, 5, -1, -1, -1, -1},
        {9, 4, 5, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {4, 11, 7, 4, 9, 11, 9, 10, 11, -1, -1, -1, -1, -1, -1, -1},
        {0, 8, 3, 4, 9, 7, 9, 11, 7, 9, 10, 11, -1, -1, -1, -1},
        {1, 10, 11, 1, 11, 4, 1, 4, 0, 7, 4, 11, -1, -1, -1, -1},
        {3, 1, 4, 3, 4, 8, 1, 10, 4, 7, 4, 11, 10, 11, 4, -1},
        {4, 11, 7, 9, 11, 4, 9, 2, 11, 9, 1, 2, -1, -1, -1, -1},
        {9, 7, 4, 9, 11, 7, 9, 1, 11, 2, 11, 1, 0, 8, 3, -1},
        {11, 7, 4, 11, 4, 2, 2, 4, 0, -1, -1, -1, -1, -1, -1, -1},
        {11, 7, 4, 11, 4, 2, 8, 3, 4, 3, 2, 4, -1, -1, -1, -1},
        {2, 9, 10, 2, 7, 9, 2, 3, 7, 7, 4, 9, -1, -1, -1, -1},
        {9, 10, 7, 9, 7, 4, 10, 2, 7, 8, 7, 0, 2, 0, 7, -1},
        {3, 7, 10, 3, 10, 2, 7, 4, 10, 1, 10, 0, 4, 0, 10, -1},
        {1, 10, 2, 8, 7, 4, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {4, 9, 1, 4, 1, 7, 7, 1, 3, -1, -1, -1, -1, -1, -1, -1},
        {4, 9, 1, 4, 1, 7, 0, 8, 1, 8, 7, 1, -1, -1, -1, -1},
        {4, 0, 3, 7, 4, 3, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {4, 8, 7, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {9, 10, 8, 10, 11, 8, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {3, 0, 9, 3, 9, 11, 11, 9, 10, -1, -1, -1, -1, -1, -1, -1},
        {0, 1, 10, 0, 10, 8, 8, 10, 11, -1, -1, -1, -1, -1, -1, -1},
        {3, 1, 10, 11, 3, 10, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {1, 2, 11, 1, 11, 9, 9, 11, 8, -1, -1, -1, -1, -1, -1, -1},
        {3, 0, 9, 3, 9, 11, 1, 2, 9, 2, 11, 9, -1, -1, -1, -1},
        {0, 2, 11, 8, 0, 11, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {3, 2, 11, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {2, 3, 8, 2, 8, 10, 10, 8, 9, -1, -1, -1, -1, -1, -1, -1},
        {9, 10, 2, 0, 9, 2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {2, 3, 8, 2, 8, 10, 0, 1, 8, 1, 10, 8, -1, -1, -1, -1},
        {1, 10, 2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {1, 3, 8, 9, 1, 8, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {0, 9, 1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {0, 3, 8, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        {-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1}
};