//
//?Marching?Cubes?Example?Program?
//?by?Cory?Bloyd?（corysama@yahoo.com）
//
//?A?simple?portable?and?complete?implementation?of?the?Marching?Cubes
//?and?Marching?Tetrahedrons?algorithms?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/
//
//?This?code?is?public?domain.
//

#include?“stdio.h“
#include?“math.h“
//This?program?requires?the?OpenGL?and?GLUT?libraries
//?You?can?obtain?them?for?free?from?http://www.opengl.org
#include?“GL/glut.h“

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

//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}
};

//a2iEdgeConnection?lists?the?index?of?the?endpoint?vertices?for?each?of?the?12?edges?of?the?cube
static?const?GLint?a2iEdgeConnection[12][2]?=?
{
????????{01}?{12}?{23}?{30}
????????{45}?{56}?{67}?{74}
????????{04}?{15}?{26}?{37}
};

//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}
};

//a2iTetrahedronEdgeConnection?lists?the?index?of?the?endpoint?vertices?for?each?of?the?6?edges?of?the?tetrahedron
static?const?GLint?a2iTetrahedronEdgeConnection[6][2]?=
{
????????{01}??{12}??{20}??{03}??{13}??{23}
};

//a2iTetrahedronEdgeConnection?lists?the?index?of?verticies?from?a?cube?
//?that?made?up?each?of?the?six?tetrahedrons?within?the?cube
static?const?GLint?a2iTetrahedronsInACube[6][4]?=
{
????????{0516}
????????{0126}
????????{0236}
????????{0376}
????????{0746}
????????{0456}
};

static?const?GLfloat?afAmbientWhite?[]?=?{0.25?0.25?0.25?1.00};?
static?const?GLfloat?afAmbientRed???[]?=?{0.25?0.00?0.00?1.00};?
static?const?GLfloat?afAmbientGreen?[]?=?{0.00?0.25?0.00?1.00};?
static?const?GLfloat?afAmbientBlue??[]?=?{0.00?0.00?0.25?1.00};?
static?const?GLfloat?afDiffuseWhite?[]?=?{0.75?0.75?0.75?1.00};?
static?const?GLfloat?afDiffuseRed???[]?=?{0.75?0.00?0.00?1.00};?
static?const?GLfloat?afDiffuseGreen?[]?=?{0.00?0.75?0.00?1.00};?
static?const?GLfloat?afDiffuseBlue??[]?=?{0.00?0.00?0.75?1.00};?
static?const?GLfloat?afSpecularWhite[]?=?{1.00?1.00?1.00?1.00};?
static?const?GLfloat?afSpecularRed??