OpenSceneGraph/src/osgPlugins/ac3d/ac3d.cpp

// 30 Oct 2002
// AC3D loader for models generated by the AC3D modeller (www.ac3d.org)
// part of this source code were supplied by the AC3D project (Andy Colebourne)
// eg the basic parsing of an AC3D file.
// Conversion from AC3D scenegraph to OSG by GW Michel.


#include <stdio.h>
#ifdef __DARWIN_OSX__
#include <sys/malloc.h>
#else
#include <malloc.h>
#endif
#include <math.h>

#include <osg/CullFace>
#include <osg/Geode>
#include <osg/Group>
#include <osg/Geometry>  //Set>
#include <osg/Light>
#include <osg/LightSource>
#include <osg/Material>
#include <osg/Texture2D>
#include <osg/TexEnv>
#include <osg/StateSet>
#include <osg/Notify>
#include <osg/Texture2D>


#include <osgDB/FileNameUtils>
#include <osgDB/Registry>
#include <osgDB/ReadFile>
#include <osgDB/FileUtils>

#include <osgUtil/Tesselator>
#include <osgUtil/SmoothingVisitor>

#include "osgac3d.h"
#include "Exception.h"
#include "Geode.h"

using namespace osg;
using namespace osgDB;

class geodeVisitor : public osg::NodeVisitor { // collects geodes from scene sub-graph attached to 'this'
        public:
            geodeVisitor():
                osg::NodeVisitor(osg::NodeVisitor::TRAVERSE_ALL_CHILDREN) {}

			~geodeVisitor() { _geodelist.clear();}

		// one apply for each type of Node that might be a user transform
         //   virtual void apply(osgAction::ActionHeader& ah);
           // virtual void apply(osg::Drawable& dr);
            virtual void apply(osg::Geode& geode) {
				_geodelist.push_back(&geode);
			}
        //    virtual void apply(osg::Billboard& geode);
            virtual void apply(osg::Group& gp){
				traverse(gp);	// must continue subgraph traversal.
			}
         //   virtual void apply(osg::Switch& sw);
           // virtual void apply(osg::Transform& transform);
			std::vector<const osg::Geode *> getGeodes() {return _geodelist;}
        protected:

            typedef std::vector<const osg::Geode *>    Geodelist;
            Geodelist  _geodelist;
};

class ReaderWriterAC : public osgDB::ReaderWriter
{
    public:
        virtual const char* className() { return "AC3D Database Reader"; }

        virtual bool acceptsExtension(const std::string& extension)
        {
            return osgDB::equalCaseInsensitive(extension,"ac");
        }
        virtual ReadResult readNode(const std::string& fileName,const osgDB::ReaderWriter::Options*)
        {
            osg::Group *grp; // holder for all loaded objects
            grp=ac_load_ac3d(fileName.c_str());
            return grp;
        };
        virtual WriteResult writeNode(const Node& node,const std::string& fileName, const osgDB::ReaderWriter::Options* /*options*/)
        {
            std::string ext = getFileExtension(fileName);
            if (!acceptsExtension(ext)) return WriteResult::FILE_NOT_HANDLED;
			geodeVisitor vs; // this collects geodes.
			Node *nd=(Node *)(&node);
			std::vector<unsigned int>iNumMaterials;
			nd->accept(vs); // this parses the tree to find Geodes
			std::vector<const osg::Geode *> glist=vs.getGeodes();
            std::ofstream fout(fileName.c_str(), std::ios::out | std::ios::binary);
			// Write out the file header
			std::vector<const osg::Geode *>::iterator itr;
			fout << "AC3Db" << std::endl;
			// output the Materials
			for (itr=glist.begin();itr!= glist.end();itr++) {
                iNumMaterials.push_back(const_cast<ac3d::Geode*>(static_cast<const ac3d::Geode*>(*itr))->ProcessMaterial(fout,itr-glist.begin()));
			}
			// output the Geometry
			unsigned int nfirstmat=0;
			fout << "OBJECT world" << std::endl;
			fout << "kids " << (glist.end()-glist.begin()) << std::endl;
			for (itr=glist.begin();itr!= glist.end();itr++) {
                const_cast<ac3d::Geode*>(static_cast<const ac3d::Geode*>(*itr))->ProcessGeometry(fout,nfirstmat);
				nfirstmat+=iNumMaterials[itr-glist.begin()];
			}
            fout.close();
            return WriteResult::FILE_SAVED;
        }
        
        virtual WriteResult writeNode(const Node& node,std::ostream& fout, const osgDB::ReaderWriter::Options* opts)
        {
            try
            {
                // write ac file.
                if(dynamic_cast<const osg::Group*>(&node)) {
					const osg::Group *gp=dynamic_cast<const osg::Group*>(&node);
					const unsigned int nch=gp->getNumChildren();
					for (unsigned int i=0; i<nch; i++) {
						writeNode(*(gp->getChild(i)), fout, opts);
					}
				}
				//const_cast<ac3d::Group*>(static_cast<const ac3d::Group*>(&node))->Process(fout, options);
             //   else if(dynamic_cast<const osg::Geode*>(&node))
             //       const_cast<ac3d::Geode*>(static_cast<const ac3d::Geode*>(&node))->Process(fout);
                else
                    std::cout<<"File must start with a geode "<<std::endl;
                fout.flush();
                return WriteResult::FILE_SAVED;
            }
            catch(ac3d::Exception e)
            {
		        osg::notify(osg::WARN)<<"Error parsing OSG tree: "<< e.getError() << std::endl;			
            }
            return WriteResult::FILE_NOT_HANDLED;

        }
private:
};

static int line = 0;
static char buff[255];



static std::vector<osg::Material*> palette; // change to dynamic array
//static int num_palette = 0;
static int startmatindex = 0;


osg::Material*ac_palette_get_material(int id)
{
    return(palette[id]);
}


Boolean read_line(FILE *f)
{
    fgets(buff, 255, f); line++;
    return(TRUE);
}



int tokc = 0;
char *tokv[30];

Prototype int get_tokens(char *s, int *argc, char *argv[])
/** bung '\0' chars at the end of tokens and set up the array (tokv) and count (tokc)
    like argv argc **/
{
char *p = s;
char *st;
char c;
//int n;
int tc;

    tc = 0;
    while ((c = *p))
        {
        if ((c != ' ') && (c != '\t') && (c != '\n') && ( c != 13))
            {
            if (c == '"')
                {
                c = *p++;
                st = p;
                while ((c = *p) && ((c != '"')&&(c != '\n')&& ( c != 13)) )
                    {
                    if (c == '\\')
                       strcpy(p, p+1);
                    p++;
                    }
                *p=0;
                argv[tc++] = st;
                }
            else
                {
                st = p;
                while ((c = *p) && ((c != ' ') && (c != '\t') && (c != '\n') && ( c != 13)) )
                        p++;
                *p=0;
                argv[tc++] = st;
                }            
            }
        p++;
        }

    *argc = tc;
    return(tc);
}


void initobject(ACObject *ob)
{
    ob->loc[0] = ob->loc[1] = ob->loc[2] = 0.0;
    ob->name = ob->url = NULL;
    ob->data = NULL;
    ob->num_vert = 0;
    ob->num_surf = 0;
    ob->texture = NULL;
    ob->texture_repeat_x = ob->texture_repeat_y = 1.0;
    ob->texture_offset_x = ob->texture_offset_y = 0.0;
    ob->kids = NULL;
    ob->num_kids = 0;
    ob->matrix[0] = 1;
    ob->matrix[1] = 0;
    ob->matrix[2] = 0;
    ob->matrix[3] = 0;
    ob->matrix[4] = 1;
    ob->matrix[5] = 0;
    ob->matrix[6] = 0;
    ob->matrix[7] = 0;
    ob->matrix[8] = 1;
}


void init_surface(ACSurface *s)
{
    s->num_vertref = 0;
    s->flags = 0;
    s->mat = 0;
//    s->normal.x = 0.0; s->normal.z = 0.0; s->normal.z = 0.0; 
}


void osgtri_calc_normal(osg::Vec3 &v1, osg::Vec3 &v2, osg::Vec3 &v3, osg::Vec3 &n)
{
    osg::Vec3 side1=v2-v1;
    osg::Vec3 side2=v3-v2;
    n=side1^side2;
    n.normalize();

}

ACSurface *read_surface(FILE *f, ACSurface *s,osg::UShortArray *nusidx,
                        osg::Vec2Array *tcs)
{
char t[20];
    init_surface(s);

    while (!feof(f))
    {
    read_line(f);
    sscanf(buff, "%s", t);

    if (streq(t, "SURF"))
        {
        int flgs;

        if (get_tokens(buff, &tokc, tokv) != 2)
            {
            printf("SURF should be followed by one flags argument\n");
            }
        else
            {
            flgs = strtol(tokv[1], NULL, 0);
            s->flags = flgs;
            }
        }
    else
    if (streq(t, "mat"))
        {
        int mindx;

        sscanf(buff, "%s %d", t, &mindx);
        s->mat = mindx+startmatindex;
        }
    else
    if (streq(t, "refs"))
        {
        int num, n;
        int ind;
        osg::Vec2 tx;
  
          sscanf(buff, "%s %d", t, &num);        

        s->num_vertref = num;

        for (n = 0; n < num; n++)
           {
           fscanf(f, "%d %f %f\n", &ind, &tx[0], &tx[1]); line++;
            nusidx->push_back(ind);
            if (tcs) tcs->push_back(tx);
           }

        return(s);
        }
    else
        printf("ignoring %s\n", t);

    }
   return(NULL);
}




/*void ac_object_calc_vertex_normals(ACObject *ob)
{
int s, v, vr;

    / ** for each vertex in this object ** /
    for (v = 0; v < ob->num_vert; v++)
        {
        ACNormal n = {0, 0, 0};
        int found = 0;

        / ** go through each surface ** /
        for (s = 0; s < ob->num_surf; s++)
            {
            ACSurface *surf = &ob->surfaces[s];

            / ** check if this vertex is used in this surface ** /
            / ** if it is, use it to create an average normal ** /
            for (vr = 0; vr < surf->num_vertref; vr++)
                if (surf->vertref[vr] == v)
                    {
                    n.x+=surf->normal.x;
                    n.y+=surf->normal.y;
                    n.z+=surf->normal.z;
                    found++;
                    }
            }
        if (found > 0)
            {
            n.x /= found;
            n.y /= found;
            n.z /= found;
            }
        ob->vertices[v].normal = n;
        }
    

} */


int string_to_objecttype(char *s)
{
    if (streq("world", s))
        return(OBJECT_WORLD);
    if (streq("poly", s))
        return(OBJECT_NORMAL);
    if (streq("group", s))
        return(OBJECT_GROUP);
    if (streq("light", s))
        return(OBJECT_LIGHT);
    return(OBJECT_NORMAL);
}

void
protate(osg::Vec3 p, float m[9])
{ // p-> m*p, m is 3.3 matrix
    osg::Vec3 t=p;
    p[0]=m[0]*t[0]+m[1]*t[1]+m[2]*t[3];
    p[1]=m[3]*t[0]+m[4]*t[1]+m[5]*t[3];
    p[2]=m[6]*t[0]+m[7]*t[1]+m[8]*t[3];
}

osg::Group *ac_load_object(FILE *f,const ACObject *parent)
{
	// most of this logic came from Andy Colebourne (developer of the AC3D editor) so it had better be right!
	char t[20];
	osg::Group *gp=NULL;
	osg::Geode *geode=NULL;
	osg::Vec3Array *normals = NULL; // new osg::Vec3Array; // NULL;

	ACObject ob; // local storage for stuff taken from AC's loader
	osg::Vec3Array *vertpool = new osg::Vec3Array;

	if (parent)
		ob.loc=parent->loc; // copy loc
	while (!feof(f))
	{
		read_line(f);

		sscanf(buff, "%s", t);

		if (streq(t, "MATERIAL"))
		{
			if (get_tokens(buff, &tokc, tokv) != 22)
			{
				printf("expected 21 params after \"MATERIAL\" - line %d\n", line);
			}
			else
			{
				osg::Material *numat=new osg::Material();
				osg::Vec4 cdiff((float)atof(tokv[3]), (float)atof(tokv[4]), 
								(float)atof(tokv[5]), 1.0-(float)atof(tokv[21]));
				numat->setDiffuse(osg::Material::FRONT_AND_BACK,cdiff);
				osg::Vec4 camb((float)atof(tokv[7]),(float)atof(tokv[8]),
								(float)atof(tokv[9]),1.0-(float)atof(tokv[21]));
				numat->setAmbient(osg::Material::FRONT_AND_BACK,camb);
				osg::Vec4 cspec((float)atof(tokv[15]), (float)atof(tokv[16]),
								(float)atof(tokv[17]),1.0-(float)atof(tokv[21]));
				numat->setSpecular(osg::Material::FRONT_AND_BACK,cspec);
				// addition 1 Nov 2003 - use shininess (was defaulted)
				float shininess=atof(tokv[19]);
				numat->setShininess(osg::Material::FRONT_AND_BACK,shininess);
				osg::Vec4 cemm((float)atof(tokv[11]),(float)atof(tokv[12]),(float)atof(tokv[13]),1.0-(float)atof(tokv[21]));
				// correction 1 Nov 2003 - from Marcio Ferraz - use emission colour for emission
				numat->setEmission(osg::Material::FRONT_AND_BACK,cemm);
				//numat->setTransparency(osg::Material::FRONT_AND_BACK, 1.0-(float)atof(tokv[21]));

				palette.push_back(numat); // [num_palette++] = numat;

			}
		}
		else if (streq(t, "OBJECT"))
		{
			char type[20];
			char str[20];
			osg::Vec3 loc=ob.loc;
			if (!gp) gp = new osg::Group();
			initobject(&ob); // rezero data for object
			ob.loc=loc;

			sscanf(buff, "%s %s", str, type);

			ob.type = string_to_objecttype(type);
		}
		else if (streq(t, "data"))
		{
			if (get_tokens(buff, &tokc, tokv) != 2)
				printf("expected 'data <number>' at line %d\n", line);
			else
			{
				char *str;
				int len;

				len = atoi(tokv[1]);
				if (len > 0)
				{
					str = (char *)myalloc(len+1);
					fread(str, len, 1, f);
					str[len] = 0;
					fscanf(f, "\n"); line++;
					ob.data = STRING(str);
					myfree(str);
				}
			}
		}
		else if (streq(t, "name"))
		{
			int numtok = get_tokens(buff, &tokc, tokv);
			if (numtok != 2)
			{
				printf("expected quoted name at line %d (got %d tokens)\n", line, numtok);
			}
			else
				if (gp) gp->setName(tokv[1]);
		}
		else if (streq(t, "texture"))
		{
			if (get_tokens(buff, &tokc, tokv) != 2)
				printf("expected quoted texture name at line %d\n", line);

			else
			{
				osg::Image *ctx= osgDB::readImageFile(tokv[1]);
				if (ctx)
				{ // image coukd be read
					ob.texture = new osg::Texture2D;// ac_load_texture(tokv[1]);
					ob.texture->setImage(ctx);
					ob.texture->setWrap(osg::Texture2D::WRAP_S, osg::Texture2D::REPEAT);
					ob.texture->setWrap(osg::Texture2D::WRAP_T, osg::Texture2D::REPEAT);
				}
			}
		}
		else if (streq(t, "texrep"))
		{
			if (get_tokens(buff, &tokc, tokv) != 3)
				printf("expected 'texrep <float> <float>' at line %d\n", line);
			else
			{
				ob.texture_repeat_x = atof(tokv[1]);
				ob.texture_repeat_y = atof(tokv[2]);
			}
		}
		else if (streq(t, "texoff"))
		{
			if (get_tokens(buff, &tokc, tokv) != 3)
				printf("expected 'texoff <float> <float>' at line %d\n", line);
			else
			{
				ob.texture_offset_x = atof(tokv[1]);
				ob.texture_offset_y = atof(tokv[2]);
			}
		}
		else if (streq(t, "rot"))
		{
			float r[9];
			char str2[5];
			int n;

			sscanf(buff, "%s %f %f %f %f %f %f %f %f %f", str2, &r[0], &r[1], &r[2], &r[3], &r[4], &r[5], &r[6], &r[7], &r[8] );

			for (n = 0; n < 9; n++)
				ob.matrix[n] = r[n];

		}
		else if (streq(t, "loc"))
		{
			char str[5];
			osg::Vec3 loc;
			sscanf(buff, "%s %f %f %f", str, &loc[0], &loc[1], &loc[2]);
			ob.loc+=loc;
		}
		else if (streq(t, "url"))
		{
			int ret;
			if ((ret = get_tokens(buff, &tokc, tokv)) != 2)
				printf("expected one arg to url at line %d (got %d)\n", line, ret); 
			else
				ob.url = STRING(tokv[1]);
		}
		else if (streq(t, "numvert"))
		{
			int num, n;
			char str[10];
			if (ob.type == OBJECT_GROUP || ob.type == OBJECT_WORLD)
			{
			}
			else if (ob.type == OBJECT_NORMAL)
			{
				if (geode)
				{
					osgUtil::Tesselator tesselator;
					for(unsigned int i=0;i<geode->getNumDrawables();++i)
					{
						osg::Geometry* geom = dynamic_cast<osg::Geometry*>(geode->getDrawable(i));
						if (geom) tesselator.retesselatePolygons(*geom);
					}
				}
				geode = new osg::Geode();
				gp->addChild(geode);
				geode->setName(gp->getName());
				normals = new osg::Vec3Array;
			}

			sscanf(buff, "%s %d", str, &num);

			if (num > 0)
			{
				ob.num_vert = num;

				for (n = 0; n < num; n++)
				{
					osg::Vec3 p;
					fscanf(f, "%f %f %f\n", &p[0], &p[1], &p[2]); line++;
					protate(p, ob.matrix);
					vertpool->push_back(p+ob.loc);
				}

			}
		}
		else if (streq(t, "numsurf"))
		{
			int num, n;
			char str[10];
			// this is not obvious (what is?).  Each set of surfaces can have different material on each surface.
			// so I set up a set of 'bins' for 
			//    the primitives (geometry list, geomlist)
			//    the coords array of each geometry (Vec3Array list, vertslist)
			//    the tx coords array for each geometry (Vec2Array list, texslist)
			// then I add a new geometry to the current Geode for each new material as it is found.

			std::vector<int> ia; // list of materials required- generate one geode per material
			typedef std::vector<osg::Geometry *> geomlist;
			geomlist glist;
			typedef std::vector<osg::Vec3Array *> vertslist;
			vertslist vlists; // list of vertices for each glist element
			typedef std::vector<osg::Vec2Array *> texslist;
			texslist txlists; // list of texture coords for each glist element

			sscanf(buff, "%s %d", str, &num);
			if (num > 0)
			{
				int needSmooth=0; // flat shaded
				ob.num_surf = num;

				for (n = 0; n < num; n++)
				{
					osg::Geometry *geom=NULL; // the surface will be addded to this geometry
					osg::Vec3Array *vgeom=NULL; // vertices corresponding to geom taken from vertexpool
					osg::Vec2Array *tgeom=NULL; // texture coords corresponding to geom taken from vertexpool
					ACSurface asurf;
					osg::UShortArray *nusidx = new osg::UShortArray; // indices into the vertices
					osg::Vec2Array *tcs=new osg::Vec2Array; // texture coordinates for this object
					ACSurface *news = read_surface(f, &asurf, nusidx, tcs);
					if (news == NULL)
					{
						printf("error whilst reading surface at line: %d\n", line);
						return(NULL);
					}
					else
					{
						int i=0;
						for (std::vector<int>::iterator itr= ia.begin(); itr<ia.end(); itr++, i++)
						{
							if ((*itr)==asurf.mat)
							{
								geom=glist[i];
								vgeom=vlists[i];
								tgeom=txlists[i]; // what is current texture array
							}
						}
						if (!geom)
						{ // then we need a new geometry
							osg::Vec3Array *verts = new osg::Vec3Array;

							osg::Vec2Array *tcrds=new osg::Vec2Array; // texture coordinates for this object
							vgeom=verts;
							tgeom=tcrds; // what is current texture array
							vlists.push_back(verts);
							txlists.push_back(tcrds);
							geom=new osg::Geometry();
							geom->setNormalBinding(osg::Geometry::BIND_PER_PRIMITIVE);
							geom->setNormalArray(normals);
							geom->setVertexArray(verts);
							if (ob.texture.valid())
							{
								geom->setTexCoordArray(0,tgeom); // share same set of TexCoords
							}
							osg::Material*mat=ac_palette_get_material(asurf.mat);
							osg::StateSet *dstate = new osg::StateSet;
							dstate->setMode( GL_LIGHTING, osg::StateAttribute::ON );
							dstate->setAttribute(mat);
							const osg::Vec4 cdiff =mat->getDiffuse(osg::Material::FRONT_AND_BACK);
							if (cdiff[3]<0.99)
							{
								dstate->setMode(GL_BLEND,osg::StateAttribute::ON);
								dstate->setRenderingHint(osg::StateSet::TRANSPARENT_BIN);
							} 
							else
							{
								dstate->setMode(GL_BLEND,osg::StateAttribute::OFF);
							}
							if (ob.texture.valid()) dstate->setTextureMode(0,GL_TEXTURE_2D,osg::StateAttribute::OFF);
							if (ob.texture.valid())
							{
								osg::TexEnv* texenv = new osg::TexEnv;
								texenv->setMode(osg::TexEnv::MODULATE);
								dstate->setTextureAttribute(0, texenv );
								dstate->setTextureAttributeAndModes(0,ob.texture.get(),osg::StateAttribute::ON);
							}
							if (asurf.flags & SURFACE_TWOSIDED)
								dstate->setMode( GL_CULL_FACE, osg::StateAttribute::OFF );
							else
								dstate->setMode( GL_CULL_FACE, osg::StateAttribute::ON );

							geom->setStateSet( dstate );
							glist.push_back(geom);
							geode->addDrawable(geom);
							ia.push_back(asurf.mat);
						}

						osg::Vec3Array* normals = geom->getNormalArray();
						/** calc surface normal **/
						if (asurf.num_vertref >= 3)
						{
							osg::Vec3 norm;
							unsigned short i1=(*nusidx)[0];
							unsigned short i2=(*nusidx)[1];
							unsigned short i3=(*nusidx)[2];
							osgtri_calc_normal((*vertpool)[i1], 
							(*vertpool)[i2], 
							(*vertpool)[i3], norm);
							normals->push_back(norm);
						}
						int nstart=(*vgeom).size();
						for (i=0; i<asurf.num_vertref; i++)
						{
							osg::Vec2 TextureCoordinate;

							int i1=(*nusidx)[i];
							(*vgeom).push_back((*vertpool)[i1]);
							TextureCoordinate = (*tcs)[i];
							TextureCoordinate._v[0] = ob.texture_offset_x + TextureCoordinate._v[0] * ob.texture_repeat_x;
							TextureCoordinate._v[1] = ob.texture_offset_y + TextureCoordinate._v[1] * ob.texture_repeat_y;
							(*tgeom).push_back(TextureCoordinate);
//							(*tgeom).push_back((*tcs)[i]);
						}
						GLenum poltype=osg::PrimitiveSet::POLYGON;
						if (asurf.flags & SURFACE_TYPE_CLOSEDLINE) poltype=osg::PrimitiveSet::LINE_LOOP;
						if (asurf.flags & SURFACE_TYPE_LINE) poltype=osg::PrimitiveSet::LINE_STRIP;
						geom->addPrimitiveSet(new osg::DrawArrays(poltype,nstart,asurf.num_vertref));
						if (asurf.flags & 0x10) needSmooth++;
					}
				}
				for (geomlist::iterator itr= glist.begin(); itr<glist.end(); itr++)
				{
					osgUtil::Tesselator tesselator;
					if (*itr) tesselator.retesselatePolygons(**itr);
					if (needSmooth)
					{
						osgUtil::SmoothingVisitor smoother;
						smoother.smooth(**itr);
					}
				}
			}
		}
		else if (streq(t, "kids")) /** 'kids' is the last token in an object **/
		{
			int num, n;

			sscanf(buff, "%s %d", t, &num);

			if (num != 0)
			{
				// ob.kids = (ACObject **)myalloc(num * sizeof(ACObject *) );
				ob.num_kids = num;

				for (n = 0; n < num; n++)
				{
					osg::Group *k = ac_load_object(f,&ob); //, ob);
					if (k == NULL)
					{
						printf("error reading expected child object %d of %d at line: %d\n", n+1, num, line);
						return(gp);
					}
					else {
						osg::LightSource *ls=dynamic_cast<osg::LightSource*>(k);
						if (ls) {
							osg::StateSet* lightStateSet = gp->getOrCreateStateSet();
							gp->setStateSet(lightStateSet);
							gp->setCullingActive(false);
							ls->setStateSetModes(*lightStateSet,osg::StateAttribute::ON);
						}
						
						gp->addChild(k);
					}
				}

			}
			if (geode)
			{
				osgUtil::Tesselator tesselator;
				for(unsigned int i=0;i<geode->getNumDrawables();++i)
				{
					osg::Geometry* geom = dynamic_cast<osg::Geometry*>(geode->getDrawable(i));
					if (geom) tesselator.retesselatePolygons(*geom);
				}
			}
			else if (ob.type == OBJECT_LIGHT)
			{ // add a light source to the scene 1 Nov 2003
				static int nlight=1;
				osg::Light* ac3dLight = new osg::Light;
				ac3dLight->setLightNum(nlight++);
				ac3dLight->setPosition(osg::Vec4(ob.loc[0],ob.loc[1],ob.loc[2],0.0f));
				ac3dLight->setAmbient(osg::Vec4(0.5f,0.5f,0.5f,1.0f));
				ac3dLight->setDiffuse(osg::Vec4(0.5f,0.5f,0.5f,1.0f));
				ac3dLight->setSpecular(osg::Vec4(1.0f,1.0f,0.5f,1.0f));
				
				osg::LightSource* ac3dLightSource = new osg::LightSource;	
				ac3dLightSource->setLight(ac3dLight);
				ac3dLightSource->setLocalStateSetModes(osg::StateAttribute::ON); 
				
				// for some mad reason, you need to set this so that the light works.  WHY?
				return ac3dLightSource;
			}
			return(gp);
		}
	}
	if (geode)
	{
		osgUtil::Tesselator tesselator;
		for(unsigned int i=0;i<geode->getNumDrawables();++i)
		{
			osg::Geometry* geom = dynamic_cast<osg::Geometry*>(geode->getDrawable(i));
			if (geom) tesselator.retesselatePolygons(*geom);
		}
	}
	return(gp);
}


/*void ac_calc_vertex_normals(ACObject *ob)
{
int n;

    ac_object_calc_vertex_normals(ob);
    if (ob->num_kids)
        for (n = 0; n < ob->num_kids; n++)
            ac_calc_vertex_normals(ob->kids[n]);
}*/


osg::Group *ac_load_ac3d(const char *fname)
{
FILE *f = fopen(fname, "r");

osg::Group *ret = NULL;

    if (f == NULL)
        {
        printf("can't open %s\n", fname);
        return(NULL);
        }

    read_line(f);

    if (strncmp(buff, "AC3D", 4))
        {
        printf("ac_load_ac '%s' is not a valid AC3D file.", fname);
        fclose(f);
        return(0);
        }


    startmatindex = palette.size(); //num_palette;


    ret = ac_load_object(f,NULL); //, NULL);

    
    fclose(f);

    // ac_calc_vertex_normals(ret);
    // here I need to calculate nromals for this object

    return(ret);
}







void ac_dump(ACObject *ob)
{ // not yet finished option ot output AC3D file from OSG scene.
int n;

    printf("OBJECT name %s\nloc %f %f %f\nnum_vert %d\nnum_surf %d\n",
        ob->name, ob->loc[0], ob->loc[1], ob->loc[2], ob->num_vert, ob->num_surf);


//    for (n=0; n < ob->num_vert; n++)
//        printf("\tv %f %f %f\n", ob->vertices[n].x, ob->vertices[n].y, ob->vertices[n].z);

    for (n=0; n < ob->num_surf; n++)
        {
////        ACSurface *s = &ob->surfaces[n];
//        printf("surface %d, %d refs, mat %d\n", n, s->num_vertref, s->mat);
        }

/* this structure not used in OSG
    if (ob->num_kids)
        for (n = 0; n < ob->num_kids; n++)
            ac_dump(ob->kids[n]); 
 */            
}



// now register with osg::Registry to instantiate the above
// reader/writer.
osgDB::RegisterReaderWriterProxy<ReaderWriterAC> g_readerWriter_AC_Proxy;