source: GTP/trunk/Lib/Vis/Preprocessing/src/ObjParser.cpp @ 1314

#include <stdlib.h>
#include <iostream>
#include <list>
#include <map>
using namespace std;

#include "Vector3.h"
#include "Mesh.h"
#include "SceneGraph.h"

#include "ObjParser.h"
//#include "Material.h"
#include "Environment.h"
#include "ResourceManager.h"
#include "KdIntersectable.h"


namespace GtpVisibilityPreprocessor {

#define ROTATE_SCENE 0
// HACK
        static void RotateMesh(Mesh *mesh)
        {
                VertexContainer::iterator it, it_end = mesh->mVertices.end();

                const float angle = 30.0f * PI / 180.0f;
                const Matrix4x4 rot = RotationYMatrix(angle);

                for (it = mesh->mVertices.begin(); it != it_end; ++ it)
                {
                        (*it) = rot * (*it);        
                }
        }


        struct ltstr
        {
                bool operator()(const string s1, const string s2) const
                {
                        return s1 < s2;
                }
        };

//const static int nMaxFaces = 6;


Face *LoadFace(char *str, 
                           const VertexContainer &vertices, 
                           map<int, Vector3> &hashTable)
{
  //    cout << "f";

        char *pch;
        
        pch = strtok(str + 1, " ");
        
        VertexIndexContainer indices;
        while (pch != NULL)
        {
                const int index = (int)strtol(pch, NULL, 10) - 1;

                //Debug << index << " x ";
                
                // store vertex in hash table
                hashTable[index] = vertices[index];
                indices.push_back(index);
                
                pch = strtok(NULL, " ");
        }
        //if (indices.size() > 4) return NULL;

        return new Face(indices); 
}


Mesh *CreateMesh(FaceContainer &faces, const map<int, Vector3> &hashTable)
{
        Mesh *mesh = MeshManager::GetSingleton()->CreateResource();
        
        FaceContainer::const_iterator fit, fit_end = faces.end();

        for (fit = faces.begin(); fit != fit_end; ++ fit)
        {
                Face *face = *fit;
                VertexIndexContainer::iterator vit, vit_end = face->mVertexIndices.end();
                
                for (vit = face->mVertexIndices.begin(); vit != vit_end; ++ vit)
                {
                        // go through indices
                        const int index = *vit;            
                        //Debug << "old idx: " << (*vit) << endl;
                        map<int, Vector3>::const_iterator hit = hashTable.find(index);

                        // correct face index (nust be relative to start of verices)
                        (*vit) = (int)distance(hashTable.begin(), hit);
                        //Debug << "new idx: " << (*vit) << endl;
                }
        }

        VertexContainer vertices;

        map<int, Vector3>::const_iterator hit, hit_end = hashTable.end();

        // store vertices in given order
        for (hit = hashTable.begin(); hit != hit_end; ++ hit)
        {
                mesh->mVertices.push_back((*hit).second);
        }

        mesh->mFaces = faces;

        // can't do cleanup because coupling with kdf file for intel ray tracer
        mesh->Preprocess(false);

        /*for (int i = 0; i < faces.size(); ++ i)
        {
                Debug << "face: ";

                for (int j = 0; j < faces[i]->mVertexIndices.size(); ++ j)
                {
                        Debug << "i " << faces[i]->mVertexIndices[j] << " " << endl;    
                        Debug << "v " << mesh->mVertices[faces[i]->mVertexIndices[j]] << " ";
                }
                Debug << endl;
        }*/

        return mesh;
}


// HACK: associate mesh instances with triangles
void AssociateFacesWithInstance(MeshInstance *mi,
                                                                vector<FaceParentInfo> &parents)
{
  Mesh *mesh = mi->GetMesh();
  
  FaceContainer::const_iterator fit, fit_end = mesh->mFaces.end();
  int i = 0;
  for (fit = mesh->mFaces.begin(); fit != fit_end; ++ fit, i++)
        {
          parents.push_back(FaceParentInfo(mi, i));
        }
}


bool ObjParser::ParseFile(const string filename,
                                                  SceneGraphNode **proot,
                                                  const bool loadPolygonsAsMeshes,
                                                  vector<FaceParentInfo> *parents)
{
        FILE *file;
        if ((file = fopen(filename.c_str(), "rt")) == NULL)
                return false;
        
        VertexContainer vertices; // table for vertices
        map<int, Vector3> hashTable; // table associating indices with vectors
        FaceContainer faces;

        char str[100];
        
        SceneGraphNode *root = new SceneGraphNode;

        int meshGrouping;
        Environment::GetSingleton()->GetIntValue("ObjParser.meshGrouping", meshGrouping);

        int nMaxFaces = meshGrouping;

        while (fgets(str, 80, file) != NULL)
        {
                switch (str[0]) 
                {
                case 'v':
                        {
                                float x,y,z;
                                //cout << "v";

                                // vertex 
                                sscanf(str + 1, "%f %f %f", &x, &y, &z);
                                vertices.push_back(Vector3(x,y,z));
                                //Debug << "vertex: " << vertices.back() << endl;
                                break;
                        }
                case 'f': 
                        {
                                Face *face = LoadFace(str, vertices, hashTable);
                                if (!face) break;
#if 1
                                faces.push_back(face);
                                if (faces.size() >= nMaxFaces)
                                {
                                        Mesh *mesh = CreateMesh(faces, hashTable);

                                        // make an instance of this mesh
                                        MeshInstance *mi = new MeshInstance(mesh);
                                        root->mGeometry.push_back(mi);
                                        
                                        if (parents) 
                                                AssociateFacesWithInstance(mi, *parents);
                                                                                
                                        // reset tables
                                        hashTable.clear();
                                        faces.clear();
                                }
#else
                                root->mGeometry.push_back(new FaceIntersectable(face));
                                hashTable.clear();
#endif
                                break;
                        }   // end face
                default:
                        break;
                }
        }

        // there could be faces remaining
        if (!faces.empty())
        {       
                Mesh *mesh = CreateMesh(faces, hashTable);

                // make an instance of this mesh
                MeshInstance *mi = new MeshInstance(mesh);
                
                if (parents) 
                        AssociateFacesWithInstance(mi, *parents);
                
                root->mGeometry.push_back(mi);  
        }

        // reset tables
        hashTable.clear();
        faces.clear();

        fclose(file);
        *proot = root;

        return true;
}

}