BSP_PlyLoader.cpp

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#include "BSP_PlyLoader.h"

#include "MT_Vector3.h"
#include "ply.h"

struct LoadVertex {
  float x,y,z;             /* the usual 3-space position of a vertex */
};

struct LoadFace {
  unsigned char intensity; /* this user attaches intensity to faces */
  unsigned char nverts;    /* number of vertex indices in list */
  int *verts;              /* vertex index list */
};


    MEM_SmartPtr<BSP_TMesh>
BSP_PlyLoader::
NewMeshFromFile(
    char * file_name,
    MT_Vector3 &min,
    MT_Vector3 &max

) {

    min = MT_Vector3(MT_INFINITY,MT_INFINITY,MT_INFINITY);
    max = MT_Vector3(-MT_INFINITY,-MT_INFINITY,-MT_INFINITY);
    
    PlyProperty vert_props[] = { /* list of property information for a vertex */
      {"x", PLY_FLOAT, PLY_FLOAT, offsetof(LoadVertex,x), 0, 0, 0, 0},
      {"y", PLY_FLOAT, PLY_FLOAT, offsetof(LoadVertex,y), 0, 0, 0, 0},
      {"z", PLY_FLOAT, PLY_FLOAT, offsetof(LoadVertex,z), 0, 0, 0, 0},
    };

    PlyProperty face_props[] = { /* list of property information for a vertex */
      {"vertex_indices", PLY_INT, PLY_INT, offsetof(LoadFace,verts),
       1, PLY_UCHAR, PLY_UCHAR, offsetof(LoadFace,nverts)},
    };

    MEM_SmartPtr<BSP_TMesh> mesh = new BSP_TMesh;

    if (mesh == NULL) return NULL;

    int i,j;
    PlyFile *ply;
    int nelems;
    char **elist;
    int file_type;
    float version;
    int nprops;
    int num_elems;
    PlyProperty **plist;

    char *elem_name;

    LoadVertex load_vertex;
    LoadFace load_face;

    /* open a PLY file for reading */
    ply = ply_open_for_reading(
        file_name,
        &nelems,
        &elist, 
        &file_type, 
        &version
    );

    if (ply == NULL) return NULL;

    /* go through each kind of element that we learned is in the file */
    /* and read them */

    for (i = 0; i < nelems; i++) {

        /* get the description of the first element */

        elem_name = elist[i];
        plist = ply_get_element_description (ply, elem_name, &num_elems, &nprops);

        /* print the name of the element, for debugging */

        /* if we're on vertex elements, read them in */

        if (equal_strings ("vertex", elem_name)) {

            /* set up for getting vertex elements */

            ply_get_property (ply, elem_name, &vert_props[0]);
            ply_get_property (ply, elem_name, &vert_props[1]);
            ply_get_property (ply, elem_name, &vert_props[2]);

            // make some memory for the vertices        
            mesh->VertexSet().reserve(num_elems);

            /* grab all the vertex elements */
            for (j = 0; j < num_elems; j++) {

                /* grab and element from the file */
                ply_get_element (ply, (void *)&load_vertex);
                // pass the vertex into the mesh builder.
                    
                if (load_vertex.x < min.x()) {
                    min.x() = load_vertex.x;
                } else
                if (load_vertex.x > max.x()) {
                    max.x()= load_vertex.x;
                }

                if (load_vertex.y < min.y()) {
                    min.y() = load_vertex.y;
                } else
                if (load_vertex.y > max.y()) {
                    max.y()= load_vertex.y;
                }

                if (load_vertex.z < min.z()) {
                    min.z() = load_vertex.z;
                } else
                if (load_vertex.z > max.z()) {
                    max.z()= load_vertex.z;
                }

                BSP_TVertex my_vert;
                my_vert.m_pos = MT_Vector3(load_vertex.x,load_vertex.y,load_vertex.z);
                mesh->VertexSet().push_back(my_vert);
            }
        

        }

        /* if we're on face elements, read them in */
        if (equal_strings ("face", elem_name)) {

            /* set up for getting face elements */

            ply_get_property (ply, elem_name, &face_props[0]);

            /* grab all the face elements */
            for (j = 0; j < num_elems; j++) {

                ply_get_element (ply, (void *)&load_face);

                int v;
                for (v = 2; v< load_face.nverts; v++) {

                    BSP_TFace f;

                    f.m_verts[0] = load_face.verts[0];
                    f.m_verts[1] = load_face.verts[v-1];
                    f.m_verts[2] = load_face.verts[v];

                    mesh->BuildNormal(f);   
                    mesh->FaceSet().push_back(f);
                }
                // free up the memory this pile of shit used to allocate the polygon's vertices
                free (load_face.verts);
            }

        }
    }
  /* close the PLY file */
  ply_close (ply);

 return mesh;
}