streaming_mesh.h

#pragma once
 
#include <vector>
#include <deque>
#include <cgv/math/fvec.h>
 
namespace cgv {
    namespace media {
        namespace mesh {
 
struct streaming_mesh_callback_handler
{
    virtual void new_vertex(unsigned int vertex_index) = 0;
    virtual void new_polygon(const std::vector<unsigned int>& vertex_indices) = 0;
    virtual void before_drop_vertex(unsigned int vertex_index) = 0;
};
 
template <typename T>
class streaming_mesh
{
public:
    typedef cgv::math::fvec<T,3> pnt_type;
    typedef cgv::math::fvec<T,3> vec_type;
protected:
    int idx_off;
    unsigned int nr_faces;
    std::deque<pnt_type> pnts;
    std::deque<vec_type> nmls;
    streaming_mesh_callback_handler* smcbh;
public:
    streaming_mesh(streaming_mesh_callback_handler* _smcbh = 0) : smcbh(_smcbh), nr_faces(0), idx_off(0) {
    }
    void set_callback_handler(streaming_mesh_callback_handler* _smcbh) {
        smcbh = _smcbh;
    }
    unsigned int get_nr_dropped_vertices() const           { return idx_off; }
    unsigned int get_nr_vertices() const                   { return (unsigned int) pnts.size()+idx_off; }
    unsigned int get_nr_faces() const                      { return nr_faces; }
    void drop_vertex() {
        if (pnts.empty())
            return;
        if (smcbh)
            smcbh->before_drop_vertex(idx_off);
        pnts.pop_front();
        nmls.pop_front();
        ++idx_off;
    }
    void drop_vertices(unsigned int n) {
        for (unsigned int i=0; i<n; ++i)
            drop_vertex();
    }
           pnt_type& vertex_location(unsigned int vi)       { return pnts[vi-idx_off]; }
    const pnt_type& vertex_location(unsigned int vi) const { return pnts[vi-idx_off]; }
    const vec_type& vertex_normal(unsigned int vi) const   { return nmls[vi-idx_off]; }
         vec_type& vertex_normal(unsigned int vi)         { return nmls[vi-idx_off]; }
    unsigned int new_vertex(const pnt_type& p) {
        unsigned int vi = (int)pnts.size()+idx_off;
        pnts.push_back(p);
        nmls.push_back(vec_type(0,0,0));
        if (smcbh)
            smcbh->new_vertex(vi);
        return vi;
    }
    void new_triangle(unsigned int vi, unsigned int vj, unsigned int vk) {
        static std::vector<unsigned int> vis(3);
        vis[0] = vi;
        vis[1] = vj;
        vis[2] = vk;
        ++nr_faces;
        if (smcbh)
            smcbh->new_polygon(vis);
    }
    void new_quad(unsigned int vi, unsigned int vj, unsigned int vk, unsigned int vl) {
        static std::vector<unsigned int> vis(4);
        vis[0] = vi;
        vis[1] = vj;
        vis[2] = vk;
        vis[3] = vl;
        ++nr_faces;
        if (smcbh)
            smcbh->new_polygon(vis);
    }
    void new_polygon(const std::vector<unsigned int>& vertex_indices) {
        ++nr_faces;
        if (smcbh)
            smcbh->new_polygon(vertex_indices);
    }
};
 
        }
    }
}