#include "uniformgrid.h"

UniformGrid::UniformGrid()
{
    stepScale = 0.5f;
    nb_point_par_ligne = 160;
    longueur=4.f;
    CreateVertexBuffer();
    CreateIndexBuffer();
}

UniformGrid::~UniformGrid()
{

}

void UniformGrid::CreateVertexBuffer()
{
    Math::Vector3 Vertices[nb_point_par_ligne*nb_point_par_ligne];
    for(float ii=0,i=-longueur/2; i<=longueur/2; i+=(longueur/(nb_point_par_ligne-1)), ii++)
        for(float jj=0,j=-longueur/2; j<=longueur/2; j+=(longueur/(nb_point_par_ligne-1)), jj++)
        {
            Vertices[(int)(ii*nb_point_par_ligne+jj)]=Math::Vector3(i,0.f,j);
        }

    float tmp[nb_point_par_ligne*nb_point_par_ligne*3];
    for(int i=0;i<nb_point_par_ligne*nb_point_par_ligne ;i++)
        for(int j=0;j<3;j++)
        {
            tmp[i*3+j]=Vertices[i][j];
        }
    glGenBuffers(1, &VBO);
    glBindBuffer(GL_ARRAY_BUFFER, VBO);
    glBufferData(GL_ARRAY_BUFFER, sizeof(tmp), tmp, GL_STATIC_DRAW);
}

void UniformGrid::CreateIndexBuffer()
{
    unsigned int Indices[3*(nb_point_par_ligne-1)*(nb_point_par_ligne-1)*2];
    int cpt=0;
    for(int i=0; i<nb_point_par_ligne-1; i++)
        for(int j=0; j<nb_point_par_ligne-1; j++)
            {
            int ind = i*nb_point_par_ligne+j;
            Indices[cpt]= ind;
            Indices[cpt+1]= ind + nb_point_par_ligne;
            Indices[cpt+2]= ind + 1;
            Indices[cpt+3]= ind + nb_point_par_ligne;
            Indices[cpt+4]= ind + nb_point_par_ligne+1;
            Indices[cpt+5]= ind + 1;
            cpt+=6;
        }

    glGenBuffers(1, &IBO);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, IBO);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(Indices), Indices, GL_STATIC_DRAW);
}