OpenGL (glut) & rafraichissement par rapport à un array

int draw(int argc, char **argv, int *vlat,const int &vlx, const int &vly)

#include <iostream>
#include <cstdlib>
#include <gl/glut.h>
using namespace std;

// function prototypes
void disp(void);
int xmax, ymax, *lat;

// window identifier
static int win;

void timer(int extra)
	{
	glutpostredisplay();
	gluttimerfunc(30,timer,0);
	}

int draw(int argc, char **argv, int *vlat,const int &vlx, const int &vly){

	//makes the variables global
	xmax = vlx;
	ymax = vly;
	lat = vlat;


	//////////
	// init //
	//////////

	// initialize glut
	glutinit(&argc, argv);
	glutinitdisplaymode(glut_rgba | glut_double);

	// define the size
	glutinitwindowsize(700,700);

	// the position where the window will appear
	glutinitwindowposition(100,100);

	// create the window, set the title and keep the 
	// window identifier.
	win = glutcreatewindow("percolation");

	//////////////
	// callback //
	//////////////

	glutdisplayfunc(disp);

	////////////
	// opengl //
	////////////

	// define the color we use to clearscreen 
	glclearcolor(0.0,0.0,0.0,0.0);
	gluttimerfunc(0,timer,0);

	
	
	// enter the main loop
	glutmainloop();

	return 0;
}


	void disp(void){

		glclear(gl_color_buffer_bit);
		int r[5], g[5], b[5];
		
		//define the colours we will use
		r[0]= 1; g[0]= 1; b[0]= 1; //white
		r[1]= 0; g[1]= 1; b[1]= 0; //green
		r[2]= 1; g[2]= 0; b[2]= 0; //red
		r[3]= 0; g[3]= 0; b[3]= 0; //black

		//begin of drawing
		glbegin(gl_points);
		for (int y=0; y<ymax; y++){
			for (int x=0; x<xmax; x++){
				glcolor3f(r[lat[y*xmax + x]], g[lat[y*xmax + x]],b[lat[y*xmax + x]]);
				glvertex2d(((double)x/xmax*1.8)-0.9,((double)y/ymax*1.8)-0.9);	
			}
		}		 
		glend();
		//glflush();

		glutswapbuffers();
		
		//glutpostredisplay();



	}