#include <stdio.h>

#define N_XPIXELS 20
#define N_YPIXELS 20
#define SLEEP 10000000

void write_2d_data();

FILE *gp;

/* data: 20 x 20 */
int I[] = {
		0,0,0,0,1,1,0,0,1,0,0,0,0,0,0,0,0,0,1,0,
		1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,1,1,1,1,
		0,0,0,0,1,1,0,0,0,0,0,0,0,0,1,1,0,0,0,0,
		0,1,1,0,1,1,0,1,1,0,0,0,0,0,1,1,0,0,0,0,
		0,1,0,0,1,1,0,1,0,0,0,1,1,0,1,1,0,1,1,0,
		1,0,1,0,1,1,0,1,1,0,0,1,1,0,1,1,1,1,1,1,
		1,0,0,1,1,1,1,0,0,1,0,1,1,0,1,1,0,1,1,0,
		0,0,0,0,1,1,0,0,0,0,0,1,1,0,1,1,0,1,1,0,
		0,0,0,1,1,1,1,1,0,0,0,1,1,0,1,1,0,1,1,0,
		0,0,1,0,1,1,0,0,1,1,0,1,1,0,1,1,0,1,1,0,
		1,1,0,0,1,1,0,0,1,1,0,1,1,0,1,1,0,1,1,0,
		0,0,0,1,0,0,0,1,0,0,0,1,1,1,1,1,1,1,1,0,
		0,0,0,1,1,1,1,1,1,0,0,1,1,0,0,0,0,1,1,0,
		0,0,1,1,0,0,0,1,0,0,0,0,0,0,0,0,0,1,1,0,
		0,1,1,0,0,0,1,0,0,0,0,0,0,0,0,0,1,1,0,0,
		1,0,0,1,0,1,0,0,0,0,0,0,0,0,1,1,1,1,0,0,
		0,0,0,0,1,1,1,0,0,0,0,0,0,0,0,0,1,0,0,0,
		0,0,0,1,1,0,1,1,1,0,0,0,0,0,0,0,0,0,0,0,
		0,0,1,1,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,
		1,1,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,0
};


int main (int argc, char *argv[] )
{ 
	int i,j,k;
	
	gp = popen("gnuplot -geometry 480x480","w");
//	fprintf(gp, "set term x11\n");
	fprintf(gp, "set yrange [] reverse\n");
	fprintf(gp, "unset key\n");
	
//	fprintf(gp, "set out 'filename%d-%d.eps'\n",k,i);

	fprintf(gp, "plot '-' matrix with image\n");

	write_2d_data(); 

	fprintf(gp,"e\n");
	fprintf(gp,"e\n");
	fflush(gp); 
	usleep(SLEEP);

	fclose(gp);
}



/* write data for gnuplot */
void write_2d_data(){ 

	int n_pixels = N_XPIXELS*N_YPIXELS;
	int i;

	for (i=0; i<n_pixels; i++){
		fprintf(gp, "%d ", I[i]);
		if (  (i+1)%N_XPIXELS  ==  0 ){
			fprintf(gp, "\n");
		}
	}
}