#include <stdio.h>

#define N_XPIXELS 3
#define N_YPIXELS 3 
#define SLEEP 10000000

void write_data();
FILE *gp;

/* data: 3 x 3 */
int IMG[] = {
		1,0,0,
		0,1,1,
		1,0,1,
};


int main (int argc, char *argv[] )
{ 
	int i,j,k;
	
	gp = popen("gnuplot -geometry 480x480","w");
	fprintf(gp, "set pm3d\n");
	fprintf(gp, "set view 0,0\n");
	fprintf(gp, "unset key\n");
	fprintf(gp, "splot '-' with pm3d\n");

	write_data(); 

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

	fclose(gp);
}



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

	int i,x,y;

	for (x=0; x<N_XPIXELS; x++){
		for (y=0; y<N_YPIXELS; y++){
			i = x + (N_YPIXELS -y -1)*N_XPIXELS; 
			fprintf(gp, "%d  %d %d\n", x, y,    IMG[i]);
			fprintf(gp, "%d  %d %d\n", x, y+1,  IMG[i]);
		}
		fprintf(gp, "\n"); 

		for (y=0; y<N_YPIXELS; y++){
			 i = x + (N_YPIXELS -y -1)*N_XPIXELS;
			 fprintf(gp, "%d  %d %d\n", x+1,   y, IMG[i]);
			 fprintf(gp, "%d  %d %d\n", x+1, y+1, IMG[i]);
		}
		fprintf(gp, "\n"); 
	}               
}