int tir_parabolic(int x_inici, int y_inici, double angle, double forca, int x_actual, int vent){
	double v_x,v_y; // Velocitats inicials
	double t; // Temps transcorregut
	
	v_x = cos((double)angle)*(double)forca;
	v_y = sin((double)angle)*(double)forca;
	if ((v_x*v_x-(double)(2*vent*(x_inici-x_actual))) != 0) {
		t = (-v_x - sqrt(v_x*v_x-(double)(2*vent*(x_inici-x_actual))))/(double)vent;
		
		if (t < 0) 
			t = (-v_x + sqrt(v_x*v_x-(double)(2*vent*(x_inici-x_actual))))/(double)vent;
	}
	
	if (vent == 0) {
		t = ((float)x_actual-(float)x_inici)/v_x;
	}
	
	if (v_x==0) {
		return -1;
	}
	else {
		return (int)(y_inici+(int)v_y*t-(int)(GRAVETAT/2.0)*(t*t));
	}
}