#define PI 3.14159

#define DPI  300              /* working with inches */
#define MESH 300                        /*  dots per inch   */
#define SIZE 6.4                  /*  width = height of picture, in inches  */


                                   /* The location of the upper left corner
                                      of the picture will be as follows:  */

#define H_OFFSET 1.2               /* inches from left edge of paper */
#define V_OFFSET 2                 /* inches from top edge of paper */

typedef 
	     	struct 
		{
	double x_coord;
	double y_coord;
		} 
point;

typedef 
	     	struct 
		{
	double coord_1;
	double coord_2;
	double coord_3;
		} 
point_3;

typedef 
	     	struct 
		{
	double coord_1;
	double coord_2;
	double coord_3;
	double coord_4;
		} 
point_4;

typedef
		struct
		{
	double a_11; double a_12;
	double a_21; double a_22;
		}
matrix_2_2;

typedef
		struct
		{
	double a_11; double a_12; double a_13;
	double a_21; double a_22; double a_23;
	double a_31; double a_32; double a_33;
		}
matrix_3_3;

typedef
		struct
		{
	double a_11; double a_12; double a_13; double a_14;
	double a_21; double a_22; double a_23; double a_24;
	double a_31; double a_32; double a_33; double a_34;
	double a_41; double a_42; double a_43; double a_44;
		}
matrix_4_4;

typedef
		struct
		{
	double a_11; double a_12; double a_13; double a_14;
	double a_21; double a_22; double a_23; double a_24;
	double a_31; double a_32; double a_33; double a_34;
		}
matrix_3_4;

typedef
		struct
		{
	double a_11; double a_12; double a_13;
	double a_21; double a_22; double a_23;
	double a_31; double a_32; double a_33;
	double a_41; double a_42; double a_43;
		}
matrix_4_3;

typedef point_4 Projective_point_3;
typedef point_3 Projective_point_2;