GPHIGS C FUNCTIONS

POLYLINE

PPOLYLINE

CALL SEQUENCE

void ppolyline(

const Ppoint_list	*point_list	/* list of points	*/

TYPES

typedef struct {
	Pint	num_points;	/* number of Ppoint in the list	*/
	Ppoint	*points;	/* list of points	*/
}	Ppoint_list;

typedef struct {
	Pfloat 	x;	/* x coordinate	*/
	Pfloat 	y;	/* y coordinate	*/
}	Ppoint;

PHIGS STATE

(PHOP, *, STOP, *).

EFFECT

This function limits the 3D polyline function to 2D (x, y). The Z coordinate is set to 0.

The POLYLINE element is inserted in the open structure after element pointer or replaces the element indicated by element pointer, depending on the edit mode value. Element pointer is updated and points to the POLYLINE structure element. The values specified in the function are associated with the element.

When an element of this type is interpreted, a series of adjacent straight line segments is generated from the first to the last point in the list. The current polyline attributes defined in the PHIGS traversal state list are applied to the polyline. A polyline with less than two points is placed in the open structure, but has no visual effect when interpreted.

Attributes associated with Polyline:

LINETYPE

LINEWIDTH SCALE FACTOR

POLYLINE COLOUR

EXTENSION TO THE PHIGS STANDARD

If used in one of the two GPHIGS specific modes NRS or NDDS, the effect of this function is different from the effect described in the standard.

In NRS mode, (see OPEN PIPE), the element is not stored in a structure. It is sent to the workstation on which the pipe is opened.

In NDDS mode, (see BEGIN NON DUPLICATE DATA STORE), the element is stored in the structure but its content is not copied into the CSS. GPHIGS stores only the pointer to the user's data.

See GPHIGS user guide for more details on NRS and NDDS modes.

ERRORS

5: Ignoring function, function requires state (PHOP,*, STOP,*)