GPHIGS C FUNCTIONS - PICK AND LOCATOR WITHOUT INTERACTION

PICK AND LOCATOR WITHOUT INTERACTION

PXPICK_LOC

CALL SEQUENCE

void pxpick_loc(

Pint	ws_id,	/* workstation identifier	*/
Pint	pick_dev_num,	/* pick device number	*/
Pint	depth,	/* pick path depth	*/
Ppoint	*point,	/* located point in DC	*/
Pin_status	*status,	/* returned status	*/
Ppick_path	*pick_path,	/* returned pick path	*/
Pint 	*view_index,	/* returned view index	*/
Ppoint3	*point_wc	/* returned picked point in WC	*/

TYPES

typedef struct {
	Pfloat	x,y;	/* coordinates	*/
} Ppoint;

typedef struct {
	Pfloat	x,y,z;	/* coordinates	*/
} Ppoint3;

typedef enum {
	PIN_STATUS_NONE,
	PIN_STATUS_OK,
	PIN_STATUS_NO_IN
} Pin_status;

typedef struct {
	Pint	depth;
	Ppick_path_elem	*path_list;
} Ppick_path;

typedef struct {
	Pint	struct_id;
	Pint	pick_id;
	Pint	elem_pos;
} Ppick_path_elem;

PHIGS STATE

(PHOP,WSOP,*,*)

EFFECT

GPHIGS uses this function to simulate a PICK without interaction. A DC point, coming from an input device external to GPHIGS, is given to this function, and this function returns the same information as the function pxpick and the localization of the picked object.

The returned point is the intersection between the picked object and the picking vector. This point is returned in WC using the standard locator routines. This means that view input priorities must be correctly set to get the point in the good view.

NOTES

If the DC point is obtained as the result of an X event, it is necessary, before sending it to the function, to transform from X device coordinates to GPHIGS device coordinates. The origin of an X window is located at upper-left corner while the origin of a GPHIGS workstation is located at the lower-left corner. It is, therefore, necessary to invert the Y values in the following manner :

point.y = window.height - ev.xbutton.y ;

where window.height is the height in pixels of the X window and ev.xbutton.y is the Y position acquired with the event.

ERRORS

3: Ignoring function, function requires state (PHOP, WSOP,*,*)
54: Ignoring function, the specified workstation is not open