GPHIGS C FUNCTIONS - LOCATOR WITHOUT INTERACTION 3

LOCATOR WITHOUT INTERACTION 3

PXLOCATOR3

CALL SEQUENCE

void pxlocator3(

Pint	ws_id,	/* workstation identifier	*/
Pint	loc_dev_num,	/* locator device number	*/
Ppoint3	*point,	/* located point in DC	*/
Pint	*view_ind,	/* view index	*/
Ppoint3	*loc_pos	/* locator position in WC	*/

TYPES

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

PHIGS STATE

(PHOP,WSOP,*,*)

EFFECT

GPHIGS uses this function to simulate a LOCATOR without interaction. A 3D 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 SAMPLE LOCATOR.

Use of this function overcomes the differences in concept between an event-driven model
( MOTIF ) and the classic sequential model required for the use of PHIGS input.

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