1.7.5. DRAWING A CIRCLE WITH 2 LINEAR AXES, AND GENERATING A POSTSCRIPT FILE

#include <phigure.h>
main () {
	Pfloat zoom=0.8, circle_radius = 5.0;
	Pint ws_id = 1, PostScript_id = 2, view_ind = 1,
	scene_id = 10, circle_id = 11, x_axis_id=12, y_axis_id=13;
	Tcircle circle;
	static Plimit viewport = {0.,1., 0., 1.}, domain = {10., 20., 10., 20. };
	static Ppoint circle_center = {15., 15.}, view_center = {0.5, 0.5};
	static Ppoint3 axis_orig = {10.0,10.0,0.0};
	static Pint struct_ids[3];
	static Pint_list struct_id_list = {3, struct_ids};

/* open PHIGURE and an X-Window type workstation (8887) */
	topen_phigure (PDEF_ERR_FILE);
	topen_ws (ws_id, PDEF_ERR_FILE, 8887);

/* define domain */
	tdomain (&domain);

/* build circle */
	circle.type = TCENTER_RADIUS;
	circle.geometry.cr.r = circle_radius;
	circle.geometry.cr.c = circle_center;
	tcircle (circle_id, &circle);

/* label attribute on the X axis */
	tset_axis_label (x_axis_id, TVISIBILITY_ON, TLABEL_AT_END, TPATH_RIGHT, 0.0, "X-axis");

/* build 2 axes */
	txy_linear_axis (x_axis_id, &axis_orig, 20.0, 0.0);
	tyx_linear_axis (y_axis_id, &axis_orig, 20.0, 0.0);

/* insert a PHIGS line type attribute in the structure x_axis_id */
	tset_linetype (x_axis_id, -1, PLINE_DASH);

/* define scene */
	struct_ids[0] = circle_id;
	struct_ids[1] = x_axis_id;
	struct_ids[2] = y_axis_id;
	tscene (scene_id, &struct_id_list, view_ind);

/* define a centered 2D view */
	tview2_center (ws_id, view_ind, &view_center, zoom, &viewport);

/* display scene on workstation */
	ppost_struct (ws_id, scene_id, 1.0);
	predraw_all_structs (ws_id, PFLAG_ALWAYS);

/* close workstation */
	tclose_ws (ws_id);

/* generate PostScript file */
	topen_ws (PostScript_id,"PostScript_file",80791);
	tview2_center (PostScript_id,view_ind,&view_center,zoom,&viewport);
	ppost_struct(PostScript_id,scene_id,1.);
	predraw_all_structs(PostScript_id,PFLAG_ALWAYS);
	tclose_ws (PostScript_id);

/* close PHIGURE */
	tclose_phigure ();
}

To generate a PostScript file corresponding to the preceding image, use a PostScript-type workstation (8079x) and apply the following rules :

define a second workstation identifier PostScript_id

open the Post-Script workstation topen_ws (PostScript_id, ...)

define a view on this workstation tview2_center (for example)

post the structures to be displayed ppost_struct (PostScript_id, ...)

plot the posted structures predraw_all_structs (PostScript_id, ...)

close the file tclose_ws (PostScript_id, ...)

In general, if the PostScript file has to correspond exactly to the image obtained on the first workstation ws_id, it suffices to duplicate all the calls with ws_id as the first parameter.