polyline.c

来自「Intro/: Directory containing introducto」· C语言 代码 · 共 36 行

#include <phigs.h>			/* get HP-PHIGS definitions for C */
#include <stdio.h>			/* get standard I/O definitions */
#include <math.h>			/* link with library "-lm" */
#define	 deg	*3.14159265358979/180.	/* convert degrees to radians */

main()					/* file "Polyline.c" */
{
    Pint	WorkstnID = 1;		/* workstation identifier */
    Pint	ConnID;			/* connection identifier */
    Pint	WorkstnType = POIDDX;	/* out/in, direct, dbl bfr, Xwindow */
    Pint	TheStructure = 1;	/* structure ID (chosen by user) */
    Ppoint	PentagonPts[100];	/* for the XYs of the polyline */
    Ppoint_list	Pentagon;		/* for the polyline */
    float	Theta = 0, Radius = 0;	/* temporary variables */
    int		I;			/* loop control variable */

    popen_phigs((char *) stderr, 0);	/* errors go to "stderr" */
    pescape_u4("/dev/screen/phigs_window", &ConnID);
    popen_ws(WorkstnID, (void *) ConnID, WorkstnType);
    popen_struct(TheStructure);
    for (I = 0; I < 100; I++) {		/* for each point... */
	PentagonPts[I].x = (Radius * cos(Theta) + 1) * 0.5;
	PentagonPts[I].y = (Radius * sin(Theta) + 1) * 0.5;
	Theta += 73 deg;		/* roughly pentagonal */
	Radius += 0.01;			/* enlarge it slightly */
    }
    Pentagon.num_points = 100;
    Pentagon.points = PentagonPts;
    ppolyline(&Pentagon);		/* polyline with 100 points */
    pclose_struct();
    ppost_struct(WorkstnID, TheStructure, 1.0);
    pupd_ws(WorkstnID, PFLAG_PERFORM);	/* (regeneration flag) */
    pclose_ws(WorkstnID);
    pclose_phigs();
}