src/rt/text.c

#ifndef lint
static const char       RCSid[] = "$Id: text.c,v 2.23 2003/07/27 22:12:03 schorsch Exp $";
#endif
/*
 *  text.c - functions for text patterns and mixtures.
 */

#include "copyright.h"

#include  "ray.h"

#include  "paths.h"

#include  "otypes.h"

#include  "font.h"

/*
 *      A text pattern is specified as the text (a file or line),
 *  the upper left anchor point, the right motion vector, the down
 *  motion vector, and the foreground and background brightness.
 *  For a file, the description is as follows:
 *
 *      modifier brighttext id
 *      2 fontfile textfile
 *      0
 *      11+
 *              Ax Ay Az
 *              Rx Ry Rz
 *              Dx Dy Dz
 *              foreground background
 *              [spacing]
 *
 *  For a single line, we use:
 *
 *      modifier brighttext id
 *      N+2 fontfile . This is a line with N words...
 *      0
 *      11+
 *              Ax Ay Az
 *              Rx Ry Rz
 *              Dx Dy Dz
 *              foreground background
 *              [spacing]
 *
 *  Colortext is identical, except colors are given rather than
 *  brightnesses.
 *
 *  Mixtext has foreground and background modifiers:
 *
 *      modifier mixtext id
 *      4+ foremod backmod fontfile text..
 *      0
 *      9+
 *              Ax Ay Az
 *              Rx Ry Rz
 *              Dx Dy Dz
 *              [spacing]
 */

#define  fndx(m)        ((m)->otype==MIX_TEXT ? 2 : 0)
#define  tndx(m)        ((m)->otype==MIX_TEXT ? 3 : 1)
#define  sndx(m)        ((m)->otype==PAT_BTEXT ? 11 : \
                                (m)->otype==PAT_CTEXT ? 15 : 9)

typedef struct tline {
        struct tline  *next;            /* pointer to next line */
        short  *spc;                    /* character spacing */
        int  width;                     /* total line width */
                                        /* followed by the string */
}  TLINE;

#define  TLSTR(l)       ((char *)((l)+1))

typedef struct {
        FVECT  right, down;             /* right and down unit vectors */
        FONT  *f;                       /* our font */
        TLINE  tl;                      /* line list */
}  TEXT;

TEXT  *gettext();

TLINE  *tlalloc();


do_text(m, r)
register OBJREC  *m;
RAY  *r;
{
        FVECT  v;
        int  foreground;
                                /* get transformed position */
        if (r->rox != NULL)
                multp3(v, r->rop, r->rox->b.xfm);
        else
                VCOPY(v, r->rop);
                                /* check if we are within a text glyph */
        foreground = intext(v, m);
                                /* modify */
        if (m->otype == MIX_TEXT) {
                OBJECT  omod;
                char  *modname = m->oargs.sarg[foreground ? 0 : 1];
                if (!strcmp(modname, VOIDID))
                        omod = OVOID;
                else if ((omod = lastmod(objndx(m), modname)) == OVOID) {
                        sprintf(errmsg, "undefined modifier \"%s\"", modname);
                        objerror(m, USER, errmsg);
                }
                if (rayshade(r, omod)) {
                        if (m->omod != OVOID)
                                objerror(m, USER, "inappropriate modifier");
                        return(1);
                }
        } else if (m->otype == PAT_BTEXT) {
                if (foreground)
                        scalecolor(r->pcol, m->oargs.farg[9]);
                else
                        scalecolor(r->pcol, m->oargs.farg[10]);
        } else { /* PAT_CTEXT */
                COLOR  cval;
                if (foreground)
                        setcolor(cval, m->oargs.farg[9],
                                        m->oargs.farg[10],
                                        m->oargs.farg[11]);
                else
                        setcolor(cval, m->oargs.farg[12],
                                        m->oargs.farg[13],
                                        m->oargs.farg[14]);
                multcolor(r->pcol, cval);
        }
        return(0);
}


TLINE *
tlalloc(s)                      /* allocate and assign text line */
char  *s;
{
        register int  siz;
        register TLINE  *tl;

        siz = strlen(s) + 1;
        if ((tl=(TLINE *)malloc(sizeof(TLINE)+siz)) == NULL ||
                        (tl->spc=(short *)malloc(siz*sizeof(short))) == NULL)
                error(SYSTEM, "out of memory in tlalloc");
        tl->next = NULL;
        strcpy(TLSTR(tl), s);
        return(tl);
}


TEXT *
gettext(tm)                     /* get text structure for material */
register OBJREC  *tm;
{
#define  R      (tm->oargs.farg+3)
#define  D      (tm->oargs.farg+6)
        FVECT  DxR;
        double  d;
        FILE  *fp;
        char  linbuf[512];
        TEXT  *t;
        register int  i;
        register TLINE  *tlp;
        register char  *s;

        if ((t = (TEXT *)tm->os) != NULL)
                return(t);
                                                /* check arguments */
        if (tm->oargs.nsargs - tndx(tm) < 1 || tm->oargs.nfargs < sndx(tm))
                objerror(tm, USER, "bad # arguments");
        if ((t = (TEXT *)malloc(sizeof(TEXT))) == NULL)
                error(SYSTEM, "out of memory in gettext");
                                                /* compute vectors */
        fcross(DxR, D, R);
        fcross(t->right, DxR, D);
        d = DOT(t->right,t->right);
        if (d <= FTINY*FTINY*FTINY*FTINY)
                objerror(tm, USER, "illegal motion vector");
        d = DOT(D,D)/d;
        for (i = 0; i < 3; i++)
                t->right[i] *= d;
        fcross(t->down, R, DxR);
        d = DOT(R,R)/DOT(t->down,t->down);
        for (i = 0; i < 3; i++)
                t->down[i] *= d;
                                                /* get text */
        tlp = &t->tl;
        if (tm->oargs.nsargs - tndx(tm) > 1) {  /* single line */
                s = linbuf;
                for (i = tndx(tm)+1; i < tm->oargs.nsargs; i++) {
                        strcpy(s, tm->oargs.sarg[i]);
                        s += strlen(s);
                        *s++ = ' ';
                }
                *--s = '\0';
                tlp->next = tlalloc(linbuf);
                tlp = tlp->next;
        } else {                                /* text file */
                if ((s = getpath(tm->oargs.sarg[tndx(tm)],
                                getrlibpath(), R_OK)) == NULL) {
                        sprintf(errmsg, "cannot find text file \"%s\"",
                                        tm->oargs.sarg[tndx(tm)]);
                        error(USER, errmsg);
                }
                if ((fp = fopen(s, "r")) == NULL) {
                        sprintf(errmsg, "cannot open text file \"%s\"", s);
                        error(SYSTEM, errmsg);
                }
                while (fgets(linbuf, sizeof(linbuf), fp) != NULL) {
                        s = linbuf + strlen(linbuf) - 1;
                        if (*s == '\n')
                                *s = '\0';
                        tlp->next = tlalloc(linbuf);
                        tlp = tlp->next;
                }
                fclose(fp);
        }
        tlp->next = NULL;
                                                /* get the font */
        t->f = getfont(tm->oargs.sarg[fndx(tm)]);
                                                /* compute character spacing */
        i = sndx(tm);
        d = i < tm->oargs.nfargs ? tm->oargs.farg[i] : 0.0;
        i = d * 255.0;
        t->tl.width = 0;
        for (tlp = t->tl.next; tlp != NULL; tlp = tlp->next) {
                if (i < 0)
                        tlp->width = squeeztext(tlp->spc, TLSTR(tlp), t->f, -i);
                else if (i > 0)
                        tlp->width = proptext(tlp->spc, TLSTR(tlp), t->f, i, 3);
                else
                        tlp->width = uniftext(tlp->spc, TLSTR(tlp), t->f);
                if (tlp->width > t->tl.width)
                        t->tl.width = tlp->width;
        }
                                                /* we're done */
        tm->os = (char *)t;
        return(t);
#undef  R
#undef  D
}


freetext(m)                     /* free text structures associated with m */
OBJREC  *m;
{
        register TEXT  *tp;
        register TLINE  *tlp;

        tp = (TEXT *)m->os;
        if (tp == NULL)
                return;
        while ((tlp = tp->tl.next) != NULL) {
                tp->tl.next = tlp->next;
                free((void *)tlp->spc);
                free((void *)tlp);
        }
        freefont(tp->f);        /* release font reference */
        free((void *)tp);
        m->os = NULL;
}


intext(p, m)                    /* check to see if p is in text glyph */
FVECT  p;
OBJREC  *m;
{
        register TEXT  *tp;
        register TLINE  *tlp;
        FVECT  v;
        double  y, x;
        register int  i, h;
                                /* first, compute position in text */
        tp = gettext(m);
        v[0] = p[0] - m->oargs.farg[0];
        v[1] = p[1] - m->oargs.farg[1];
        v[2] = p[2] - m->oargs.farg[2];
        x = DOT(v, tp->right);
        i = sndx(m);
        if (i < m->oargs.nfargs)
                x *= tp->f->mwidth + 255.*fabs(m->oargs.farg[i]);
        else
                x *= 255.;
        h = x;
        i = y = DOT(v, tp->down);
        if (x < 0.0 || y < 0.0)
                return(0);
        x -= (double)h;
        y = ((i+1) - y)*255.;
                                /* find the line position */
        for (tlp = tp->tl.next; tlp != NULL; tlp = tlp->next)
                if (--i < 0)
                        break;
        if (tlp == NULL || h >= tlp->width)
                return(0);
        for (i = 0; (h -= tlp->spc[i]) >= 0; i++)
                if (h < 255 && inglyph(h+x, y,
                                tp->f->fg[TLSTR(tlp)[i]&0xff]))
                        return(1);
        return(0);
}


inglyph(x, y, gl)               /* (x,y) within font glyph gl? */
double  x, y;           /* real coordinates in range [0,255) */
register GLYPH  *gl;
{
        int  n, ncross;
        int  xlb, ylb;
        int  tv;
        register GORD  *p0, *p1;

        if (gl == NULL)
                return(0);
        xlb = x;
        ylb = y;
        if (gl->left > xlb || gl->right <= xlb ||       /* check extent */
                        gl->bottom > ylb || gl->top <= ylb)
                return(0);
        xlb = xlb<<1 | 1;               /* add 1/2 to test points... */
        ylb = ylb<<1 | 1;               /* ...so no equal comparisons */
        n = gl->nverts;                 /* get # of vertices */
        p0 = gvlist(gl) + 2*(n-1);      /* connect last to first */
        p1 = gvlist(gl);
        ncross = 0;
                                        /* positive x axis cross test */
        while (n--) {
                if ((p0[1]<<1 > ylb) ^ (p1[1]<<1 > ylb)) {
                        tv = (p0[0]<<1 > xlb) | ((p1[0]<<1 > xlb) << 1);
                        if (tv == 03)
                                ncross++;
                        else if (tv)
                                ncross += (p1[1] > p0[1]) ^
                                                ((p0[1]-y)*(p1[0]-x) >
                                                (p0[0]-x)*(p1[1]-y));
                }
                p0 = p1;
                p1 += 2;
        }
        return(ncross & 01);
}
Revision:	2.24
Committed:	Thu Feb 12 18:55:50 2004 UTC (20 years, 2 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.23:	+3 -1 lines
Log Message:	Moved paths.h out of rtio.h and included it manually where R_OK was needed
#	User	Rev	Content
1	greg	1.1	#ifndef lint
2	greg	2.24	static const char RCSid[] = "$Id: text.c,v 2.23 2003/07/27 22:12:03 schorsch Exp $";
3	greg	1.1	#endif
4			/*
5			* text.c - functions for text patterns and mixtures.
6			*/
7
8	greg	2.21	#include "copyright.h"
9	greg	2.20
10	greg	1.1	#include "ray.h"
11	greg	2.24
12			#include "paths.h"
13	greg	1.1
14			#include "otypes.h"
15
16	greg	2.2	#include "font.h"
17
18	greg	1.1	/*
19			* A text pattern is specified as the text (a file or line),
20			* the upper left anchor point, the right motion vector, the down
21			* motion vector, and the foreground and background brightness.
22			* For a file, the description is as follows:
23			*
24			* modifier brighttext id
25			* 2 fontfile textfile
26			* 0
27	greg	2.4	* 11+
28	greg	1.1	* Ax Ay Az
29			* Rx Ry Rz
30			* Dx Dy Dz
31			* foreground background
32	greg	2.4	* [spacing]
33	greg	1.1	*
34			* For a single line, we use:
35			*
36			* modifier brighttext id
37			* N+2 fontfile . This is a line with N words...
38			* 0
39	greg	2.4	* 11+
40	greg	1.1	* Ax Ay Az
41			* Rx Ry Rz
42			* Dx Dy Dz
43			* foreground background
44	greg	2.4	* [spacing]
45	greg	1.1	*
46			* Colortext is identical, except colors are given rather than
47	greg	2.15	* brightnesses.
48	greg	1.1	*
49	greg	2.15	* Mixtext has foreground and background modifiers:
50			*
51	greg	1.1	* modifier mixtext id
52			* 4+ foremod backmod fontfile text..
53			* 0
54	greg	2.4	* 9+
55	greg	1.1	* Ax Ay Az
56			* Rx Ry Rz
57			* Dx Dy Dz
58	greg	2.4	* [spacing]
59	greg	1.1	*/
60
61			#define fndx(m) ((m)->otype==MIX_TEXT ? 2 : 0)
62			#define tndx(m) ((m)->otype==MIX_TEXT ? 3 : 1)
63	greg	2.4	#define sndx(m) ((m)->otype==PAT_BTEXT ? 11 : \
64			(m)->otype==PAT_CTEXT ? 15 : 9)
65	greg	1.1
66	greg	1.8	typedef struct tline {
67			struct tline next; / pointer to next line */
68	greg	2.4	short spc; / character spacing */
69			int width; /* total line width */
70	greg	1.8	/* followed by the string */
71			} TLINE;
72
73	greg	1.9	#define TLSTR(l) ((char *)((l)+1))
74	greg	1.8
75	greg	1.7	typedef struct {
76			FVECT right, down; /* right and down unit vectors */
77			FONT f; / our font */
78	greg	1.8	TLINE tl; /* line list */
79	greg	1.7	} TEXT;
80
81			TEXT *gettext();
82	greg	1.1
83	greg	1.8	TLINE *tlalloc();
84
85	greg	1.1
86	greg	2.16	do_text(m, r)
87	greg	1.1	register OBJREC *m;
88			RAY *r;
89			{
90	greg	1.10	FVECT v;
91	greg	1.1	int foreground;
92	greg	1.7	/* get transformed position */
93	greg	1.4	if (r->rox != NULL)
94			multp3(v, r->rop, r->rox->b.xfm);
95			else
96			VCOPY(v, r->rop);
97	greg	1.7	/* check if we are within a text glyph */
98			foreground = intext(v, m);
99	greg	1.1	/* modify */
100			if (m->otype == MIX_TEXT) {
101			OBJECT omod;
102			char *modname = m->oargs.sarg[foreground ? 0 : 1];
103			if (!strcmp(modname, VOIDID))
104			omod = OVOID;
105	gwlarson	2.18	else if ((omod = lastmod(objndx(m), modname)) == OVOID) {
106	greg	1.1	sprintf(errmsg, "undefined modifier \"%s\"", modname);
107			objerror(m, USER, errmsg);
108			}
109	greg	2.12	if (rayshade(r, omod)) {
110			if (m->omod != OVOID)
111			objerror(m, USER, "inappropriate modifier");
112			return(1);
113			}
114	greg	2.15	} else if (m->otype == PAT_BTEXT) {
115	greg	1.1	if (foreground)
116	greg	1.7	scalecolor(r->pcol, m->oargs.farg[9]);
117	greg	1.1	else
118	greg	1.7	scalecolor(r->pcol, m->oargs.farg[10]);
119	greg	1.1	} else { /* PAT_CTEXT */
120			COLOR cval;
121			if (foreground)
122	greg	1.7	setcolor(cval, m->oargs.farg[9],
123			m->oargs.farg[10],
124			m->oargs.farg[11]);
125	greg	1.1	else
126	greg	1.7	setcolor(cval, m->oargs.farg[12],
127			m->oargs.farg[13],
128			m->oargs.farg[14]);
129	greg	1.1	multcolor(r->pcol, cval);
130			}
131	greg	2.12	return(0);
132	greg	1.1	}
133
134
135	greg	1.8	TLINE *
136			tlalloc(s) /* allocate and assign text line */
137			char *s;
138			{
139	greg	2.4	register int siz;
140	greg	1.8	register TLINE *tl;
141
142	greg	2.4	siz = strlen(s) + 1;
143			if ((tl=(TLINE *)malloc(sizeof(TLINE)+siz)) == NULL \|\|
144			(tl->spc=(short )malloc(sizsizeof(short))) == NULL)
145	greg	1.8	error(SYSTEM, "out of memory in tlalloc");
146			tl->next = NULL;
147			strcpy(TLSTR(tl), s);
148			return(tl);
149			}
150
151
152	greg	1.7	TEXT *
153			gettext(tm) /* get text structure for material */
154	greg	1.1	register OBJREC *tm;
155			{
156	greg	1.7	#define R (tm->oargs.farg+3)
157			#define D (tm->oargs.farg+6)
158			FVECT DxR;
159			double d;
160	greg	1.1	FILE *fp;
161			char linbuf[512];
162	greg	1.8	TEXT *t;
163	greg	1.1	register int i;
164	greg	1.8	register TLINE *tlp;
165	greg	1.1	register char *s;
166
167	greg	1.7	if ((t = (TEXT *)tm->os) != NULL)
168			return(t);
169			/* check arguments */
170	greg	2.4	if (tm->oargs.nsargs - tndx(tm) < 1 \|\| tm->oargs.nfargs < sndx(tm))
171	greg	1.7	objerror(tm, USER, "bad # arguments");
172			if ((t = (TEXT *)malloc(sizeof(TEXT))) == NULL)
173	greg	2.10	error(SYSTEM, "out of memory in gettext");
174	greg	1.7	/* compute vectors */
175			fcross(DxR, D, R);
176			fcross(t->right, DxR, D);
177	gregl	2.17	d = DOT(t->right,t->right);
178	gwlarson	2.19	if (d <= FTINYFTINYFTINY*FTINY)
179	gregl	2.17	objerror(tm, USER, "illegal motion vector");
180			d = DOT(D,D)/d;
181	greg	1.7	for (i = 0; i < 3; i++)
182			t->right[i] *= d;
183			fcross(t->down, R, DxR);
184	greg	1.9	d = DOT(R,R)/DOT(t->down,t->down);
185	greg	1.7	for (i = 0; i < 3; i++)
186			t->down[i] *= d;
187			/* get text */
188	greg	1.8	tlp = &t->tl;
189	greg	1.7	if (tm->oargs.nsargs - tndx(tm) > 1) { /* single line */
190			s = linbuf;
191			for (i = tndx(tm)+1; i < tm->oargs.nsargs; i++) {
192			strcpy(s, tm->oargs.sarg[i]);
193			s += strlen(s);
194			*s++ = ' ';
195	greg	1.1	}
196	greg	1.7	*--s = '\0';
197	greg	1.8	tlp->next = tlalloc(linbuf);
198			tlp = tlp->next;
199	greg	1.7	} else { /* text file */
200			if ((s = getpath(tm->oargs.sarg[tndx(tm)],
201	greg	2.22	getrlibpath(), R_OK)) == NULL) {
202	greg	1.7	sprintf(errmsg, "cannot find text file \"%s\"",
203			tm->oargs.sarg[tndx(tm)]);
204			error(USER, errmsg);
205			}
206			if ((fp = fopen(s, "r")) == NULL) {
207	greg	2.4	sprintf(errmsg, "cannot open text file \"%s\"", s);
208	greg	1.7	error(SYSTEM, errmsg);
209			}
210	greg	1.8	while (fgets(linbuf, sizeof(linbuf), fp) != NULL) {
211	greg	1.7	s = linbuf + strlen(linbuf) - 1;
212			if (*s == '\n')
213			*s = '\0';
214	greg	1.8	tlp->next = tlalloc(linbuf);
215			tlp = tlp->next;
216	greg	1.7	}
217			fclose(fp);
218	greg	1.1	}
219	greg	1.8	tlp->next = NULL;
220	greg	1.7	/* get the font */
221			t->f = getfont(tm->oargs.sarg[fndx(tm)]);
222	greg	2.4	/* compute character spacing */
223			i = sndx(tm);
224			d = i < tm->oargs.nfargs ? tm->oargs.farg[i] : 0.0;
225	greg	2.14	i = d * 255.0;
226	greg	2.6	t->tl.width = 0;
227	greg	2.4	for (tlp = t->tl.next; tlp != NULL; tlp = tlp->next) {
228			if (i < 0)
229			tlp->width = squeeztext(tlp->spc, TLSTR(tlp), t->f, -i);
230			else if (i > 0)
231			tlp->width = proptext(tlp->spc, TLSTR(tlp), t->f, i, 3);
232			else
233			tlp->width = uniftext(tlp->spc, TLSTR(tlp), t->f);
234	greg	2.6	if (tlp->width > t->tl.width)
235			t->tl.width = tlp->width;
236	greg	2.4	}
237	greg	1.7	/* we're done */
238			tm->os = (char *)t;
239			return(t);
240			#undef R
241			#undef D
242	greg	1.1	}
243
244
245	greg	1.7	freetext(m) /* free text structures associated with m */
246			OBJREC *m;
247			{
248	greg	2.9	register TEXT *tp;
249			register TLINE *tlp;
250	greg	1.7
251			tp = (TEXT *)m->os;
252			if (tp == NULL)
253			return;
254	greg	2.9	while ((tlp = tp->tl.next) != NULL) {
255			tp->tl.next = tlp->next;
256	greg	2.20	free((void *)tlp->spc);
257			free((void *)tlp);
258	greg	2.4	}
259	greg	2.20	freefont(tp->f); /* release font reference */
260			free((void *)tp);
261	greg	1.7	m->os = NULL;
262			}
263
264
265			intext(p, m) /* check to see if p is in text glyph */
266			FVECT p;
267	greg	1.8	OBJREC *m;
268	greg	1.7	{
269			register TEXT *tp;
270	greg	1.8	register TLINE *tlp;
271	greg	1.10	FVECT v;
272			double y, x;
273	greg	2.4	register int i, h;
274	greg	1.7	/* first, compute position in text */
275	greg	1.9	tp = gettext(m);
276	greg	1.7	v[0] = p[0] - m->oargs.farg[0];
277			v[1] = p[1] - m->oargs.farg[1];
278			v[2] = p[2] - m->oargs.farg[2];
279	greg	2.6	x = DOT(v, tp->right);
280			i = sndx(m);
281			if (i < m->oargs.nfargs)
282	greg	2.14	x = tp->f->mwidth + 255.fabs(m->oargs.farg[i]);
283	greg	2.6	else
284	greg	2.14	x *= 255.;
285	greg	2.6	h = x;
286	greg	2.4	i = y = DOT(v, tp->down);
287	greg	1.7	if (x < 0.0 \|\| y < 0.0)
288			return(0);
289	greg	2.4	x -= (double)h;
290	greg	2.14	y = ((i+1) - y)*255.;
291	greg	2.4	/* find the line position */
292	greg	1.8	for (tlp = tp->tl.next; tlp != NULL; tlp = tlp->next)
293	greg	2.4	if (--i < 0)
294	greg	1.8	break;
295	greg	2.4	if (tlp == NULL \|\| h >= tlp->width)
296	greg	1.7	return(0);
297	greg	2.4	for (i = 0; (h -= tlp->spc[i]) >= 0; i++)
298	greg	2.14	if (h < 255 && inglyph(h+x, y,
299	greg	2.4	tp->f->fg[TLSTR(tlp)[i]&0xff]))
300			return(1);
301			return(0);
302	greg	1.7	}
303
304
305	greg	1.1	inglyph(x, y, gl) /* (x,y) within font glyph gl? */
306	greg	2.14	double x, y; /* real coordinates in range [0,255) */
307	greg	2.3	register GLYPH *gl;
308	greg	1.1	{
309			int n, ncross;
310	greg	2.5	int xlb, ylb;
311			int tv;
312	greg	2.2	register GORD p0, p1;
313	greg	1.1
314	greg	1.7	if (gl == NULL)
315	greg	1.1	return(0);
316	greg	2.5	xlb = x;
317			ylb = y;
318			if (gl->left > xlb \|\| gl->right <= xlb \|\| /* check extent */
319			gl->bottom > ylb \|\| gl->top <= ylb)
320			return(0);
321			xlb = xlb<<1 \| 1; /* add 1/2 to test points... */
322			ylb = ylb<<1 \| 1; /* ...so no equal comparisons */
323	greg	2.2	n = gl->nverts; /* get # of vertices */
324			p0 = gvlist(gl) + 2(n-1); / connect last to first */
325			p1 = gvlist(gl);
326	greg	1.1	ncross = 0;
327			/* positive x axis cross test */
328			while (n--) {
329	greg	2.5	if ((p0[1]<<1 > ylb) ^ (p1[1]<<1 > ylb)) {
330	schorsch	2.23	tv = (p0[0]<<1 > xlb) \| ((p1[0]<<1 > xlb) << 1);
331	greg	2.5	if (tv == 03)
332	greg	1.1	ncross++;
333	greg	2.5	else if (tv)
334	greg	1.1	ncross += (p1[1] > p0[1]) ^
335			((p0[1]-y)*(p1[0]-x) >
336			(p0[0]-x)*(p1[1]-y));
337	greg	2.5	}
338	greg	1.1	p0 = p1;
339			p1 += 2;
340			}
341			return(ncross & 01);
342			}