src/rt/text.c

/* Copyright (c) 1991 Regents of the University of California */

#ifndef lint
static char SCCSid[] = "$SunId$ LBL";
#endif

/*
 *  text.c - functions for text patterns and mixtures.
 *
 *     11/12/86
 */

#include  "ray.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;

extern char  *libpath;

extern char  *fgetword();

TEXT  *gettext();

TLINE  *tlalloc();


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 = modifier(modname)) == OVOID) {
                        sprintf(errmsg, "undefined modifier \"%s\"", modname);
                        objerror(m, USER, errmsg);
                }
                raytexture(r, omod);
        } 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);
        }
}


TLINE *
tlalloc(s)                      /* allocate and assign text line */
char  *s;
{
        extern char  *strcpy();
        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->spc = NULL;
        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)
        extern char  *strcpy(), *fgets();
        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)
                goto memerr;
                                                /* compute vectors */
        fcross(DxR, D, R);
        fcross(t->right, DxR, D);
        d = DOT(D,D)/DOT(t->right,t->right);
        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)],
                                libpath, 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 * 256.0;
        t->tl.width = 0;
        for (tlp = t->tl.next; tlp != NULL; tlp = tlp->next) {
                if ((tlp->spc = (short *)malloc(
                                (strlen(TLSTR(tlp))+1)*sizeof(short))) == NULL)
                        goto memerr;
                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);
memerr:
        error(SYSTEM, "out of memory in gettext");
#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;
        for (tlp = tp->tl.next; tlp != NULL; tlp = tlp->next) {
                free((char *)tlp->spc);
                free((char *)tlp);
        }
        free((char *)tp);
        m->os = NULL;
}


intext(p, m)                    /* check to see if p is in text glyph */
FVECT  p;
OBJREC  *m;
{
        extern double  fabs();
        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 + 256.*fabs(m->oargs.farg[i]);
        else
                x *= 256.;
        h = x;
        i = y = DOT(v, tp->down);
        if (x < 0.0 || y < 0.0)
                return(0);
        x -= (double)h;
        y = ((i+1) - y)*256.;
                                /* 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 < 256 && 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 [0,256) */
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:	2.6
Committed:	Thu Jun 25 12:05:10 1992 UTC (33 years, 4 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.5:	+11 -1 lines
Log Message:	fixed proportional spacing distances
#	User	Rev	Content
1	greg	1.7	/* Copyright (c) 1991 Regents of the University of California */
2	greg	1.1
3			#ifndef lint
4			static char SCCSid[] = "$SunId$ LBL";
5			#endif
6
7			/*
8			* text.c - functions for text patterns and mixtures.
9			*
10			* 11/12/86
11			*/
12
13			#include "ray.h"
14
15			#include "otypes.h"
16
17	greg	2.2	#include "font.h"
18
19	greg	1.1	/*
20			* A text pattern is specified as the text (a file or line),
21			* the upper left anchor point, the right motion vector, the down
22			* motion vector, and the foreground and background brightness.
23			* For a file, the description is as follows:
24			*
25			* modifier brighttext id
26			* 2 fontfile textfile
27			* 0
28	greg	2.4	* 11+
29	greg	1.1	* Ax Ay Az
30			* Rx Ry Rz
31			* Dx Dy Dz
32			* foreground background
33	greg	2.4	* [spacing]
34	greg	1.1	*
35			* For a single line, we use:
36			*
37			* modifier brighttext id
38			* N+2 fontfile . This is a line with N words...
39			* 0
40	greg	2.4	* 11+
41	greg	1.1	* Ax Ay Az
42			* Rx Ry Rz
43			* Dx Dy Dz
44			* foreground background
45	greg	2.4	* [spacing]
46	greg	1.1	*
47			* Colortext is identical, except colors are given rather than
48			* brightnesses. Mixtext has foreground and background modifiers:
49			*
50			* modifier mixtext id
51			* 4+ foremod backmod fontfile text..
52			* 0
53	greg	2.4	* 9+
54	greg	1.1	* Ax Ay Az
55			* Rx Ry Rz
56			* Dx Dy Dz
57	greg	2.4	* [spacing]
58	greg	1.1	*/
59
60			#define fndx(m) ((m)->otype==MIX_TEXT ? 2 : 0)
61			#define tndx(m) ((m)->otype==MIX_TEXT ? 3 : 1)
62	greg	2.4	#define sndx(m) ((m)->otype==PAT_BTEXT ? 11 : \
63			(m)->otype==PAT_CTEXT ? 15 : 9)
64	greg	1.1
65	greg	1.8	typedef struct tline {
66			struct tline next; / pointer to next line */
67	greg	2.4	short spc; / character spacing */
68			int width; /* total line width */
69	greg	1.8	/* followed by the string */
70			} TLINE;
71
72	greg	1.9	#define TLSTR(l) ((char *)((l)+1))
73	greg	1.8
74	greg	1.7	typedef struct {
75			FVECT right, down; /* right and down unit vectors */
76			FONT f; / our font */
77	greg	1.8	TLINE tl; /* line list */
78	greg	1.7	} TEXT;
79
80	greg	2.3	extern char *libpath;
81
82	greg	1.6	extern char *fgetword();
83
84	greg	1.7	TEXT *gettext();
85	greg	1.1
86	greg	1.8	TLINE *tlalloc();
87
88	greg	1.1
89			text(m, r)
90			register OBJREC *m;
91			RAY *r;
92			{
93	greg	1.10	FVECT v;
94	greg	1.1	int foreground;
95	greg	1.7	/* get transformed position */
96	greg	1.4	if (r->rox != NULL)
97			multp3(v, r->rop, r->rox->b.xfm);
98			else
99			VCOPY(v, r->rop);
100	greg	1.7	/* check if we are within a text glyph */
101			foreground = intext(v, m);
102	greg	1.1	/* modify */
103			if (m->otype == MIX_TEXT) {
104			OBJECT omod;
105			char *modname = m->oargs.sarg[foreground ? 0 : 1];
106			if (!strcmp(modname, VOIDID))
107			omod = OVOID;
108			else if ((omod = modifier(modname)) == OVOID) {
109			sprintf(errmsg, "undefined modifier \"%s\"", modname);
110			objerror(m, USER, errmsg);
111			}
112	greg	1.7	raytexture(r, omod);
113	greg	1.1	} else if (m->otype == PAT_BTEXT) {
114			if (foreground)
115	greg	1.7	scalecolor(r->pcol, m->oargs.farg[9]);
116	greg	1.1	else
117	greg	1.7	scalecolor(r->pcol, m->oargs.farg[10]);
118	greg	1.1	} else { /* PAT_CTEXT */
119			COLOR cval;
120			if (foreground)
121	greg	1.7	setcolor(cval, m->oargs.farg[9],
122			m->oargs.farg[10],
123			m->oargs.farg[11]);
124	greg	1.1	else
125	greg	1.7	setcolor(cval, m->oargs.farg[12],
126			m->oargs.farg[13],
127			m->oargs.farg[14]);
128	greg	1.1	multcolor(r->pcol, cval);
129			}
130			}
131
132
133	greg	1.8	TLINE *
134			tlalloc(s) /* allocate and assign text line */
135			char *s;
136			{
137			extern char *strcpy();
138	greg	2.4	register int siz;
139	greg	1.8	register TLINE *tl;
140
141	greg	2.4	siz = strlen(s) + 1;
142			if ((tl=(TLINE *)malloc(sizeof(TLINE)+siz)) == NULL \|\|
143			(tl->spc=(short )malloc(sizsizeof(short))) == NULL)
144	greg	1.8	error(SYSTEM, "out of memory in tlalloc");
145	greg	2.4	tl->spc = NULL;
146	greg	1.8	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	greg	1.1	extern char strcpy(), fgets();
159	greg	1.7	FVECT DxR;
160			double d;
161	greg	1.1	FILE *fp;
162			char linbuf[512];
163	greg	1.8	TEXT *t;
164	greg	1.1	register int i;
165	greg	1.8	register TLINE *tlp;
166	greg	1.1	register char *s;
167
168	greg	1.7	if ((t = (TEXT *)tm->os) != NULL)
169			return(t);
170			/* check arguments */
171	greg	2.4	if (tm->oargs.nsargs - tndx(tm) < 1 \|\| tm->oargs.nfargs < sndx(tm))
172	greg	1.7	objerror(tm, USER, "bad # arguments");
173			if ((t = (TEXT *)malloc(sizeof(TEXT))) == NULL)
174	greg	2.4	goto memerr;
175	greg	1.7	/* compute vectors */
176			fcross(DxR, D, R);
177			fcross(t->right, DxR, D);
178	greg	1.9	d = DOT(D,D)/DOT(t->right,t->right);
179	greg	1.7	for (i = 0; i < 3; i++)
180			t->right[i] *= d;
181			fcross(t->down, R, DxR);
182	greg	1.9	d = DOT(R,R)/DOT(t->down,t->down);
183	greg	1.7	for (i = 0; i < 3; i++)
184			t->down[i] *= d;
185			/* get text */
186	greg	1.8	tlp = &t->tl;
187	greg	1.7	if (tm->oargs.nsargs - tndx(tm) > 1) { /* single line */
188			s = linbuf;
189			for (i = tndx(tm)+1; i < tm->oargs.nsargs; i++) {
190			strcpy(s, tm->oargs.sarg[i]);
191			s += strlen(s);
192			*s++ = ' ';
193	greg	1.1	}
194	greg	1.7	*--s = '\0';
195	greg	1.8	tlp->next = tlalloc(linbuf);
196			tlp = tlp->next;
197	greg	1.7	} else { /* text file */
198			if ((s = getpath(tm->oargs.sarg[tndx(tm)],
199			libpath, R_OK)) == NULL) {
200			sprintf(errmsg, "cannot find text file \"%s\"",
201			tm->oargs.sarg[tndx(tm)]);
202			error(USER, errmsg);
203			}
204			if ((fp = fopen(s, "r")) == NULL) {
205	greg	2.4	sprintf(errmsg, "cannot open text file \"%s\"", s);
206	greg	1.7	error(SYSTEM, errmsg);
207			}
208	greg	1.8	while (fgets(linbuf, sizeof(linbuf), fp) != NULL) {
209	greg	1.7	s = linbuf + strlen(linbuf) - 1;
210			if (*s == '\n')
211			*s = '\0';
212	greg	1.8	tlp->next = tlalloc(linbuf);
213			tlp = tlp->next;
214	greg	1.7	}
215			fclose(fp);
216	greg	1.1	}
217	greg	1.8	tlp->next = NULL;
218	greg	1.7	/* get the font */
219			t->f = getfont(tm->oargs.sarg[fndx(tm)]);
220	greg	2.4	/* compute character spacing */
221			i = sndx(tm);
222			d = i < tm->oargs.nfargs ? tm->oargs.farg[i] : 0.0;
223			i = d * 256.0;
224	greg	2.6	t->tl.width = 0;
225	greg	2.4	for (tlp = t->tl.next; tlp != NULL; tlp = tlp->next) {
226			if ((tlp->spc = (short *)malloc(
227			(strlen(TLSTR(tlp))+1)*sizeof(short))) == NULL)
228			goto memerr;
229			if (i < 0)
230			tlp->width = squeeztext(tlp->spc, TLSTR(tlp), t->f, -i);
231			else if (i > 0)
232			tlp->width = proptext(tlp->spc, TLSTR(tlp), t->f, i, 3);
233			else
234			tlp->width = uniftext(tlp->spc, TLSTR(tlp), t->f);
235	greg	2.6	if (tlp->width > t->tl.width)
236			t->tl.width = tlp->width;
237	greg	2.4	}
238	greg	1.7	/* we're done */
239			tm->os = (char *)t;
240			return(t);
241	greg	2.4	memerr:
242			error(SYSTEM, "out of memory in gettext");
243	greg	1.7	#undef R
244			#undef D
245	greg	1.1	}
246
247
248	greg	1.7	freetext(m) /* free text structures associated with m */
249			OBJREC *m;
250			{
251			register TEXT *tp;
252	greg	1.8	register TLINE *tlp;
253	greg	1.7
254			tp = (TEXT *)m->os;
255			if (tp == NULL)
256			return;
257	greg	2.4	for (tlp = tp->tl.next; tlp != NULL; tlp = tlp->next) {
258			free((char *)tlp->spc);
259	greg	1.9	free((char *)tlp);
260	greg	2.4	}
261	greg	1.7	free((char *)tp);
262			m->os = NULL;
263			}
264
265
266			intext(p, m) /* check to see if p is in text glyph */
267			FVECT p;
268	greg	1.8	OBJREC *m;
269	greg	1.7	{
270	greg	2.6	extern double fabs();
271	greg	1.7	register TEXT *tp;
272	greg	1.8	register TLINE *tlp;
273	greg	1.10	FVECT v;
274			double y, x;
275	greg	2.4	register int i, h;
276	greg	1.7	/* first, compute position in text */
277	greg	1.9	tp = gettext(m);
278	greg	1.7	v[0] = p[0] - m->oargs.farg[0];
279			v[1] = p[1] - m->oargs.farg[1];
280			v[2] = p[2] - m->oargs.farg[2];
281	greg	2.6	x = DOT(v, tp->right);
282			i = sndx(m);
283			if (i < m->oargs.nfargs)
284			x = tp->f->mwidth + 256.fabs(m->oargs.farg[i]);
285			else
286			x *= 256.;
287			h = x;
288	greg	2.4	i = y = DOT(v, tp->down);
289	greg	1.7	if (x < 0.0 \|\| y < 0.0)
290			return(0);
291	greg	2.4	x -= (double)h;
292			y = ((i+1) - y)*256.;
293			/* find the line position */
294	greg	1.8	for (tlp = tp->tl.next; tlp != NULL; tlp = tlp->next)
295	greg	2.4	if (--i < 0)
296	greg	1.8	break;
297	greg	2.4	if (tlp == NULL \|\| h >= tlp->width)
298	greg	1.7	return(0);
299	greg	2.4	for (i = 0; (h -= tlp->spc[i]) >= 0; i++)
300			if (h < 256 && inglyph(h+x, y,
301			tp->f->fg[TLSTR(tlp)[i]&0xff]))
302			return(1);
303			return(0);
304	greg	1.7	}
305
306
307	greg	1.1	inglyph(x, y, gl) /* (x,y) within font glyph gl? */
308	greg	2.5	double x, y; /* real coordinates in range [0,256) */
309	greg	2.3	register GLYPH *gl;
310	greg	1.1	{
311			int n, ncross;
312	greg	2.5	int xlb, ylb;
313			int tv;
314	greg	2.2	register GORD p0, p1;
315	greg	1.1
316	greg	1.7	if (gl == NULL)
317	greg	1.1	return(0);
318	greg	2.5	xlb = x;
319			ylb = y;
320			if (gl->left > xlb \|\| gl->right <= xlb \|\| /* check extent */
321			gl->bottom > ylb \|\| gl->top <= ylb)
322			return(0);
323			xlb = xlb<<1 \| 1; /* add 1/2 to test points... */
324			ylb = ylb<<1 \| 1; /* ...so no equal comparisons */
325	greg	2.2	n = gl->nverts; /* get # of vertices */
326			p0 = gvlist(gl) + 2(n-1); / connect last to first */
327			p1 = gvlist(gl);
328	greg	1.1	ncross = 0;
329			/* positive x axis cross test */
330			while (n--) {
331	greg	2.5	if ((p0[1]<<1 > ylb) ^ (p1[1]<<1 > ylb)) {
332			tv = p0[0]<<1 > xlb \| (p1[0]<<1 > xlb) << 1;
333			if (tv == 03)
334	greg	1.1	ncross++;
335	greg	2.5	else if (tv)
336	greg	1.1	ncross += (p1[1] > p0[1]) ^
337			((p0[1]-y)*(p1[0]-x) >
338			(p0[0]-x)*(p1[1]-y));
339	greg	2.5	}
340	greg	1.1	p0 = p1;
341			p1 += 2;
342			}
343			return(ncross & 01);
344			}