Correct math and limerick.

[dragonfly.git] / contrib / mdocml / term_ps.c

/*      $Id: term_ps.c,v 1.54 2011/10/16 12:20:34 schwarze Exp $ */
/*
 * Copyright (c) 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <sys/types.h>

#include <assert.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include "mandoc.h"
#include "out.h"
#include "main.h"
#include "term.h"

/* These work the buffer used by the header and footer. */
#define PS_BUFSLOP        128

/* Convert PostScript point "x" to an AFM unit. */
#define PNT2AFM(p, x) /* LINTED */ \
        (size_t)((double)(x) * (1000.0 / (double)(p)->ps->scale))

/* Convert an AFM unit "x" to a PostScript points */
#define AFM2PNT(p, x) /* LINTED */ \
        ((double)(x) / (1000.0 / (double)(p)->ps->scale))

struct  glyph {
        unsigned short    wx; /* WX in AFM */
};

struct  font {
        const char       *name; /* FontName in AFM */
#define MAXCHAR           95 /* total characters we can handle */
        struct glyph      gly[MAXCHAR]; /* glyph metrics */
};

struct  termp_ps {
        int               flags;
#define PS_INLINE        (1 << 0)       /* we're in a word */
#define PS_MARGINS       (1 << 1)       /* we're in the margins */
#define PS_NEWPAGE       (1 << 2)       /* new page, no words yet */
        size_t            pscol;        /* visible column (AFM units) */
        size_t            psrow;        /* visible row (AFM units) */
        char             *psmarg;       /* margin buf */
        size_t            psmargsz;     /* margin buf size */
        size_t            psmargcur;    /* cur index in margin buf */
        char              last;         /* character buffer */
        enum termfont     lastf;        /* last set font */
        size_t            scale;        /* font scaling factor */
        size_t            pages;        /* number of pages shown */
        size_t            lineheight;   /* line height (AFM units) */
        size_t            top;          /* body top (AFM units) */
        size_t            bottom;       /* body bottom (AFM units) */
        size_t            height;       /* page height (AFM units */
        size_t            width;        /* page width (AFM units) */
        size_t            left;         /* body left (AFM units) */
        size_t            header;       /* header pos (AFM units) */
        size_t            footer;       /* footer pos (AFM units) */
        size_t            pdfbytes;     /* current output byte */
        size_t            pdflastpg;    /* byte of last page mark */
        size_t            pdfbody;      /* start of body object */
        size_t           *pdfobjs;      /* table of object offsets */
        size_t            pdfobjsz;     /* size of pdfobjs */
};

static  double            ps_hspan(const struct termp *,
                                const struct roffsu *);
static  size_t            ps_width(const struct termp *, int);
static  void              ps_advance(struct termp *, size_t);
static  void              ps_begin(struct termp *);
static  void              ps_closepage(struct termp *);
static  void              ps_end(struct termp *);
static  void              ps_endline(struct termp *);
static  void              ps_fclose(struct termp *);
static  void              ps_growbuf(struct termp *, size_t);
static  void              ps_letter(struct termp *, int);
static  void              ps_pclose(struct termp *);
static  void              ps_pletter(struct termp *, int);
static  void              ps_printf(struct termp *, const char *, ...);
static  void              ps_putchar(struct termp *, char);
static  void              ps_setfont(struct termp *, enum termfont);
static  struct termp     *pspdf_alloc(char *);
static  void              pdf_obj(struct termp *, size_t);

/*
 * We define, for the time being, three fonts: bold, oblique/italic, and
 * normal (roman).  The following table hard-codes the font metrics for
 * ASCII, i.e., 32--127.
 */

static  const struct font fonts[TERMFONT__MAX] = {
        { "Times-Roman", {
                { 250 },
                { 333 },
                { 408 },
                { 500 },
                { 500 },
                { 833 },
                { 778 },
                { 333 },
                { 333 },
                { 333 },
                { 500 },
                { 564 },
                { 250 },
                { 333 },
                { 250 },
                { 278 },
                { 500 },
                { 500 },
                { 500 },
                { 500 },
                { 500 },
                { 500 },
                { 500 },
                { 500 },
                { 500 },
                { 500 },
                { 278 },
                { 278 },
                { 564 },
                { 564 },
                { 564 },
                { 444 },
                { 921 },
                { 722 },
                { 667 },
                { 667 },
                { 722 },
                { 611 },
                { 556 },
                { 722 },
                { 722 },
                { 333 },
                { 389 },
                { 722 },
                { 611 },
                { 889 },
                { 722 },
                { 722 },
                { 556 },
                { 722 },
                { 667 },
                { 556 },
                { 611 },
                { 722 },
                { 722 },
                { 944 },
                { 722 },
                { 722 },
                { 611 },
                { 333 },
                { 278 },
                { 333 },
                { 469 },
                { 500 },
                { 333 },
                { 444 },
                { 500 },
                { 444 },
                {  500},
                {  444},
                {  333},
                {  500},
                {  500},
                {  278},
                {  278},
                {  500},
                {  278},
                {  778},
                {  500},
                {  500},
                {  500},
                {  500},
                {  333},
                {  389},
                {  278},
                {  500},
                {  500},
                {  722},
                {  500},
                {  500},
                {  444},
                {  480},
                {  200},
                {  480},
                {  541},
        } },
        { "Times-Bold", {
                { 250  },
                { 333  },
                { 555  },
                { 500  },
                { 500  },
                { 1000 },
                { 833  },
                { 333  },
                { 333  },
                { 333  },
                { 500  },
                { 570  },
                { 250  },
                { 333  },
                { 250  },
                { 278  },
                { 500  },
                { 500  },
                { 500  },
                { 500  },
                { 500  },
                { 500  },
                { 500  },
                { 500  },
                { 500  },
                { 500  },
                { 333  },
                { 333  },
                { 570  },
                { 570  },
                { 570  },
                { 500  },
                { 930  },
                { 722  },
                { 667  },
                { 722  },
                { 722  },
                { 667  },
                { 611  },
                { 778  },
                { 778  },
                { 389  },
                { 500  },
                { 778  },
                { 667  },
                { 944  },
                { 722  },
                { 778  },
                { 611  },
                { 778  },
                { 722  },
                { 556  },
                { 667  },
                { 722  },
                { 722  },
                { 1000 },
                { 722  },
                { 722  },
                { 667  },
                { 333  },
                { 278  },
                { 333  },
                { 581  },
                { 500  },
                { 333  },
                { 500  },
                { 556  },
                { 444  },
                {  556 },
                {  444 },
                {  333 },
                {  500 },
                {  556 },
                {  278 },
                {  333 },
                {  556 },
                {  278 },
                {  833 },
                {  556 },
                {  500 },
                {  556 },
                {  556 },
                {  444 },
                {  389 },
                {  333 },
                {  556 },
                {  500 },
                {  722 },
                {  500 },
                {  500 },
                {  444 },
                {  394 },
                {  220 },
                {  394 },
                {  520 },
        } },
        { "Times-Italic", {
                { 250  },
                { 333  },
                { 420  },
                { 500  },
                { 500  },
                { 833  },
                { 778  },
                { 333  },
                { 333  },
                { 333  },
                { 500  },
                { 675  },
                { 250  },
                { 333  },
                { 250  },
                { 278  },
                { 500  },
                { 500  },
                { 500  },
                { 500  },
                { 500  },
                { 500  },
                { 500  },
                { 500  },
                { 500  },
                { 500  },
                { 333  },
                { 333  },
                { 675  },
                { 675  },
                { 675  },
                { 500  },
                { 920  },
                { 611  },
                { 611  },
                { 667  },
                { 722  },
                { 611  },
                { 611  },
                { 722  },
                { 722  },
                { 333  },
                { 444  },
                { 667  },
                { 556  },
                { 833  },
                { 667  },
                { 722  },
                { 611  },
                { 722  },
                { 611  },
                { 500  },
                { 556  },
                { 722  },
                { 611  },
                { 833  },
                { 611  },
                { 556  },
                { 556  },
                { 389  },
                { 278  },
                { 389  },
                { 422  },
                { 500  },
                { 333  },
                { 500  },
                { 500  },
                { 444  },
                {  500 },
                {  444 },
                {  278 },
                {  500 },
                {  500 },
                {  278 },
                {  278 },
                {  444 },
                {  278 },
                {  722 },
                {  500 },
                {  500 },
                {  500 },
                {  500 },
                {  389 },
                {  389 },
                {  278 },
                {  500 },
                {  444 },
                {  667 },
                {  444 },
                {  444 },
                {  389 },
                {  400 },
                {  275 },
                {  400 },
                {  541 },
        } },
};

void *
pdf_alloc(char *outopts)
{
        struct termp    *p;

        if (NULL != (p = pspdf_alloc(outopts)))
                p->type = TERMTYPE_PDF;

        return(p);
}

void *
ps_alloc(char *outopts)
{
        struct termp    *p;

        if (NULL != (p = pspdf_alloc(outopts)))
                p->type = TERMTYPE_PS;

        return(p);
}

static struct termp *
pspdf_alloc(char *outopts)
{
        struct termp    *p;
        unsigned int     pagex, pagey;
        size_t           marginx, marginy, lineheight;
        const char      *toks[2];
        const char      *pp;
        char            *v;

        p = mandoc_calloc(1, sizeof(struct termp));
        p->enc = TERMENC_ASCII;
        p->ps = mandoc_calloc(1, sizeof(struct termp_ps));

        p->advance = ps_advance;
        p->begin = ps_begin;
        p->end = ps_end;
        p->endline = ps_endline;
        p->hspan = ps_hspan;
        p->letter = ps_letter;
        p->width = ps_width;
        
        toks[0] = "paper";
        toks[1] = NULL;

        pp = NULL;

        while (outopts && *outopts)
                switch (getsubopt(&outopts, UNCONST(toks), &v)) {
                case (0):
                        pp = v;
                        break;
                default:
                        break;
                }

        /* Default to US letter (millimetres). */

        pagex = 216;
        pagey = 279;

        /*
         * The ISO-269 paper sizes can be calculated automatically, but
         * it would require bringing in -lm for pow() and I'd rather not
         * do that.  So just do it the easy way for now.  Since this
         * only happens once, I'm not terribly concerned.
         */

        if (pp && strcasecmp(pp, "letter")) {
                if (0 == strcasecmp(pp, "a3")) {
                        pagex = 297;
                        pagey = 420;
                } else if (0 == strcasecmp(pp, "a4")) {
                        pagex = 210;
                        pagey = 297;
                } else if (0 == strcasecmp(pp, "a5")) {
                        pagex = 148;
                        pagey = 210;
                } else if (0 == strcasecmp(pp, "legal")) {
                        pagex = 216;
                        pagey = 356;
                } else if (2 != sscanf(pp, "%ux%u", &pagex, &pagey))
                        fprintf(stderr, "%s: Unknown paper\n", pp);
        }

        /* 
         * This MUST be defined before any PNT2AFM or AFM2PNT
         * calculations occur.
         */

        p->ps->scale = 11;

        /* Remember millimetres -> AFM units. */

        pagex = PNT2AFM(p, ((double)pagex * 2.834));
        pagey = PNT2AFM(p, ((double)pagey * 2.834));

        /* Margins are 1/9 the page x and y. */

        marginx = /* LINTED */
                (size_t)((double)pagex / 9.0);
        marginy = /* LINTED */
                (size_t)((double)pagey / 9.0);

        /* Line-height is 1.4em. */

        lineheight = PNT2AFM(p, ((double)p->ps->scale * 1.4));

        p->ps->width = (size_t)pagex;
        p->ps->height = (size_t)pagey;
        p->ps->header = pagey - (marginy / 2) - (lineheight / 2);
        p->ps->top = pagey - marginy;
        p->ps->footer = (marginy / 2) - (lineheight / 2);
        p->ps->bottom = marginy;
        p->ps->left = marginx;
        p->ps->lineheight = lineheight;

        p->defrmargin = pagex - (marginx * 2);
        return(p);
}


void
pspdf_free(void *arg)
{
        struct termp    *p;

        p = (struct termp *)arg;

        if (p->ps->psmarg)
                free(p->ps->psmarg);
        if (p->ps->pdfobjs)
                free(p->ps->pdfobjs);

        free(p->ps);
        term_free(p);
}


static void
ps_printf(struct termp *p, const char *fmt, ...)
{
        va_list          ap;
        int              pos, len;

        va_start(ap, fmt);

        /*
         * If we're running in regular mode, then pipe directly into
         * vprintf().  If we're processing margins, then push the data
         * into our growable margin buffer.
         */

        if ( ! (PS_MARGINS & p->ps->flags)) {
                len = vprintf(fmt, ap);
                va_end(ap);
                p->ps->pdfbytes += /* LINTED */
                        len < 0 ? 0 : (size_t)len;
                return;
        }

        /* 
         * XXX: I assume that the in-margin print won't exceed
         * PS_BUFSLOP (128 bytes), which is reasonable but still an
         * assumption that will cause pukeage if it's not the case.
         */

        ps_growbuf(p, PS_BUFSLOP);

        pos = (int)p->ps->psmargcur;
        vsnprintf(&p->ps->psmarg[pos], PS_BUFSLOP, fmt, ap);

        va_end(ap);

        p->ps->psmargcur = strlen(p->ps->psmarg);
}


static void
ps_putchar(struct termp *p, char c)
{
        int              pos;

        /* See ps_printf(). */

        if ( ! (PS_MARGINS & p->ps->flags)) {
                /* LINTED */
                putchar(c);
                p->ps->pdfbytes++;
                return;
        }

        ps_growbuf(p, 2);

        pos = (int)p->ps->psmargcur++;
        p->ps->psmarg[pos++] = c;
        p->ps->psmarg[pos] = '\0';
}


static void
pdf_obj(struct termp *p, size_t obj)
{

        assert(obj > 0);

        if ((obj - 1) >= p->ps->pdfobjsz) {
                p->ps->pdfobjsz = obj + 128;
                p->ps->pdfobjs = realloc
                        (p->ps->pdfobjs, 
                         p->ps->pdfobjsz * sizeof(size_t));
                if (NULL == p->ps->pdfobjs) {
                        perror(NULL);
                        exit((int)MANDOCLEVEL_SYSERR);
                }
        }

        p->ps->pdfobjs[(int)obj - 1] = p->ps->pdfbytes;
        ps_printf(p, "%zu 0 obj\n", obj);
}


static void
ps_closepage(struct termp *p)
{
        int              i;
        size_t           len, base;

        /*
         * Close out a page that we've already flushed to output.  In
         * PostScript, we simply note that the page must be showed.  In
         * PDF, we must now create the Length, Resource, and Page node
         * for the page contents.
         */

        assert(p->ps->psmarg && p->ps->psmarg[0]);
        ps_printf(p, "%s", p->ps->psmarg);

        if (TERMTYPE_PS != p->type) {
                ps_printf(p, "ET\n");

                len = p->ps->pdfbytes - p->ps->pdflastpg;
                base = p->ps->pages * 4 + p->ps->pdfbody;

                ps_printf(p, "endstream\nendobj\n");

                /* Length of content. */
                pdf_obj(p, base + 1);
                ps_printf(p, "%zu\nendobj\n", len);

                /* Resource for content. */
                pdf_obj(p, base + 2);
                ps_printf(p, "<<\n/ProcSet [/PDF /Text]\n");
                ps_printf(p, "/Font <<\n");
                for (i = 0; i < (int)TERMFONT__MAX; i++) 
                        ps_printf(p, "/F%d %d 0 R\n", i, 3 + i);
                ps_printf(p, ">>\n>>\n");

                /* Page node. */
                pdf_obj(p, base + 3);
                ps_printf(p, "<<\n");
                ps_printf(p, "/Type /Page\n");
                ps_printf(p, "/Parent 2 0 R\n");
                ps_printf(p, "/Resources %zu 0 R\n", base + 2);
                ps_printf(p, "/Contents %zu 0 R\n", base);
                ps_printf(p, ">>\nendobj\n");
        } else
                ps_printf(p, "showpage\n");

        p->ps->pages++;
        p->ps->psrow = p->ps->top;
        assert( ! (PS_NEWPAGE & p->ps->flags));
        p->ps->flags |= PS_NEWPAGE;
}


/* ARGSUSED */
static void
ps_end(struct termp *p)
{
        size_t           i, xref, base;

        /*
         * At the end of the file, do one last showpage.  This is the
         * same behaviour as groff(1) and works for multiple pages as
         * well as just one.
         */

        if ( ! (PS_NEWPAGE & p->ps->flags)) {
                assert(0 == p->ps->flags);
                assert('\0' == p->ps->last);
                ps_closepage(p);
        }

        if (TERMTYPE_PS == p->type) {
                ps_printf(p, "%%%%Trailer\n");
                ps_printf(p, "%%%%Pages: %zu\n", p->ps->pages);
                ps_printf(p, "%%%%EOF\n");
                return;
        } 

        pdf_obj(p, 2);
        ps_printf(p, "<<\n/Type /Pages\n");
        ps_printf(p, "/MediaBox [0 0 %zu %zu]\n",
                        (size_t)AFM2PNT(p, p->ps->width),
                        (size_t)AFM2PNT(p, p->ps->height));

        ps_printf(p, "/Count %zu\n", p->ps->pages);
        ps_printf(p, "/Kids [");

        for (i = 0; i < p->ps->pages; i++)
                ps_printf(p, " %zu 0 R", i * 4 +
                                p->ps->pdfbody + 3);

        base = (p->ps->pages - 1) * 4 + 
                p->ps->pdfbody + 4;

        ps_printf(p, "]\n>>\nendobj\n");
        pdf_obj(p, base);
        ps_printf(p, "<<\n");
        ps_printf(p, "/Type /Catalog\n");
        ps_printf(p, "/Pages 2 0 R\n");
        ps_printf(p, ">>\n");
        xref = p->ps->pdfbytes;
        ps_printf(p, "xref\n");
        ps_printf(p, "0 %zu\n", base + 1);
        ps_printf(p, "0000000000 65535 f \n");

        for (i = 0; i < base; i++)
                ps_printf(p, "%.10zu 00000 n \n", 
                                p->ps->pdfobjs[(int)i]);

        ps_printf(p, "trailer\n");
        ps_printf(p, "<<\n");
        ps_printf(p, "/Size %zu\n", base + 1);
        ps_printf(p, "/Root %zu 0 R\n", base);
        ps_printf(p, "/Info 1 0 R\n");
        ps_printf(p, ">>\n");
        ps_printf(p, "startxref\n");
        ps_printf(p, "%zu\n", xref);
        ps_printf(p, "%%%%EOF\n");
}


static void
ps_begin(struct termp *p)
{
        time_t           t;
        int              i;

        /* 
         * Print margins into margin buffer.  Nothing gets output to the
         * screen yet, so we don't need to initialise the primary state.
         */

        if (p->ps->psmarg) {
                assert(p->ps->psmargsz);
                p->ps->psmarg[0] = '\0';
        }

        /*p->ps->pdfbytes = 0;*/
        p->ps->psmargcur = 0;
        p->ps->flags = PS_MARGINS;
        p->ps->pscol = p->ps->left;
        p->ps->psrow = p->ps->header;

        ps_setfont(p, TERMFONT_NONE);

        (*p->headf)(p, p->argf);
        (*p->endline)(p);

        p->ps->pscol = p->ps->left;
        p->ps->psrow = p->ps->footer;

        (*p->footf)(p, p->argf);
        (*p->endline)(p);

        p->ps->flags &= ~PS_MARGINS;

        assert(0 == p->ps->flags);
        assert(p->ps->psmarg);
        assert('\0' != p->ps->psmarg[0]);

        /* 
         * Print header and initialise page state.  Following this,
         * stuff gets printed to the screen, so make sure we're sane.
         */

        t = time(NULL);

        if (TERMTYPE_PS == p->type) {
                ps_printf(p, "%%!PS-Adobe-3.0\n");
                ps_printf(p, "%%%%CreationDate: %s", ctime(&t));
                ps_printf(p, "%%%%DocumentData: Clean7Bit\n");
                ps_printf(p, "%%%%Orientation: Portrait\n");
                ps_printf(p, "%%%%Pages: (atend)\n");
                ps_printf(p, "%%%%PageOrder: Ascend\n");
                ps_printf(p, "%%%%DocumentMedia: "
                                "Default %zu %zu 0 () ()\n",
                                (size_t)AFM2PNT(p, p->ps->width),
                                (size_t)AFM2PNT(p, p->ps->height));
                ps_printf(p, "%%%%DocumentNeededResources: font");

                for (i = 0; i < (int)TERMFONT__MAX; i++)
                        ps_printf(p, " %s", fonts[i].name);

                ps_printf(p, "\n%%%%EndComments\n");
        } else {
                ps_printf(p, "%%PDF-1.1\n");
                pdf_obj(p, 1);
                ps_printf(p, "<<\n");
                ps_printf(p, ">>\n");
                ps_printf(p, "endobj\n");

                for (i = 0; i < (int)TERMFONT__MAX; i++) {
                        pdf_obj(p, (size_t)i + 3);
                        ps_printf(p, "<<\n");
                        ps_printf(p, "/Type /Font\n");
                        ps_printf(p, "/Subtype /Type1\n");
                        ps_printf(p, "/Name /F%zu\n", i);
                        ps_printf(p, "/BaseFont /%s\n", fonts[i].name);
                        ps_printf(p, ">>\n");
                }
        }

        p->ps->pdfbody = (size_t)TERMFONT__MAX + 3;
        p->ps->pscol = p->ps->left;
        p->ps->psrow = p->ps->top;
        p->ps->flags |= PS_NEWPAGE;
        ps_setfont(p, TERMFONT_NONE);
}


static void
ps_pletter(struct termp *p, int c)
{
        int              f;

        /*
         * If we haven't opened a page context, then output that we're
         * in a new page and make sure the font is correctly set.
         */

        if (PS_NEWPAGE & p->ps->flags) {
                if (TERMTYPE_PS == p->type) {
                        ps_printf(p, "%%%%Page: %zu %zu\n", 
                                        p->ps->pages + 1, 
                                        p->ps->pages + 1);
                        ps_printf(p, "/%s %zu selectfont\n", 
                                        fonts[(int)p->ps->lastf].name, 
                                        p->ps->scale);
                } else {
                        pdf_obj(p, p->ps->pdfbody + 
                                        p->ps->pages * 4);
                        ps_printf(p, "<<\n");
                        ps_printf(p, "/Length %zu 0 R\n", 
                                        p->ps->pdfbody + 1 +
                                        p->ps->pages * 4);
                        ps_printf(p, ">>\nstream\n");
                }
                p->ps->pdflastpg = p->ps->pdfbytes;
                p->ps->flags &= ~PS_NEWPAGE;
        }
        
        /*
         * If we're not in a PostScript "word" context, then open one
         * now at the current cursor.
         */

        if ( ! (PS_INLINE & p->ps->flags)) {
                if (TERMTYPE_PS != p->type) {
                        ps_printf(p, "BT\n/F%d %zu Tf\n", 
                                        (int)p->ps->lastf,
                                        p->ps->scale);
                        ps_printf(p, "%.3f %.3f Td\n(",
                                        AFM2PNT(p, p->ps->pscol),
                                        AFM2PNT(p, p->ps->psrow));
                } else
                        ps_printf(p, "%.3f %.3f moveto\n(", 
                                        AFM2PNT(p, p->ps->pscol),
                                        AFM2PNT(p, p->ps->psrow));
                p->ps->flags |= PS_INLINE;
        }

        assert( ! (PS_NEWPAGE & p->ps->flags));

        /*
         * We need to escape these characters as per the PostScript
         * specification.  We would also escape non-graphable characters
         * (like tabs), but none of them would get to this point and
         * it's superfluous to abort() on them.
         */

        switch (c) {
        case ('('):
                /* FALLTHROUGH */
        case (')'):
                /* FALLTHROUGH */
        case ('\\'):
                ps_putchar(p, '\\');
                break;
        default:
                break;
        }

        /* Write the character and adjust where we are on the page. */

        f = (int)p->ps->lastf;

        if (c <= 32 || (c - 32 >= MAXCHAR)) {
                ps_putchar(p, ' ');
                p->ps->pscol += (size_t)fonts[f].gly[0].wx;
                return;
        } 

        ps_putchar(p, (char)c);
        c -= 32;
        p->ps->pscol += (size_t)fonts[f].gly[c].wx;
}


static void
ps_pclose(struct termp *p)
{

        /* 
         * Spit out that we're exiting a word context (this is a
         * "partial close" because we don't check the last-char buffer
         * or anything).
         */

        if ( ! (PS_INLINE & p->ps->flags))
                return;
        
        if (TERMTYPE_PS != p->type) {
                ps_printf(p, ") Tj\nET\n");
        } else
                ps_printf(p, ") show\n");

        p->ps->flags &= ~PS_INLINE;
}


static void
ps_fclose(struct termp *p)
{

        /*
         * Strong closure: if we have a last-char, spit it out after
         * checking that we're in the right font mode.  This will of
         * course open a new scope, if applicable.
         *
         * Following this, close out any scope that's open.
         */

        if ('\0' != p->ps->last) {
                if (p->ps->lastf != TERMFONT_NONE) {
                        ps_pclose(p);
                        ps_setfont(p, TERMFONT_NONE);
                }
                ps_pletter(p, p->ps->last);
                p->ps->last = '\0';
        }

        if ( ! (PS_INLINE & p->ps->flags))
                return;

        ps_pclose(p);
}


static void
ps_letter(struct termp *p, int arg)
{
        char            cc, c;

        /* LINTED */
        c = arg >= 128 || arg <= 0 ? '?' : arg;

        /*
         * State machine dictates whether to buffer the last character
         * or not.  Basically, encoded words are detected by checking if
         * we're an "8" and switching on the buffer.  Then we put "8" in
         * our buffer, and on the next charater, flush both character
         * and buffer.  Thus, "regular" words are detected by having a
         * regular character and a regular buffer character.
         */

        if ('\0' == p->ps->last) {
                assert(8 != c);
                p->ps->last = c;
                return;
        } else if (8 == p->ps->last) {
                assert(8 != c);
                p->ps->last = '\0';
        } else if (8 == c) {
                assert(8 != p->ps->last);
                if ('_' == p->ps->last) {
                        if (p->ps->lastf != TERMFONT_UNDER) {
                                ps_pclose(p);
                                ps_setfont(p, TERMFONT_UNDER);
                        }
                } else if (p->ps->lastf != TERMFONT_BOLD) {
                        ps_pclose(p);
                        ps_setfont(p, TERMFONT_BOLD);
                }
                p->ps->last = c;
                return;
        } else {
                if (p->ps->lastf != TERMFONT_NONE) {
                        ps_pclose(p);
                        ps_setfont(p, TERMFONT_NONE);
                }
                cc = p->ps->last;
                p->ps->last = c;
                c = cc;
        }

        ps_pletter(p, c);
}


static void
ps_advance(struct termp *p, size_t len)
{

        /*
         * Advance some spaces.  This can probably be made smarter,
         * i.e., to have multiple space-separated words in the same
         * scope, but this is easier:  just close out the current scope
         * and readjust our column settings.
         */

        ps_fclose(p);
        p->ps->pscol += len;
}


static void
ps_endline(struct termp *p)
{

        /* Close out any scopes we have open: we're at eoln. */

        ps_fclose(p);

        /*
         * If we're in the margin, don't try to recalculate our current
         * row.  XXX: if the column tries to be fancy with multiple
         * lines, we'll do nasty stuff. 
         */

        if (PS_MARGINS & p->ps->flags)
                return;

        /* Left-justify. */

        p->ps->pscol = p->ps->left;

        /* If we haven't printed anything, return. */

        if (PS_NEWPAGE & p->ps->flags)
                return;

        /*
         * Put us down a line.  If we're at the page bottom, spit out a
         * showpage and restart our row.
         */

        if (p->ps->psrow >= p->ps->lineheight + 
                        p->ps->bottom) {
                p->ps->psrow -= p->ps->lineheight;
                return;
        }

        ps_closepage(p);
}


static void
ps_setfont(struct termp *p, enum termfont f)
{

        assert(f < TERMFONT__MAX);
        p->ps->lastf = f;
        
        /*
         * If we're still at the top of the page, let the font-setting
         * be delayed until we actually have stuff to print.
         */

        if (PS_NEWPAGE & p->ps->flags)
                return;

        if (TERMTYPE_PS == p->type)
                ps_printf(p, "/%s %zu selectfont\n", 
                                fonts[(int)f].name, 
                                p->ps->scale);
        else
                ps_printf(p, "/F%d %zu Tf\n", 
                                (int)f, 
                                p->ps->scale);
}


/* ARGSUSED */
static size_t
ps_width(const struct termp *p, int c)
{

        if (c <= 32 || c - 32 >= MAXCHAR)
                return((size_t)fonts[(int)TERMFONT_NONE].gly[0].wx);

        c -= 32;
        return((size_t)fonts[(int)TERMFONT_NONE].gly[c].wx);
}


static double
ps_hspan(const struct termp *p, const struct roffsu *su)
{
        double           r;
        
        /*
         * All of these measurements are derived by converting from the
         * native measurement to AFM units.
         */

        switch (su->unit) {
        case (SCALE_CM):
                r = PNT2AFM(p, su->scale * 28.34);
                break;
        case (SCALE_IN):
                r = PNT2AFM(p, su->scale * 72);
                break;
        case (SCALE_PC):
                r = PNT2AFM(p, su->scale * 12);
                break;
        case (SCALE_PT):
                r = PNT2AFM(p, su->scale * 100);
                break;
        case (SCALE_EM):
                r = su->scale *
                        fonts[(int)TERMFONT_NONE].gly[109 - 32].wx;
                break;
        case (SCALE_MM):
                r = PNT2AFM(p, su->scale * 2.834);
                break;
        case (SCALE_EN):
                r = su->scale *
                        fonts[(int)TERMFONT_NONE].gly[110 - 32].wx;
                break;
        case (SCALE_VS):
                r = su->scale * p->ps->lineheight;
                break;
        default:
                r = su->scale;
                break;
        }

        return(r);
}

static void
ps_growbuf(struct termp *p, size_t sz)
{
        if (p->ps->psmargcur + sz <= p->ps->psmargsz)
                return;

        if (sz < PS_BUFSLOP)
                sz = PS_BUFSLOP;

        p->ps->psmargsz += sz;

        p->ps->psmarg = mandoc_realloc
                (p->ps->psmarg, p->ps->psmargsz);
}