Rough-and-ready line wrapping for PostScript, to keep us below the DSC-mandated

255 characters per line (excluding newline characters).  In fact, it tries to
keep us below 80 characters so as to make the PostScript more readable (and
demonstrate that it's working).

git-svn-id: svn://svn.tartarus.org/sgt/halibut@6993 cda61777-01e9-0310-a592-d414129be87e

diff --git a/bk_ps.c b/bk_ps.c
index 4e47767..e722b10 100644 (file)
--- a/bk_ps.c
+++ b/bk_ps.c
@@ -3,12 +3,19 @@
  */
 
 #include <assert.h>
+#include <stdarg.h>
 #include "halibut.h"
 #include "paper.h"
 
+/* Ideal number of characters per line, for use in PostScript code */
+#define PS_WIDTH 79
+/* Absolute maxiumum characters per line, for use in DSC comments */
+#define PS_MAXWIDTH 255
+
 static void ps_comment(FILE *fp, char const *leader, word *words);
-static void ps_string_len(FILE *fp, char const *str, int len);
-static void ps_string(FILE *fp, char const *str);
+static void ps_token(FILE *fp, int *cc, char const *fmt, ...);
+static void ps_string_len(FILE *fp, int *cc, char const *str, int len);
+static void ps_string(FILE *fp, int *cc, char const *str);
 
 paragraph *ps_config_filename(char *filename)
 {
@@ -27,7 +34,7 @@ void ps_backend(paragraph *sourceform, keywordlist *keywords,
     paragraph *p;
     outline_element *oe;
     int noe;
-
+    int cc; /* Character count on current line */
 
     IGNORE(keywords);
     IGNORE(idx);
@@ -143,21 +150,22 @@ void ps_backend(paragraph *sourceform, keywordlist *keywords,
        if (p->type == para_VersionID)
            ps_comment(fp, "% ", p->words);
 
+    cc = 0;
     /*
      * Request the correct page size.  We might want to bracket this
      * with "%%BeginFeature: *PageSize A4" or similar, and "%%EndFeature",
      * but that would require us to have a way of getting the name of
      * the page size given its dimensions.
      */
-    fprintf(fp, "/setpagedevice where {\n");
-    fprintf(fp, "  pop 2 dict dup /PageSize [%g %g] put setpagedevice\n",
-           doc->paper_width / FUNITS_PER_PT,
-           doc->paper_height / FUNITS_PER_PT);
-    fprintf(fp, "} if\n");
+    ps_token(fp, &cc, "/setpagedevice where {\n");
+    ps_token(fp, &cc, "  pop 2 dict dup /PageSize [%g %g] put setpagedevice\n",
+            doc->paper_width / FUNITS_PER_PT,
+            doc->paper_height / FUNITS_PER_PT);
+    ps_token(fp, &cc, "} if\n");
 
     /* Outline etc, only if pdfmark is supported */
-    fprintf(fp, "/pdfmark where { pop %% if\n");
-    fprintf(fp, "  [/PageMode/UseOutlines/DOCVIEW pdfmark\n");
+    ps_token(fp, &cc, "/pdfmark where { pop %% if\n");
+    ps_token(fp, &cc, "  [/PageMode/UseOutlines/DOCVIEW pdfmark\n");
     noe = doc->n_outline_elements;
     for (oe = doc->outline_elements; noe; oe++, noe--) {
        char *title;
@@ -165,9 +173,9 @@ void ps_backend(paragraph *sourceform, keywordlist *keywords,
 
        title = pdf_outline_convert(oe->pdata->outline_title, &titlelen);
        if (oe->level == 0) {
-           fprintf(fp, "  [/Title");
-           ps_string_len(fp, title, titlelen);
-           fprintf(fp, "/DOCINFO pdfmark\n");
+           ps_token(fp, &cc, "  [/Title");
+           ps_string_len(fp, &cc, title, titlelen);
+           ps_token(fp, &cc, "/DOCINFO pdfmark\n");
        }
 
        count = 0;
@@ -176,13 +184,13 @@ void ps_backend(paragraph *sourceform, keywordlist *keywords,
                count++;
        if (oe->level > 0) count = -count;
 
-       fprintf(fp, "  [/Title");
-       ps_string_len(fp, title, titlelen);
+       ps_token(fp, &cc, "  [/Title");
+       ps_string_len(fp, &cc, title, titlelen);
        sfree(title);
-       fprintf(fp, "/Dest%s/Count %d/OUT pdfmark\n",
+       ps_token(fp, &cc, "/Dest%s/Count %d/OUT pdfmark\n",
                (char *)oe->pdata->first->page->spare, count);
     }
-    fprintf(fp, "} if\n");
+    ps_token(fp, &cc, "} if\n");
 
     for (fe = doc->fonts->head; fe; fe = fe->next) {
        /* XXX This may request the same font multiple times. */
@@ -213,17 +221,17 @@ void ps_backend(paragraph *sourceform, keywordlist *keywords,
        sprintf(fname, "f%d", font_index++);
        fe->name = dupstr(fname);
 
-       fprintf(fp, "/%s findfont dup length dict begin\n",
+       ps_token(fp, &cc, "/%s findfont dup length dict begin\n",
            fe->font->info->name);
-       fprintf(fp, "{1 index /FID ne {def} {pop pop} ifelse} forall\n");
-       fprintf(fp, "/Encoding [\n");
+       ps_token(fp, &cc, "{1 index /FID ne {def} {pop pop} ifelse} forall\n");
+       ps_token(fp, &cc, "/Encoding [\n");
        for (i = 0; i < 256; i++)
-           fprintf(fp, "/%s%c", fe->vector[i] ? fe->vector[i] : ".notdef",
-                   i % 4 == 3 ? '\n' : ' ');
-       fprintf(fp, "] def\n");
-       fprintf(fp, "currentdict end\n");
-       fprintf(fp, "/fontname-%s exch definefont /%s exch def\n\n",
-              fe->name, fe->name);
+           ps_token(fp, &cc, "/%s",
+                    fe->vector[i] ? fe->vector[i] : ".notdef");
+       ps_token(fp, &cc, "] def\n");
+       ps_token(fp, &cc, "currentdict end\n");
+       ps_token(fp, &cc, "/fontname-%s exch definefont /%s exch def\n",
+                fe->name, fe->name);
     }
     fprintf(fp, "%%%%EndSetup\n");
 
@@ -240,22 +248,23 @@ void ps_backend(paragraph *sourceform, keywordlist *keywords,
 
        pageno++;
        fprintf(fp, "%%%%Page: %d %d\n", pageno, pageno);
-       fprintf(fp, "save %s p\n", (char *)page->spare);
+       cc = 0;
+       ps_token(fp, &cc, "save %s p\n", (char *)page->spare);
        
        for (xr = page->first_xref; xr; xr = xr->next) {
-           fprintf(fp, "[%g %g %g %g]",
+           ps_token(fp, &cc, "[%g %g %g %g]",
                    xr->lx/FUNITS_PER_PT, xr->by/FUNITS_PER_PT,
                    xr->rx/FUNITS_PER_PT, xr->ty/FUNITS_PER_PT);
            if (xr->dest.type == PAGE) {
-               fprintf(fp, "%s x\n", (char *)xr->dest.page->spare);
+               ps_token(fp, &cc, "%s x\n", (char *)xr->dest.page->spare);
            } else {
-               ps_string(fp, xr->dest.url);
-               fprintf(fp, "u\n");
+               ps_string(fp, &cc, xr->dest.url);
+               ps_token(fp, &cc, "u\n");
            }
        }
 
        for (r = page->first_rect; r; r = r->next) {
-           fprintf(fp, "%g %g %g %g r\n",
+           ps_token(fp, &cc, "%g %g %g %g r\n",
                    r->x / FUNITS_PER_PT, r->y / FUNITS_PER_PT,
                    r->w / FUNITS_PER_PT, r->h / FUNITS_PER_PT);
        }
@@ -272,25 +281,26 @@ void ps_backend(paragraph *sourceform, keywordlist *keywords,
                 frag_end && frag_end->y == frag->y;
                 frag_end = frag_end->next);
 
-           fprintf(fp, "%g[", frag->y / FUNITS_PER_PT);
+           ps_token(fp, &cc, "%g[", frag->y / FUNITS_PER_PT);
 
            while (frag && frag != frag_end) {
 
                if (frag->fe != fe || frag->fontsize != fs)
-                   fprintf(fp, "[%s %d]", frag->fe->name, frag->fontsize);
+                   ps_token(fp, &cc, "[%s %d]",
+                            frag->fe->name, frag->fontsize);
                fe = frag->fe;
                fs = frag->fontsize;
 
-               fprintf(fp, "%g", frag->x/FUNITS_PER_PT);
-               ps_string(fp, frag->text);
+               ps_token(fp, &cc, "%g", frag->x/FUNITS_PER_PT);
+               ps_string(fp, &cc, frag->text);
 
                frag = frag->next;
            }
 
-           fprintf(fp, "]t\n");
+           ps_token(fp, &cc, "]t\n");
        }
 
-       fprintf(fp, "restore showpage\n");
+       ps_token(fp, &cc, "restore showpage\n");
     }
 
     fprintf(fp, "%%%%EOF\n");
@@ -300,9 +310,10 @@ void ps_backend(paragraph *sourceform, keywordlist *keywords,
     sfree(filename);
 }
 
-static void ps_comment(FILE *fp, char const *leader, word *words)
-{
-    fprintf(fp, "%s", leader);
+static void ps_comment(FILE *fp, char const *leader, word *words) {
+    int cc = 0;
+
+    cc += fprintf(fp, "%s", leader);
 
     for (; words; words = words->next) {
        char *text;
@@ -332,14 +343,30 @@ static void ps_comment(FILE *fp, char const *leader, word *words)
            break;
        }
 
-       fputs(text, fp);
+       if (cc + strlen(text) > PS_MAXWIDTH)
+           text[PS_MAXWIDTH - cc] = 0;
+       cc += fprintf(fp, "%s", text);
        sfree(text);
     }
 
     fprintf(fp, "\n");
 }
 
-static void ps_string_len(FILE *fp, char const *str, int len) {
+static void ps_token(FILE *fp, int *cc, char const *fmt, ...) {
+    va_list ap;
+
+    va_start(ap, fmt);
+    if (*cc >= PS_WIDTH - 10) {
+       fprintf(fp, "\n");
+       *cc = 0;
+    }
+    *cc += vfprintf(fp, fmt, ap);
+    /* Assume that \n only occurs at the end of a string */
+    if (fmt[strlen(fmt) - 1] == '\n')
+       *cc = 0;
+}
+
+static void ps_string_len(FILE *fp, int *cc, char const *str, int len) {
     char const *c;
     int score = 0;
 
@@ -352,26 +379,33 @@ static void ps_string_len(FILE *fp, char const *str, int len) {
            score -= 1;
     }
     if (score > 0) {
-       fprintf(fp, "<");
+       ps_token(fp, cc, "<");
        for (c = str; c < str+len; c++) {
-           fprintf(fp, "%02X", 0xFF & (int)*c);
+           ps_token(fp, cc, "%02X", 0xFF & (int)*c);
        }
-       fprintf(fp, ">");
+       ps_token(fp, cc, ">");
     } else {
-       fprintf(fp, "(");
+       *cc += fprintf(fp, "(");
        for (c = str; c < str+len; c++) {
+           if (*cc >= PS_WIDTH - 4) {
+               fprintf(fp, "\\\n");
+               *cc = 0;
+           }
            if (*c < ' ' || *c > '~') {
-               fprintf(fp, "\\%03o", 0xFF & (int)*c);
+               *cc += fprintf(fp, "\\%03o", 0xFF & (int)*c);
            } else {
-               if (*c == '(' || *c == ')' || *c == '\\')
+               if (*c == '(' || *c == ')' || *c == '\\') {
                    fputc('\\', fp);
+                   (*cc)++;
+               }
                fputc(*c, fp);
+               (*cc)++;
            }
        }
-       fprintf(fp, ")");
+       *cc += fprintf(fp, ")");
     }
 }
 
-static void ps_string(FILE *fp, char const *str) {
-    ps_string_len(fp, str, strlen(str));
+static void ps_string(FILE *fp, int *cc, char const *str) {
+    ps_string_len(fp, cc, str, strlen(str));
 }