* PDF backend for Halibut
*/
+#include <assert.h>
#include "halibut.h"
+#include "paper.h"
+
+#define TREE_BRANCH 2 /* max branching factor in page tree */
paragraph *pdf_config_filename(char *filename)
{
- return NULL;
+ return cmdline_cfg_simple("pdf-filename", filename, NULL);
}
+typedef struct object_Tag object;
+typedef struct objlist_Tag objlist;
+
+struct object_Tag {
+ objlist *list;
+ object *next;
+ int number;
+ rdstringc main, stream;
+ int size, fileoff;
+ char *final;
+};
+
+struct objlist_Tag {
+ int number;
+ object *head, *tail;
+};
+
+static object *new_object(objlist *list);
+static void objtext(object *o, char const *text);
+static void objstream(object *o, char const *text);
+static void pdf_string(void (*add)(object *, char const *),
+ object *, char const *);
+static void pdf_string_len(void (*add)(object *, char const *),
+ object *, char const *, int);
+static void objref(object *o, object *dest);
+
+static void make_pages_node(object *node, object *parent, page_data *first,
+ page_data *last, object *resources);
+static int make_outline(object *parent, outline_element *start, int n,
+ int open);
+static int pdf_versionid(FILE *fp, word *words);
+
void pdf_backend(paragraph *sourceform, keywordlist *keywords,
- indexdata *idx, void *unused) {
+ indexdata *idx, void *vdoc) {
+ document *doc = (document *)vdoc;
+ int font_index;
+ font_encoding *fe;
+ page_data *page;
+ int pageno;
+ FILE *fp;
+ char *filename;
+ paragraph *p;
+ objlist olist;
+ object *o, *cat, *outlines, *pages, *resources;
+ int fileoff;
+
+ IGNORE(keywords);
+ IGNORE(idx);
+
+ filename = dupstr("output.pdf");
+ for (p = sourceform; p; p = p->next) {
+ if (p->type == para_Config) {
+ if (!ustricmp(p->keyword, L"pdf-filename")) {
+ sfree(filename);
+ filename = dupstr(adv(p->origkeyword));
+ }
+ }
+ }
+
+ olist.head = olist.tail = NULL;
+ olist.number = 1;
+
+ cat = new_object(&olist);
+ if (doc->n_outline_elements > 0)
+ outlines = new_object(&olist);
+ else
+ outlines = NULL;
+ pages = new_object(&olist);
+ resources = new_object(&olist);
+
+ /*
+ * The catalogue just contains references to the outlines and
+ * pages objects.
+ */
+ objtext(cat, "<<\n/Type /Catalog");
+ if (outlines) {
+ objtext(cat, "\n/Outlines ");
+ objref(cat, outlines);
+ }
+ objtext(cat, "\n/Pages ");
+ objref(cat, pages);
+ if (outlines)
+ objtext(cat, "\n/PageMode /UseOutlines");
+ objtext(cat, "\n>>\n");
+
+ /*
+ * Set up the resources dictionary, which mostly means
+ * providing all the font objects and names to call them by.
+ */
+ font_index = 0;
+ objtext(resources, "<<\n/Font <<\n");
+ for (fe = doc->fonts->head; fe; fe = fe->next) {
+ char fname[40];
+ int i;
+ object *font;
+
+ sprintf(fname, "f%d", font_index++);
+ fe->name = dupstr(fname);
+
+ font = new_object(&olist);
+
+ objtext(resources, "/");
+ objtext(resources, fe->name);
+ objtext(resources, " ");
+ objref(resources, font);
+ objtext(resources, "\n");
+
+ objtext(font, "<<\n/Type /Font\n/Subtype /Type1\n/Name /");
+ objtext(font, fe->name);
+ objtext(font, "\n/BaseFont /");
+ objtext(font, fe->font->name);
+ objtext(font, "\n/Encoding <<\n/Type /Encoding\n/Differences [");
+
+ for (i = 0; i < 256; i++) {
+ char buf[20];
+ if (!fe->vector[i])
+ continue;
+ sprintf(buf, "\n%d /", i);
+ objtext(font, buf);
+ objtext(font, fe->vector[i] ? fe->vector[i] : ".notdef");
+ }
+
+ objtext(font, "\n]\n>>\n");
+
+ {
+ object *widths = new_object(&olist);
+ objtext(font, "/FirstChar 0\n/LastChar 255\n/Widths ");
+ objref(font, widths);
+ objtext(font, "\n");
+ objtext(widths, "[\n");
+ for (i = 0; i < 256; i++) {
+ char buf[80];
+ double width;
+ if (fe->indices[i] < 0)
+ width = 0.0;
+ else
+ width = fe->font->widths[fe->indices[i]];
+ sprintf(buf, "%g\n", 1000.0 * width / FUNITS_PER_PT);
+ objtext(widths, buf);
+ }
+ objtext(widths, "]\n");
+ }
+
+ objtext(font, ">>\n");
+ }
+ objtext(resources, ">>\n>>\n");
+
+ /*
+ * Define the page objects for each page, and get each one
+ * ready to have a `Parent' specification added to it.
+ */
+ for (page = doc->pages; page; page = page->next) {
+ object *opage;
+
+ opage = new_object(&olist);
+ page->spare = opage;
+ objtext(opage, "<<\n/Type /Page\n");
+ }
+
+ /*
+ * Recursively build the page tree.
+ */
+ make_pages_node(pages, NULL, doc->pages, NULL, resources);
+
+ /*
+ * Create and render the individual pages.
+ */
+ pageno = 0;
+ for (page = doc->pages; page; page = page->next) {
+ object *opage, *cstr;
+ rect *r;
+ text_fragment *frag, *frag_end;
+ char buf[256];
+ int x, y, lx, ly;
+
+ opage = (object *)page->spare;
+ /*
+ * At this point the page dictionary is already
+ * half-written, with /Type and /Parent already present. We
+ * continue from there.
+ */
+
+ /*
+ * The PDF spec says /Resources is required, but also says
+ * that it's inheritable and may be omitted if it's present
+ * in a Pages node. In our case it is: it's present in the
+ * topmost /Pages node because we carefully put it there.
+ * So we don't need a /Resources entry here.
+ */
+ sprintf(buf, "/MediaBox [0 0 %g %g]\n",
+ doc->paper_width / FUNITS_PER_PT,
+ doc->paper_height / FUNITS_PER_PT);
+ objtext(opage, buf);
+
+ /*
+ * Now we're ready to define a content stream containing
+ * the actual text on the page.
+ */
+ cstr = new_object(&olist);
+ objtext(opage, "/Contents ");
+ objref(opage, cstr);
+ objtext(opage, "\n");
+
+ /*
+ * Render any rectangles on the page.
+ */
+ for (r = page->first_rect; r; r = r->next) {
+ char buf[512];
+ sprintf(buf, "%g %g %g %g re f\n",
+ r->x / FUNITS_PER_PT, r->y / FUNITS_PER_PT,
+ r->w / FUNITS_PER_PT, r->h / FUNITS_PER_PT);
+ objstream(cstr, buf);
+ }
+
+ objstream(cstr, "BT\n");
+
+ /*
+ * PDF tracks two separate current positions: the position
+ * given in the `line matrix' and the position given in the
+ * `text matrix'. We must therefore track both as well.
+ * They start off at -1 (unset).
+ */
+ lx = ly = -1;
+ x = y = -1;
+
+ frag = page->first_text;
+ while (frag) {
+ /*
+ * For compactness, I'm going to group text fragments
+ * into subsequences that use the same font+size. So
+ * first find the end of this subsequence.
+ */
+ for (frag_end = frag;
+ (frag_end &&
+ frag_end->fe == frag->fe &&
+ frag_end->fontsize == frag->fontsize);
+ frag_end = frag_end->next);
+
+ /*
+ * Now select the text fragment, and prepare to display
+ * the text.
+ */
+ objstream(cstr, "/");
+ objstream(cstr, frag->fe->name);
+ sprintf(buf, " %d Tf ", frag->fontsize);
+ objstream(cstr, buf);
+
+ while (frag && frag != frag_end) {
+ /*
+ * Place the text position for the first piece of
+ * text.
+ */
+ if (lx < 0) {
+ sprintf(buf, "1 0 0 1 %g %g Tm ",
+ frag->x/FUNITS_PER_PT, frag->y/FUNITS_PER_PT);
+ } else {
+ sprintf(buf, "%g %g Td ",
+ (frag->x - lx)/FUNITS_PER_PT,
+ (frag->y - ly)/FUNITS_PER_PT);
+ }
+ objstream(cstr, buf);
+ lx = x = frag->x;
+ ly = y = frag->y;
+
+ /*
+ * See if we're going to use Tj (show a single
+ * string) or TJ (show an array of strings with
+ * x-spacings between them). We determine this by
+ * seeing if there's more than one text fragment in
+ * sequence with the same y-coordinate.
+ */
+ if (frag->next && frag->next != frag_end &&
+ frag->next->y == y) {
+ /*
+ * The TJ strategy.
+ */
+ objstream(cstr, "[");
+ while (frag && frag != frag_end && frag->y == y) {
+ if (frag->x != x) {
+ sprintf(buf, "%g",
+ (x - frag->x) * 1000.0 /
+ (FUNITS_PER_PT * frag->fontsize));
+ objstream(cstr, buf);
+ }
+ pdf_string(objstream, cstr, frag->text);
+ x = frag->x + frag->width;
+ frag = frag->next;
+ }
+ objstream(cstr, "]TJ\n");
+ } else
+ {
+ /*
+ * The Tj strategy.
+ */
+ pdf_string(objstream, cstr, frag->text);
+ objstream(cstr, "Tj\n");
+ frag = frag->next;
+ }
+ }
+ }
+ objstream(cstr, "ET");
+
+ /*
+ * Also, we want an annotation dictionary containing the
+ * cross-references from this page.
+ */
+ if (page->first_xref) {
+ xref *xr;
+ objtext(opage, "/Annots [\n");
+
+ for (xr = page->first_xref; xr; xr = xr->next) {
+ object *annot;
+ char buf[256];
+
+ annot = new_object(&olist);
+ objref(opage, annot);
+ objtext(opage, "\n");
+
+ objtext(annot, "<<\n/Type /Annot\n/Subtype /Link\n/Rect [");
+ sprintf(buf, "%g %g %g %g",
+ xr->lx / FUNITS_PER_PT, xr->by / FUNITS_PER_PT,
+ xr->rx / FUNITS_PER_PT, xr->ty / FUNITS_PER_PT);
+ objtext(annot, buf);
+ objtext(annot, "]\n/Border [0 0 0]\n");
+
+ if (xr->dest.type == PAGE) {
+ objtext(annot, "/Dest [");
+ objref(annot, (object *)xr->dest.page->spare);
+ objtext(annot, " /XYZ null null null]\n");
+ } else {
+ objtext(annot, "/A <<\n/Type /Action\n/S /URI\n/URI ");
+ pdf_string(objtext, annot, xr->dest.url);
+ objtext(annot, "\n>>\n");
+ }
+
+ objtext(annot, ">>\n");
+ }
+
+ objtext(opage, "]\n");
+ }
+
+ objtext(opage, ">>\n");
+ }
+
+ /*
+ * Set up the outlines dictionary.
+ */
+ if (outlines) {
+ int topcount;
+ char buf[80];
+
+ objtext(outlines, "<<\n/Type /Outlines\n");
+ topcount = make_outline(outlines, doc->outline_elements,
+ doc->n_outline_elements, TRUE);
+ sprintf(buf, "/Count %d\n>>\n", topcount);
+ objtext(outlines, buf);
+ }
+
+ /*
+ * Assemble the final linear form of every object.
+ */
+ for (o = olist.head; o; o = o->next) {
+ rdstringc rs = {0, 0, NULL};
+ char text[80];
+
+ sprintf(text, "%d 0 obj\n", o->number);
+ rdaddsc(&rs, text);
+
+ if (!o->main.text && o->stream.text) {
+ sprintf(text, "<<\n/Length %d\n>>\n", o->stream.pos);
+ rdaddsc(&o->main, text);
+ }
+
+ assert(o->main.text);
+ rdaddsc(&rs, o->main.text);
+ sfree(o->main.text);
+
+ if (rs.text[rs.pos-1] != '\n')
+ rdaddc(&rs, '\n');
+
+ if (o->stream.text) {
+ /*
+ * FIXME: If we ever start compressing stream data then
+ * it will have zero bytes in it, so we'll have to be
+ * more careful than this.
+ */
+ rdaddsc(&rs, "stream\n");
+ rdaddsc(&rs, o->stream.text);
+ rdaddsc(&rs, "\nendstream\n");
+ sfree(o->stream.text);
+ }
+
+ rdaddsc(&rs, "endobj\n");
+
+ o->final = rs.text;
+ o->size = rs.pos;
+ }
+
+ /*
+ * Write out the PDF file.
+ */
+
+ fp = fopen(filename, "wb");
+ if (!fp) {
+ error(err_cantopenw, filename);
+ return;
+ }
+
+ /*
+ * Header. I'm going to put the version IDs in the header as
+ * well, simply in PDF comments.
+ */
+ fileoff = fprintf(fp, "%%PDF-1.3\n");
+ for (p = sourceform; p; p = p->next)
+ if (p->type == para_VersionID)
+ fileoff += pdf_versionid(fp, p->words);
+
+ /*
+ * Body
+ */
+ for (o = olist.head; o; o = o->next) {
+ o->fileoff = fileoff;
+ fwrite(o->final, 1, o->size, fp);
+ fileoff += o->size;
+ }
+
+ /*
+ * Cross-reference table
+ */
+ fprintf(fp, "xref\n");
+ assert(olist.head->number == 1);
+ fprintf(fp, "0 %d\n", olist.tail->number + 1);
+ fprintf(fp, "0000000000 65535 f \n");
+ for (o = olist.head; o; o = o->next) {
+ char entry[40];
+ sprintf(entry, "%010d 00000 n \n", o->fileoff);
+ assert(strlen(entry) == 20);
+ fputs(entry, fp);
+ }
+
/*
- * FIXME
+ * Trailer
*/
- printf("[pdf] %p = %s\n", unused, unused);
+ fprintf(fp, "trailer\n<<\n/Size %d\n/Root %d 0 R\n>>\n",
+ olist.tail->number + 1, cat->number);
+ fprintf(fp, "startxref\n%d\n%%%%EOF\n", fileoff);
+
+ fclose(fp);
+
+ sfree(filename);
+}
+
+static object *new_object(objlist *list)
+{
+ object *obj = snew(object);
+
+ obj->list = list;
+
+ obj->main.text = NULL;
+ obj->main.pos = obj->main.size = 0;
+ obj->stream.text = NULL;
+ obj->stream.pos = obj->stream.size = 0;
+
+ obj->number = list->number++;
+
+ obj->next = NULL;
+ if (list->tail)
+ list->tail->next = obj;
+ else
+ list->head = obj;
+ list->tail = obj;
+
+ obj->size = 0;
+ obj->final = NULL;
+
+ return obj;
+}
+
+static void objtext(object *o, char const *text)
+{
+ rdaddsc(&o->main, text);
+}
+
+static void objstream(object *o, char const *text)
+{
+ rdaddsc(&o->stream, text);
+}
+
+static void objref(object *o, object *dest)
+{
+ char buf[40];
+ sprintf(buf, "%d 0 R", dest->number);
+ rdaddsc(&o->main, buf);
+}
+
+static void make_pages_node(object *node, object *parent, page_data *first,
+ page_data *last, object *resources)
+{
+ int count;
+ page_data *page;
+ char buf[80];
+
+ objtext(node, "<<\n/Type /Pages\n");
+ if (parent) {
+ objtext(node, "/Parent ");
+ objref(node, parent);
+ objtext(node, "\n");
+ }
+
+ /*
+ * Count the pages in this stretch, to see if there are few
+ * enough to reference directly.
+ */
+ count = 0;
+ for (page = first; page; page = page->next) {
+ count++;
+ if (page == last)
+ break;
+ }
+
+ sprintf(buf, "/Count %d\n/Kids [\n", count);
+ objtext(node, buf);
+
+ if (count > TREE_BRANCH) {
+ int i;
+ page_data *thisfirst, *thislast;
+
+ page = first;
+
+ for (i = 0; i < TREE_BRANCH; i++) {
+ int number = (i+1) * count / TREE_BRANCH - i * count / TREE_BRANCH;
+ thisfirst = page;
+ while (number--) {
+ thislast = page;
+ page = page->next;
+ }
+
+ if (thisfirst == thislast) {
+ objref(node, (object *)thisfirst->spare);
+ objtext((object *)thisfirst->spare, "/Parent ");
+ objref((object *)thisfirst->spare, node);
+ objtext((object *)thisfirst->spare, "\n");
+ } else {
+ object *newnode = new_object(node->list);
+ make_pages_node(newnode, node, thisfirst, thislast, NULL);
+ objref(node, newnode);
+ }
+ objtext(node, "\n");
+ }
+
+ assert(thislast == last || page == NULL);
+
+ } else {
+ for (page = first; page; page = page->next) {
+ objref(node, (object *)page->spare);
+ objtext(node, "\n");
+ objtext((object *)page->spare, "/Parent ");
+ objref((object *)page->spare, node);
+ objtext((object *)page->spare, "\n");
+ if (page == last)
+ break;
+ }
+ }
+
+ objtext(node, "]\n");
+
+ if (resources) {
+ objtext(node, "/Resources ");
+ objref(node, resources);
+ objtext(node, "\n");
+ }
+
+ objtext(node, ">>\n");
+}
+
+/*
+ * In text on the page, PDF uses the PostScript font model, which
+ * means that glyphs are identified by PS strings and hence font
+ * encoding can be managed independently of the supplied encoding
+ * of the font. However, in the document outline, the PDF spec
+ * encodes in either PDFDocEncoding (a custom superset of
+ * ISO-8859-1) or UTF-16BE.
+ */
+static char *pdf_outline_convert(wchar_t *s, int *len) {
+ char *ret;
+
+ ret = utoa_careful_dup(s, CS_PDF);
+
+ /*
+ * Very silly special case: if the returned string begins with
+ * FE FF, then the PDF reader will mistake it for a UTF-16BE
+ * string. So in this case we give up on PDFDocEncoding and
+ * encode it in UTF-16 straight away.
+ */
+ if (ret && ret[0] == '\xFE' && ret[1] == '\xFF') {
+ sfree(ret);
+ ret = NULL;
+ }
+
+ if (!ret) {
+ ret = utoa_dup_len(s, CS_UTF16BE, len);
+ } else {
+ *len = strlen(ret);
+ }
+
+ return ret;
+}
+
+static int make_outline(object *parent, outline_element *items, int n,
+ int open)
+{
+ int level, totalcount = 0;
+ outline_element *itemp;
+ object *curr, *prev = NULL, *first = NULL, *last = NULL;
+
+ assert(n > 0);
+
+ level = items->level;
+
+ while (n > 0) {
+ char *title;
+ int titlelen;
+
+ /*
+ * Here we expect to be sitting on an item at the given
+ * level. So we start by constructing an outline entry for
+ * that item.
+ */
+ assert(items->level == level);
+
+ title = pdf_outline_convert(items->pdata->outline_title, &titlelen);
+
+ totalcount++;
+ curr = new_object(parent->list);
+ if (!first) first = curr;
+ last = curr;
+ objtext(curr, "<<\n/Title ");
+ pdf_string_len(objtext, curr, title, titlelen);
+ objtext(curr, "\n/Parent ");
+ objref(curr, parent);
+ objtext(curr, "\n/Dest [");
+ objref(curr, (object *)items->pdata->first->page->spare);
+ objtext(curr, " /XYZ null null null]\n");
+ if (prev) {
+ objtext(curr, "/Prev ");
+ objref(curr, prev);
+ objtext(curr, "\n");
+
+ objtext(prev, "/Next ");
+ objref(prev, curr);
+ objtext(prev, "\n>>\n");
+ }
+ prev = curr;
+
+ items++, n--;
+ for (itemp = items; itemp < items+n && itemp->level > level;
+ itemp++);
+
+ if (itemp > items) {
+ char buf[80];
+ int count = make_outline(curr, items, itemp - items, FALSE);
+ if (!open)
+ count = -count;
+ else
+ totalcount += count;
+ sprintf(buf, "/Count %d\n", count);
+ objtext(curr, buf);
+ }
+
+ n -= itemp - items;
+ items = itemp;
+ }
+ objtext(prev, ">>\n");
+
+ assert(first && last);
+ objtext(parent, "/First ");
+ objref(parent, first);
+ objtext(parent, "\n/Last ");
+ objref(parent, last);
+ objtext(parent, "\n");
+
+ return totalcount;
+}
+
+static int pdf_versionid(FILE *fp, word *words)
+{
+ int ret;
+
+ ret = fprintf(fp, "%% ");
+
+ for (; words; words = words->next) {
+ char *text;
+ int type;
+
+ switch (words->type) {
+ case word_HyperLink:
+ case word_HyperEnd:
+ case word_UpperXref:
+ case word_LowerXref:
+ case word_XrefEnd:
+ case word_IndexRef:
+ continue;
+ }
+
+ type = removeattr(words->type);
+
+ switch (type) {
+ case word_Normal:
+ text = utoa_dup(words->text, CS_ASCII);
+ break;
+ case word_WhiteSpace:
+ text = dupstr(" ");
+ break;
+ case word_Quote:
+ text = dupstr("'");
+ break;
+ }
+
+ fputs(text, fp);
+ ret += strlen(text);
+ sfree(text);
+ }
+
+ ret += fprintf(fp, "\n");
+
+ return ret;
+}
+
+static void pdf_string_len(void (*add)(object *, char const *),
+ object *o, char const *str, int len)
+{
+ char const *p;
+
+ add(o, "(");
+ for (p = str; len > 0; p++, len--) {
+ char c[10];
+ if (*p < ' ' || *p > '~') {
+ sprintf(c, "\\%03o", 0xFF & (int)*p);
+ } else {
+ int n = 0;
+ if (*p == '\\' || *p == '(' || *p == ')')
+ c[n++] = '\\';
+ c[n++] = *p;
+ c[n] = '\0';
+ }
+ add(o, c);
+ }
+ add(o, ")");
+}
+
+static void pdf_string(void (*add)(object *, char const *),
+ object *o, char const *str)
+{
+ pdf_string_len(add, o, str, strlen(str));
}
~mdw / sgt / halibut / blobdiff