Use regular font for whitespace before monospace text.

doc/pdfio.md

@@ -2,7 +2,7 @@ Introduction
 ============
 
 PDFio is a simple C library for reading and writing PDF files.  The primary
-goals of pdfio are:
+goals of PDFio are:
 
 - Read and write any version of PDF file
 - Provide access to pages, objects, and streams within a PDF file
@@ -1203,5 +1203,228 @@ a PDF file that can be distributed.
 
 > Note: The md2pdf example is by far the most complex example code included with
 > PDFio and shows how to layout text, add headers and footers, add links, embed
-> images, and format tables.
+> images, format tables, and add an outline (table of contents) for navigation.
 
+### Managing Document State
+
+The `md2pdf` program needs to maintain three sets of state - one for the
+markdown document which is represented by nodes of type `mmd_t` and the others
+for the PDF document and current PDF page which are contained in the `docdata_t`
+structure:
+
+```c
+typedef struct docdata_s                // Document formatting data
+{
+  // State for the whole document
+  pdfio_file_t  *pdf;                   // PDF file
+  pdfio_rect_t  media_box;              // Media (page) box
+  pdfio_rect_t  crop_box;               // Crop box (for margins)
+  pdfio_rect_t  art_box;                // Art box (for markdown content)
+  pdfio_obj_t   *fonts[DOCFONT_MAX];    // Embedded fonts
+  size_t        num_images;             // Number of embedded images
+  docimage_t    images[DOCIMAGE_MAX];   // Embedded images
+  const char    *title;                 // Document title
+  char          *heading;               // Current document heading
+  size_t        num_actions;            // Number of actions for this document
+  docaction_t   actions[DOCACTION_MAX]; // Actions for this document
+  size_t        num_targets;            // Number of targets for this document
+  doctarget_t   targets[DOCTARGET_MAX]; // Targets for this document
+  size_t        num_toc;                // Number of table-of-contents entries
+  doctoc_t      toc[DOCTOC_MAX];        // Table-of-contents entries
+
+  // State for the current page
+  pdfio_stream_t *st;                   // Current page stream
+  double        y;                      // Current position on page
+  docfont_t     font;                   // Current font
+  double        fsize;                  // Current font size
+  doccolor_t    color;                  // Current color
+  pdfio_array_t *annots_array;          // Annotations array (for links)
+  pdfio_obj_t   *annots_obj;            // Annotations object (for links)
+  size_t        num_links;              // Number of links for this page
+  doclink_t     links[DOCLINK_MAX];     // Links for this page
+} docdata_t;
+```
+
+
+#### Document State
+
+The output is fixed to the "universal" media size (the intersection of US Letter
+and ISO A4) with 1/2 inch margins - the `PAGE_` constants can be changed to
+select a different size or margins.  The `media_box` member contains the
+"MediaBox" rectangle for the PDF pages, while the `crop_box` and `art_box`
+members contain the "CropBox" and "ArtBox" values, respectively.
+
+Four embedded fonts are used:
+
+- `DOCFONT_REGULAR`: the default font used for text,
+- `DOCFONT_BOLD`: a boldface font used for heading and strong text,
+- `DOCFONT_ITALIC`: an italic/oblique font used for emphasized text, and
+- `DOCFONT_MONOSPACE`: a fixed-width font used for code.
+
+By default the code uses the base PostScript fonts Helvetica, Helvetica-Bold,
+Helvetica-Oblique, and Courier.  The `USE_TRUETYPE` define can be used to
+replace these with the Roboto TrueType fonts.
+
+Embedded JPEG and PNG images are copied into the PDF document, with the `images`
+array containing the list of the images and their objects.
+
+The `title` member contains the document title, while the `heading` member
+contains the current heading text.
+
+The `actions` array contains a list of action dictionaries for interior document
+links that need to be resolved, while the `targets` array keeps track of the
+location of the headings in the PDF document.
+
+The `toc` array contains a list of headings and is used to construct the PDF
+outlines dictionaries/objects, which provides a table of contents for navigation
+in most PDF readers.
+
+
+#### Page State
+
+The `st` member provides the stream for the current page content.  The `color`,
+`font`, `fsize`, and `y` members provide the current graphics state on the page.
+
+The `annots_array`, `annots_obj`, `num_links`, and `links` members contain a
+list of hyperlinks on the current page.
+
+
+### Creating Pages
+
+The `new_page` function is used to start a new page.  Aside from creating the
+new page object and stream, it adds a standard header and footer to the page.
+It starts by closing the current page if it is open:
+
+```c
+// Close the current page...
+if (dd->st)
+{
+  pdfioStreamClose(dd->st);
+  add_links(dd);
+}
+```
+
+The new page needs a dictionary containing any link annotations, the media and
+art boxes, the four fonts, and any images:
+
+```c
+// Prep the new page...
+page_dict = pdfioDictCreate(dd->pdf);
+
+dd->annots_array = pdfioArrayCreate(dd->pdf);
+dd->annots_obj   = pdfioFileCreateArrayObj(dd->pdf, dd->annots_array);
+pdfioDictSetObj(page_dict, "Annots", dd->annots_obj);
+
+pdfioDictSetRect(page_dict, "MediaBox", &dd->media_box);
+pdfioDictSetRect(page_dict, "ArtBox", &dd->art_box);
+
+for (fontface = DOCFONT_REGULAR; fontface < DOCFONT_MAX; fontface ++)
+  pdfioPageDictAddFont(page_dict, docfont_names[fontface],
+                       dd->fonts[fontface]);
+
+for (i = 0; i < dd->num_images; i ++)
+  pdfioPageDictAddImage(page_dict,
+                        pdfioStringCreatef(dd->pdf, "I%u",
+                                           (unsigned)i),
+                        dd->images[i].obj);
+```
+
+Once the page dictionary is initialized, we create a new page and initialize
+the current graphics state:
+
+```c
+dd->st    = pdfioFileCreatePage(dd->pdf, page_dict);
+dd->color = DOCCOLOR_BLACK;
+dd->font  = DOCFONT_MAX;
+dd->fsize = 0.0;
+dd->y     = dd->art_box.y2;
+```
+
+The header consists of a dark gray separating line and the document title.  We
+don't show the header on the first page:
+
+```c
+// Add header/footer text
+set_color(dd, DOCCOLOR_GRAY);
+set_font(dd, DOCFONT_REGULAR, SIZE_HEADFOOT);
+
+if (pdfioFileGetNumPages(dd->pdf) > 1 && dd->title)
+{
+  // Show title in header...
+  width = pdfioContentTextMeasure(dd->fonts[DOCFONT_REGULAR],
+                                  dd->title, SIZE_HEADFOOT);
+
+  pdfioContentTextBegin(dd->st);
+  pdfioContentTextMoveTo(dd->st,
+                         dd->crop_box.x1 + 0.5 * (dd->crop_box.x2 -
+                             dd->crop_box.x1 - width),
+                         dd->crop_box.y2 - SIZE_HEADFOOT);
+  pdfioContentTextShow(dd->st, UNICODE_VALUE, dd->title);
+  pdfioContentTextEnd(dd->st);
+
+  pdfioContentPathMoveTo(dd->st, dd->crop_box.x1,
+                         dd->crop_box.y2 -
+                             2 * SIZE_HEADFOOT * LINE_HEIGHT +
+                             SIZE_HEADFOOT);
+  pdfioContentPathLineTo(dd->st, dd->crop_box.x2,
+                         dd->crop_box.y2 -
+                             2 * SIZE_HEADFOOT * LINE_HEIGHT +
+                             SIZE_HEADFOOT);
+  pdfioContentStroke(dd->st);
+}
+```
+
+The footer contains the same dark gray separating line with the current heading
+and page number on opposite sides.  The page number is always positioned on the
+outer edge for a two-sided print - right justified on odd numbered pages and
+left justified on even numbered pages:
+
+```c
+// Show page number and current heading...
+pdfioContentPathMoveTo(dd->st, dd->crop_box.x1,
+                       dd->crop_box.y1 + SIZE_HEADFOOT * LINE_HEIGHT);
+pdfioContentPathLineTo(dd->st, dd->crop_box.x2,
+                       dd->crop_box.y1 + SIZE_HEADFOOT * LINE_HEIGHT);
+pdfioContentStroke(dd->st);
+
+pdfioContentTextBegin(dd->st);
+snprintf(temp, sizeof(temp), "%u",
+         (unsigned)pdfioFileGetNumPages(dd->pdf));
+if (pdfioFileGetNumPages(dd->pdf) & 1)
+{
+  // Page number on right...
+  width = pdfioContentTextMeasure(dd->fonts[DOCFONT_REGULAR], temp,
+                                  SIZE_HEADFOOT);
+  pdfioContentTextMoveTo(dd->st, dd->crop_box.x2 - width,
+                         dd->crop_box.y1);
+}
+else
+{
+  // Page number on left...
+  pdfioContentTextMoveTo(dd->st, dd->crop_box.x1, dd->crop_box.y1);
+}
+
+pdfioContentTextShow(dd->st, UNICODE_VALUE, temp);
+pdfioContentTextEnd(dd->st);
+
+if (dd->heading)
+{
+  pdfioContentTextBegin(dd->st);
+
+  if (pdfioFileGetNumPages(dd->pdf) & 1)
+  {
+    // Current heading on left...
+    pdfioContentTextMoveTo(dd->st, dd->crop_box.x1, dd->crop_box.y1);
+  }
+  else
+  {
+    width = pdfioContentTextMeasure(dd->fonts[DOCFONT_REGULAR],
+                                    dd->heading, SIZE_HEADFOOT);
+    pdfioContentTextMoveTo(dd->st, dd->crop_box.x2 - width,
+                           dd->crop_box.y1);
+  }
+
+  pdfioContentTextShow(dd->st, UNICODE_VALUE, dd->heading);
+  pdfioContentTextEnd(dd->st);
+}
+```

examples/Makefile

@@ -12,8 +12,8 @@
 
 
 # Common options
-CFLAGS		=	-g $(CPPFLAGS)
-#CFLAGS		=	-g -fsanitize=address $(CPPFLAGS)
+#CFLAGS		=	-g $(CPPFLAGS)
+CFLAGS		=	-g -fsanitize=address $(CPPFLAGS)
 CPPFLAGS	=	-I..
 LIBS		=	-L.. -lpdfio -lz
 

examples/md2pdf.c

@@ -101,15 +101,25 @@ typedef struct doctoc_s			// Document table-of-contents entry
 
 typedef struct docdata_s		// Document formatting data
 {
+  // State for the whole document
   pdfio_file_t	*pdf;			// PDF file
   pdfio_rect_t	media_box;		// Media (page) box
   pdfio_rect_t	crop_box;		// Crop box (for margins)
   pdfio_rect_t	art_box;		// Art box (for markdown content)
   pdfio_obj_t	*fonts[DOCFONT_MAX];	// Embedded fonts
+  double	font_space;		// Unit width of a space
   size_t	num_images;		// Number of embedded images
   docimage_t	images[DOCIMAGE_MAX];	// Embedded images
   const char	*title;			// Document title
   char		*heading;		// Current document heading
+  size_t	num_actions;		// Number of actions for this document
+  docaction_t	actions[DOCACTION_MAX];	// Actions for this document
+  size_t	num_targets;		// Number of targets for this document
+  doctarget_t	targets[DOCTARGET_MAX];	// Targets for this document
+  size_t	num_toc;		// Number of table-of-contents entries
+  doctoc_t	toc[DOCTOC_MAX];	// Table-of-contents entries
+
+  // State for the current page
   pdfio_stream_t *st;			// Current page stream
   double	y;			// Current position on page
   docfont_t	font;			// Current font
@@ -119,12 +129,6 @@ typedef struct docdata_s		// Document formatting data
   pdfio_obj_t	*annots_obj;		// Annotations object (for links)
   size_t	num_links;		// Number of links for this page
   doclink_t	links[DOCLINK_MAX];	// Links for this page
-  size_t	num_actions;		// Number of actions for this document
-  docaction_t	actions[DOCACTION_MAX];	// Actions for this document
-  size_t	num_targets;		// Number of targets for this document
-  doctarget_t	targets[DOCTARGET_MAX];	// Targets for this document
-  size_t	num_toc;		// Number of table-of-contents entries
-  doctoc_t	toc[DOCTOC_MAX];	// Table-of-contents entries
 } docdata_t;
 
 typedef struct linefrag_s		// Line fragment
@@ -302,7 +306,8 @@ main(int  argc,				// I - Number of command-line arguments
   dd.art_box.x2  = PAGE_RIGHT;
   dd.art_box.y2  = PAGE_TOP;
 
-  dd.title       = mmdGetMetadata(doc, "title");
+  if ((dd.title = mmdGetMetadata(doc, "title")) == NULL)
+    dd.art_box.y2 = PAGE_HEADER;	// No header if there is no title
 
   if (argc == 2)
   {
@@ -345,6 +350,8 @@ main(int  argc,				// I - Number of command-line arguments
 #endif // USE_TRUETYPE
   }
 
+  dd.font_space = pdfioContentTextMeasure(dd.fonts[DOCFONT_REGULAR], " ", 1.0);
+
   // Add images...
   add_images(&dd, doc);
 
@@ -587,10 +594,14 @@ format_block(docdata_t  *dd,		// I - Document data
   if (leader)
   {
     // Add leader text on first line...
+    frags[0].type     = MMD_TYPE_NORMAL_TEXT;
     frags[0].width    = pdfioContentTextMeasure(dd->fonts[deffont], leader, fsize);
     frags[0].height   = fsize;
     frags[0].x        = left - frags[0].width;
+    frags[0].imagenum = 0;
     frags[0].text     = leader;
+    frags[0].url      = NULL;
+    frags[0].ws       = false;
     frags[0].font     = deffont;
     frags[0].color    = DOCCOLOR_BLACK;
 
@@ -616,7 +627,7 @@ format_block(docdata_t  *dd,		// I - Document data
     imagenum = 0;
     url      = mmdGetURL(current);
     ws       = mmdGetWhitespace(current);
-    wswidth  = 0.0;
+    wswidth  = ws ? dd->font_space * fsize : 0.0;
     next     = mmd_walk_next(block, current);
 
     // Process the node...
@@ -706,9 +717,6 @@ format_block(docdata_t  *dd,		// I - Document data
 
       width  = pdfioContentTextMeasure(dd->fonts[font], text, fsize);
       height = fsize * LINE_HEIGHT;
-
-      if (ws)
-	wswidth = pdfioContentTextMeasure(dd->fonts[font], " ", fsize);
     }
 
     // See if this node will fit on the current line...
@@ -806,20 +814,29 @@ format_code(docdata_t *dd,		// I - Document data
             double    right)		// I - Right margin
 {
   mmd_t		*code;			// Current code block
-  double	lineheight;		// Line height
+  double	lineheight,		// Line height
+		margin_top;		// Top margin
 
 
+  // Compute line height and initial top margin...
+  lineheight = SIZE_CODEBLOCK * LINE_HEIGHT;
+  margin_top = lineheight;
+
   // Start a new page as needed...
   if (!dd->st)
+  {
     new_page(dd);
 
-  lineheight = SIZE_CODEBLOCK * LINE_HEIGHT;
-  dd->y      -= 2.0 * lineheight;
+    margin_top = (1.0 - LINE_HEIGHT) * lineheight;
+  }
+
+  dd->y -= lineheight + margin_top;
+
   if ((dd->y - lineheight) < dd->art_box.y1)
   {
     new_page(dd);
 
-    dd->y -= lineheight;
+    dd->y -= lineheight / LINE_HEIGHT;
   }
 
   // Start a code text block...
@@ -1338,15 +1355,15 @@ new_page(docdata_t *dd)			// I - Document data
 
   // Prep the new page...
   page_dict = pdfioDictCreate(dd->pdf);
+
   dd->annots_array = pdfioArrayCreate(dd->pdf);
   dd->annots_obj   = pdfioFileCreateArrayObj(dd->pdf, dd->annots_array);
+  pdfioDictSetObj(page_dict, "Annots", dd->annots_obj);
 
   pdfioDictSetRect(page_dict, "MediaBox", &dd->media_box);
 //  pdfioDictSetRect(page_dict, "CropBox", &dd->crop_box);
   pdfioDictSetRect(page_dict, "ArtBox", &dd->art_box);
 
-  pdfioDictSetObj(page_dict, "Annots", dd->annots_obj);
-
   for (fontface = DOCFONT_REGULAR; fontface < DOCFONT_MAX; fontface ++)
     pdfioPageDictAddFont(page_dict, docfont_names[fontface], dd->fonts[fontface]);
 
@@ -1457,7 +1474,7 @@ render_line(docdata_t  *dd,		// I - Document data
   if (!dd->st)
   {
     new_page(dd);
-    margin_top = 0.0;
+    margin_top = (1.0 - LINE_HEIGHT) * lineheight;
   }
 
   dd->y -= margin_top + lineheight;
@@ -1465,7 +1482,7 @@ render_line(docdata_t  *dd,		// I - Document data
   {
     new_page(dd);
 
-    dd->y -= lineheight;
+    dd->y -= lineheight / LINE_HEIGHT;
   }
 
   for (i = 0, frag = frags; i < num_frags; i ++, frag ++)
@@ -1499,9 +1516,6 @@ render_line(docdata_t  *dd,		// I - Document data
     else if (frag->text)
     {
       // Draw text
-      set_color(dd, frag->color);
-      set_font(dd, frag->font, frag->height);
-
       if (!in_text)
       {
 	pdfioContentTextBegin(dd->st);
@@ -1510,10 +1524,19 @@ render_line(docdata_t  *dd,		// I - Document data
 	in_text = true;
       }
 
-      if (frag->ws)
-	pdfioContentTextShowf(dd->st, UNICODE_VALUE, " %s", frag->text);
-      else
+      if (frag->ws && frag->font == DOCFONT_MONOSPACE)
+      {
+	set_font(dd, DOCFONT_REGULAR, frag->height);
+	pdfioContentTextShow(dd->st, UNICODE_VALUE, " ");
+      }
+
+      set_color(dd, frag->color);
+      set_font(dd, frag->font, frag->height);
+
+      if (frag->font == DOCFONT_MONOSPACE)
 	pdfioContentTextShow(dd->st, UNICODE_VALUE, frag->text);
+      else
+	pdfioContentTextShowf(dd->st, UNICODE_VALUE, "%s%s", frag->ws ? " " : "", frag->text);
 
       if (frag->url && dd->num_links < DOCLINK_MAX)
       {