mdw@git.distorted.org.uk Git - sgt/halibut/blob - paper.h

   1 /*
   2  * Paper printing definitions.
   3  *
   4  * This header file defines data structures and constants which are
   5  * shared between bk_paper.c and its clients bk_ps.c and bk_pdf.c.
   6  */
   7
   8 #ifndef HALIBUT_PAPER_H
   9 #define HALIBUT_PAPER_H
  10
  11 typedef struct document_Tag document;
  12 typedef struct font_data_Tag font_data;
  13 typedef struct font_encoding_Tag font_encoding;
  14 typedef struct font_list_Tag font_list;
  15 typedef struct para_data_Tag para_data;
  16 typedef struct line_data_Tag line_data;
  17 typedef struct page_data_Tag page_data;
  18 typedef struct subfont_map_entry_Tag subfont_map_entry;
  19 typedef struct text_fragment_Tag text_fragment;
  20 typedef struct xref_Tag xref;
  21 typedef struct xref_dest_Tag xref_dest;
  22 typedef struct rect_Tag rect;
  23 typedef struct outline_element_Tag outline_element;
  24
  25 /*
  26  * This data structure represents the overall document, in the form
  27  * it will be given to the client backends.
  28  */
  29 struct document_Tag {
  30     int paper_width, paper_height;
  31     font_list *fonts;
  32     page_data *pages;
  33     outline_element *outline_elements;
  34     int n_outline_elements;
  35 };
  36
  37 /*
  38  * This data structure represents a particular font.
  39  */
  40 struct font_data_Tag {
  41     /*
  42      * Specify the PostScript name of the font and its point size.
  43      */
  44     const char *name;
  45     /*
  46      * An array of pointers to the available glyph names, and their
  47      * corresponding character widths. These two arrays have
  48      * parallel indices.
  49      */
  50     int nglyphs;
  51     const char *const *glyphs;
  52     const int *widths;
  53     /*
  54      * For reasonably speedy lookup, we set up a 65536-element
  55      * table representing the Unicode BMP (I can conveniently
  56      * restrict myself to the BMP for the moment since I happen to
  57      * know that no glyph in the Adobe Glyph List falls outside
  58      * it), whose elements are indices into the above two arrays.
  59      */
  60     unsigned short bmp[65536];
  61     /*
  62      * At some point I'm going to divide the font into sub-fonts
  63      * with largely non-overlapping encoding vectors. This array
  64      * will track which glyphs go into which subfonts. Also here I
  65      * keep track of the latest subfont of any given font, so I can
  66      * go back and extend its encoding.
  67      */
  68     subfont_map_entry *subfont_map;
  69     font_encoding *latest_subfont;
  70     /*
  71      * The font list to which this font belongs.
  72      */
  73     font_list *list;
  74 };
  75
  76 struct subfont_map_entry_Tag {
  77     font_encoding *subfont;
  78     unsigned char position;
  79 };
  80
  81 /*
  82  * This data structure represents a sub-font: a font with an
  83  * encoding vector.
  84  */
  85 struct font_encoding_Tag {
  86     font_encoding *next;
  87
  88     char *name;                        /* used by client backends */
  89
  90     font_data *font;                   /* the parent font structure */
  91     const char *vector[256];           /* the actual encoding vector */
  92     int indices[256];                  /* indices back into main font struct */
  93     wchar_t to_unicode[256];           /* PDF will want to know this */
  94     int free_pos;                      /* space left to extend encoding */
  95 };
  96
  97 /*
  98  * This data structure represents the overall list of sub-fonts in
  99  * the whole document.
 100  */
 101 struct font_list_Tag {
 102     font_encoding *head;
 103     font_encoding *tail;
 104 };
 105
 106 /*
 107  * Constants defining array indices for the various fonts used in a
 108  * paragraph.
 109  */
 110 enum {
 111     FONT_NORMAL,
 112     FONT_EMPH,
 113     FONT_CODE,
 114     NFONTS
 115 };
 116
 117 /*
 118  * This is the data structure which is stored in the private_data
 119  * field of each paragraph. It divides the paragraph up into a
 120  * linked list of lines, while at the same time providing for those
 121  * lines to be linked together into a much longer list spanning the
 122  * whole document for page-breaking purposes.
 123  */
 124
 125 struct para_data_Tag {
 126     para_data *next;
 127     /*
 128      * Data about the fonts used in this paragraph. Indices are the
 129      * FONT_* constants defined above.
 130      */
 131     font_data *fonts[NFONTS];
 132     int sizes[NFONTS];
 133     /*
 134      * Pointers to the first and last line of the paragraph. The
 135      * line structures are linked into a list, which runs from
 136      * `first' to `last' as might be expected. However, the list
 137      * does not terminate there: first->prev will end up pointing
 138      * to the last line of the previous paragraph in most cases,
 139      * and likewise last->next will point to the first line of the
 140      * next paragraph.
 141      */
 142     line_data *first;                  /* first line in paragraph */
 143     line_data *last;                   /* last line in paragraph */
 144     /*
 145      * Some paragraphs have associated graphics; currently this is
 146      * nothing more complex than a single black rectangle.
 147      */
 148     enum {
 149         RECT_NONE, RECT_CHAPTER_UNDERLINE, RECT_RULE
 150     } rect_type;
 151     /*
 152      * We left- and right-justify in special circumstances.
 153      */
 154     enum {
 155         JUST, LEFT, RIGHT
 156     } justification;
 157     /*
 158      * For constructing the page outline.
 159      */
 160     int outline_level;                 /* 0=title 1=C 2=H 3=S 4=S2... */
 161     wchar_t *outline_title;
 162     /*
 163      * For adding the page number of a contents entry afterwards.
 164      */
 165     paragraph *contents_entry;
 166 };
 167
 168 struct line_data_Tag {
 169     /*
 170      * The parent paragraph.
 171      */
 172     para_data *pdata;
 173     /*
 174      * Pointers to join lines into a linked list.
 175      */
 176     line_data *prev;
 177     line_data *next;
 178     /*
 179      * The extent of the text displayed on this line. Also mention
 180      * its starting x position, and by how much the width of spaces
 181      * needs to be adjusted for paragraph justification.
 182      *
 183      * (Unlike most of the `last' pointers defined in this file,
 184      * this `end' pointer points to the word _after_ the last one
 185      * that should be displayed on the line. This is how it's
 186      * returned from wrap_para().)
 187      */
 188     word *first;
 189     word *end;
 190     int xpos;
 191     int hshortfall, nspaces;           /* for justifying paragraphs */
 192     int real_shortfall;
 193     /*
 194      * Auxiliary text: a section number in a margin, or a list item
 195      * bullet or number. Also mention where to display this text
 196      * relative to the left margin.
 197      */
 198     word *aux_text;
 199     word *aux_text_2;
 200     int aux_left_indent;
 201     /*
 202      * This line might have a non-negotiable page break before it.
 203      * Also there will be space required above and below it; also I
 204      * store the physical line height (defined as the maximum of
 205      * the heights of the three fonts in the pdata) because it's
 206      * easier than looking it up repeatedly during page breaking.
 207      */
 208     int page_break;
 209     int space_before;
 210     int space_after;
 211     int line_height;
 212     /*
 213      * Penalties for page breaking before or after this line.
 214      */
 215     int penalty_before, penalty_after;
 216     /*
 217      * These fields are used in the page breaking algorithm.
 218      */
 219     int *bestcost;
 220     int *vshortfall, *text, *space;
 221     line_data **page_last;             /* last line on a page starting here */
 222     /*
 223      * After page breaking, we can assign an actual y-coordinate on
 224      * the page to each line. Also we store a pointer back to the
 225      * page structure itself.
 226      */
 227     int ypos;
 228     page_data *page;
 229 };
 230
 231 /*
 232  * This data structure is constructed to describe each page of the
 233  * printed output.
 234  */
 235 struct page_data_Tag {
 236     /*
 237      * Pointers to join pages into a linked list.
 238      */
 239     page_data *prev;
 240     page_data *next;
 241     /*
 242      * The set of lines displayed on this page.
 243      */
 244     line_data *first_line;
 245     line_data *last_line;
 246     /*
 247      * After text rendering: the set of actual pieces of text
 248      * needing to be displayed on this page.
 249      */
 250     text_fragment *first_text;
 251     text_fragment *last_text;
 252     /*
 253      * Cross-references.
 254      */
 255     xref *first_xref;
 256     xref *last_xref;
 257     /*
 258      * Rectangles to be drawn. (These are currently only used for
 259      * underlining chapter titles and drawing horizontal rules.)
 260      */
 261     rect *first_rect;
 262     rect *last_rect;
 263     /*
 264      * The page number, as a string.
 265      */
 266     wchar_t *number;
 267     /*
 268      * This spare pointer field is for use by the client backends.
 269      */
 270     void *spare;
 271 };
 272
 273 struct text_fragment_Tag {
 274     text_fragment *next;
 275     int x, y;
 276     font_encoding *fe;
 277     int fontsize;
 278     char *text;
 279     int width;
 280 };
 281
 282 struct xref_dest_Tag {
 283     enum { NONE, PAGE, URL } type;
 284     page_data *page;
 285     char *url;
 286 };
 287
 288 struct xref_Tag {
 289     xref *next;
 290     int lx, rx, ty, by;
 291     xref_dest dest;
 292 };
 293
 294 struct rect_Tag {
 295     rect *next;
 296     int x, y, w, h;
 297 };
 298
 299 struct outline_element_Tag {
 300     int level;                         /* 0=title 1=C 2=H 3=S 4=S2... */
 301     para_data *pdata;
 302 };
 303
 304 /*
 305  * Functions and data exported from psdata.c.
 306  */
 307 wchar_t ps_glyph_to_unicode(char const *glyph);
 308 extern const char *const ps_std_glyphs[];
 309 const int *ps_std_font_widths(char const *fontname);
 310
 311 #endif