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 /* Number of internal units per PostScript point. */
  12 #define UNITS_PER_PT 1000
  13 #define FUNITS_PER_PT 1000.0
  14
  15 typedef struct document_Tag document;
  16 typedef struct kern_pair_Tag kern_pair;
  17 typedef struct font_info_Tag font_info;
  18 typedef struct font_data_Tag font_data;
  19 typedef struct font_encoding_Tag font_encoding;
  20 typedef struct font_list_Tag font_list;
  21 typedef struct para_data_Tag para_data;
  22 typedef struct line_data_Tag line_data;
  23 typedef struct page_data_Tag page_data;
  24 typedef struct subfont_map_entry_Tag subfont_map_entry;
  25 typedef struct text_fragment_Tag text_fragment;
  26 typedef struct xref_Tag xref;
  27 typedef struct xref_dest_Tag xref_dest;
  28 typedef struct rect_Tag rect;
  29 typedef struct outline_element_Tag outline_element;
  30
  31 /*
  32  * This data structure represents the overall document, in the form
  33  * it will be given to the client backends.
  34  */
  35 struct document_Tag {
  36     int paper_width, paper_height;
  37     font_list *fonts;
  38     page_data *pages;
  39     outline_element *outline_elements;
  40     int n_outline_elements;
  41 };
  42
  43 /*
  44  * This data structure represents a kerning pair within a font.
  45  */
  46 struct kern_pair_Tag {
  47     /* Glyph indices, in font_data.glyphs. */
  48     unsigned short left, right;
  49     /* Kern amount, in internal units. */
  50     int kern;
  51 };
  52
  53 /*
  54  * This data structure holds static information about a font that doesn't
  55  * depend on the particular document.  It gets generated when the font's
  56  * metrics are read in.
  57  */
  58
  59 font_info *all_fonts;
  60
  61 struct font_info_Tag {
  62     font_info *next;
  63     /*
  64      * Specify the PostScript name of the font and its point size.
  65      */
  66     const char *name;
  67     /*
  68      * The file containing this font, if any.
  69      */
  70     FILE *fp;
  71     /*
  72      * An array of pointers to the available glyph names, and their
  73      * corresponding character widths. These two arrays have
  74      * parallel indices.
  75      */
  76     int nglyphs;
  77     const char *const *glyphs;
  78     const int *widths;
  79     /*
  80      * Glyph indices sorted into glyph-name order, for name-to-index
  81      * mapping.
  82      */
  83     unsigned short *glyphsbyname;
  84     /* A tree of kern_pairs */
  85     tree234 *kerns;
  86     /*
  87      * For reasonably speedy lookup, we set up a 65536-element
  88      * table representing the Unicode BMP (I can conveniently
  89      * restrict myself to the BMP for the moment since I happen to
  90      * know that no glyph in the Adobe Glyph List falls outside
  91      * it), whose elements are indices into the above two arrays.
  92      */
  93     unsigned short bmp[65536];
  94     /*
  95      * Various bits of metadata needed for the /FontDescriptor dictionary
  96      * in PDF.
  97      */
  98     float fontbbox[4];
  99     float capheight;
 100     float xheight;
 101     float ascent;
 102     float descent;
 103     float stemv;
 104     float stemh;
 105     float italicangle;
 106 };
 107
 108 /*
 109  * This structure holds the information about how a font is used
 110  * in a document.
 111  */
 112 struct font_data_Tag {
 113     font_info const *info;
 114     /*
 115      * At some point I'm going to divide the font into sub-fonts
 116      * with largely non-overlapping encoding vectors. This array
 117      * will track which glyphs go into which subfonts. Also here I
 118      * keep track of the latest subfont of any given font, so I can
 119      * go back and extend its encoding.
 120      */
 121     subfont_map_entry *subfont_map;
 122     font_encoding *latest_subfont;
 123     /*
 124      * The font list to which this font belongs.
 125      */
 126     font_list *list;
 127 };
 128
 129 struct subfont_map_entry_Tag {
 130     font_encoding *subfont;
 131     unsigned char position;
 132 };
 133
 134 /*
 135  * This data structure represents a sub-font: a font with an
 136  * encoding vector.
 137  */
 138 struct font_encoding_Tag {
 139     font_encoding *next;
 140
 141     char *name;                        /* used by client backends */
 142
 143     font_data *font;                   /* the parent font structure */
 144     const char *vector[256];           /* the actual encoding vector */
 145     int indices[256];                  /* indices back into main font struct */
 146     wchar_t to_unicode[256];           /* PDF will want to know this */
 147     int free_pos;                      /* space left to extend encoding */
 148 };
 149
 150 /*
 151  * This data structure represents the overall list of sub-fonts in
 152  * the whole document.
 153  */
 154 struct font_list_Tag {
 155     font_encoding *head;
 156     font_encoding *tail;
 157 };
 158
 159 /*
 160  * Constants defining array indices for the various fonts used in a
 161  * paragraph.
 162  */
 163 enum {
 164     FONT_NORMAL,
 165     FONT_EMPH,
 166     FONT_CODE,
 167     NFONTS
 168 };
 169
 170 /*
 171  * This is the data structure which is stored in the private_data
 172  * field of each paragraph. It divides the paragraph up into a
 173  * linked list of lines, while at the same time providing for those
 174  * lines to be linked together into a much longer list spanning the
 175  * whole document for page-breaking purposes.
 176  */
 177
 178 struct para_data_Tag {
 179     para_data *next;
 180     /*
 181      * Data about the fonts used in this paragraph. Indices are the
 182      * FONT_* constants defined above.
 183      */
 184     font_data *fonts[NFONTS];
 185     int sizes[NFONTS];
 186     /*
 187      * Pointers to the first and last line of the paragraph. The
 188      * line structures are linked into a list, which runs from
 189      * `first' to `last' as might be expected. However, the list
 190      * does not terminate there: first->prev will end up pointing
 191      * to the last line of the previous paragraph in most cases,
 192      * and likewise last->next will point to the first line of the
 193      * next paragraph.
 194      */
 195     line_data *first;                  /* first line in paragraph */
 196     line_data *last;                   /* last line in paragraph */
 197     /*
 198      * Some paragraphs have associated graphics; currently this is
 199      * nothing more complex than a single black rectangle.
 200      */
 201     enum {
 202         RECT_NONE, RECT_CHAPTER_UNDERLINE, RECT_RULE
 203     } rect_type;
 204     /*
 205      * We left- and right-justify in special circumstances.
 206      */
 207     enum {
 208         JUST, LEFT, RIGHT
 209     } justification;
 210     /*
 211      * For constructing the page outline.
 212      */
 213     int outline_level;                 /* 0=title 1=C 2=H 3=S 4=S2... */
 214     wchar_t *outline_title;
 215     /*
 216      * For adding the page number of a contents entry afterwards.
 217      */
 218     paragraph *contents_entry;
 219 };
 220
 221 struct line_data_Tag {
 222     /*
 223      * The parent paragraph.
 224      */
 225     para_data *pdata;
 226     /*
 227      * Pointers to join lines into a linked list.
 228      */
 229     line_data *prev;
 230     line_data *next;
 231     /*
 232      * The extent of the text displayed on this line. Also mention
 233      * its starting x position, and by how much the width of spaces
 234      * needs to be adjusted for paragraph justification.
 235      *
 236      * (Unlike most of the `last' pointers defined in this file,
 237      * this `end' pointer points to the word _after_ the last one
 238      * that should be displayed on the line. This is how it's
 239      * returned from wrap_para().)
 240      */
 241     word *first;
 242     word *end;
 243     int xpos;
 244     int hshortfall, nspaces;           /* for justifying paragraphs */
 245     int real_shortfall;
 246     /*
 247      * Auxiliary text: a section number in a margin, or a list item
 248      * bullet or number. Also mention where to display this text
 249      * relative to the left margin.
 250      */
 251     word *aux_text;
 252     word *aux_text_2;
 253     int aux_left_indent;
 254     /*
 255      * This line might have a non-negotiable page break before it.
 256      * Also there will be space required above and below it; also I
 257      * store the physical line height (defined as the maximum of
 258      * the heights of the three fonts in the pdata) because it's
 259      * easier than looking it up repeatedly during page breaking.
 260      */
 261     int page_break;
 262     int space_before;
 263     int space_after;
 264     int line_height;
 265     /*
 266      * Penalties for page breaking before or after this line.
 267      */
 268     int penalty_before, penalty_after;
 269     /*
 270      * These fields are used in the page breaking algorithm.
 271      */
 272     int *bestcost;
 273     int *vshortfall, *text, *space;
 274     line_data **page_last;             /* last line on a page starting here */
 275     /*
 276      * After page breaking, we can assign an actual y-coordinate on
 277      * the page to each line. Also we store a pointer back to the
 278      * page structure itself.
 279      */
 280     int ypos;
 281     page_data *page;
 282 };
 283
 284 /*
 285  * This data structure is constructed to describe each page of the
 286  * printed output.
 287  */
 288 struct page_data_Tag {
 289     /*
 290      * Pointers to join pages into a linked list.
 291      */
 292     page_data *prev;
 293     page_data *next;
 294     /*
 295      * The set of lines displayed on this page.
 296      */
 297     line_data *first_line;
 298     line_data *last_line;
 299     /*
 300      * After text rendering: the set of actual pieces of text
 301      * needing to be displayed on this page.
 302      */
 303     text_fragment *first_text;
 304     text_fragment *last_text;
 305     /*
 306      * Cross-references.
 307      */
 308     xref *first_xref;
 309     xref *last_xref;
 310     /*
 311      * Rectangles to be drawn. (These are currently only used for
 312      * underlining chapter titles and drawing horizontal rules.)
 313      */
 314     rect *first_rect;
 315     rect *last_rect;
 316     /*
 317      * The page number, as a string.
 318      */
 319     wchar_t *number;
 320     /*
 321      * This spare pointer field is for use by the client backends.
 322      */
 323     void *spare;
 324 };
 325
 326 struct text_fragment_Tag {
 327     text_fragment *next;
 328     int x, y;
 329     font_encoding *fe;
 330     int fontsize;
 331     char *text;
 332     int width;
 333 };
 334
 335 struct xref_dest_Tag {
 336     enum { NONE, PAGE, URL } type;
 337     page_data *page;
 338     char *url;
 339 };
 340
 341 struct xref_Tag {
 342     xref *next;
 343     int lx, rx, ty, by;
 344     xref_dest dest;
 345 };
 346
 347 struct rect_Tag {
 348     rect *next;
 349     int x, y, w, h;
 350 };
 351
 352 struct outline_element_Tag {
 353     int level;                         /* 0=title 1=C 2=H 3=S 4=S2... */
 354     para_data *pdata;
 355 };
 356
 357 /*
 358  * Functions exported from bk_paper.c
 359  */
 360 int kern_cmp(void *, void *); /* use when setting up kern_pairs */
 361 void font_index_glyphs(font_info *fi);
 362 int find_glyph(font_info *fi, char const *name);
 363
 364
 365 /*
 366  * Functions and data exported from psdata.c.
 367  */
 368 wchar_t ps_glyph_to_unicode(char const *glyph);
 369 extern const char *const ps_std_glyphs[];
 370 void init_std_fonts(void);
 371 const int *ps_std_font_widths(char const *fontname);
 372 const kern_pair *ps_std_font_kerns(char const *fontname);
 373
 374 #endif