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