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
  92 /*
  93  * This structure holds the information about how a font is used
  94  * in a document.
  95  */
  96 struct font_data_Tag {
  97     font_info const *info;
  98     /*
  99      * At some point I'm going to divide the font into sub-fonts
 100      * with largely non-overlapping encoding vectors. This array
 101      * will track which glyphs go into which subfonts. Also here I
 102      * keep track of the latest subfont of any given font, so I can
 103      * go back and extend its encoding.
 104      */
 105     subfont_map_entry *subfont_map;
 106     font_encoding *latest_subfont;
 107     /*
 108      * The font list to which this font belongs.
 109      */
 110     font_list *list;
 111 };
 112
 113 struct subfont_map_entry_Tag {
 114     font_encoding *subfont;
 115     unsigned char position;
 116 };
 117
 118 /*
 119  * This data structure represents a sub-font: a font with an
 120  * encoding vector.
 121  */
 122 struct font_encoding_Tag {
 123     font_encoding *next;
 124
 125     char *name;                        /* used by client backends */
 126
 127     font_data *font;                   /* the parent font structure */
 128     const char *vector[256];           /* the actual encoding vector */
 129     int indices[256];                  /* indices back into main font struct */
 130     wchar_t to_unicode[256];           /* PDF will want to know this */
 131     int free_pos;                      /* space left to extend encoding */
 132 };
 133
 134 /*
 135  * This data structure represents the overall list of sub-fonts in
 136  * the whole document.
 137  */
 138 struct font_list_Tag {
 139     font_encoding *head;
 140     font_encoding *tail;
 141 };
 142
 143 /*
 144  * Constants defining array indices for the various fonts used in a
 145  * paragraph.
 146  */
 147 enum {
 148     FONT_NORMAL,
 149     FONT_EMPH,
 150     FONT_CODE,
 151     NFONTS
 152 };
 153
 154 /*
 155  * This is the data structure which is stored in the private_data
 156  * field of each paragraph. It divides the paragraph up into a
 157  * linked list of lines, while at the same time providing for those
 158  * lines to be linked together into a much longer list spanning the
 159  * whole document for page-breaking purposes.
 160  */
 161
 162 struct para_data_Tag {
 163     para_data *next;
 164     /*
 165      * Data about the fonts used in this paragraph. Indices are the
 166      * FONT_* constants defined above.
 167      */
 168     font_data *fonts[NFONTS];
 169     int sizes[NFONTS];
 170     /*
 171      * Pointers to the first and last line of the paragraph. The
 172      * line structures are linked into a list, which runs from
 173      * `first' to `last' as might be expected. However, the list
 174      * does not terminate there: first->prev will end up pointing
 175      * to the last line of the previous paragraph in most cases,
 176      * and likewise last->next will point to the first line of the
 177      * next paragraph.
 178      */
 179     line_data *first;                  /* first line in paragraph */
 180     line_data *last;                   /* last line in paragraph */
 181     /*
 182      * Some paragraphs have associated graphics; currently this is
 183      * nothing more complex than a single black rectangle.
 184      */
 185     enum {
 186         RECT_NONE, RECT_CHAPTER_UNDERLINE, RECT_RULE
 187     } rect_type;
 188     /*
 189      * We left- and right-justify in special circumstances.
 190      */
 191     enum {
 192         JUST, LEFT, RIGHT
 193     } justification;
 194     /*
 195      * For constructing the page outline.
 196      */
 197     int outline_level;                 /* 0=title 1=C 2=H 3=S 4=S2... */
 198     wchar_t *outline_title;
 199     /*
 200      * For adding the page number of a contents entry afterwards.
 201      */
 202     paragraph *contents_entry;
 203 };
 204
 205 struct line_data_Tag {
 206     /*
 207      * The parent paragraph.
 208      */
 209     para_data *pdata;
 210     /*
 211      * Pointers to join lines into a linked list.
 212      */
 213     line_data *prev;
 214     line_data *next;
 215     /*
 216      * The extent of the text displayed on this line. Also mention
 217      * its starting x position, and by how much the width of spaces
 218      * needs to be adjusted for paragraph justification.
 219      *
 220      * (Unlike most of the `last' pointers defined in this file,
 221      * this `end' pointer points to the word _after_ the last one
 222      * that should be displayed on the line. This is how it's
 223      * returned from wrap_para().)
 224      */
 225     word *first;
 226     word *end;
 227     int xpos;
 228     int hshortfall, nspaces;           /* for justifying paragraphs */
 229     int real_shortfall;
 230     /*
 231      * Auxiliary text: a section number in a margin, or a list item
 232      * bullet or number. Also mention where to display this text
 233      * relative to the left margin.
 234      */
 235     word *aux_text;
 236     word *aux_text_2;
 237     int aux_left_indent;
 238     /*
 239      * This line might have a non-negotiable page break before it.
 240      * Also there will be space required above and below it; also I
 241      * store the physical line height (defined as the maximum of
 242      * the heights of the three fonts in the pdata) because it's
 243      * easier than looking it up repeatedly during page breaking.
 244      */
 245     int page_break;
 246     int space_before;
 247     int space_after;
 248     int line_height;
 249     /*
 250      * Penalties for page breaking before or after this line.
 251      */
 252     int penalty_before, penalty_after;
 253     /*
 254      * These fields are used in the page breaking algorithm.
 255      */
 256     int *bestcost;
 257     int *vshortfall, *text, *space;
 258     line_data **page_last;             /* last line on a page starting here */
 259     /*
 260      * After page breaking, we can assign an actual y-coordinate on
 261      * the page to each line. Also we store a pointer back to the
 262      * page structure itself.
 263      */
 264     int ypos;
 265     page_data *page;
 266 };
 267
 268 /*
 269  * This data structure is constructed to describe each page of the
 270  * printed output.
 271  */
 272 struct page_data_Tag {
 273     /*
 274      * Pointers to join pages into a linked list.
 275      */
 276     page_data *prev;
 277     page_data *next;
 278     /*
 279      * The set of lines displayed on this page.
 280      */
 281     line_data *first_line;
 282     line_data *last_line;
 283     /*
 284      * After text rendering: the set of actual pieces of text
 285      * needing to be displayed on this page.
 286      */
 287     text_fragment *first_text;
 288     text_fragment *last_text;
 289     /*
 290      * Cross-references.
 291      */
 292     xref *first_xref;
 293     xref *last_xref;
 294     /*
 295      * Rectangles to be drawn. (These are currently only used for
 296      * underlining chapter titles and drawing horizontal rules.)
 297      */
 298     rect *first_rect;
 299     rect *last_rect;
 300     /*
 301      * The page number, as a string.
 302      */
 303     wchar_t *number;
 304     /*
 305      * This spare pointer field is for use by the client backends.
 306      */
 307     void *spare;
 308 };
 309
 310 struct text_fragment_Tag {
 311     text_fragment *next;
 312     int x, y;
 313     font_encoding *fe;
 314     int fontsize;
 315     char *text;
 316     int width;
 317 };
 318
 319 struct xref_dest_Tag {
 320     enum { NONE, PAGE, URL } type;
 321     page_data *page;
 322     char *url;
 323 };
 324
 325 struct xref_Tag {
 326     xref *next;
 327     int lx, rx, ty, by;
 328     xref_dest dest;
 329 };
 330
 331 struct rect_Tag {
 332     rect *next;
 333     int x, y, w, h;
 334 };
 335
 336 struct outline_element_Tag {
 337     int level;                         /* 0=title 1=C 2=H 3=S 4=S2... */
 338     para_data *pdata;
 339 };
 340
 341 /*
 342  * Functions exported from bk_paper.c
 343  */
 344 int kern_cmp(void *, void *); /* use when setting up kern_pairs */
 345 void font_index_glyphs(font_info *fi);
 346 int find_glyph(font_info *fi, char const *name);
 347
 348
 349 /*
 350  * Functions and data exported from psdata.c.
 351  */
 352 wchar_t ps_glyph_to_unicode(char const *glyph);
 353 extern const char *const ps_std_glyphs[];
 354 void init_std_fonts(void);
 355 const int *ps_std_font_widths(char const *fontname);
 356 const kern_pair *ps_std_font_kerns(char const *fontname);
 357
 358 #endif