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
  21 /*
  22  * This data structure represents the overall document, in the form
  23  * it will be given to the client backends.
  24  */
  25 struct document_Tag {
  26     int paper_width, paper_height;
  27     font_list *fonts;
  28     page_data *pages;
  29 };
  30
  31 /*
  32  * This data structure represents a particular font.
  33  */
  34 struct font_data_Tag {
  35     /*
  36      * Specify the PostScript name of the font and its point size.
  37      */
  38     const char *name;
  39     /*
  40      * An array of pointers to the available glyph names, and their
  41      * corresponding character widths. These two arrays have
  42      * parallel indices.
  43      */
  44     int nglyphs;
  45     const char *const *glyphs;
  46     const int *widths;
  47     /*
  48      * For reasonably speedy lookup, we set up a 65536-element
  49      * table representing the Unicode BMP (I can conveniently
  50      * restrict myself to the BMP for the moment since I happen to
  51      * know that no glyph in the Adobe Glyph List falls outside
  52      * it), whose elements are indices into the above two arrays.
  53      */
  54     unsigned short bmp[65536];
  55     /*
  56      * At some point I'm going to divide the font into sub-fonts
  57      * with largely non-overlapping encoding vectors. This array
  58      * will track which glyphs go into which subfonts. Also here I
  59      * keep track of the latest subfont of any given font, so I can
  60      * go back and extend its encoding.
  61      */
  62     subfont_map_entry *subfont_map;
  63     font_encoding *latest_subfont;
  64     /*
  65      * The font list to which this font belongs.
  66      */
  67     font_list *list;
  68 };
  69
  70 struct subfont_map_entry_Tag {
  71     font_encoding *subfont;
  72     unsigned char position;
  73 };
  74
  75 /*
  76  * This data structure represents a sub-font: a font with an
  77  * encoding vector.
  78  */
  79 struct font_encoding_Tag {
  80     font_encoding *next;
  81
  82     char *name;                        /* used by client backends */
  83
  84     font_data *font;                   /* the parent font structure */
  85     const char *vector[256];           /* the actual encoding vector */
  86     int indices[256];                  /* indices back into main font struct */
  87     wchar_t to_unicode[256];           /* PDF will want to know this */
  88     int free_pos;                      /* space left to extend encoding */
  89 };
  90
  91 /*
  92  * This data structure represents the overall list of sub-fonts in
  93  * the whole document.
  94  */
  95 struct font_list_Tag {
  96     font_encoding *head;
  97     font_encoding *tail;
  98 };
  99
 100 /*
 101  * Constants defining array indices for the various fonts used in a
 102  * paragraph.
 103  */
 104 enum {
 105     FONT_NORMAL,
 106     FONT_EMPH,
 107     FONT_CODE,
 108     NFONTS
 109 };
 110
 111 /*
 112  * This is the data structure which is stored in the private_data
 113  * field of each paragraph. It divides the paragraph up into a
 114  * linked list of lines, while at the same time providing for those
 115  * lines to be linked together into a much longer list spanning the
 116  * whole document for page-breaking purposes.
 117  */
 118
 119 struct para_data_Tag {
 120     /*
 121      * Data about the fonts used in this paragraph. Indices are the
 122      * FONT_* constants defined above.
 123      */
 124     font_data *fonts[NFONTS];
 125     int sizes[NFONTS];
 126     /*
 127      * Pointers to the first and last line of the paragraph. The
 128      * line structures are linked into a list, which runs from
 129      * `first' to `last' as might be expected. However, the list
 130      * does not terminate there: first->prev will end up pointing
 131      * to the last line of the previous paragraph in most cases,
 132      * and likewise last->next will point to the first line of the
 133      * next paragraph.
 134      */
 135     line_data *first;                  /* first line in paragraph */
 136     line_data *last;                   /* last line in paragraph */
 137 };
 138
 139 struct line_data_Tag {
 140     /*
 141      * The parent paragraph.
 142      */
 143     para_data *pdata;
 144     /*
 145      * Pointers to join lines into a linked list.
 146      */
 147     line_data *prev;
 148     line_data *next;
 149     /*
 150      * The extent of the text displayed on this line. Also mention
 151      * its starting x position, and by how much the width of spaces
 152      * needs to be adjusted for paragraph justification.
 153      *
 154      * (`last' may be NULL if it's more convenient.)
 155      */
 156     word *first;
 157     word *last;
 158     int xpos;
 159     int space_adjust;                  /* for justifying paragraphs */
 160     /*
 161      * Auxiliary text: a section number in a margin, or a list item
 162      * bullet or number. Also mention where to display this text
 163      * relative to the left margin.
 164      */
 165     word *aux_text;
 166     int aux_left_indent;
 167     /*
 168      * This line might have a non-negotiable page break before it.
 169      * Also there will be space required above and below it; also I
 170      * store the physical line height (defined as the maximum of
 171      * the heights of the three fonts in the pdata) because it's
 172      * easier than looking it up repeatedly during page breaking.
 173      */
 174     int page_break;
 175     int space_before;
 176     int space_after;
 177     int line_height;
 178     /*
 179      * These fields are used in the page breaking algorithm.
 180      */
 181     int bestcost;
 182     int shortfall, text, space;
 183     line_data *page_last;              /* last line on a page starting here */
 184     /*
 185      * After page breaking, we can assign an actual y-coordinate on
 186      * the page to each line. Also we store a pointer back to the
 187      * page structure itself.
 188      */
 189     int ypos;
 190     page_data *page;
 191 };
 192
 193 /*
 194  * This data structure is constructed to describe each page of the
 195  * printed output.
 196  */
 197 struct page_data_Tag {
 198     /*
 199      * Pointers to join pages into a linked list.
 200      */
 201     page_data *prev;
 202     page_data *next;
 203     /*
 204      * The set of lines displayed on this page.
 205      */
 206     line_data *first_line;
 207     line_data *last_line;
 208     /*
 209      * After text rendering: the set of actual pieces of text
 210      * needing to be displayed on this page.
 211      */
 212     text_fragment *first_text;
 213     text_fragment *last_text;
 214     /*
 215      * This spare pointer field is for use by the client backends.
 216      */
 217     void *spare;
 218 };
 219
 220 struct text_fragment_Tag {
 221     text_fragment *next;
 222     int x, y;
 223     font_encoding *fe;
 224     int fontsize;
 225     char *text;
 226 };
 227
 228 /*
 229  * Functions and data exported from psdata.c.
 230  */
 231 wchar_t ps_glyph_to_unicode(char const *glyph);
 232 extern const char *const ps_std_glyphs[];
 233 const int *ps_std_font_widths(char const *fontname);
 234
 235 #endif