source/texk/web2c/luatexdir/pdf/pdfglyph.w

   1 % pdfglyph.w
   2 %
   3 % Copyright 2009-2011 Taco Hoekwater <taco@@luatex.org>
   4 %
   5 % This file is part of LuaTeX.
   6 %
   7 % LuaTeX is free software; you can redistribute it and/or modify it under
   8 % the terms of the GNU General Public License as published by the Free
   9 % Software Foundation; either version 2 of the License, or (at your
  10 % option) any later version.
  11 %
  12 % LuaTeX is distributed in the hope that it will be useful, but WITHOUT
  13 % ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 % FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  15 % License for more details.
  16 %
  17 % You should have received a copy of the GNU General Public License along
  18 % with LuaTeX; if not, see <http://www.gnu.org/licenses/>.
  19
  20 @ @c
  21
  22 #include "ptexlib.h"
  23 #include "pdf/pdfpage.h"
  24
  25 #define pdf2double(a) ((double) (a).m / ten_pow[(a).e])
  26
  27 @ eternal constants
  28
  29 @c
  30 #define one_bp ((double) 65536 * (double) 72.27 / 72)  /* number of sp per 1bp */
  31 #define e_tj 3                                         /* must be 3; movements in []TJ are in fontsize/$10^3$ units */
  32
  33 @ @c
  34 static int64_t pdf_char_width(pdfstructure * p, internal_font_number f, int i)
  35 {
  36     /* use exactly this formula also for calculating the /Width array values */
  37     return i64round((double) char_width(f, i) / font_size(f) * ten_pow[e_tj + p->cw.e]);
  38 }
  39
  40 @ @c
  41 void pdf_print_charwidth(PDF pdf, internal_font_number f, int i)
  42 {
  43     pdffloat cw;
  44     pdfstructure *p = pdf->pstruct;
  45     cw.m = pdf_char_width(p, f, i);
  46     cw.e = p->cw.e;
  47     print_pdffloat(pdf, cw);
  48 }
  49
  50 @ @c
  51 static void setup_fontparameters(PDF pdf, internal_font_number f, int ex_glyph)
  52 {
  53     float slant, extend, expand, scale = 1.0;
  54     float u = 1.0;
  55     pdfstructure *p = pdf->pstruct;
  56     /* fix mantis bug \# 0000200 (acroread "feature") */
  57     if ((font_format(f) == opentype_format || (font_format(f) == type1_format && font_encodingbytes(f) == 2))  && font_units_per_em(f) > 0)
  58         u = font_units_per_em(f) / 1000.0;
  59     pdf->f_cur = f;
  60     p->f_pdf = pdf_set_font(pdf, f);
  61     p->fs.m = i64round(font_size(f) / u / one_bp * ten_pow[p->fs.e]);
  62     slant = font_slant(f) / 1000.0;
  63     extend = font_extend(f) / 1000.0;
  64     expand = 1.0 + (ex_glyph/1) / 1000.0;
  65     p->tj_delta.e = p->cw.e - 1;        /* "- 1" makes less corrections inside []TJ */
  66     /* no need to be more precise than TeX (1sp) */
  67     while (p->tj_delta.e > 0 && (double) font_size(f) / ten_pow[p->tj_delta.e + e_tj] < 0.5)
  68         p->tj_delta.e--;        /* happens for very tiny fonts */
  69     p->tm[0].m = i64round(scale * expand * extend * ten_pow[p->tm[0].e]);
  70     p->tm[2].m = i64round(slant * ten_pow[p->tm[2].e]);
  71     p->tm[3].m = i64round(scale * ten_pow[p->tm[3].e]);
  72     p->k2 = ten_pow[e_tj + p->cw.e] * scale / (ten_pow[p->pdf.h.e] * pdf2double(p->fs) * pdf2double(p->tm[0]));
  73     p->cur_ex = ex_glyph ;  /* we keep track of the state of ex */
  74 }
  75
  76
  77 @ @c
  78 static void set_font(PDF pdf)
  79 {
  80     pdfstructure *p = pdf->pstruct;
  81     pdf_printf(pdf, "/F%d", (int) p->f_pdf);
  82     pdf_print_resname_prefix(pdf);
  83     pdf_out(pdf, ' ');
  84     print_pdffloat(pdf, p->fs);
  85     pdf_puts(pdf, " Tf ");
  86     p->f_pdf_cur = p->f_pdf;
  87     p->fs_cur.m = p->fs.m;
  88     p->need_tf = false;
  89     p->need_tm = true; /* always follow Tf by Tm */
  90 }
  91
  92 @ @c
  93 static void set_textmatrix(PDF pdf, scaledpos pos)
  94 {
  95     boolean move;
  96     pdfstructure *p = pdf->pstruct;
  97     if (!is_textmode(p))
  98         normal_error("pdf backend","text mode expected in set_textmatrix");
  99     move = calc_pdfpos(p, pos);
 100     if (p->need_tm || move) {
 101         print_pdf_matrix(pdf, p->tm);
 102         pdf_puts(pdf, " Tm ");
 103         p->pdf.h.m = p->pdf_bt_pos.h.m + p->tm[4].m; /* Tm replaces */
 104         p->pdf.v.m = p->pdf_bt_pos.v.m + p->tm[5].m;
 105         p->need_tm = false;
 106     }
 107     p->tm0_cur.m = p->tm[0].m;
 108 }
 109
 110 @ Print out a character to PDF buffer; the character will be printed in octal
 111 form in the following cases: chars <= 32, backslash (92), left parenthesis
 112 (40), and right parenthesis (41).
 113
 114 @c
 115 static void pdf_print_char(PDF pdf, int c)
 116 {
 117     if (c > 255)
 118         return;
 119     /* pdf_print_escaped(c) */
 120     if (c <= 32 || c == '\\' || c == '(' || c == ')' || c > 127) {
 121         pdf_room(pdf, 4);
 122         pdf_quick_out(pdf, '\\');
 123         pdf_quick_out(pdf, (unsigned char) ('0' + ((c >> 6) & 0x3)));
 124         pdf_quick_out(pdf, (unsigned char) ('0' + ((c >> 3) & 0x7)));
 125         pdf_quick_out(pdf, (unsigned char) ('0' + (c & 0x7)));
 126     } else
 127         pdf_out(pdf, c);
 128 }
 129
 130 static void pdf_print_wide_char(PDF pdf, int c)
 131 {
 132     char hex[5];
 133     snprintf(hex, 5, "%04X", c);
 134     pdf_out_block(pdf, (const char *) hex, 4);
 135 }
 136
 137 @ @c
 138 static void begin_charmode(PDF pdf, internal_font_number f, pdfstructure * p)
 139 {
 140     if (!is_chararraymode(p))
 141         normal_error("pdf backend","char array mode expected in begin_char_mode");
 142     if (font_encodingbytes(f) == 2) {
 143         p->ishex = 1;
 144         pdf_out(pdf, '<');
 145     } else {
 146         p->ishex = 0;
 147         pdf_out(pdf, '(');
 148     }
 149     p->mode = PMODE_CHAR;
 150 }
 151
 152 @ @c
 153 void end_charmode(PDF pdf)
 154 {
 155     pdfstructure *p = pdf->pstruct;
 156     if (!is_charmode(p))
 157         normal_error("pdf backend","char mode expected in end_char_mode");
 158     if (p->ishex == 1) {
 159         p->ishex = 0;
 160         pdf_out(pdf, '>');
 161     } else {
 162         pdf_out(pdf, ')');
 163     }
 164     p->mode = PMODE_CHARARRAY;
 165 }
 166
 167 @ @c
 168 static void begin_chararray(PDF pdf)
 169 {
 170     pdfstructure *p = pdf->pstruct;
 171     if (!is_textmode(p))
 172         normal_error("pdf backend","text mode expected in begin_char_array");
 173     p->pdf_tj_pos = p->pdf;
 174     p->cw.m = 0;
 175     pdf_out(pdf, '[');
 176     p->mode = PMODE_CHARARRAY;
 177 }
 178
 179 @ @c
 180 void end_chararray(PDF pdf)
 181 {
 182     pdfstructure *p = pdf->pstruct;
 183     if (!is_chararraymode(p))
 184         normal_error("pdf backend","char array mode expected in end_char_array");
 185     pdf_puts(pdf, "]TJ\n");
 186     p->pdf = p->pdf_tj_pos;
 187     p->mode = PMODE_TEXT;
 188 }
 189
 190 @ We need to adapt the tm when a font changes. A change can be a change in id
 191 (frontend) or pdf reference (backend, as we share font resources). At such a
 192 change we also need to adapt to the slant and extend. Initially we also need to
 193 take the exfactor of a glyph into account. When the font is unchanged, we still
 194 need to check each glyph for a change in exfactor. We store the current one on
 195 the state record so that we can minimize testing.
 196
 197 @c
 198 void pdf_place_glyph(PDF pdf, internal_font_number f, int c, int ex)
 199 {
 200     boolean move;
 201     pdfstructure *p = pdf->pstruct;
 202     scaledpos pos = pdf->posstruct->pos;
 203     if (!char_exists(f, c))
 204         return;
 205     if (p->need_tf || f != pdf->f_cur || p->f_pdf != p->f_pdf_cur || p->fs.m != p->fs_cur.m || is_pagemode(p)) {
 206          pdf_goto_textmode(pdf);
 207          setup_fontparameters(pdf, f, ex);
 208          set_font(pdf);
 209     } else if (p->tm0_cur.m != p->tm[0].m || p->cur_ex != ex) {
 210          setup_fontparameters(pdf, f, ex);
 211          p->need_tm = true;
 212     }
 213     /* all movements */
 214     move = calc_pdfpos(p, pos); /* within text or chararray or char mode */
 215     if (move || p->need_tm) {
 216         if (p->need_tm || (p->wmode == WMODE_H && (p->pdf_bt_pos.v.m + p->tm[5].m) != p->pdf.v.m)
 217         || (p->wmode == WMODE_V && (p->pdf_bt_pos.h.m + p->tm[4].m) != p->pdf.h.m)
 218         || abs(p->tj_delta.m) >= 1000000) {
 219             pdf_goto_textmode(pdf);
 220             set_textmatrix(pdf, pos);
 221             begin_chararray(pdf);
 222             move = calc_pdfpos(p, pos); /* for fine adjustment */
 223         }
 224         if (move) {
 225             if (is_charmode(p))
 226                 end_charmode(pdf);
 227             print_pdffloat(pdf, p->tj_delta);
 228             p->cw.m -= p->tj_delta.m * ten_pow[p->cw.e - p->tj_delta.e];
 229         }
 230     }
 231     /* glyph output */
 232     if (is_chararraymode(p))
 233         begin_charmode(pdf, f, p);
 234     else if (!is_charmode(p))
 235         normal_error("pdf backend","char (array) mode expected in place_glyph");
 236     pdf_mark_char(f, c);
 237     if (font_encodingbytes(f) == 2)
 238         pdf_print_wide_char(pdf, char_index(f, c));
 239     else
 240         pdf_print_char(pdf, c);
 241     p->cw.m += pdf_char_width(p, p->f_pdf, c);  /* aka |adv_char_width()| */
 242 }