1 /* Copyright (C) 2002 Aladdin Enterprises. All rights reserved. 2 3 This software is provided AS-IS with no warranty, either express or 4 implied. 5 6 This software is distributed under license and may not be copied, 7 modified or distributed except as expressly authorized under the terms 8 of the license contained in the file LICENSE in this distribution. 9 10 For more information about licensing, please refer to 11 http://www.ghostscript.com/licensing/. For information on 12 commercial licensing, go to http://www.artifex.com/licensing/ or 13 contact Artifex Software, Inc., 101 Lucas Valley Road #110, 14 San Rafael, CA 94903, U.S.A., +1(415)492-9861. 15 */ 16 17 /* $Id: gdevpdtt.h,v 1.25 2004/10/15 18:24:31 igor Exp $ */ 18 /* Internal text processing interface for pdfwrite */ 19 20 #ifndef gdevpdtt_INCLUDED 21 # define gdevpdtt_INCLUDED 22 23 /* 24 * This file is only used internally to define the interface between 25 * gdevpdtt.c, gdevpdtc.c, and gdevpdte.c. 26 */ 27 28 /* ---------------- Coordinate systems ---------------- */ 29 30 /* 31 32 The current text code has to deal with 6 different coordinate systems. 33 This situation is complex, confusing, and fragile, but despite literally 34 years of struggle we have been unable to understand how to simplify it. 35 36 1) PostScript user space at the time a text operator is invoked. The 37 width values for ashow, xshow, etc. are specified in this space: these 38 values appear in the delta_all, delta_space, x_widths, and y_widths 39 members of the text member of the common part of the text enumerator 40 (pdf_text_enum_t). 41 42 2) Device space. For the pdfwrite device, this is a straightforward space 43 with (0,0) in the lower left corner. The usual resolution is 720 dpi, 44 but this is user-settable to provide a tradeoff between file size and 45 bitmap resolution (for rendered Patterns and fonts that have to be 46 converted to bitmaps). 47 48 3) PDF user space. During the processing of text operators, this is 49 always the same as the default PDF user space, in which 1 unit = 1/72", 50 because an Acrobat quirk apparently requires this. (See stream_to_text 51 in gdevpdfu.c.) 52 53 4) Font design space. This is the space in which the font's character 54 outlines and advance widths are specified, including the width values 55 returned by font->procs.glyph_info and by pdf_char_widths. 56 57 5) PDF unscaled text space. This space is used for the PDF width 58 adjustment values (Tc, Tw, and TL parameters, and " operator) and 59 positioning coordinates (Td and TD operators). 60 61 6) PDF text space. This space is used for the width adjustments for the 62 TJ operator. 63 64 The following convert between these spaces: 65 66 - The PostScript CTM (pte->pis->ctm) maps #1 to #2. 67 68 - The mapping from #3 to #2 is a scaling by pdev->HWResolution / 72. 69 70 - The mapping from #5 to #6 is a scaling by the size member of 71 pdf_text_state_values_t, which is the size value for the Tf operator. 72 73 - The matrix member of pdf_text_state_values_t maps #5 to #2, which is the 74 matrix for the Tm operator or its abbreviations. 75 76 - The FontMatrix of a font maps #4 to #1. 77 78 Note that the PDF text matrix (set by the Tm operator) maps #5 to #3. 79 However, this is not actually stored anywhere: it is computed by 80 multiplying the #5->#2 matrix by the #2->#3 scaling. 81 82 */ 83 84 /* ---------------- Types and structures ---------------- */ 85 86 #ifndef pdf_char_glyph_pair_DEFINED 87 # define pdf_char_glyph_pair_DEFINED 88 typedef struct pdf_char_glyph_pair_s pdf_char_glyph_pair_t; 89 #endif 90 91 #ifndef pdf_char_glyph_pairs_DEFINED 92 # define pdf_char_glyph_pairs_DEFINED 93 typedef struct pdf_char_glyph_pairs_s pdf_char_glyph_pairs_t; 94 #endif 95 96 /* Define a structure for a text characters list. */ 97 /* It must not contain pointers due to variable length. */ 98 struct pdf_char_glyph_pairs_s { 99 int num_all_chars; 100 int num_unused_chars; 101 int unused_offset; /* The origin of the unused character table.*/ 102 pdf_char_glyph_pair_t s[1]; /* Variable length. */ 103 }; 104 105 /* Define the text enumerator. */ 106 typedef struct pdf_text_enum_s { 107 gs_text_enum_common; 108 gs_text_enum_t *pte_default; 109 gs_fixed_point origin; 110 bool charproc_accum; 111 bool cdevproc_callout; 112 double cdevproc_result[10]; 113 pdf_char_glyph_pairs_t *cgp; 114 } pdf_text_enum_t; 115 #define private_st_pdf_text_enum()\ 116 extern_st(st_gs_text_enum);\ 117 gs_private_st_suffix_add2(st_pdf_text_enum, pdf_text_enum_t,\ 118 "pdf_text_enum_t", pdf_text_enum_enum_ptrs, pdf_text_enum_reloc_ptrs,\ 119 st_gs_text_enum, pte_default, cgp) 120 121 /* 122 * Define quantities derived from the current font and CTM, used within 123 * the text processing loop. NOTE: This structure has no GC descriptor 124 * and must therefore only be used locally (allocated on the C stack). 125 */ 126 typedef struct pdf_text_process_state_s { 127 pdf_text_state_values_t values; 128 gs_font *font; 129 } pdf_text_process_state_t; 130 131 /* 132 * Define the structure used to return glyph width information. Note that 133 * there are two different sets of width information: real-number (x,y) 134 * values, which give the true advance width, and an integer value, which 135 * gives an X advance width for WMode = 0 or a Y advance width for WMode = 1. 136 * The return value from pdf_glyph_width() indicates which of these is/are 137 * valid. 138 */ 139 typedef struct pdf_glyph_width_s { 140 double w; 141 gs_point xy; 142 gs_point v; /* glyph origin shift */ 143 } pdf_glyph_width_t; 144 typedef struct pdf_glyph_widths_s { 145 pdf_glyph_width_t Width; /* unmodified, for Widths */ 146 pdf_glyph_width_t real_width; /* possibly modified, for rendering */ 147 bool replaced_v; 148 } pdf_glyph_widths_t; 149 150 /* ---------------- Procedures ---------------- */ 151 152 /* 153 * Declare the procedures for processing different species of text. 154 * These procedures may, but need not, copy pte->text into buf 155 * (a caller-supplied buffer large enough to hold the string). 156 */ 157 #define PROCESS_TEXT_PROC(proc)\ 158 int proc(gs_text_enum_t *pte, void *vbuf, uint bsize) 159 160 /* ------ gdevpdtt.c ------ */ 161 162 /* 163 * Compute and return the orig_matrix of a font. 164 */ 165 int pdf_font_orig_matrix(const gs_font *font, gs_matrix *pmat); 166 int font_orig_scale(const gs_font *font, double *sx); 167 168 /* 169 * Check the Encoding compatibility 170 */ 171 bool pdf_check_encoding_compatibility(const pdf_font_resource_t *pdfont, 172 const pdf_char_glyph_pair_t *pairs, int num_chars); 173 174 /* 175 * Create or find a font resource object for a text. 176 */ 177 int 178 pdf_obtain_font_resource(pdf_text_enum_t *penum, 179 const gs_string *pstr, pdf_font_resource_t **ppdfont); 180 181 /* 182 * Create or find a font resource object for a glyphshow text. 183 */ 184 int pdf_obtain_font_resource_unencoded(pdf_text_enum_t *penum, 185 const gs_string *pstr, pdf_font_resource_t **ppdfont, const gs_glyph *gdata); 186 187 /* 188 * Create or find a CID font resource object for a glyph set. 189 */ 190 int pdf_obtain_cidfont_resource(gx_device_pdf *pdev, gs_font *subfont, 191 pdf_font_resource_t **ppdsubf, 192 pdf_char_glyph_pairs_t *cgp); 193 194 /* 195 * Create or find a parent Type 0 font resource object for a CID font resource. 196 */ 197 int pdf_obtain_parent_type0_font_resource(gx_device_pdf *pdev, pdf_font_resource_t *pdsubf, 198 const gs_const_string *CMapName, pdf_font_resource_t **pdfont); 199 200 /* 201 * Retrive font resource attached to a font. 202 * allocating glyph_usage and real_widths on request. 203 */ 204 int pdf_attached_font_resource(gx_device_pdf *pdev, gs_font *font, 205 pdf_font_resource_t **pdfont, byte **glyph_usage, 206 double **real_widths, int *num_chars, int *num_widths); 207 208 /* 209 * Attach font resource to a font. 210 */ 211 int pdf_attach_font_resource(gx_device_pdf *pdev, gs_font *font, 212 pdf_font_resource_t *pdfont); 213 214 /* 215 * Create a font resource object for a gs_font of Type 3. 216 */ 217 int pdf_make_font3_resource(gx_device_pdf *pdev, gs_font *font, 218 pdf_font_resource_t **ppdfont); 219 220 /* 221 * Compute the cached values in the text processing state from the text 222 * parameters, pdfont, and pis->ctm. Return either an error code (< 0) or a 223 * mask of operation attributes that the caller must emulate. Currently the 224 * only such attributes are TEXT_ADD_TO_ALL_WIDTHS and 225 * TEXT_ADD_TO_SPACE_WIDTH. 226 */ 227 int pdf_update_text_state(pdf_text_process_state_t *ppts, 228 const pdf_text_enum_t *penum, 229 pdf_font_resource_t *pdfont, 230 const gs_matrix *pfmat); 231 232 /* 233 * Set up commands to make the output state match the processing state. 234 * General graphics state commands are written now; text state commands 235 * are written later. 236 */ 237 int pdf_set_text_process_state(gx_device_pdf *pdev, 238 const gs_text_enum_t *pte, /*for pdcolor, pis*/ 239 pdf_text_process_state_t *ppts); 240 241 /* 242 * Get the widths (unmodified and possibly modified) of a glyph in a (base) 243 * font. If the width is cachable (implying that the w values area valid), 244 * return 0; if only the xy values are valid, or the width is not cachable 245 * for some other reason, return 1. 246 * Return TEXT_PROCESS_CDEVPROC if a CDevProc callout is needed. 247 * cdevproc_result != NULL if we restart after a CDevProc callout. 248 */ 249 int pdf_glyph_widths(pdf_font_resource_t *pdfont, int wmode, gs_glyph glyph, 250 gs_font *font, pdf_glyph_widths_t *pwidths, 251 const double cdevproc_result[10]); 252 253 /* 254 * Fall back to the default text processing code when needed. 255 */ 256 int pdf_default_text_begin(gs_text_enum_t *pte, const gs_text_params_t *text, 257 gs_text_enum_t **ppte); 258 259 /* 260 * Check for simple font. 261 */ 262 bool pdf_is_simple_font(gs_font *font); 263 264 /* 265 * Check for CID font. 266 */ 267 bool pdf_is_CID_font(gs_font *font); 268 269 /* Get a synthesized Type 3 font scale. */ 270 void pdf_font3_scale(gx_device_pdf *pdev, gs_font *font, double *scale); 271 272 /* Release a text characters colloction. */ 273 void pdf_text_release_cgp(pdf_text_enum_t *penum); 274 275 276 /* ------ gdevpdtc.c ------ */ 277 278 PROCESS_TEXT_PROC(process_composite_text); 279 PROCESS_TEXT_PROC(process_cmap_text); 280 PROCESS_TEXT_PROC(process_cid_text); 281 282 /* ------ gdevpdte.c ------ */ 283 284 PROCESS_TEXT_PROC(process_plain_text); 285 286 /* 287 * Encode and process a string with a simple gs_font. 288 */ 289 int pdf_encode_process_string(pdf_text_enum_t *penum, gs_string *pstr, 290 const gs_glyph *gdata, const gs_matrix *pfmat, 291 pdf_text_process_state_t *ppts); 292 293 /* 294 * Emulate TEXT_ADD_TO_ALL_WIDTHS and/or TEXT_ADD_TO_SPACE_WIDTH, 295 * and implement TEXT_REPLACE_WIDTHS if requested. 296 * Uses and updates ppts->values.matrix; uses ppts->values.pdfont. 297 */ 298 int process_text_modify_width(pdf_text_enum_t *pte, gs_font *font, 299 pdf_text_process_state_t *ppts, 300 const gs_const_string *pstr, 301 gs_point *pdpt); 302 303 /* 304 * Add char code pair to ToUnicode CMap, 305 * creating the CMap on neccessity. 306 */ 307 int 308 pdf_add_ToUnicode(gx_device_pdf *pdev, gs_font *font, pdf_font_resource_t *pdfont, 309 gs_glyph glyph, gs_char ch); 310 311 /* 312 * Get character code from a glyph code. 313 * An usage of this function is very undesirable, 314 * because a glyph may be unlisted in Encoding. 315 */ 316 int pdf_encode_glyph(gs_font_base *bfont, gs_glyph glyph0, 317 byte *buf, int buf_size, int *char_code_length); 318 319 int pdf_shift_text_currentpoint(pdf_text_enum_t *penum, gs_point *wpt); 320 321 #endif /* gdevpdtt_INCLUDED */ 322