src/tacvt.c

   1 /* tacvt.c */
   2
   3 /*
   4  * Copyright (C) 2011 by Werner Lemberg.
   5  *
   6  * This file is part of the ttfautohint library, and may only be used,
   7  * modified, and distributed under the terms given in `COPYING'.  By
   8  * continuing to use, modify, or distribute this file you indicate that you
   9  * have read `COPYING' and understand and accept it fully.
  10  *
  11  * The file `COPYING' mentioned in the previous paragraph is distributed
  12  * with the ttfautohint library.
  13  */
  14
  15
  16 #include "ta.h"
  17
  18
  19 static FT_Error
  20 TA_sfnt_compute_global_hints(SFNT* sfnt,
  21                              FONT* font)
  22 {
  23   FT_Error error;
  24   FT_Face face = sfnt->face;
  25   FT_UInt enc;
  26   FT_UInt idx;
  27
  28   static const FT_Encoding latin_encs[] =
  29   {
  30     FT_ENCODING_UNICODE,
  31     FT_ENCODING_APPLE_ROMAN,
  32     FT_ENCODING_ADOBE_STANDARD,
  33     FT_ENCODING_ADOBE_LATIN_1,
  34
  35     FT_ENCODING_NONE /* end of list */
  36   };
  37
  38
  39   error = ta_loader_init(font->loader);
  40   if (error)
  41     return error;
  42
  43   /* try to select a latin charmap */
  44   for (enc = 0; latin_encs[enc] != FT_ENCODING_NONE; enc++)
  45   {
  46     error = FT_Select_Charmap(face, latin_encs[enc]);
  47     if (!error)
  48       break;
  49   }
  50
  51   /* load latin glyph `a' to trigger all initializations */
  52   idx = FT_Get_Char_Index(face, 'a');
  53   error = ta_loader_load_glyph(font->loader, face, idx,
  54                                font->fallback_script << 30);
  55
  56   return error;
  57 }
  58
  59
  60 static FT_Error
  61 TA_table_build_cvt(FT_Byte** cvt,
  62                    FT_ULong* cvt_len,
  63                    SFNT* sfnt,
  64                    FONT* font)
  65 {
  66   TA_LatinAxis haxis;
  67   TA_LatinAxis vaxis;
  68
  69   FT_UInt i;
  70   FT_UInt buf_len;
  71   FT_UInt len;
  72   FT_Byte* buf;
  73   FT_Byte* buf_p;
  74
  75   FT_Error error;
  76
  77
  78   error = TA_sfnt_compute_global_hints(sfnt, font);
  79   if (error)
  80     return error;
  81
  82   haxis = &((TA_LatinMetrics)font->loader->hints.metrics)->axis[0];
  83   vaxis = &((TA_LatinMetrics)font->loader->hints.metrics)->axis[1];
  84
  85   buf_len = 2 * (cvtl_max_runtime /* runtime values */
  86                  + 2 /* vertical and horizontal standard width */
  87                  + haxis->width_count
  88                  + vaxis->width_count
  89                  + 2 * vaxis->blue_count);
  90
  91   /* buffer length must be a multiple of four */
  92   len = (buf_len + 3) & ~3;
  93   buf = (FT_Byte*)malloc(len);
  94   if (!buf)
  95     return FT_Err_Out_Of_Memory;
  96
  97   /* pad end of buffer with zeros */
  98   buf[len - 1] = 0x00;
  99   buf[len - 2] = 0x00;
 100   buf[len - 3] = 0x00;
 101
 102   buf_p = buf;
 103
 104   /* some CVT values are initialized (and modified) at runtime; */
 105   /* see the `cvtl_xxx' macros in tabytecode.h */
 106   for (i = 0; i < cvtl_max_runtime; i++)
 107   {
 108     *(buf_p++) = 0;
 109     *(buf_p++) = 0;
 110   }
 111
 112   if (haxis->width_count > 0)
 113   {
 114     *(buf_p++) = HIGH(haxis->widths[0].org);
 115     *(buf_p++) = LOW(haxis->widths[0].org);
 116   }
 117   else
 118   {
 119     *(buf_p++) = 0;
 120     *(buf_p++) = 50;
 121   }
 122   if (vaxis->width_count > 0)
 123   {
 124     *(buf_p++) = HIGH(vaxis->widths[0].org);
 125     *(buf_p++) = LOW(vaxis->widths[0].org);
 126   }
 127   else
 128   {
 129     *(buf_p++) = 0;
 130     *(buf_p++) = 50;
 131   }
 132
 133   for (i = 0; i < haxis->width_count; i++)
 134   {
 135     if (haxis->widths[i].org > 0xFFFF)
 136       goto Err;
 137     *(buf_p++) = HIGH(haxis->widths[i].org);
 138     *(buf_p++) = LOW(haxis->widths[i].org);
 139   }
 140
 141   for (i = 0; i < vaxis->width_count; i++)
 142   {
 143     if (vaxis->widths[i].org > 0xFFFF)
 144       goto Err;
 145     *(buf_p++) = HIGH(vaxis->widths[i].org);
 146     *(buf_p++) = LOW(vaxis->widths[i].org);
 147   }
 148
 149   for (i = 0; i < vaxis->blue_count; i++)
 150   {
 151     if (vaxis->blues[i].ref.org > 0xFFFF)
 152       goto Err;
 153     *(buf_p++) = HIGH(vaxis->blues[i].ref.org);
 154     *(buf_p++) = LOW(vaxis->blues[i].ref.org);
 155   }
 156
 157   for (i = 0; i < vaxis->blue_count; i++)
 158   {
 159     if (vaxis->blues[i].shoot.org > 0xFFFF)
 160       goto Err;
 161     *(buf_p++) = HIGH(vaxis->blues[i].shoot.org);
 162     *(buf_p++) = LOW(vaxis->blues[i].shoot.org);
 163   }
 164
 165 #if 0
 166   TA_LOG(("--------------------------------------------------\n"));
 167   TA_LOG(("glyph %d:\n", idx));
 168   ta_glyph_hints_dump_edges(_ta_debug_hints);
 169   ta_glyph_hints_dump_segments(_ta_debug_hints);
 170   ta_glyph_hints_dump_points(_ta_debug_hints);
 171 #endif
 172
 173   *cvt = buf;
 174   *cvt_len = buf_len;
 175
 176   return FT_Err_Ok;
 177
 178 Err:
 179   free(buf);
 180   return TA_Err_Hinter_Overflow;
 181 }
 182
 183
 184 FT_Error
 185 TA_sfnt_build_cvt_table(SFNT* sfnt,
 186                         FONT* font)
 187 {
 188   FT_Error error;
 189
 190   FT_Byte* cvt_buf;
 191   FT_ULong cvt_len;
 192
 193
 194   error = TA_sfnt_add_table_info(sfnt);
 195   if (error)
 196     return error;
 197
 198   error = TA_table_build_cvt(&cvt_buf, &cvt_len, sfnt, font);
 199   if (error)
 200     return error;
 201
 202   /* in case of success, `cvt_buf' gets linked */
 203   /* and is eventually freed in `TA_font_unload' */
 204   error = TA_font_add_table(font,
 205                             &sfnt->table_infos[sfnt->num_table_infos - 1],
 206                             TTAG_cvt, cvt_len, cvt_buf);
 207   if (error)
 208   {
 209     free(cvt_buf);
 210     return error;
 211   }
 212
 213   return FT_Err_Ok;
 214 }
 215
 216 /* end of tacvt.c */