algo/Text.algo.h

   1 /*****************************************************************************
   2  * This file is part of gfxprim library.                                     *
   3  *                                                                           *
   4  * Gfxprim is free software; you can redistribute it and/or                  *
   5  * modify it under the terms of the GNU Lesser General Public                *
   6  * License as published by the Free Software Foundation; either              *
   7  * version 2.1 of the License, or (at your option) any later version.        *
   8  *                                                                           *
   9  * Gfxprim is distributed in the hope that it will be useful,                *
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of            *
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU         *
  12  * Lesser General Public License for more details.                           *
  13  *                                                                           *
  14  * You should have received a copy of the GNU Lesser General Public          *
  15  * License along with gfxprim; if not, write to the Free Software            *
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor,                        *
  17  * Boston, MA  02110-1301  USA                                               *
  18  *                                                                           *
  19  * Copyright (C) 2009-2010 Jiri "BlueBear" Dluhos                            *
  20  *                         <jiri.bluebear.dluhos@gmail.com>                  *
  21  *                                                                           *
  22  * Copyright (C) 2009-2010 Cyril Hrubis <metan@ucw.cz>                       *
  23  *                                                                           *
  24  *****************************************************************************/
  25
  26 /*
  27  * A bitmap text drawing algorithm.
  28  */
  29
  30 #define DEF_TEXT_FN(FN_NAME, CONTEXT_T, PIXVAL_T, HLINE) \
  31 void FN_NAME(CONTEXT_T context, const GP_TextStyle *style, int x, int y, \
  32         const char *str, PIXVAL_T pixval) \
  33 { \
  34         /* Remember the original starting height. */ \
  35         int y0 = y; \
  36 \
  37         const char *p; \
  38         for (p = str; *p != '\0'; p++) { \
  39 \
  40                 /* Calculate the address of the character data. */ \
  41                 const GP_CharData *data = GP_GetCharData(style->font, *p); \
  42                 if (data == NULL) { \
  43 \
  44                         /* unencoded character */ \
  45                         data = GP_GetCharData(style->font, ' '); \
  46                 } \
  47 \
  48                 /* Starting and final X for each character line. */ \
  49                 int x0 = x + data->pre_offset * (style->pixel_xmul + style->pixel_xspace); \
  50                 int x1 = x0 + data->char_width * (style->pixel_xmul + style->pixel_xspace); \
  51 \
  52                 /* Draw the character line by line. */ \
  53                 const uint8_t *src = data->bitmap; \
  54                 int line, linerep; \
  55                 for (line = 0, y = y0; line < style->font->height; line++, y += style->pixel_yspace) { \
  56 \
  57                         /* repeat the line as specified by pixel_ymul */ \
  58                         for (linerep = 0; linerep < style->pixel_ymul; linerep++, y++) { \
  59                                 uint8_t const * linesrc = src + line * style->font->bytes_per_line; \
  60                                 uint8_t mask = 0x80; \
  61 \
  62                                 /* draw the line of the character bitmap */ \
  63                                 for (x = x0; x < x1; x += style->pixel_xmul + style->pixel_xspace) { \
  64                                         if (*linesrc & mask) { \
  65                                                 HLINE(context, \
  66                                                         x, x + style->pixel_xmul - 1, \
  67                                                         y, pixval); \
  68                                         } \
  69                                         mask >>= 1; \
  70                                         if (mask == 0) { \
  71                                                 linesrc++; \
  72                                                 mask = 0x80; \
  73                                         } \
  74                                 } \
  75                         } \
  76                 } \
  77 \
  78                 /* Update the X position. */ \
  79                 x = x0 + data->post_offset * (style->pixel_xmul + style->pixel_xspace);  \
  80                 x += style->char_xspace * style->pixel_xmul;    /* optional extra spacing */ \
  81         } \
  82 }
  83