images/image-walk.h

   1 /*
   2  *      Image Library -- Pixels iteration
   3  *
   4  *      (c) 2006 Pavel Charvat <pchar@ucw.cz>
   5  *
   6  *      This software may be freely distributed and used according to the terms
   7  *      of the GNU Lesser General Public License.
   8  */
   9
  10 #if !defined(IMAGE_WALK_INLINE) && !defined(IMAGE_WALK_STATIC)
  11 #  error Missing IMAGE_WALK_INLINE or IMAGE_WALK_STATIC
  12 #endif
  13
  14 #if !defined(IMAGE_WALK_UNROLL)
  15 #  define IMAGE_WALK_UNROLL 1
  16 #elif IMAGE_WALK_UNROLL != 1 && IMAGE_WALK_UNROLL != 2 && IMAGE_WALK_UNROLL != 4
  17 #  error IMAGE_WALK_UNROLL must be 1, 2 or 4
  18 #endif
  19
  20 #ifndef IMAGE_WALK_PIXELS
  21 #  define IMAGE_WALK_PIXELS (img->pixels)
  22 #endif
  23 #ifndef IMAGE_WALK_COLS
  24 #  define IMAGE_WALK_COLS (img->cols)
  25 #endif
  26 #ifndef IMAGE_WALK_ROWS
  27 #  define IMAGE_WALK_ROWS (img->rows)
  28 #endif
  29 #ifndef IMAGE_WALK_COL_STEP
  30 #  define IMAGE_WALK_COL_STEP (img->pixel_size)
  31 #endif
  32 #ifndef IMAGE_WALK_ROW_STEP
  33 #  define IMAGE_WALK_ROW_STEP (img->row_size)
  34 #endif
  35
  36 #ifdef IMAGE_WALK_DOUBLE
  37 #  ifndef IMAGE_WALK_SEC_PIXELS
  38 #    define IMAGE_WALK_SEC_PIXELS (sec_img->pixels)
  39 #  endif
  40 #  ifndef IMAGE_WALK_SEC_COLS
  41 #    define IMAGE_WALK_SEC_COLS (sec_img->cols)
  42 #  endif
  43 #  ifndef IMAGE_WALK_SEC_ROWS
  44 #    define IMAGE_WALK_SEC_ROWS (sec_img->rows)
  45 #  endif
  46 #  ifndef IMAGE_WALK_SEC_COL_STEP
  47 #    define IMAGE_WALK_SEC_COL_STEP (sec_img->pixel_size)
  48 #  endif
  49 #  ifndef IMAGE_WALK_SEC_ROW_STEP
  50 #    define IMAGE_WALK_SEC_ROW_STEP (sec_img->row_size)
  51 #  endif
  52 #  define STEP IMAGE_WALK_DO_STEP; pos += col_step; sec_pos += sec_col_step
  53 #else
  54 #  define STEP IMAGE_WALK_DO_STEP; pos += col_step
  55 #endif
  56
  57 #ifndef IMAGE_WALK_DO_START
  58 #  define IMAGE_WALK_DO_START
  59 #endif
  60
  61 #ifndef IMAGE_WALK_DO_END
  62 #  define IMAGE_WALK_DO_END
  63 #endif
  64
  65 #ifndef IMAGE_WALK_DO_ROW_START
  66 #  define IMAGE_WALK_DO_ROW_START
  67 #endif
  68
  69 #ifndef IMAGE_WALK_DO_ROW_END
  70 #  define IMAGE_WALK_DO_ROW_END
  71 #endif
  72
  73 #ifndef IMAGE_WALK_DO_STEP
  74 #  define IMAGE_WALK_DO_STEP
  75 #endif
  76
  77 #ifndef IMAGE_WALK_INLINE
  78 static void IMAGE_WALK_STATIC
  79     (struct image *img
  80 #   ifdef IMAGE_WALK_DOUBLE
  81     , struct image *sec_img
  82 #   endif
  83 #   ifdef IMAGE_WALK_EXTRA_ARGS
  84     , IMAGE_WALK_EXTRA_ARGS
  85 #   endif
  86     )
  87 #endif
  88 {
  89   uns cols = IMAGE_WALK_COLS;
  90   uns rows = IMAGE_WALK_ROWS;
  91 # if IMAGE_WALK_UNROLL > 1
  92   uns cols_unroll_block_count = cols / IMAGE_WALK_UNROLL;
  93   uns cols_unroll_end_count = cols % IMAGE_WALK_UNROLL;
  94 # endif
  95   byte *pos = IMAGE_WALK_PIXELS, *row_start = pos;
  96   int col_step = IMAGE_WALK_COL_STEP;
  97   int row_step = IMAGE_WALK_ROW_STEP;
  98 # ifdef IMAGE_WALK_DOUBLE
  99   byte *sec_pos = IMAGE_WALK_SEC_PIXELS, *sec_row_start = sec_pos;
 100   int sec_col_step = IMAGE_WALK_SEC_COL_STEP;
 101   int sec_row_step = IMAGE_WALK_SEC_ROW_STEP;
 102 # endif
 103   IMAGE_WALK_DO_START;
 104   while (rows--)
 105     {
 106       IMAGE_WALK_DO_ROW_START;
 107 #     if IMAGE_WALK_UNROLL == 1
 108       for (uns i = cols; i--; )
 109 #     else
 110       for (uns i = cols_unroll_block_count; i--; )
 111 #     endif
 112         {
 113 #         if IMAGE_WALK_UNROLL >= 4
 114           STEP;
 115           STEP;
 116 #         endif
 117 #         if IMAGE_WALK_UNROLL >= 2
 118           STEP;
 119 #         endif
 120           STEP;
 121         }
 122 #     if IMAGE_WALK_UNROLL > 1
 123       for (uns i = cols_unroll_end_count; i--; )
 124         {
 125           STEP;
 126         }
 127 #     endif
 128       IMAGE_WALK_DO_ROW_END;
 129       pos = (row_start += row_step);
 130 #     ifdef IMAGE_WALK_DOUBLE
 131       sec_pos = (sec_row_start += sec_row_step);
 132 #     endif
 133     }
 134   IMAGE_WALK_DO_END;
 135 }
 136
 137 #undef IMAGE_WALK_INLINE
 138 #undef IMAGE_WALK_STATIC
 139 #undef IMAGE_WALK_UNROLL
 140 #undef IMAGE_WALK_DOUBLE
 141 #undef IMAGE_WALK_EXTRA_ARGS
 142 #undef IMAGE_WALK_PIXELS
 143 #undef IMAGE_WALK_COLS
 144 #undef IMAGE_WALK_ROWS
 145 #undef IMAGE_WALK_COL_STEP
 146 #undef IMAGE_WALK_ROW_STEP
 147 #undef IMAGE_WALK_SEC_PIXELS
 148 #undef IMAGE_WALK_SEC_COLS
 149 #undef IMAGE_WALK_SEC_ROWS
 150 #undef IMAGE_WALK_SEC_COL_STEP
 151 #undef IMAGE_WALK_SEC_ROW_STEP
 152 #undef IMAGE_WALK_DO_START
 153 #undef IMAGE_WALK_DO_END
 154 #undef IMAGE_WALK_DO_ROW_START
 155 #undef IMAGE_WALK_DO_ROW_END
 156 #undef IMAGE_WALK_DO_STEP
 157 #undef STEP