video/fb/fbutil.c

   1 /*
   2  *  GRUB  --  GRand Unified Bootloader
   3  *  Copyright (C) 2006,2007,2009  Free Software Foundation, Inc.
   4  *
   5  *  GRUB is free software: you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation, either version 3 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  GRUB is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <grub/fbutil.h>
  20 #include <grub/types.h>
  21 #include <grub/video.h>
  22
  23 grub_uint8_t *
  24 get_data_ptr (struct grub_video_fbblit_info *source,
  25               unsigned int x, unsigned int y)
  26 {
  27   grub_uint8_t *ptr = 0;
  28
  29   switch (source->mode_info->bpp)
  30     {
  31     case 32:
  32       ptr = (grub_uint8_t *)source->data
  33             + y * source->mode_info->pitch
  34             + x * 4;
  35       break;
  36
  37     case 24:
  38       ptr = (grub_uint8_t *)source->data
  39             + y * source->mode_info->pitch
  40             + x * 3;
  41       break;
  42
  43     case 16:
  44     case 15:
  45       ptr = (grub_uint8_t *)source->data
  46             + y * source->mode_info->pitch
  47             + x * 2;
  48       break;
  49
  50     case 8:
  51       ptr = (grub_uint8_t *)source->data
  52             + y * source->mode_info->pitch
  53             + x;
  54       break;
  55
  56     case 1:
  57       /* For 1-bit bitmaps, addressing needs to be done at the bit level
  58          and it doesn't make sense, in general, to ask for a pointer
  59          to a particular pixel's data.  */
  60       break;
  61     }
  62
  63   return ptr;
  64 }
  65
  66 grub_video_color_t
  67 get_pixel (struct grub_video_fbblit_info *source,
  68            unsigned int x, unsigned int y)
  69 {
  70   grub_video_color_t color = 0;
  71
  72   switch (source->mode_info->bpp)
  73     {
  74     case 32:
  75       color = *(grub_uint32_t *)get_data_ptr (source, x, y);
  76       break;
  77
  78     case 24:
  79       {
  80         grub_uint8_t *ptr;
  81         ptr = get_data_ptr (source, x, y);
  82         color = ptr[0] | (ptr[1] << 8) | (ptr[2] << 16);
  83       }
  84       break;
  85
  86     case 16:
  87     case 15:
  88       color = *(grub_uint16_t *)get_data_ptr (source, x, y);
  89       break;
  90
  91     case 8:
  92       color = *(grub_uint8_t *)get_data_ptr (source, x, y);
  93       break;
  94
  95     case 1:
  96       if (source->mode_info->blit_format == GRUB_VIDEO_BLIT_FORMAT_1BIT_PACKED)
  97         {
  98           int bit_index = y * source->mode_info->width + x;
  99           grub_uint8_t *ptr = (grub_uint8_t *)source->data
 100                               + bit_index / 8;
 101           int bit_pos = 7 - bit_index % 8;
 102           color = (*ptr >> bit_pos) & 0x01;
 103         }
 104       break;
 105
 106     default:
 107       break;
 108     }
 109
 110   return color;
 111 }
 112
 113 void
 114 set_pixel (struct grub_video_fbblit_info *source,
 115            unsigned int x, unsigned int y, grub_video_color_t color)
 116 {
 117   switch (source->mode_info->bpp)
 118     {
 119     case 32:
 120       {
 121         grub_uint32_t *ptr;
 122
 123         ptr = (grub_uint32_t *)get_data_ptr (source, x, y);
 124
 125         *ptr = color;
 126       }
 127       break;
 128
 129     case 24:
 130       {
 131         grub_uint8_t *ptr;
 132         grub_uint8_t *colorptr = (grub_uint8_t *)&color;
 133
 134         ptr = get_data_ptr (source, x, y);
 135
 136         ptr[0] = colorptr[0];
 137         ptr[1] = colorptr[1];
 138         ptr[2] = colorptr[2];
 139       }
 140       break;
 141
 142     case 16:
 143     case 15:
 144       {
 145         grub_uint16_t *ptr;
 146
 147         ptr = (grub_uint16_t *)get_data_ptr (source, x, y);
 148
 149         *ptr = (grub_uint16_t) (color & 0xFFFF);
 150       }
 151       break;
 152
 153     case 8:
 154       {
 155         grub_uint8_t *ptr;
 156
 157         ptr = (grub_uint8_t *)get_data_ptr (source, x, y);
 158
 159         *ptr = (grub_uint8_t) (color & 0xFF);
 160       }
 161       break;
 162
 163     case 1:
 164       if (source->mode_info->blit_format == GRUB_VIDEO_BLIT_FORMAT_1BIT_PACKED)
 165         {
 166           int bit_index = y * source->mode_info->width + x;
 167           grub_uint8_t *ptr = (grub_uint8_t *)source->data
 168                               + bit_index / 8;
 169           int bit_pos = 7 - bit_index % 8;
 170           *ptr = (*ptr & ~(1 << bit_pos)) | ((color & 0x01) << bit_pos);
 171         }
 172       break;
 173
 174     default:
 175       break;
 176     }
 177 }