core/GP_WritePixel.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 #ifndef GP_WRITEPIXEL_H
  27 #define GP_WRITEPIXEL_H
  28
  29 #include <endian.h>
  30 #include <stdint.h>
  31 #include <unistd.h>
  32
  33 /*
  34  * Macros for writing a single pixel value to the specified address,
  35  * provided that the target buffer has 8, 16, 24, or 32 bytes per pixel.
  36  */
  37
  38 #define GP_WritePixel8bpp(ptr, pixel) { \
  39         *((uint8_t *) ptr) = (uint8_t) pixel; \
  40 }
  41
  42 #define GP_WritePixel16bpp(ptr, pixel) { \
  43         *((uint16_t *) ptr) = (uint16_t) pixel; \
  44 }
  45
  46 #if __BYTE_ORDER == __BIG_ENDIAN
  47
  48 #define GP_WritePixel24bpp(ptr, pixel) { \
  49         ((uint8_t *) ptr)[0] = (pixel >> 16) & 0xff; \
  50         ((uint8_t *) ptr)[1] = (pixel >> 8) & 0xff; \
  51         ((uint8_t *) ptr)[2] = pixel & 0xff; \
  52 }
  53
  54 #elif __BYTE_ORDER == __LITTLE_ENDIAN
  55
  56 #define GP_WritePixel24bpp(ptr, pixel) { \
  57         ((uint8_t *) ptr)[0] = pixel & 0xff; \
  58         ((uint8_t *) ptr)[1] = (pixel >> 8) & 0xff; \
  59         ((uint8_t *) ptr)[2] = (pixel >> 16) & 0xff; \
  60 }
  61
  62 #else
  63 #error "Could not detect machine endianity"
  64 #endif
  65
  66 #define GP_WritePixel32bpp(ptr, pixel) { \
  67         *((uint32_t *) ptr) = (uint32_t) pixel; \
  68 }
  69
  70 /*
  71  * Calls for writing a linear block of pixels.
  72  */
  73
  74 /*
  75  * These calls are not byte aligned, thuss needs start offset.
  76  */
  77 void GP_WritePixels1bpp(uint8_t *start, uint8_t off, size_t cnt, uint8_t val);
  78 void GP_WritePixels2bpp(uint8_t *start, uint8_t off, size_t cnt, uint8_t val);
  79 void GP_WritePixels4bpp(uint8_t *start, uint8_t off, size_t cnt, uint8_t val);
  80
  81 void GP_WritePixels8bpp(void *start, size_t count, uint8_t value);
  82 void GP_WritePixels16bpp(void *start, size_t count, uint16_t value);
  83 void GP_WritePixels24bpp(void *start, size_t count, uint32_t value);
  84 void GP_WritePixels32bpp(void *start, size_t count, uint32_t value);
  85
  86 #endif /* GP_WRITEPIXEL_H */