File content as of revision 0:972874f31c98:

/*

  u8g_com_api_16gr.c
  
  Extension of the com api for devices with 16 graylevels (4 bit per pixel).
  This should fit to the 8h and 16h architectures (pb8v1, pb8v2, pb16v1, pb16v2), 
  mainly intended for SSD OLEDs

  Universal 8bit Graphics Library
  
  Copyright (c) 2011, olikraus@gmail.com
  All rights reserved.

  Redistribution and use in source and binary forms, with or without modification, 
  are permitted provided that the following conditions are met:

  * Redistributions of source code must retain the above copyright notice, this list 
    of conditions and the following disclaimer.
    
  * Redistributions in binary form must reproduce the above copyright notice, this 
    list of conditions and the following disclaimer in the documentation and/or other 
    materials provided with the distribution.

  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 
  CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, 
  INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 
  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 
  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 
  STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 
  ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.  
  
  
*/

#include "u8g.h"

/* interpret b as a monochrome bit pattern, write value 15 for high bit and value 0 for a low bit */
/* topbit (msb) is sent last */
/* example: b = 0x083 will send 0xff, 0x00, 0x00, 0xf0 */
uint8_t u8g_WriteByteBWTo16GrDevice(u8g_t *u8g, u8g_dev_t *dev, uint8_t b)
{
  static uint8_t buf[4];
  static uint8_t map[4] = { 0, 0x00f, 0x0f0, 0x0ff };
  buf [3] = map[b & 3];
  b>>=2;
  buf [2] = map[b & 3];
  b>>=2;
  buf [1] = map[b & 3];
  b>>=2;
  buf [0] = map[b & 3];
  return dev->com_fn(u8g, U8G_COM_MSG_WRITE_SEQ, 4, buf);
}

uint8_t u8g_WriteSequenceBWTo16GrDevice(u8g_t *u8g, u8g_dev_t *dev, uint8_t cnt, uint8_t *ptr)
{
  do
  {
    if ( u8g_WriteByteBWTo16GrDevice(u8g, dev, *ptr++) == 0 )
      return 0;
    cnt--;
  } while( cnt != 0 );
  return 1;
}

/* interpret b as a 4L bit pattern, write values 0x000, 0x004, 0x008, 0x00c */
uint8_t u8g_WriteByte4LTo16GrDevice(u8g_t *u8g, u8g_dev_t *dev, uint8_t b)
{
  //static uint8_t map[16] = { 0x000, 0x004, 0x008, 0x00c, 0x040, 0x044, 0x048, 0x04c, 0x080, 0x084, 0x088, 0x08c, 0x0c0, 0x0c4, 0x0c8, 0x0cc};
  //static uint8_t map[16] = { 0x000, 0x004, 0x00a, 0x00f, 0x040, 0x044, 0x04a, 0x04f, 0x0a0, 0x0a4, 0x0aa, 0x0af, 0x0f0, 0x0f4, 0x0fa, 0x0ff};
  static uint8_t map[16] = { 0x000, 0x040, 0x0a0, 0x0f0, 0x004, 0x044, 0x0a4, 0x0f4, 0x00a, 0x04a, 0x0aa, 0x0fa, 0x00f, 0x04f, 0x0af, 0x0ff};
  uint8_t bb;
  bb = b;
  bb &= 15;
  b>>=4;
  dev->com_fn(u8g, U8G_COM_MSG_WRITE_BYTE, map[bb], NULL);
  return dev->com_fn(u8g, U8G_COM_MSG_WRITE_BYTE, map[b], NULL);
}

uint8_t u8g_WriteSequence4LTo16GrDevice(u8g_t *u8g, u8g_dev_t *dev, uint8_t cnt, uint8_t *ptr)
{
  do
  {
    if ( u8g_WriteByte4LTo16GrDevice(u8g, dev, *ptr++) == 0 )
      return 0;
    cnt--;
  } while( cnt != 0 );
  return 1;
}