matrixorbital / eve-knob Goto Github PK

void Cmd_Keys(uint16_t x, uint16_t y, uint16_t w, uint16_t h, uint16_t font, uint16_t options, const char * str)
{
  
  uint16_t DataPtr, LoopCount, StrPtr;
  uint16_t length = (uint16_t)strlen(str);
  if(!length) 
    return;

  // Create a data the same size as the string only make it in 32 bit chunks instead of 8 bit.
  uint32_t* data = (uint32_t*) calloc((length/4)+1, sizeof(uint32_t));
  // With a length of three this allocates int(3/4 + 1) == 1 uint32.

  // Loop over the incoming  string and combine 4 consecutive elements into a single data element.
  StrPtr = 0;
  //for(DataPtr=0; DataPtr<(length/4); DataPtr++, StrPtr += 4)
  for(DataPtr=0; DataPtr<(length/4); DataPtr++, StrPtr += 4)
    data[DataPtr] = (uint32_t)str[StrPtr+3]<<24 | (uint32_t)str[StrPtr+2]<<16 | (uint32_t)str[StrPtr+1]<<8 | (uint32_t)str[StrPtr];
  
  // insert the remaining (less than 4) characters into the last element in data array.
  for(LoopCount=0; LoopCount<(length%4); LoopCount++, StrPtr++)
    data[DataPtr] |= (uint32_t)str[StrPtr] << (LoopCount * 8);

  //printf("-- CMD_KEYS -- Size(%d), DataPtr(%d), LoopCount(%d), Data0(%x)\n", sizeof(data[0]), DataPtr, LoopCount,  data[0]);
 
  Send_CMD(CMD_KEYS);
  Send_CMD( ((uint32_t)y << 16) | x ); // Put two 16 bit values together into one 32 bit value - do it little endian
  Send_CMD( ((uint32_t)h << 16) | w );
  Send_CMD( ((uint32_t)options << 16) | font );
  
  // Loop over the data array and send each 32 bit chunk to the display.
  for (LoopCount = 0; LoopCount <= length / 4; LoopCount++)
  {
	  Send_CMD(data[LoopCount]);
  }

  free(data);

}