void TIA::computePlayerMaskTable()

in atari_py/ale_interface/src/emucore/TIA.cxx [917:1019]
90 lines of code
58 McCabe index (conditional complexity)

void TIA::computePlayerMaskTable()
{
  // First, calculate masks for alignment 0
  Int32 x, enable, mode;

  // Set the player mask table to all zeros
  for(enable = 0; enable < 2; ++enable)
    for(mode = 0; mode < 8; ++mode)
      for(x = 0; x < 160; ++x)
        ourPlayerMaskTable[0][enable][mode][x] = 0x00;

  // Now, compute the player mask table
  for(enable = 0; enable < 2; ++enable)
  {
    for(mode = 0; mode < 8; ++mode)
    {
      for(x = 0; x < 160 + 72; ++x)
      {
        if(mode == 0x00)
        {
          if((enable == 0) && (x >= 0) && (x < 8))
            ourPlayerMaskTable[0][enable][mode][x % 160] = 0x80 >> x;
        }
        else if(mode == 0x01)
        {
          if((enable == 0) && (x >= 0) && (x < 8))
            ourPlayerMaskTable[0][enable][mode][x % 160] = 0x80 >> x;
          else if(((x - 16) >= 0) && ((x - 16) < 8))
            ourPlayerMaskTable[0][enable][mode][x % 160] = 0x80 >> (x - 16);
        }
        else if(mode == 0x02)
        {
          if((enable == 0) && (x >= 0) && (x < 8))
            ourPlayerMaskTable[0][enable][mode][x % 160] = 0x80 >> x;
          else if(((x - 32) >= 0) && ((x - 32) < 8))
            ourPlayerMaskTable[0][enable][mode][x % 160] = 0x80 >> (x - 32);
        }
        else if(mode == 0x03)
        {
          if((enable == 0) && (x >= 0) && (x < 8))
            ourPlayerMaskTable[0][enable][mode][x % 160] = 0x80 >> x;
          else if(((x - 16) >= 0) && ((x - 16) < 8))
            ourPlayerMaskTable[0][enable][mode][x % 160] = 0x80 >> (x - 16);
          else if(((x - 32) >= 0) && ((x - 32) < 8))
            ourPlayerMaskTable[0][enable][mode][x % 160] = 0x80 >> (x - 32);
        }
        else if(mode == 0x04)
        {
          if((enable == 0) && (x >= 0) && (x < 8))
            ourPlayerMaskTable[0][enable][mode][x % 160] = 0x80 >> x;
          else if(((x - 64) >= 0) && ((x - 64) < 8))
            ourPlayerMaskTable[0][enable][mode][x % 160] = 0x80 >> (x - 64);
        }
        else if(mode == 0x05)
        {
          // For some reason in double size mode the player's output
          // is delayed by one pixel thus we use > instead of >=
          if((enable == 0) && (x > 0) && (x <= 16))
            ourPlayerMaskTable[0][enable][mode][x % 160] = 0x80 >> ((x - 1)/2);
        }
        else if(mode == 0x06)
        {
          if((enable == 0) && (x >= 0) && (x < 8))
            ourPlayerMaskTable[0][enable][mode][x % 160] = 0x80 >> x;
          else if(((x - 32) >= 0) && ((x - 32) < 8))
            ourPlayerMaskTable[0][enable][mode][x % 160] = 0x80 >> (x - 32);
          else if(((x - 64) >= 0) && ((x - 64) < 8))
            ourPlayerMaskTable[0][enable][mode][x % 160] = 0x80 >> (x - 64);
        }
        else if(mode == 0x07)
        {
          // For some reason in quad size mode the player's output
          // is delayed by one pixel thus we use > instead of >=
          if((enable == 0) && (x > 0) && (x <= 32))
            ourPlayerMaskTable[0][enable][mode][x % 160] = 0x80 >> ((x - 1)/4);
        }
      }
  
      // Copy data into wrap-around area
      for(x = 0; x < 160; ++x)
      {
        ourPlayerMaskTable[0][enable][mode][x + 160] = 
            ourPlayerMaskTable[0][enable][mode][x];
      }
    }
  }

  // Now, copy data for alignments of 1, 2 and 3
  for(uInt32 align = 1; align < 4; ++align)
  {
    for(enable = 0; enable < 2; ++enable)
    {
      for(mode = 0; mode < 8; ++mode)
      {
        for(x = 0; x < 320; ++x)
        {
          ourPlayerMaskTable[align][enable][mode][x] =
              ourPlayerMaskTable[0][enable][mode][(x + 320 - align) % 320];
        }
      }
    }
  }
}