void TIATables::buildMxMaskTable()

in cores/atari2600/stella/src/emucore/TIATables.cxx [192:336]

• 125 lines of code
• 87 McCabe index (conditional complexity)

void TIATables::buildMxMaskTable()
{
  Int32 x, size, number;

  // Clear the missle table to start with
  for(number = 0; number < 8; ++number)
    for(size = 0; size < 5; ++size)
      for(x = 0; x < 160; ++x)
        MxMask[number][size][x] = false;

  for(number = 0; number < 8; ++number)
  {
    for(size = 0; size < 5; ++size)
    {
      for(x = 0; x < 160 + 72; ++x)
      {
        // For the following, size index = 4 is almost exactly the same as
        // index = 2; that is, 1 << 2, or 4 colour clocks wide
        // To simulate the weirdness in the Cosmic Ark starfield effect,
        // each group of 4 pixels has its 3rd pixel blanked
        switch(number)
        {
          // Only one copy of the missle
          case 0x00:
          case 0x05:
          case 0x07:
            if(size != 4)
            {
              if((x >= 0) && (x < (1 << size)))
                MxMask[number][size][x % 160] = true;
            }
            else
            {
              if((x >= 0) && (x < (1 << 2)))
                MxMask[number][4][x % 160] = ((x - 2) % 4 == 0 ? false : true);
            }
          break;

          // Two copies - close
          case 0x01:
            if(size != 4)
            {
              if((x >= 0) && (x < (1 << size)))
                MxMask[number][size][x % 160] = true;
              else if(((x - 16) >= 0) && ((x - 16) < (1 << size)))
                MxMask[number][size][x % 160] = true;
            }
            else
            {
              if((x >= 0) && (x < (1 << 2)))
                MxMask[number][4][x % 160] = ((x - 2) % 4 == 0 ? false : true);
              else if(((x - 16) >= 0) && ((x - 16) < (1 << 2)))
                MxMask[number][4][x % 160] = ((x - 2) % 4 == 0 ? false : true);
            }
            break;

          // Two copies - medium
          case 0x02:
            if(size != 4)
            {
              if((x >= 0) && (x < (1 << size)))
                MxMask[number][size][x % 160] = true;
              else if(((x - 32) >= 0) && ((x - 32) < (1 << size)))
                MxMask[number][size][x % 160] = true;
            }
            else
            {
              if((x >= 0) && (x < (1 << 2)))
                MxMask[number][4][x % 160] = ((x - 2) % 4 == 0 ? false : true);
              else if(((x - 32) >= 0) && ((x - 32) < (1 << 2)))
                MxMask[number][4][x % 160] = ((x - 2) % 4 == 0 ? false : true);
            }
            break;

          // Three copies - close
          case 0x03:
            if(size != 4)
            {
              if((x >= 0) && (x < (1 << size)))
                MxMask[number][size][x % 160] = true;
              else if(((x - 16) >= 0) && ((x - 16) < (1 << size)))
                MxMask[number][size][x % 160] = true;
              else if(((x - 32) >= 0) && ((x - 32) < (1 << size)))
                MxMask[number][size][x % 160] = true;
            }
            else
            {
              if((x >= 0) && (x < (1 << 2)))
                MxMask[number][4][x % 160] = ((x - 2) % 4 == 0 ? false : true);
              else if(((x - 16) >= 0) && ((x - 16) < (1 << 2)))
                MxMask[number][4][x % 160] = ((x - 2) % 4 == 0 ? false : true);
              else if(((x - 32) >= 0) && ((x - 32) < (1 << 2)))
                MxMask[number][4][x % 160] = ((x - 2) % 4 == 0 ? false : true);
            }
            break;

          // Two copies - wide
          case 0x04:
            if(size != 4)
            {
              if((x >= 0) && (x < (1 << size)))
                MxMask[number][size][x % 160] = true;
              else if(((x - 64) >= 0) && ((x - 64) < (1 << size)))
                MxMask[number][size][x % 160] = true;
            }
            else
            {
              if((x >= 0) && (x < (1 << 2)))
                MxMask[number][4][x % 160] = ((x - 2) % 4 == 0 ? false : true);
              else if(((x - 64) >= 0) && ((x - 64) < (1 << 2)))
                MxMask[number][4][x % 160] = ((x - 2) % 4 == 0 ? false : true);
            }
            break;

          // Three copies - medium
          case 0x06:
            if(size != 4)
            {
              if((x >= 0) && (x < (1 << size)))
                MxMask[number][size][x % 160] = true;
              else if(((x - 32) >= 0) && ((x - 32) < (1 << size)))
                MxMask[number][size][x % 160] = true;
              else if(((x - 64) >= 0) && ((x - 64) < (1 << size)))
                MxMask[number][size][x % 160] = true;
            }
            else
            {
              if((x >= 0) && (x < (1 << 2)))
                MxMask[number][4][x % 160] = ((x - 2) % 4 == 0 ? false : true);
              else if(((x - 32) >= 0) && ((x - 32) < (1 << 2)))
                MxMask[number][4][x % 160] = ((x - 2) % 4 == 0 ? false : true);
              else if(((x - 64) >= 0) && ((x - 64) < (1 << 2)))
                MxMask[number][4][x % 160] = ((x - 2) % 4 == 0 ? false : true);
            }
            break;
        }
      }

      // Copy data into wrap-around area
      for(x = 0; x < 160; ++x)
        MxMask[number][size][x + 160] = 
          MxMask[number][size][x];
    }
  }
}