if(!gbSgbMask) { if(gbBorderOn) gbSgbRenderBorder(); }
void gbSgbMaskEnable(){  int gbSgbMaskFlag = gbSgbPacket[1] & 3;  gbSgbMask = gbSgbMaskFlag;    switch(gbSgbMaskFlag) {  case 1:    break;  case 2:    gbSgbFillScreen(0x0000);    //    memset(&gbPalette[0], 0, 128*sizeof(u16));    break;  case 3:    gbSgbFillScreen(gbPalette[0]);    break;  }}