mirror of
https://github.com/RaySollium99/picodrive.git
synced 2025-09-05 15:27:46 -04:00
38 lines
720 B
C
38 lines
720 B
C
|
|
// 64 x32 x16 x8 x4 x4
|
|
static unsigned int cell_map(int celln)
|
|
{
|
|
int col, row;
|
|
|
|
switch ((celln >> 12) & 7) { // 0-0x8000
|
|
case 0: // x32 cells
|
|
case 1:
|
|
case 2:
|
|
case 3:
|
|
col = celln >> 8;
|
|
row = celln & 0xff;
|
|
break;
|
|
case 4: // x16
|
|
case 5:
|
|
col = celln >> 7;
|
|
row = celln & 0x7f;
|
|
row |= 0x10000 >> 8;
|
|
break;
|
|
case 6: // x8
|
|
col = celln >> 6;
|
|
row = celln & 0x3f;
|
|
row |= 0x18000 >> 8;
|
|
break;
|
|
case 7: // x4
|
|
col = celln >> 5;
|
|
row = celln & 0x1f;
|
|
row |= (celln & 0x7800) >> 6;
|
|
break;
|
|
default: // just to make compiler happy
|
|
col = row = 0;
|
|
break;
|
|
}
|
|
|
|
return (col & 0x3f) + row*64;
|
|
}
|
|
|