private void ay_UpdateIRA(AY8910 sender, AyPortState state)
{
//
// Emulation AY-Mouse (V.M.G. schema)
//
int x = 0;
int y = 0;
int b = 0;
if (MouseState != null)
{
x = MouseState.X;
y = MouseState.Y;
b = MouseState.Buttons;
}
int pcDelta;
if ((state.OutState & 0x40) != 0) // selected V counter
pcDelta = _lastAyMouseY - y / 4;
else // selected H counter
pcDelta = x / 4 - _lastAyMouseX;
// make signed 4 bit integer...
pcDelta = pcDelta + 8;
// prevent overflow (this feature not present in original schema)...
if (pcDelta < 0) pcDelta = 0;
if (pcDelta > 15) pcDelta = 15;
// buttons 0 and 1...
state.InState = (byte)((pcDelta & 0x0F) | ((b & 3) ^ 3) << 4 | (state.OutState & 0xC0));
if (state.DirOut && ((state.OutState ^ state.OldOutState) & 0x40) != 0 && (state.OutState & 0x40) == 0)
{
// reset H and V counters
_lastAyMouseX = x / 4;
_lastAyMouseY = y / 4;
}
}
public override void BusInit(IBusManager bmgr)
{
m_ay8910 = bmgr.FindDevice<AY8910>();
}