Function _rcntSet

pcsx2/Counters.cpp:68–124

Updates the state of the nextCounter value (if needed) to serve any pending events for the given counter. Call this method after any modifications to the state of a counter.

// any pending events for the given counter.
// Call this method after any modifications to the state of a counter.
static __fi void _rcntSet(int cntidx)
{
	s32 c;
	pxAssume(cntidx <= 4); // rcntSet isn't valid for h/vsync counters.

	const Counter& counter = counters[cntidx];

	// Stopped or special hsync gate?
	if (!rcntCanCount(cntidx) || (counter.mode.ClockSource == 0x3))
		return;

	if (!counter.mode.TargetInterrupt && !counter.mode.OverflowInterrupt && !counter.mode.ZeroReturn)
		return;
	// check for special cases where the overflow or target has just passed
	// (we probably missed it because we're doing/checking other things)
	if (counter.count > 0x10000 || counter.count > counter.target)
	{
		nextDeltaCounter = 4;
		return;
	}

	// nextCounter is relative to the cpuRegs.cycle when rcntUpdate() was last called.
	// However, the current _rcntSet could be called at any cycle count, so we need to take
	// that into account.  Adding the difference from that cycle count to the current one
	// will do the trick!

	c = ((0x10000 - counter.count) * counter.rate) - (cpuRegs.cycle - counter.startCycle);
	c += cpuRegs.cycle - nextStartCounter; // adjust for time passed since last rcntUpdate();

	if (c < nextDeltaCounter)
	{
		nextDeltaCounter = c;

		cpuSetNextEvent(nextStartCounter, nextDeltaCounter); // Need to update on counter resets/target changes
	}

	// Ignore target diff if target is currently disabled.
	// (the overflow is all we care about since it goes first, and then the
	// target will be turned on afterward, and handled in the next event test).

	if (counter.target & EECNT_FUTURE_TARGET)
	{
		return;
	}
	else
	{

		c = ((counter.target - counter.count) * counter.rate) - (cpuRegs.cycle - counter.startCycle);
		c += cpuRegs.cycle - nextStartCounter; // adjust for time passed since last rcntUpdate();

		if (c < nextDeltaCounter)
		{
			nextDeltaCounter = c;
			cpuSetNextEvent(nextStartCounter, nextDeltaCounter); // Need to update on counter resets/target changes
		}
	}
}