Method CanAddMove

src/Movement/DDARing.cpp:157–188

}

bool DDARing::CanAddMove() const noexcept
{
	// We have two constraints here that may prevent us from using the last free element in the ring:
	// 1. DDA::Prepare needs to access the previous DDA in the ring to find the endpoints of the previous move.
	//    So we must not allocate an empty slot if the next one has state 'provisional'.
	// 2. If all DDAs in the ring have state 'committed' then function ManageIOBitsAndFeedforward may loop indefinitely.
	//    So we must not allocate an empty slot if the next one has state 'committed'.
	// The simplest solution is not to allow the last free slot to be allocated.
	if (   addPointer->GetState() == DDA::empty
		&& addPointer->GetNext()->GetState() == DDA::empty
	   )
	 {
			// In order to react faster to speed and extrusion rate changes, only add more moves if the total duration of
			// all un-frozen moves is less than 2 seconds, or the total duration of all but the first un-frozen move is less than 0.5 seconds.
			const DDA *dda = addPointer;
			uint32_t unPreparedTime = 0;
			uint32_t prevMoveTime = 0;
			for(;;)
			{
				dda = dda->GetPrevious();
				if (dda->GetState() != DDA::provisional)
				{
					break;
				}
				unPreparedTime += prevMoveTime;
				prevMoveTime = dda->GetClocksNeeded();
			}

			return (unPreparedTime < StepClockRate/2 || unPreparedTime + prevMoveTime < 2 * StepClockRate);
	 }
	 return false;
}

// Add a new move, returning true if it represents real movement
MovementError DDARing::AddStandardMove(const RawMove &nextMove, bool doMotorMapping) noexcept