Alpha compare in 2-cycle mode is broken because the threshold is performed using next pixel's output of the first stage of the combiner.
However, assuming the user configured a 1-step combiner (or a 2-step combiner which actually only uses one step of alpha), there is a workaround. In fact you can put the actual alpha formula in the second step, and use COMBINED as first step. In fact, COMBINED in first step is actually ill-defined and fetched the output the previous pixel, which perfectly counter-balances alpha thresholding against the next pixel's first step.
This can be a little tricky to implement in rdpq, but it would solve this little nuisance.
Alpha compare in 2-cycle mode is broken because the threshold is performed using next pixel's output of the first stage of the combiner.
However, assuming the user configured a 1-step combiner (or a 2-step combiner which actually only uses one step of alpha), there is a workaround. In fact you can put the actual alpha formula in the second step, and use COMBINED as first step. In fact, COMBINED in first step is actually ill-defined and fetched the output the previous pixel, which perfectly counter-balances alpha thresholding against the next pixel's first step.
This can be a little tricky to implement in rdpq, but it would solve this little nuisance.