I’ve implemented platformer collision dozens of times now and the only way I’ve found it to be genuinely smooth is to do it one pixel at a time, just like the author suggests.
But something always bugs me about that - we know the closest edge of the closest obstacle, we know the vector of the player’s motion, by all accounts we should be able to calculate the point of contact in one go without doing any substeps.
And yet, doing it in one pass always seems to result in a myriad of edge cases (literal!) that break the whole thing, unless you do heavy preprocessing, converting your tiles to a graph of lined surfaces, etc etc.
But something always bugs me about that - we know the closest edge of the closest obstacle, we know the vector of the player’s motion, by all accounts we should be able to calculate the point of contact in one go without doing any substeps.
And yet, doing it in one pass always seems to result in a myriad of edge cases (literal!) that break the whole thing, unless you do heavy preprocessing, converting your tiles to a graph of lined surfaces, etc etc.