Ah, so the quick explanation is how many bins per unit time does the line hit (how many pixels in a vertical stack). If the line is horizontal and hits one bin,

Ah, so the quick explanation is how many bins per unit time does the line hit (how many pixels in a vertical stack). If the line is horizontal and hits one bin, then it should have a weight of 1. If it's steep and hits 3 or 5 bins, then the weight should be 1/3 or 1/5 for each bin-pixel. That makes sense. Thanks!