drag the points
update log: v1 - bad texture, super slow v2 - ~500x quicker as stamp line with thickness used, fills most of tri v2.1 - fills all of tri, removed sqrt2 calculations v2.2 - big speed increase, now fills at avg 300tps as changed sin and cos(90 - a) to there derivatives; then precalculated values v2.2.1 - 2% faster by normalising instead of trig
