switch to split draw, either pixel-aligned fast or smooth slower

[guzba]

before:

0.537 ms    0.552 ms  ±0.022  x1000  pixie draw normal
0.538 ms    0.550 ms  ±0.016  x1000  pixie draw overwrite
0.715 ms    0.730 ms  ±0.021  x1000  pixie draw mask

after:

0.256 ms    0.266 ms  ±0.008  x1000  pixie draw normal
0.224 ms    0.243 ms  ±0.021  x1000  pixie draw overwrite
0.283 ms    0.329 ms  ±0.043  x1000  pixie draw mask