line(0,0,100,0), note: line is blured (spans 2 pixels)
line(0,0,100,0)
line(0.5,0.5,100.5,0.5), note: line starts/ends in the middle of the pixel
line(0.5,0.5,100.5,0.5)
line(0,0,100,0), but translate(0.5,0.5) to shift coordinate system