Fraction of the room to the border a shift may use before it is shaped. Below it the
field is untouched; above it, the tanh roll-off takes over. Half: a shift is left
alone until it would carry the sample halfway from its pixel to the screen edge, so
only refraction that already reaches toward the border is ever changed.
Fraction of the room to the border a shift may use before it is shaped. Below it the field is untouched; above it, the tanh roll-off takes over. Half: a shift is left alone until it would carry the sample halfway from its pixel to the screen edge, so only refraction that already reaches toward the border is ever changed.