FG_MAX_PSPANS_PER_AXIS
FG_MAX_PSPANS_PER_AXIS, sc->sc_pspans_x, &n_xpspans);
FG_MAX_PSPANS_PER_AXIS, sc->sc_pspans_y, &n_ypspans);
fg_pspan spans[2][FG_MAX_PSPANS_PER_AXIS];
#define FG_MAX_STROKES (2 * FG_MAX_PSPANS_PER_AXIS)
fg_pspan sc_pspans_x[FG_MAX_PSPANS_PER_AXIS];
fg_pspan sc_pspans_y[FG_MAX_PSPANS_PER_AXIS];