web2c/mplibdir/mp.w

9438 $dz_2$. This |arc_test| routine also takes an arc length goal |a_goal| and
9439 returns the time when the arc length reaches |a_goal| if there is such a time.
9440 Thus the return value is either an arc length less than |a_goal| or, if the
9441 arc length would be at least |a_goal|, it returns a time value decreased by
9444 possible for |a_goal| and the result of |arc_test| both to be |EL_GORDO|.
9445 Otherwise, the result is always less than |a_goal|.
9464                            mp_number v02, mp_number v2, mp_number a_goal, mp_number tol_orig) {
9500     if (number_less(arc, a_goal)){
9503       @<Estimate when the arc length reaches |a_goal| and set |arc_test| to
9532   mp_number a_new, a_aux;    /* the sum of these gives the |a_goal| */
9538   @<Set |a_new| and |a_aux| so their sum is |2*a_goal| and |a_new| is as
9591 @ @<Set |a_new| and |a_aux| so their sum is |2*a_goal| and |a_new| is...@>=
9593 number_substract(a_aux, a_goal);
9594 if (number_greater(a_goal, a_aux)) {
9595   set_number_from_substraction(a_aux, a_goal, a_aux);
9598   set_number_from_addition(a_new, a_goal, a_goal);
9633 |a_goal=EL_GORDO| is guaranteed to yield the arc length.
9684     if (number_infinite(a_goal)) {
9729 reaches the intermediate value |a_goal|.  At this point
9756 |a_goal| by solving a cubic equation of the form
9758 where $\tau$ is $2t$ or $2t+1$, $x$ is |a_goal| or |a_goal-arc1|, and $a$, $b$,
9764 @<Estimate when the arc length reaches |a_goal| and set |arc_test| to...@>=
9780   if (number_lessequal(a_goal, arc1)) {
9785     mp_solve_rising_cubic (mp, &tmp5, tmp2, tmp3, tmp, a_goal);
9797     set_number_from_substraction(tmp4, a_goal, arc1);
9928                               mp_number dy1, mp_number dx2, mp_number dy2, mp_number a_goal) {
9941     if (number_infinite(a_goal)) {
9962     mp_arc_test (mp, ret, dx0, dy0, dx1, dy1, dx2, dy2, v0, v02, v2, a_goal, arc_tol_k);