diff options
Diffstat (limited to 'klippy/stepcompress.c')
| -rw-r--r-- | klippy/stepcompress.c | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/klippy/stepcompress.c b/klippy/stepcompress.c index 301f2527..eb9abf2c 100644 --- a/klippy/stepcompress.c +++ b/klippy/stepcompress.c @@ -115,7 +115,7 @@ minmax_point(struct stepcompress *sc, uint64_t *pos) // The maximum add delta between two valid quadratic sequences of the // form "add*count*(count-1)/2 + interval*count" is "(6 + 4*sqrt(2)) * // maxerror / (count*count)". The "6 + 4*sqrt(2)" is 11.65685, but -// using 11 and rounding up when dividing works well in practice. +// using 11 works well in practice. #define QUADRATIC_DEV 11 struct step_move { @@ -130,7 +130,7 @@ compress_bisect_add(struct stepcompress *sc) { struct points point = minmax_point(sc, sc->queue_pos); int32_t outer_mininterval = point.minp, outer_maxinterval = point.maxp; - int32_t add = 0, minadd = -0x8001, maxadd = 0x8000; + int32_t add = 0, minadd = -0x8000, maxadd = 0x7fff; int32_t bestinterval = 0, bestcount = 1, bestadd = 1, bestreach = INT32_MIN; for (;;) { @@ -174,17 +174,17 @@ compress_bisect_add(struct stepcompress *sc) int32_t nextaddfactor = nextcount*(nextcount-1)/2; int32_t nextreach = add*nextaddfactor + interval*nextcount; if (nextreach < nextpoint.minp) { - minadd = add; + minadd = add + 1; outer_maxinterval = nextmaxinterval; } else { - maxadd = add; + maxadd = add - 1; outer_mininterval = nextmininterval; } // The maximum valid deviation between two quadratic sequences // can be calculated and used to further limit the add range. if (count > 1) { - int32_t errdelta = DIV_UP(sc->max_error*QUADRATIC_DEV, count*count); + int32_t errdelta = sc->max_error*QUADRATIC_DEV / (count*count); if (minadd < add - errdelta) minadd = add - errdelta; if (maxadd > add + errdelta) @@ -193,16 +193,16 @@ compress_bisect_add(struct stepcompress *sc) // See if next point would further limit the add range int32_t c = outer_maxinterval * nextcount; - if ((minadd+1)*nextaddfactor < nextpoint.minp - c) - minadd = idiv_up(nextpoint.minp - c, nextaddfactor) - 1; + if (minadd*nextaddfactor < nextpoint.minp - c) + minadd = idiv_up(nextpoint.minp - c, nextaddfactor); c = outer_mininterval * nextcount; - if ((maxadd-1)*nextaddfactor > nextpoint.maxp - c) - maxadd = idiv_down(nextpoint.maxp - c, nextaddfactor) + 1; + if (maxadd*nextaddfactor > nextpoint.maxp - c) + maxadd = idiv_down(nextpoint.maxp - c, nextaddfactor); // Bisect valid add range and try again with new 'add' - add = (minadd + maxadd) / 2; - if (add <= minadd || add >= maxadd) + if (minadd > maxadd) break; + add = (minadd + maxadd) / 2; } return (struct step_move){ bestinterval, bestcount, bestadd }; } |