diff options
Diffstat (limited to 'klippy/stepcompress.c')
| -rw-r--r-- | klippy/stepcompress.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/klippy/stepcompress.c b/klippy/stepcompress.c index 55cb09e8..be431e20 100644 --- a/klippy/stepcompress.c +++ b/klippy/stepcompress.c @@ -249,6 +249,17 @@ check_line(struct stepcompress *sc, struct step_move move) * Step compress interface ****************************************************************/ +// Wrapper around sqrt() to handle small negative numbers +static inline double +safe_sqrt(double v) +{ + if (v < 0. && v > -0.001) + // Due to floating point truncation, it's possible to get a + // small negative number - treat it as zero. + return 0.; + return sqrt(v); +} + // Allocate a new 'stepcompress' object struct stepcompress * stepcompress_alloc(uint32_t max_error, uint32_t queue_step_msgid, uint32_t oid) @@ -325,12 +336,12 @@ stepcompress_push_sqrt(struct stepcompress *sc, double steps, double step_offset double pos = step_offset + sqrt_offset/factor; if (factor >= 0.0) while (qn < end) { - *qn++ = clock_offset + sqrt(pos*factor); + *qn++ = clock_offset + safe_sqrt(pos*factor); pos += 1.0; } else while (qn < end) { - *qn++ = clock_offset - sqrt(pos*factor); + *qn++ = clock_offset - safe_sqrt(pos*factor); pos += 1.0; } sc->queue_next = qn; |