I'm pretty sure there's a bug in the way ChucK prints time. Or there may be a bug in the way I think. Bear with me...<br><br>You would expect that two time values that print identically would compare as equal. But I can show you a case where t0 and t1 print as "44100.000000" yet they're not equal. You'd also expect t1 to have a fractional part of 0.0. But in this case:<br>
<br> <<< (t1 % 1::second) >>> prints "1.000000"<br><br>and<br><br> <<< t1 - (t1 % 1::second) >>> prints "44099.000000"<br><br>Mind you, I'm NOT complaining about roundoff error -- I understand that converting between floats and time is subject to roundoff -- but it has certainly cost me a LOT of debugging time discovering that 44100.000000 != 44100.000000. It's a printing bug.<br>
<br>Here's the code. It's longer than it needs to be, so if anyone asks for it, I'll strip it down to a three line example.<br><br>// In ChucK, two times can appear to be equal when printed,<br>// but compare as not equal, as demonstrated here.<br>
<br>72.511111111 => float tempo; // intentionally subject to roundoff<br><br>now => time t0; // base time<br>100.0 => float b0; // beat at t0<br>1::second / tempo => dur i0; // duration of one beat<br>
<br>// convert from system time to beat<br>fun float time_to_beat(time t) { return b0 + (t - t0)/i0; }<br><br>// convert from beat to system time<br>fun time beat_to_time(float b) { return t0 + (b - b0)::i0; }<br><br>// for debugging: extract fractional and whole parts from time<br>
fun dur frac_time(time t) { return t % 1::samp; }<br>fun time whol_time(time t) { return t - (t % 1::samp); }<br><br>fun void test_time(time t0) {<br> beat_to_time(time_to_beat(t0)) => time t1;<br> if (t0 != t1) {<br>
<<< "t0:",t0,"is not equal to t1:",t1>>>;<br> frac_time(t0) => dur f0;<br> frac_time(t1) => dur f1;<br> whol_time(t0) => time w0;<br> whol_time(t1) => time w1;<br>
<<< f0, f1, f0==f1, w0, w1, w0==w1 >>>;<br> }<br>}<br><br>test_time(now);<br>test_time(now+1::second);<br>test_time(now+1::samp);<br><br>