fix(vm): nans in the Go VM trisaw oscillator when the color was 0

CHANGELOG.md

@@ -27,6 +27,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
   roughly to -12 dBFS true peak. ([#211][i211])
 
 ### Fixed
+- Occasional NaNs in the Trisaw oscillator when the color was 0 in the Go VM.
 - The tracker thought that "sync" unit pops the value from stack, even if the VM
   did not, resulting it claiming errors in patches that worked once compiled.
 

vm/go_synth.go

@@ -500,7 +500,7 @@ func (s *GoSynth) Render(buffer sointu.AudioBuffer, maxtime int) (samples int, r
 							*statevar -= float32(int(*statevar+1) - 1)
 							phase := *statevar
 							phase += params[2]
-							phase -= float32(int(phase))
+							phase -= float32(int(phase+1) - 1)
 							color := params[3]
 							switch {
 							case flags&0x40 == 0x40: // Sine