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SoundWaveform

SoundWaveform (Statement)​

Format​

soundwaveform number
soundwaveform array[]
soundwaveform array[], logic

Description​

Chooses the shape of the wave used to generate tones by Sound, SoundPlay, and SoundLoad. It affects tones generated after it is called; it has no effect on media files or raw sounds.

Built-in waveforms — pass a number:

NumberWaveform
0Sine (the default)
1Square
2Triangle
3Sawtooth
4Pulse

Custom waveform — pass a one-dimensional array describing one full cycle of the wave. There are two interpretations, selected by the optional logic flag (default false / off):

  • logic off — the array is a list of raw amplitude values (each -1.0 to 1.0) sampled evenly across one cycle. Passing exactly SoundSampleRate values defines the cycle sample-for-sample.
  • logic on — the array is a list of amplitude, length breakpoints (a1, len1, a2, len2, ...); the wave is drawn by interpolating straight lines between the amplitudes, with each segment given its relative length.

Example​

soundwaveform 1        # square wave
sound 440, 500

rem custom triangle from breakpoints (logic form)
soundwaveform {-1, 1, 1, 1, -1, 0}, true
sound 440, 500

soundwaveform 0        # back to the default sine

See Also​

Sound, SoundEnvelope, SoundHarmonics, SoundLoadRaw, SoundSampleRate

Availability​

BASIC-256 2.0 and later. Documented from the BASIC-256 v2.1 continuation project.