Module sfxr
A port of the sfxr sound effect synthesizer to pure Lua, designed to be used
together with the awesome LÖVE game framework.
| self.envelope |
The ASD envelope that controls the sound
amplitude (volume) over time |
| self.envelope.attack |
Attack time:
Time the sound takes to reach its peak amplitude
(default 0.0, min 0.0, max 1.0) |
| self.envelope.sustain |
Sustain time:
Time the sound stays on its peak amplitude
(default 0.0, min 0.0, max 1.0) |
| self.envelope.punch |
Sustain punch:
Amount by which the sound peak amplitude is increased at the start of the
sustain time
(default 0.0, min 0.0, max 1.0) |
| self.envelope.decay |
Decay time:
Time the sound takes to decay after its sustain time
(default 0.0, min 0.0, max 1.0) |
| self.frequency |
The base and minimum frequencies of the tone generator and their
slides |
| self.frequency.start |
Start frequency:
Base tone of the sound, before sliding
(default 0.0, min 0.0, max 1.0) |
| self.frequency.min |
Min frequency:
Tone below which the sound will get cut off
(default 0.0, min 0.0, max 1.0) |
| self.frequency.slide |
Slide:
Amount by which the frequency is increased or decreased over time
(default 0.0, min -1.0, max 1.0) |
| self.frequency.dslide |
Delta slide:
Amount by which the slide is increased or decreased over time
(default 0.0, min -1.0, max 1.0) |
| self.change |
Changes the frequency mid-sound to create a characteristic
"coin"-effect |
| self.change.amount |
Change amount:
Amount by which the frequency is changed mid-sound
(default 0.0, min -1.0, max 1.0) |
| self.change.speed |
Change speed:
Time before the frequency change happens
(default 0.0, min 0.0, max 1.0) |
| self.duty |
The duty of the square
waveform |
| self.duty.ratio |
Square duty:
Width of the square wave pulse cycle (doesn't affect other waveforms)
(default 0.0, min 0.0, max 1.0) |
| self.duty.sweep |
Duty sweep:
Amount by which the square duty is increased or decreased over time
(default 0.0, min -1.0, max 1.0) |
| self.phaser |
A simple phaser
effect |
| self.phaser.offset |
Phaser offset:
Amount by which the phaser signal is offset from the sound
(default 0.0, min -1.0, max 1.0) |
| self.phaser.sweep |
Phaser sweep:
Amount by which the phaser offset is increased or decreased over time
(default 0.0, min -1.0, max 1.0) |
| self.lowpass |
A lowpass filter
effect |
| self.lowpass.cutoff |
Lowpass filter cutoff:
Lower bound for frequencies allowed to pass through this filter
(default 0.0, min 0.0, max 1.0) |
| self.lowpass.sweep |
Lowpass filter cutoff sweep:
Amount by which the LP filter cutoff is increased or decreased
over time
(default 0.0, min -1.0, max 1.0) |
| self.lowpass.resonance |
Lowpass filter resonance:
Amount by which certain resonant frequencies near the cutoff are
increased
(default 0.0, min 0.0, max 1.0) |
| self.highpass |
A highpass filter
effect |
| self.highpass.cutoff |
Highpass filter cutoff:
Upper bound for frequencies allowed to pass through this filter
(default 0.0, min 0.0, max 1.0) |
| self.highpass.sweep |
Highpass filter cutoff sweep:
Amount by which the HP filter cutoff is increased or decreased
over time
(default 0.0, min -1.0, max 1.0) |
-
newSound (...)
-
Construct and return a new Sound instance.
Parameters:
Returns:
Sound
a Sound instance
-
VERSION
-
The module version (SemVer format)
-
WAVEFORM
-
Waveform constants
Fields:
-
SAMPLERATE
-
Sampling rate constants
(use the number values directly, these are just for lookup)
Fields:
- 22050
22.05 kHz (
= 22050)
- 44100
44.1 kHz (
= 44100)
-
BITDEPTH
-
Bit depth constants
(use the number values directly, these are just for lookup)
Fields:
- 0
floating point bit depth, -1 to 1 (
= 0)
- 8
unsigned 8 bit, 0x00 to 0xFF (
= 8)
- 16
unsigned 16 bit, 0x0000 to 0xFFFF (
= 16)
-
ENDIANNESS
-
Endianness constants
Fields:
- LITTLE
little endian (
= 0)
- BIG
big endian (
= 1)
The main Sound class.
-
sfxr.Sound:__init ()
-
Initialize the Sound instance.
Called by the constructor.
-
sfxr.Sound:resetParameters ()
-
Set all parameters to their default values. Does not affect
supersampling and volume.
Called by the initializer.
-
sfxr.Sound:sanitizeParameters ()
-
Clamp all parameters within their sane ranges.
-
sfxr.Sound:generate ([rate=44100[, depth=0]])
-
Generate the sound and yield the sample data.
Parameters:
- rate
SAMPLERATE
the sampling rate
(default 44100)
- depth
BITDEPTH
the bit depth
(default 0)
Returns:
function()
a generator that yields the next sample when called
Raises:
"invalid sampling rate: x", "invalid bit depth: x"
Usage:
for s in sound:generate(44100, 0) do
end
-
sfxr.Sound:getEnvelopeLimit ([rate=44100])
-
Get the maximum sample limit allowed by the current envelope.
Does not take any other limits into account, so the returned count might be
higher than samples actually generated. Still useful though.
Parameters:
Raises:
"invalid sampling rate: x", "invalid bit depth: x"
-
sfxr.Sound:generateTable ([rate=44100[, depth=0[, tab]]])
-
Generate the sound into a table.
Parameters:
- rate
SAMPLERATE
the sampling rate
(default 44100)
- depth
BITDEPTH
the bit depth
(default 0)
- tab
{}
the table to synthesize into
(optional)
Returns:
-
{number,...}
the table filled with sample data
-
int
the number of written samples (== #tab)
Raises:
"invalid sampling rate: x", "invalid bit depth: x"
-
sfxr.Sound:generateString ([rate=44100[, depth=16[, endianness=0]]])
-
Generate the sound to a binary string.
Parameters:
- rate
SAMPLERATE
the sampling rate
(default 44100)
- depth
BITDEPTH
the bit depth (may not be 0)
(default 16)
- endianness
ENDIANNESS
the endianness (ignored when depth == 8)
(default 0)
Returns:
-
string
a binary string of sample data
-
int
the number of written samples
Raises:
"invalid sampling rate: x", "invalid bit depth: x", "invalid endianness: x"
-
sfxr.Sound:generateSoundData ([rate=44100[, depth=0[, sounddata]]])
-
Synthesize the sound to a LÖVE SoundData instance.
Parameters:
- rate
SAMPLERATE
the sampling rate
(default 44100)
- depth
BITDEPTH
the bit depth
(default 0)
- sounddata
love.sound.SoundData
a SoundData instance (will be
created if not passed)
(optional)
Returns:
-
love.sound.SoundData
a SoundData instance
-
int
the number of written samples
Raises:
"invalid sampling rate: x", "invalid bit depth: x"
-
self.volume
-
The sound volume and gain all samples are multiplied with
-
self.supersampling
-
Number of supersampling passes to perform (default 8)
-
self.repeatspeed
-
Repeat speed:
Times to repeat the frequency slide over the course of the envelope
(default 0.0, min 0.0, max 1.0)
-
self.waveform
-
The base waveform (default SQUARE)
-
self.envelope
-
The ASD envelope that controls the sound
amplitude (volume) over time
-
self.envelope.attack
-
Attack time:
Time the sound takes to reach its peak amplitude
(default 0.0, min 0.0, max 1.0)
-
self.envelope.sustain
-
Sustain time:
Time the sound stays on its peak amplitude
(default 0.0, min 0.0, max 1.0)
-
self.envelope.punch
-
Sustain punch:
Amount by which the sound peak amplitude is increased at the start of the
sustain time
(default 0.0, min 0.0, max 1.0)
-
self.envelope.decay
-
Decay time:
Time the sound takes to decay after its sustain time
(default 0.0, min 0.0, max 1.0)
-
self.frequency
-
The base and minimum frequencies of the tone generator and their
slides
-
self.frequency.start
-
Start frequency:
Base tone of the sound, before sliding
(default 0.0, min 0.0, max 1.0)
-
self.frequency.min
-
Min frequency:
Tone below which the sound will get cut off
(default 0.0, min 0.0, max 1.0)
-
self.frequency.slide
-
Slide:
Amount by which the frequency is increased or decreased over time
(default 0.0, min -1.0, max 1.0)
-
self.frequency.dslide
-
Delta slide:
Amount by which the slide is increased or decreased over time
(default 0.0, min -1.0, max 1.0)
-
self.vibrato
-
A vibrato-like amplitude
modulation effect
-
self.vibrato.depth
-
Vibrato depth:
Amount of amplitude modulation
(default 0.0, min 0.0, max 1.0)
-
self.vibrato.speed
-
Vibrato speed:
Oscillation speed of the vibrato
(default 0.0, min 0.0, max 1.0)
-
self.vibrato.delay
-
Vibrato delay:
Unused and unimplemented
(default 0.0, min 0.0, max 1.0)
-
self.change
-
Changes the frequency mid-sound to create a characteristic
"coin"-effect
-
self.change.amount
-
Change amount:
Amount by which the frequency is changed mid-sound
(default 0.0, min -1.0, max 1.0)
-
self.change.speed
-
Change speed:
Time before the frequency change happens
(default 0.0, min 0.0, max 1.0)
-
self.duty
-
The duty of the square
waveform
-
self.duty.ratio
-
Square duty:
Width of the square wave pulse cycle (doesn't affect other waveforms)
(default 0.0, min 0.0, max 1.0)
-
self.duty.sweep
-
Duty sweep:
Amount by which the square duty is increased or decreased over time
(default 0.0, min -1.0, max 1.0)
-
self.phaser
-
A simple phaser
effect
-
self.phaser.offset
-
Phaser offset:
Amount by which the phaser signal is offset from the sound
(default 0.0, min -1.0, max 1.0)
-
self.phaser.sweep
-
Phaser sweep:
Amount by which the phaser offset is increased or decreased over time
(default 0.0, min -1.0, max 1.0)
-
self.lowpass
-
A lowpass filter
effect
-
self.lowpass.cutoff
-
Lowpass filter cutoff:
Lower bound for frequencies allowed to pass through this filter
(default 0.0, min 0.0, max 1.0)
-
self.lowpass.sweep
-
Lowpass filter cutoff sweep:
Amount by which the LP filter cutoff is increased or decreased
over time
(default 0.0, min -1.0, max 1.0)
-
self.lowpass.resonance
-
Lowpass filter resonance:
Amount by which certain resonant frequencies near the cutoff are
increased
(default 0.0, min 0.0, max 1.0)
-
self.highpass
-
A highpass filter
effect
-
self.highpass.cutoff
-
Highpass filter cutoff:
Upper bound for frequencies allowed to pass through this filter
(default 0.0, min 0.0, max 1.0)
-
self.highpass.sweep
-
Highpass filter cutoff sweep:
Amount by which the HP filter cutoff is increased or decreased
over time
(default 0.0, min -1.0, max 1.0)
-
self.volume.master
-
Master volume (default 0.5)
-
self.volume.sound
-
Additional gain (default 0.5)
-
sfxr.Sound:randomize ([seed])
-
Randomize all sound parameters
Parameters:
- seed
number
a random seed
(optional)
-
sfxr.Sound:mutate ([amount=1][, seed], changefreq)
-
Mutate all sound parameters
Parameters:
- amount
number
by how much to mutate the parameters
(default 1)
- seed
number
a random seed
(optional)
- changefreq
bool
whether to change the frequency parameters
-
sfxr.Sound:randomPickup ([seed])
-
Randomize all sound parameters to generate a "pick up" sound
Parameters:
- seed
number
a random seed
(optional)
-
sfxr.Sound:randomLaser ([seed])
-
Randomize all sound parameters to generate a laser sound
Parameters:
- seed
number
a random seed
(optional)
-
sfxr.Sound:randomExplosion ([seed])
-
Randomize all sound parameters to generate an explosion sound
Parameters:
- seed
number
a random seed
(optional)
-
sfxr.Sound:randomPowerup ([seed])
-
Randomize all sound parameters to generate a "power up" sound
Parameters:
- seed
number
a random seed
(optional)
-
sfxr.Sound:randomHit ([seed])
-
Randomize all sound parameters to generate a hit sound
Parameters:
- seed
number
a random seed
(optional)
-
sfxr.Sound:randomJump ([seed])
-
Randomize all sound parameters to generate a jump sound
Parameters:
- seed
number
a random seed
(optional)
-
sfxr.Sound:randomBlip ([seed])
-
Randomize all sound parameters to generate a "blip" sound
Parameters:
- seed
number
a random seed
(optional)
-
sfxr.Sound:exportWAV (f[, rate=44100[, depth=0]])
-
Generate and export the audio data to a PCM WAVE file.
Parameters:
- f
string, file or love.filesystem.File
a path or file in
wb-mode
(passed files will not be closed)
- rate
SAMPLERATE
the sampling rate
(default 44100)
- depth
BITDEPTH
the bit depth
(default 0)
Raises:
"invalid sampling rate: x", "invalid bit depth: x"
-
sfxr.Sound:save (f[, minify=true])
-
Save the sound parameters to a file as a Lua table
Parameters:
- f
string, file or love.filesystem.File
a path or file in
w-mode
(passed files will not be closed)
- minify
bool
whether to minify the output or not
(default true)
-
sfxr.Sound:load (f)
-
Load the sound parameters from a file containing a Lua table
Parameters:
- f
string, file or love.filesystem.File
a path or file in
r-mode
(passed files will not be closed)
Raises:
"incompatible version: x.x.x"
-
sfxr.Sound:saveBinary (f)
-
Save the sound parameters to a file in the sfxr binary format (version 102)
Parameters:
- f
string, file or love.filesystem.File
a path or file in
wb-mode
(passed files will not be closed)
-
sfxr.Sound:loadBinary (f)
-
Load the sound parameters from a file in the sfxr binary format
(version 100-102)
Parameters:
- f
string, file or love.filesystem.File
a path or file in
rb-mode
(passed files will not be closed)
Raises:
"incompatible version: x", "unexpected file length"