Oscil plays a wavetable, cycling through the table to generate an audio or control signal. More...
Public Member Functions | |
Oscil (const char *TABLE_NAME) | |
Constructor. | |
Oscil () | |
Constructor. | |
char | next () |
Updates the phase according to the current frequency and returns the sample at the new phase position. | |
void | setTable (const char *TABLE_NAME) |
Change the sound table which will be played by the Oscil. | |
void | setPhase (unsigned int phase) |
Set the phase of the Oscil. | |
void | setPhaseFractional (unsigned long phase) |
Set the phase of the Oscil. | |
unsigned long | getPhaseFractional () |
Get the phase of the Oscil in fractional format. | |
char | phMod (Q15n16 phmod_proportion) |
Returns the next sample given a phase modulation value. | |
void | setFreq (unsigned int frequency) |
Set the oscillator frequency with an unsigned int. | |
void | setFreq (float frequency) |
Set the oscillator frequency with a float. | |
void | setFreq_Q24n8 (Q24n8 frequency) |
Set the frequency using Q24n8 fixed-point number format. | |
void | setFreq_Q16n16 (Q16n16 frequency) |
Set the frequency using Q16n16 fixed-point number format. | |
char | atIndex (unsigned int index) |
Returns the sample at the given table index. | |
unsigned long | phaseIncFromFreq (unsigned int frequency) |
phaseIncFromFreq() and setPhaseInc() are for saving processor time when sliding between frequencies. | |
void | setPhaseInc (unsigned long phaseinc_fractional) |
Set a specific phase increment. |
Oscil plays a wavetable, cycling through the table to generate an audio or control signal.
The frequency of the signal can be set or changed with setFreq(), and the output of an Oscil can be produced with next() for a simple cycling oscillator, or atIndex() for a particular sample in the table.
NUM_TABLE_CELLS | This is defined in the table ".h" file the Oscil will be using. It's important that it's a power of 2, and either a literal number (eg. "8192") or a defined macro, rather than a const or int, for the Oscil to run fast enough. |
UPDATE_RATE | This will be AUDIO_RATE if the Oscil is updated in updateAudio(), or CONTROL_RATE if it's updated each time updateControl() is called. It could also be a fraction of CONTROL_RATE if you are doing some kind of cyclic updating in updateControl(), for example, to spread out the processor load. |
Converting soundfiles for Mozzi There is a python script called char2mozzi.py in the Mozzi/python folder. The usage is: python char2mozzi.py infilename outfilename tablename samplerate
Oscil< NUM_TABLE_CELLS, UPDATE_RATE >::Oscil | ( | const char * | TABLE_NAME | ) | [inline] |
Constructor.
TABLE_NAME | the name of the array the Oscil will be using. This can be found in the table ".h" file if you are using a table made for Mozzi by the char2mozzi.py python script in Mozzi's python folder. |
Oscil< NUM_TABLE_CELLS, UPDATE_RATE >::Oscil | ( | ) | [inline] |
Constructor.
Declare an Oscil with template TABLE_NUM_CELLS and UPDATE_RATE parameters, without specifying a particular wave table for it to play. The table can be set or changed on the fly with setTable(). Any tables used by the Oscil must be the same size.
unsigned long Oscil< NUM_TABLE_CELLS, UPDATE_RATE >::getPhaseFractional | ( | ) | [inline] |
unsigned long Oscil< NUM_TABLE_CELLS, UPDATE_RATE >::phaseIncFromFreq | ( | unsigned int | frequency | ) | [inline] |
phaseIncFromFreq() and setPhaseInc() are for saving processor time when sliding between frequencies.
Instead of recalculating the phase increment for each frequency in between, you can just calculate the phase increment for each end frequency with phaseIncFromFreq(), then use a Line to interpolate on the fly and use setPhaseInc() to set the phase increment at each step. (Note: I should really profile this with the oscilloscope to see if it's worth the extra confusion!)
frequency | for which you want to calculate a phase increment value. |
char Oscil< NUM_TABLE_CELLS, UPDATE_RATE >::phMod | ( | Q15n16 | phmod_proportion | ) | [inline] |
Returns the next sample given a phase modulation value.
a | phase modulation value given as a proportion of the wave. The phmod_proportion parameter is a Q15n16 fixed-point number where the fractional n16 part represents -1 to 1, modulating the phase by one whole table length in each direction. |
void Oscil< NUM_TABLE_CELLS, UPDATE_RATE >::setFreq | ( | unsigned int | frequency | ) | [inline] |
Set the oscillator frequency with an unsigned int.
This is faster than using a float, so it's useful when processor time is tight, but it can be tricky with low and high frequencies, depending on the size of the wavetable being used. If you're not getting the results you expect, try explicitly using a float, or try setFreq_Q24n8() or or setFreq_Q16n16().
frequency | to play the wave table. |
void Oscil< NUM_TABLE_CELLS, UPDATE_RATE >::setFreq | ( | float | frequency | ) | [inline] |
Set the oscillator frequency with a float.
Using a float is the most reliable way to set frequencies, -Might- be slower than using an int but you need either this, setFreq_Q24n8() or setFreq_Q16n16() for fractional frequencies.
frequency | to play the wave table. |
void Oscil< NUM_TABLE_CELLS, UPDATE_RATE >::setFreq_Q16n16 | ( | Q16n16 | frequency | ) | [inline] |
Set the frequency using Q16n16 fixed-point number format.
This is useful in combination with Q16n16_mtof(), a fast alternative to mtof(), using Q16n16 fixed-point format instead of floats. Note: this should work OK with tables 2048 cells or smaller and frequencies up to 4096 Hz. Can't be used with UPDATE_RATE less than 64 Hz.
frequency | in Q16n16 fixed-point number format. |
void Oscil< NUM_TABLE_CELLS, UPDATE_RATE >::setFreq_Q24n8 | ( | Q24n8 | frequency | ) | [inline] |
Set the frequency using Q24n8 fixed-point number format.
This might be faster than the float version for setting low frequencies such as 1.5 Hz, or other values which may not work well with your table size. A Q24n8 representation of 1.5 is 384 (ie. 1.5 * 256). Can't be used with UPDATE_RATE less than 64 Hz.
frequency | in Q24n8 fixed-point number format. |
void Oscil< NUM_TABLE_CELLS, UPDATE_RATE >::setPhaseFractional | ( | unsigned long | phase | ) | [inline] |
Set the phase of the Oscil.
Might be useful with getPhaseFractional().
phase | a position in the wavetable. |
void Oscil< NUM_TABLE_CELLS, UPDATE_RATE >::setPhaseInc | ( | unsigned long | phaseinc_fractional | ) | [inline] |
Set a specific phase increment.
See phaseIncFromFreq().
phaseinc_fractional | a phase increment value as calculated by phaseIncFromFreq(). |