wavetable oscillator

Matthew Wang committed 6 years ago

Commit 9862cbb1 parent fdb31242 files · +129 −0Browse files

Unified · Split

2 files

leaf/Inc/leaf-oscillators.h +62 −0
leaf/Src/leaf-oscillators.c +67 −0

@@ -25,7 +25,69 @@ extern "C" { · 24 unmodified lines
25	@example basic-oscillators.c	25	@example basic-oscillators.c
26	An example.	26	An example.
27	*/	27	*/
		28
		29	//==============================================================================
		30
		31	/*!
		32	@defgroup ttable tTable
		33	@ingroup oscillators
		34	@brief A general wavetable oscillator.
		35	@{
		36	*/
		37
		38	/*!
		39	@fn void tTable_init (tTable* const osc)
		40	@brief Initialize a tTable to the default LEAF mempool.
		41	@param osc A pointer to the tTable to be initialized.
		42	*/
		43
		44	/*!
		45	@fn void tTable_initToPool (tTable* const osc, tMempool* const mempool)
		46	@brief Initialize a tTable to a specified mempool.
		47	@param osc A pointer to the tTable to be initialized.
		48	@param pool A pointer to the tMempool to which the tTable should be initialized.
		49	*/
		50
		51	/*!
		52	@fn void tTable_free (tTable* const osc)
		53	@brief Free a tTable from the default LEAF mempool.
		54	@param osc A pointer to the tTable to be freed.
		55	*/
		56
		57	/*!
		58	@fn float tTable_tick (tTable* const osc)
		59	@brief Tick a tTable oscillator.
		60	@param osc A pointer to the relevant tTable.
		61	@return The ticked sample as a float from -1 to 1.
		62	*/
		63
		64	/*!
		65	@fn void tTable_setFreq (tTable* const osc, float freq)
		66	@brief Set the frequency of a tTable oscillator.
		67	@param osc A pointer to the relevant tTable.
		68	@param freq The frequency to set the oscillator to.
		69	*/
		70
		71	/! @} /
		72
		73	typedef struct _tTable
		74	{
		75	tMempool mempool;
		76
		77	float* waveTable;
		78	int size;
		79	float inc, freq;
		80	float phase;
		81	} _tTable;
		82
		83	typedef _tTable* tTable;
28		84
		85	void tTable_init(tTable* const osc, float* waveTable, int size);
		86	void tTable_initToPool(tTable* const osc, float* waveTable, int size, tMempool* const mempool);
		87	void tTable_free(tTable* const osc);
		88
		89	float tTable_tick(tTable* const osc);
		90	void tTable_setFreq(tTable* const osc, float freq);
29		91
30	//==============================================================================	92	//==============================================================================
31		93

leaf/Src/leaf-oscillators.c+67−0

@@ -16,6 +16,73 @@ · 15 unmodified lines
16		16
17	#endif	17	#endif
18		18
		19	// WaveTable
		20	void tTable_init(tTable* const cy, float* waveTable, int size)
		21	{
		22	tTable_initToPool(cy, waveTable, size, &leaf.mempool);
		23	}
		24
		25	void tTable_initToPool(tTable* const cy, float* waveTable, int size, tMempool* const mp)
		26	{
		27	_tMempool* m = *mp;
		28	_tTable* c = cy = (_tTable)mpool_alloc(sizeof(_tTable), m);
		29	c->mempool = m;
		30
		31	c->waveTable = waveTable;
		32	c->size = size;
		33	c->inc = 0.0f;
		34	c->phase = 0.0f;
		35	}
		36
		37	void tTable_free(tTable* const cy)
		38	{
		39	_tTable* c = *cy;
		40
		41	mpool_free((char*)c, c->mempool);
		42	}
		43
		44	void tTable_setFreq(tTable* const cy, float freq)
		45	{
		46	_tTable* c = *cy;
		47
		48	c->freq = freq;
		49	c->inc = freq * leaf.invSampleRate;
		50	}
		51
		52	float tTable_tick(tTable* const cy)
		53	{
		54	_tTable* c = *cy;
		55	float temp;
		56	int intPart;
		57	float fracPart;
		58	float samp0;
		59	float samp1;
		60
		61	// Phasor increment
		62	c->phase += c->inc;
		63	while (c->phase >= 1.0f) c->phase -= 1.0f;
		64	while (c->phase < 0.0f) c->phase += 1.0f;
		65
		66	// Wavetable synthesis
		67
		68	temp = c->size * c->phase;
		69	intPart = (int)temp;
		70	fracPart = temp - (float)intPart;
		71	samp0 = c->waveTable[intPart];
		72	if (++intPart >= c->size) intPart = 0;
		73	samp1 = c->waveTable[intPart];
		74
		75	return (samp0 + (samp1 - samp0) * fracPart);
		76
		77	}
		78
		79	void tTableSampleRateChanged(tTable* const cy)
		80	{
		81	_tTable* c = *cy;
		82
		83	c->inc = c->freq * leaf.invSampleRate;
		84	}
		85
19	// Cycle	86	// Cycle
20	void tCycle_init(tCycle* const cy)	87	void tCycle_init(tCycle* const cy)
21	{	88	{

wavetable oscillator

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