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	25	@example basic-oscillators.c
26	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	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	86	// Cycle
20	87	void tCycle_init(tCycle* const cy)
21	88	{

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