From e67a18d2e2e4c38a1fe3bd7e6c8486363ba20e26 Mon Sep 17 00:00:00 2001
From: fakebitpolytechnic <fakebitpoly@gmail.com>
Date: Tue, 6 Aug 2013 20:34:29 +0100
Subject: 3(+?)note polyphony, plus nice delay, LPF, "phaser" f/x

---
 PolyDrums_v0_1_3_DelayLPF/Wave.h | 183 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 183 insertions(+)
 create mode 100644 PolyDrums_v0_1_3_DelayLPF/Wave.h

(limited to 'PolyDrums_v0_1_3_DelayLPF/Wave.h')

diff --git a/PolyDrums_v0_1_3_DelayLPF/Wave.h b/PolyDrums_v0_1_3_DelayLPF/Wave.h
new file mode 100644
index 0000000..a9afd72
--- /dev/null
+++ b/PolyDrums_v0_1_3_DelayLPF/Wave.h
@@ -0,0 +1,183 @@
+/*
+ * Wave.h
+ *
+ * Simon Green 2013.
+ *
+ * Based on Mozzi "Oscil.h"
+ */
+
+#ifndef WAVE_H_
+#define WAVE_H_
+
+#include "Arduino.h"
+#include "mozzi_fixmath.h"
+#include <util/atomic.h>
+
+// fractional bits for oscillator index precision
+#define OSCIL_F_BITS 16
+#define OSCIL_F_BITS_AS_MULTIPLIER 65536
+#define NUM_TABLE_CELLS 256
+#define ADJUST_FOR_NUM_TABLE_CELLS 8
+#define UPDATE_RATE AUDIO_RATE
+
+/** Generate waveform
+*/
+
+enum WaveType { WAVE_SAW=0, WAVE_TRI, WAVE_RECT, WAVE_NOISE };
+
+class Wave
+{
+public:
+	/** Constructor. "Wave mywave;" makes a Wave oscillator
+	*/
+	Wave () {
+          phase_fractional = 0;
+          phase_increment_fractional = 0;
+          wavetype = WAVE_SAW;
+          noise = 0xACE1;
+          pulse_width = 128;
+	}
+
+	/** Increments one step along the phase.
+	@return the next value.
+	 */
+	inline
+	char next()
+	{
+  		incrementPhase();
+
+                char w;
+  		//ATOMIC_BLOCK(ATOMIC_RESTORESTATE)
+		{
+                        int n = (phase_fractional >> OSCIL_F_BITS) & (NUM_TABLE_CELLS-1);
+                        switch(wavetype) {
+                          case WAVE_SAW:
+                            w = n - 128;
+                            break;
+                          case WAVE_TRI:
+                            if (n & 0x80)  // >= 128
+                              w = ((n^0xFF)<<1)-128;
+                            else 
+                              w = (n<<1)-128;
+                            break;
+                          case WAVE_RECT:
+                            if (n > pulse_width)
+                              w = 127;
+                            else
+                              w = -127;
+                            break;
+                          case WAVE_NOISE:
+                            noise = (noise >> 1) ^ (-(noise & 1) & 0xB400u);
+                            w = noise>>8;
+                            break;
+                        }
+		}
+                return w;
+	}
+
+	/** Set the wave type
+	 */
+	inline
+	void setType(WaveType x)
+	{
+		wavetype = x;
+	}
+
+        WaveType getType() { return wavetype; }
+
+	/** Set the pulse width for rectangle wave
+	 */
+	inline
+	void setPulseWidth(unsigned char x)
+	{
+		pulse_width = x;
+	}
+
+	/** 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().
+	@param frequency to play the wave table.
+	*/
+	inline
+	void setFreq (unsigned int frequency) {
+		ATOMIC_BLOCK(ATOMIC_RESTORESTATE)
+		{
+			phase_increment_fractional = ((((unsigned long)NUM_TABLE_CELLS<<ADJUST_FOR_NUM_TABLE_CELLS)*frequency)/UPDATE_RATE) << (OSCIL_F_BITS - ADJUST_FOR_NUM_TABLE_CELLS);
+		}
+	}
+	
+	
+	/** 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.
+	@param frequency to play the wave table.
+	 */
+	inline
+	void setFreq(float frequency)
+	{ // 1 us - using float doesn't seem to incur measurable overhead with the oscilloscope
+		ATOMIC_BLOCK(ATOMIC_RESTORESTATE)
+		{
+			phase_increment_fractional = (unsigned long)((((float)NUM_TABLE_CELLS * frequency)/UPDATE_RATE) * OSCIL_F_BITS_AS_MULTIPLIER);
+		}
+	}
+	
+	
+	/** 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.
+	@param frequency in Q24n8 fixed-point number format.
+	*/
+	inline
+	void setFreq_Q24n8(Q24n8 frequency)
+	{
+		ATOMIC_BLOCK(ATOMIC_RESTORESTATE)
+		{
+			//phase_increment_fractional = (frequency* (NUM_TABLE_CELLS>>3)/(UPDATE_RATE>>6)) << (F_BITS-(8-3+6));
+			phase_increment_fractional = (((((unsigned long)NUM_TABLE_CELLS<<ADJUST_FOR_NUM_TABLE_CELLS)>>3)*frequency)/(UPDATE_RATE>>6)) 
+				<< (OSCIL_F_BITS - ADJUST_FOR_NUM_TABLE_CELLS - (8-3+6));
+		}
+	}
+
+
+	/** 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.
+	@param frequency in Q16n16 fixed-point number format.
+	*/
+	inline
+	void setFreq_Q16n16(Q16n16 frequency)
+	{
+		ATOMIC_BLOCK(ATOMIC_RESTORESTATE)
+		{
+			//phase_increment_fractional = ((frequency * (NUM_TABLE_CELLS>>7))/(UPDATE_RATE>>6)) << (F_BITS-16+1);
+			phase_increment_fractional = (((((unsigned long)NUM_TABLE_CELLS<<ADJUST_FOR_NUM_TABLE_CELLS)>>7)*frequency)/(UPDATE_RATE>>6)) 
+				<< (OSCIL_F_BITS - ADJUST_FOR_NUM_TABLE_CELLS - 16 + 1);
+
+		}
+	}
+
+private:
+	/** Increments the phase of the oscillator without returning a sample.
+	 */
+	inline
+	void incrementPhase()
+	{
+		//phase_fractional += (phase_increment_fractional | 1); // odd phase incr, attempt to reduce frequency spurs in output
+		phase_fractional += phase_increment_fractional;
+	}
+
+	unsigned long phase_fractional;
+	volatile unsigned long phase_increment_fractional;
+
+        unsigned char pulse_width;
+        uint16_t noise;
+        
+        WaveType wavetype;
+};
+
+#endif /* WAVE_H_ */
-- 
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