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- /* Audio Library for Teensy 3.X
- * Copyright (c) 2014, Paul Stoffregen, paul@pjrc.com
- *
- * Development of this audio library was funded by PJRC.COM, LLC by sales of
- * Teensy and Audio Adaptor boards. Please support PJRC's efforts to develop
- * open source software by purchasing Teensy or other PJRC products.
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice, development funding notice, and this permission
- * notice shall be included in all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
- #ifndef synth_waveform_h_
- #define synth_waveform_h_
-
- #include "AudioStream.h"
- #include "arm_math.h"
-
- // waveforms.c
- extern "C" {
- extern const int16_t AudioWaveformSine[257];
- }
-
- #define AUDIO_SAMPLE_RATE_ROUNDED (44118)
-
- #define DELAY_PASSTHRU -1
-
- #define TONE_TYPE_SINE 0
- #define TONE_TYPE_SAWTOOTH 1
- #define TONE_TYPE_SQUARE 2
- #define TONE_TYPE_TRIANGLE 3
-
- class AudioSynthWaveform :
- public AudioStream
- {
- public:
- AudioSynthWaveform(void) :
- AudioStream(0,NULL),
- tone_freq(0), tone_phase(0), tone_incr(0), tone_type(0)
- {
- }
-
- void frequency(float t_hi)
- {
- if (t_hi > AUDIO_SAMPLE_RATE_EXACT / 2 || t_hi < 0.0) return;
- tone_incr = ((0x80000000LL*t_hi)/AUDIO_SAMPLE_RATE_EXACT) + 0.5;
- }
-
- void amplitude(float n) { // 0 to 1.0
- if (n < 0) n = 0;
- else if (n > 1.0) n = 1.0;
- // Ramp code
- if(tone_amp && (n == 0)) {
- last_tone_amp = tone_amp;
- }
- else if((tone_amp == 0) && n) {
- // reset the phase when the amplitude was zero
- // and has now been increased.
- tone_phase = 0;
- }
- // set new magnitude
- tone_amp = n * 32767.0;
- }
-
- boolean begin(float t_amp,float t_hi,short t_type);
- virtual void update(void);
-
- private:
- short tone_amp;
- short last_tone_amp;
- short tone_freq;
- uint32_t tone_phase;
- // volatile prevents the compiler optimizing out the frequency function
- volatile uint32_t tone_incr;
- short tone_type;
-
- };
-
-
-
- #endif
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