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-
-
- #include <Arduino.h>
- #include "effect_fade.h"
- #include "utility/dspinst.h"
-
- extern "C" {
- extern const int16_t fader_table[257];
- };
-
- void AudioEffectFade::update(void)
- {
- audio_block_t *block;
- uint32_t i, pos, inc, index, scale;
- int32_t val1, val2, val, sample;
- uint8_t dir;
-
- pos = position;
- if (pos == 0) {
-
- block = receiveReadOnly();
- if (block) release(block);
- return;
- } else if (pos == 0xFFFFFFFF) {
-
- block = receiveReadOnly();
- if (!block) return;
- transmit(block);
- release(block);
- return;
- }
- block = receiveWritable();
- if (!block) return;
- inc = rate;
- dir = direction;
- for (i=0; i < AUDIO_BLOCK_SAMPLES; i++) {
- index = pos >> 24;
- val1 = fader_table[index];
- val2 = fader_table[index+1];
- scale = (pos >> 8) & 0xFFFF;
- val2 *= scale;
- val1 *= 0x10000 - scale;
- val = (val1 + val2) >> 16;
- sample = block->data[i];
- sample = (sample * val) >> 15;
- block->data[i] = sample;
- if (dir > 0) {
-
- if (inc < 0xFFFFFFFF - pos) pos += inc;
- else pos = 0xFFFFFFFF;
- } else {
-
- if (inc < pos) pos -= inc;
- else pos = 0;
- }
- }
- position = pos;
- transmit(block);
- release(block);
- }
-
- void AudioEffectFade::fadeBegin(uint32_t newrate, uint8_t dir)
- {
- __disable_irq();
- uint32_t pos = position;
- if (pos == 0) position = 1;
- else if (pos == 0xFFFFFFFF) position = 0xFFFFFFFE;
- rate = newrate;
- direction = dir;
- __enable_irq();
- }
-
-
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