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#include <math.h>
#include "basic_source.h"
#include "internal.h"
#include "types.h"
namespace audiere {
static const double PI = 3.14159265358979323846;
class SineWave : public BasicSource {
public:
SineWave(double frequency) {
m_frequency = frequency;
doReset(); // not supposed to call virtual functions in constructors
}
void ADR_CALL getFormat(
int& channel_count,
int& sample_rate,
SampleFormat& sample_format)
{
channel_count = 1;
sample_rate = 44100;
sample_format = SF_S16;
}
int doRead(int frame_count, void* buffer) {
// if frequency is 0 Hz, use silence
if (m_frequency == 0) {
memset(buffer, 0, frame_count * 2);
return frame_count;
}
s16* out = (s16*)buffer;
for (int i = 0; i < frame_count; ++i) {
double h = sin(2 * PI * m_frequency / 44100 * elapsed++);
out[i] = normal_to_s16(h);
}
return frame_count;
}
void ADR_CALL reset() {
doReset();
}
private:
void doReset() {
elapsed = 0;
}
s16 normal_to_s16(double d) {
d = (d + 1) / 2; // convert from [-1, 1] to [0, 1]
return s16(d * 32767 - 16384);
}
double m_frequency;
long elapsed;
};
ADR_EXPORT(SampleSource*) AdrCreateTone(double frequency) {
return new SineWave(frequency);
}
}
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