Mercurial > hg > beaglert
diff projects/basic/render.cpp @ 0:8a575ba3ab52
Initial commit.
author | andrewm |
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date | Fri, 31 Oct 2014 19:10:17 +0100 |
parents | |
children | a6beeba3a648 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/projects/basic/render.cpp Fri Oct 31 19:10:17 2014 +0100 @@ -0,0 +1,65 @@ +/* + * render.cpp + * + * Created on: Oct 24, 2014 + * Author: parallels + */ + + +#include "../../include/render.h" +#include <cmath> + +float gFrequency; +float gPhase; +float gInverseSampleRate; +int gNumChannels; + +// initialise_render() is called once before the audio rendering starts. +// Use it to perform any initialisation and allocation which is dependent +// on the period size or sample rate. +// +// userData holds an opaque pointer to a data structure that was passed +// in from the call to initAudio(). +// +// Return true on success; returning false halts the program. + +bool initialise_render(int numChannels, int numMatrixFramesPerPeriod, + int numAudioFramesPerPeriod, float matrixSampleRate, + float audioSampleRate, void *userData) +{ + // Retrieve a parameter passed in from the initAudio() call + gFrequency = *(float *)userData; + + gNumChannels = numChannels; + gInverseSampleRate = 1.0 / audioSampleRate; + gPhase = 0.0; + + return true; +} + +// render() is called regularly at the highest priority by the audio engine. +// Input and output are given from the audio hardware and the other +// ADCs and DACs (if available). If only audio is available, numMatrixFrames +// will be 0. + +void render(int numMatrixFrames, int numAudioFrames, float *audioIn, float *audioOut, + uint16_t *matrixIn, uint16_t *matrixOut) +{ + for(int n = 0; n < numAudioFrames; n++) { + float out = 0.8f * sinf(gPhase); + gPhase += 2.0 * M_PI * gFrequency * gInverseSampleRate; + if(gPhase > 2.0 * M_PI) + gPhase -= 2.0 * M_PI; + + for(int channel = 0; channel < gNumChannels; channel++) + audioOut[n * gNumChannels + channel] = out; + } +} + +// cleanup_render() is called once at the end, after the audio has stopped. +// Release any resources that were allocated in initialise_render(). + +void cleanup_render() +{ + +}