victor@4: /*
victor@4:  * render.cpp
victor@4:  *
victor@4:  *  Created on: Oct 24, 2014
victor@4:  *      Author: parallels
victor@4:  */
victor@4: 
victor@4: 
victor@4: #include "../../include/render.h"
victor@4: #include <rtdk.h>
victor@4: #include <NE10.h>					// neon library
victor@4: #include <cmath>
victor@4: 
andrewm@5: int gFFTSize;
andrewm@5: float gFFTScaleFactor = 0;
victor@4: int gNumChannels;
victor@4: 
victor@4: int gReadPointer = 0;
victor@4: int gWritePointer = 0;
victor@4: 
victor@4: // FFT vars
andrewm@5: ne10_fft_cpx_float32_t* timeDomainIn;
andrewm@5: ne10_fft_cpx_float32_t* timeDomainOut;
victor@4: ne10_fft_cpx_float32_t* frequencyDomain;
victor@4: ne10_fft_cfg_float32_t cfg;
victor@4: 
victor@4: // initialise_render() is called once before the audio rendering starts.
victor@4: // Use it to perform any initialisation and allocation which is dependent
victor@4: // on the period size or sample rate.
victor@4: //
victor@4: // userData holds an opaque pointer to a data structure that was passed
victor@4: // in from the call to initAudio().
victor@4: //
victor@4: // Return true on success; returning false halts the program.
victor@4: 
victor@4: bool initialise_render(int numChannels, int numMatrixFramesPerPeriod,
victor@4: 					   int numAudioFramesPerPeriod, float matrixSampleRate,
victor@4: 					   float audioSampleRate, void *userData)
victor@4: {
victor@4: 	// Retrieve a parameter passed in from the initAudio() call
andrewm@5: 	gFFTSize = *(int *)userData;
andrewm@5: 	gFFTScaleFactor = 1.0f / (float)gFFTSize;
victor@4: 	gNumChannels = numChannels;
victor@4: 
andrewm@5: 	timeDomainIn = (ne10_fft_cpx_float32_t*) NE10_MALLOC (gFFTSize * sizeof (ne10_fft_cpx_float32_t));
andrewm@5: 	timeDomainOut = (ne10_fft_cpx_float32_t*) NE10_MALLOC (gFFTSize * sizeof (ne10_fft_cpx_float32_t));
andrewm@5: 	frequencyDomain = (ne10_fft_cpx_float32_t*) NE10_MALLOC (gFFTSize * sizeof (ne10_fft_cpx_float32_t));
andrewm@5: 	cfg = ne10_fft_alloc_c2c_float32 (gFFTSize);
victor@4: 
andrewm@5: 	memset(timeDomainOut, 0, gFFTSize * sizeof (ne10_fft_cpx_float32_t));
victor@4: 
victor@4: 	return true;
victor@4: }
victor@4: 
victor@4: // render() is called regularly at the highest priority by the audio engine.
victor@4: // Input and output are given from the audio hardware and the other
victor@4: // ADCs and DACs (if available). If only audio is available, numMatrixFrames
victor@4: // will be 0.
victor@4: 
victor@4: void render(int numMatrixFrames, int numAudioFrames, float *audioIn, float *audioOut,
victor@4: 			uint16_t *matrixIn, uint16_t *matrixOut)
victor@4: {
victor@4: 	for(int n = 0; n < numAudioFrames; n++) {
andrewm@5: 		timeDomainIn[gReadPointer].r = (ne10_float32_t) ((audioIn[n*gNumChannels] + audioIn[n*gNumChannels+1]) * 0.5);
andrewm@5: 		timeDomainIn[gReadPointer].i = 0;
victor@4: 
andrewm@5: 		if(++gReadPointer >= gFFTSize)
andrewm@5: 		{
andrewm@5: 			//FFT
andrewm@5: 			ne10_fft_c2c_1d_float32_neon (frequencyDomain, timeDomainIn, cfg->twiddles, cfg->factors, gFFTSize, 0);
victor@4: 
andrewm@5: 			//Do frequency domain stuff
victor@4: 
andrewm@5: 			//IFFT
andrewm@5: 			ne10_fft_c2c_1d_float32_neon (timeDomainOut, frequencyDomain, cfg->twiddles, cfg->factors, gFFTSize, 1);
victor@4: 
andrewm@5: 			gReadPointer = 0;
andrewm@5: 			gWritePointer = 0;
andrewm@5: 		}
victor@4: 
victor@4: 		for(int channel = 0; channel < gNumChannels; channel++)
andrewm@5: 			audioOut[n * gNumChannels + channel] = (float) timeDomainOut[gWritePointer].r * gFFTScaleFactor;
andrewm@5: 		gWritePointer++;
victor@4: 	}
victor@4: }
victor@4: 
victor@4: // cleanup_render() is called once at the end, after the audio has stopped.
victor@4: // Release any resources that were allocated in initialise_render().
victor@4: 
victor@4: void cleanup_render()
victor@4: {
andrewm@5: 	NE10_FREE(timeDomainIn);
andrewm@5: 	NE10_FREE(timeDomainOut);
victor@4: 	NE10_FREE(frequencyDomain);
victor@4: 	NE10_FREE(cfg);
victor@4: }