victor@1: /*
victor@1:  * render.cpp
victor@1:  *
victor@1:  *  Created on: Oct 24, 2014
victor@1:  *      Author: Andrew McPherson and Victor Zappi
victor@1:  */
victor@1: 
victor@1: 
victor@1: #include "../../include/render.h"
victor@1: #include "../../include/RTAudio.h"	// to schedule lower prio parallel process
victor@1: #include <rtdk.h>
victor@1: #include <cmath>
victor@1: #include <stdio.h>
victor@1: #include "SampleData.h"
victor@1: 
victor@1: SampleData gSampleData;	// User defined structure to get complex data from main
victor@1: int gReadPtr;			// Position of last read sample from file
victor@1: int gNumChannels;
victor@1: 
victor@1: // Task for handling the update of the frequencies using the matrix
victor@1: AuxiliaryTask gTriggerSamplesTask;
victor@1: 
victor@1: bool initialise_trigger();
victor@1: void trigger_samples();
victor@1: 
victor@1: // initialise_render() is called once before the audio rendering starts.
victor@1: // Use it to perform any initialisation and allocation which is dependent
victor@1: // on the period size or sample rate.
victor@1: //
victor@1: // userData holds an opaque pointer to a data structure that was passed
victor@1: // in from the call to initAudio().
victor@1: //
victor@1: // Return true on success; returning false halts the program.
victor@1: 
victor@1: bool initialise_render(int numChannels, int numMatrixFramesPerPeriod,
victor@1: 					   int numAudioFramesPerPeriod, float matrixSampleRate,
victor@1: 					   float audioSampleRate, void *userData)
victor@1: {
victor@1: 
victor@1: 	// Retrieve a parameter passed in from the initAudio() call
victor@1: 	gSampleData = *(SampleData *)userData;
victor@1: 
victor@1: 	gReadPtr = -1;
victor@1: 	gNumChannels = numChannels;
victor@1: 
victor@1: 	// Initialise auxiliary tasks
victor@1: 	if(!initialise_trigger())
victor@1: 		return false;
victor@1: 
victor@1: 	return true;
victor@1: }
victor@1: 
victor@1: // render() is called regularly at the highest priority by the audio engine.
victor@1: // Input and output are given from the audio hardware and the other
victor@1: // ADCs and DACs (if available). If only audio is available, numMatrixFrames
victor@1: // will be 0.
victor@1: 
victor@1: void render(int numMatrixFrames, int numAudioFrames, float *audioIn, float *audioOut,
victor@1: 			uint16_t *matrixIn, uint16_t *matrixOut)
victor@1: {
victor@1: 	for(int n = 0; n < numAudioFrames; n++) {
victor@1: 		float out = 0;
victor@1: 
victor@1: 		// If triggered...
victor@1: 		if(gReadPtr != -1)
victor@1: 			out += gSampleData.samples[gReadPtr++];	// ...read each sample...
victor@1: 
victor@1: 		if(gReadPtr >= gSampleData.sampleLen)
victor@1: 			gReadPtr = -1;
victor@1: 
victor@1: 		for(int channel = 0; channel < gNumChannels; channel++)
victor@1: 			audioOut[n * gNumChannels + channel] = out;	// ...and put it in both left and right channel
victor@1: 	}
victor@1: 
victor@1: 	// Request that the lower-priority task run at next opportunity
victor@1: 	scheduleAuxiliaryTask(gTriggerSamplesTask);
victor@1: }
victor@1: 
victor@1: // Initialise the auxiliary task
victor@1: // and print info
victor@1: 
victor@1: bool initialise_trigger()
victor@1: {
victor@1: 	if((gTriggerSamplesTask = createAuxiliaryTaskLoop(&trigger_samples, 50, "beaglert-trigger-samples")) == 0)
victor@1: 		return false;
victor@1: 
victor@1: 	rt_printf("Press 'a' to trigger sample, 's' to stop\n");
victor@1: 	rt_printf("Press 'q' to quit\n");
victor@1: 
victor@1: 	return true;
victor@1: }
victor@1: 
victor@1: // This is a lower-priority call to periodically read keyboard input
victor@1: // and trigger samples. By placing it at a lower priority,
victor@1: // it has minimal effect on the audio performance but it will take longer to
victor@1: // complete if the system is under heavy audio load.
victor@1: 
victor@1: void trigger_samples()
victor@1: {
victor@1: 	// This is not a real-time task!
victor@1: 	// Cos getchar is a system call, not handled by Xenomai.
victor@1: 	// This task will be automatically down graded.
victor@1: 
victor@1: 	char keyStroke = '.';
victor@1: 
victor@1: 	keyStroke =	getchar();
victor@1: 	while(getchar()!='\n'); // to read the first stroke
victor@1: 
victor@1: 	switch (keyStroke)
victor@1: 	{
victor@1: 		case 'a':
victor@1: 			gReadPtr = 0;
victor@1: 			break;
victor@1: 		case 's':
victor@1: 			gReadPtr = -1;
victor@1: 			break;
victor@1: 		case 'q':
victor@1: 			gShouldStop = true;
victor@1: 			break;
victor@1: 		default:
victor@1: 			break;
victor@1: 	}
victor@1: }
victor@1: 
victor@1: 
victor@1: 
victor@1: // cleanup_render() is called once at the end, after the audio has stopped.
victor@1: // Release any resources that were allocated in initialise_render().
victor@1: 
victor@1: void cleanup_render()
victor@1: {
victor@1: 	delete[] gSampleData.samples;
victor@1: }