andrewm@13: /*
robert@269:  ____  _____ _        _    
robert@269: | __ )| ____| |      / \   
robert@269: |  _ \|  _| | |     / _ \  
robert@269: | |_) | |___| |___ / ___ \ 
robert@269: |____/|_____|_____/_/   \_\.io
robert@269: 
robert@269:  */
robert@269: 
robert@269:  /*
andrewm@13:  * render.cpp
andrewm@13:  *
andrewm@13:  *  Created on: Oct 24, 2014
andrewm@13:  *      Author: parallels
andrewm@13:  */
andrewm@13: 
robert@269: /**
robert@269: \example 1_basic_audio_passthrough
robert@269: 
robert@269: Audio passthrough: input to output
robert@269: -----------------------------------------
robert@269: 
robert@269: This sketch demonstrates the simplest possible case of using audio: it passes 
robert@269: audio input straight to audio output.
robert@269: 
robert@269: Note the nested `for` loop structure. You will see this in all Bela projects. The 
robert@269: first `for` loop cycles through the audio frames, the second through each of the 
robert@269: audio channels (in this case left 0 and right 1).
robert@269: 
robert@269: 
robert@269: We write samples to the audio output buffer like this: 
robert@269: `context->audioOut[n * context->audioChannels + ch]` where `n` is the current audio 
robert@269: frame and `ch` is the current channel, both provided by the nested for loop structure.
robert@269: 
robert@269: We can access samples in the audio input buffer in a similar way, like this: 
robert@269: `context->audioIn[n * context->audioChannels + ch]`.
robert@269: 
robert@269: So a simple audio pass through is achieved by setting output buffer equal to 
robert@269: input buffer: 
robert@269: `context->audioOut[n * context->audioChannels + ch] = context->audioIn[n * context->audioChannels + ch]`.
robert@269: 
robert@269: 
robert@269: */
robert@269: 
robert@269: 
robert@269: 
robert@269: 
andrewm@13: 
andrewm@56: #include <BeagleRT.h>
andrewm@56: #include <Utilities.h>
andrewm@13: #include <rtdk.h>
andrewm@13: 
andrewm@56: // setup() is called once before the audio rendering starts.
andrewm@13: // Use it to perform any initialisation and allocation which is dependent
andrewm@13: // on the period size or sample rate.
andrewm@13: //
andrewm@13: // userData holds an opaque pointer to a data structure that was passed
andrewm@13: // in from the call to initAudio().
andrewm@13: //
andrewm@13: // Return true on success; returning false halts the program.
andrewm@13: 
andrewm@56: bool setup(BeagleRTContext *context, void *userData)
andrewm@13: {
andrewm@13: 	// Nothing to do here...
andrewm@13: 	return true;
andrewm@13: }
andrewm@13: 
andrewm@13: // render() is called regularly at the highest priority by the audio engine.
andrewm@13: // Input and output are given from the audio hardware and the other
andrewm@13: // ADCs and DACs (if available). If only audio is available, numMatrixFrames
andrewm@13: // will be 0.
andrewm@13: 
andrewm@52: void render(BeagleRTContext *context, void *userData)
andrewm@13: {
andrewm@13: 	// Simplest possible case: pass inputs through to outputs
andrewm@52: 	for(unsigned int n = 0; n < context->audioFrames; n++) {
giuliomoro@180: 		for(unsigned int ch = 0; ch < context->audioChannels; ch++){
giuliomoro@180: 			// Two equivalent ways to write this code
giuliomoro@180: 
giuliomoro@180: 			// The long way, using the buffers directly:
giuliomoro@180: 			// context->audioOut[n * context->audioChannels + ch] =
giuliomoro@180: 			// 		context->audioIn[n * context->audioChannels + ch];
giuliomoro@180: 
giuliomoro@180: 			// Or using the macros:
giuliomoro@180: 			audioWriteFrame(context, n, ch, audioReadFrame(context, n, ch));
giuliomoro@180: 		}
andrewm@13: 	}
andrewm@13: 
giuliomoro@180: 	// Same with analog channelss
giuliomoro@180: 	for(unsigned int n = 0; n < context->analogFrames; n++) {
giuliomoro@180: 		for(unsigned int ch = 0; ch < context->analogChannels; ch++) {
giuliomoro@180: 			// Two equivalent ways to write this code
giuliomoro@180: 
giuliomoro@180: 			// The long way, using the buffers directly:
giuliomoro@180: 			// context->analogOut[n * context->analogChannels + ch] = context->analogIn[n * context->analogChannels + ch];
giuliomoro@180: 
giuliomoro@180: 			// Or using the macros:
giuliomoro@180: 			analogWriteFrame(context, n, ch, analogReadFrame(context, n, ch));
giuliomoro@180: 		}
giuliomoro@180: 	}
andrewm@13: }
andrewm@13: 
andrewm@56: // cleanup() is called once at the end, after the audio has stopped.
andrewm@56: // Release any resources that were allocated in setup().
andrewm@13: 
andrewm@56: void cleanup(BeagleRTContext *context, void *userData)
andrewm@13: {
andrewm@13: 
andrewm@13: }