comparison examples/01-Basics/passthrough/render.cpp @ 464:8fcfbfb32aa0 prerelease

Examples reorder with subdirectories. Added header to each project. Moved Doxygen to bottom of render.cpp.

+/*
+ ____  _____ _        _    
+| __ )| ____| |      / \   
+|  _ \|  _| | |     / _ \  
+| |_) | |___| |___ / ___ \ 
+|____/|_____|_____/_/   \_\
+
+The platform for ultra-low latency audio and sensor processing
+
+http://bela.io
+
+A project of the Augmented Instruments Laboratory within the
+Centre for Digital Music at Queen Mary University of London.
+http://www.eecs.qmul.ac.uk/~andrewm
+
+(c) 2016 Augmented Instruments Laboratory: Andrew McPherson,
+	Astrid Bin, Liam Donovan, Christian Heinrichs, Robert Jack,
+	Giulio Moro, Laurel Pardue, Victor Zappi. All rights reserved.
+
+The Bela software is distributed under the GNU Lesser General Public License
+(LGPL 3.0), available here: https://www.gnu.org/licenses/lgpl-3.0.txt
+*/
+
+#include <Bela.h>
+#include <rtdk.h>
+
+bool setup(BelaContext *context, void *userData)
+{
+	// Nothing to do here...
+	return true;
+}
+
+void render(BelaContext *context, void *userData)
+{
+	// Simplest possible case: pass inputs through to outputs
+	for(unsigned int n = 0; n < context->audioFrames; n++) {
+		for(unsigned int ch = 0; ch < context->audioChannels; ch++){
+			// Two equivalent ways to write this code
+
+			// The long way, using the buffers directly:
+			// context->audioOut[n * context->audioChannels + ch] =
+			// 		context->audioIn[n * context->audioChannels + ch];
+
+			// Or using the macros:
+			audioWrite(context, n, ch, audioRead(context, n, ch));
+		}
+	}
+
+	// Same with analog channelss
+	for(unsigned int n = 0; n < context->analogFrames; n++) {
+		for(unsigned int ch = 0; ch < context->analogChannels; ch++) {
+			// Two equivalent ways to write this code
+
+			// The long way, using the buffers directly:
+			// context->analogOut[n * context->analogChannels + ch] = context->analogIn[n * context->analogChannels + ch];
+
+			// Or using the macros:
+			analogWrite(context, n, ch, analogRead(context, n, ch));
+		}
+	}
+}
+
+void cleanup(BelaContext *context, void *userData)
+{
+
+}
+
+/* ------------ Project Explantation ------------ */
+
+/**
+\example 01-passthrough
+
+Audio and analog passthrough: input to output
+-----------------------------------------
+
+This sketch demonstrates how to read from and write to the audio and analog input and output buffers.
+
+In `render()` you'll see a nested for loop structure. You'll see this in all Bela projects. 
+The first for loop cycles through `audioFrames`, the second through 
+`audioChannels` (in this case left 0 and right 1).
+
+You can access any information about current audio and sensor settings you can do the following: 
+`context->name_of_item`. For example `context->audioChannels` returns current number of channels,
+`context->audioFrames` returns the current number of audio frames, 
+`context->audioSampleRate` returns the audio sample rate.
+
+You can look at all the information you can access in ::BeagleRTContext.
+
+Reading and writing from the audio buffers
+------------------------------------------
+
+The simplest way to read samples from the audio input buffer is with
+`audioRead()` which we pass three arguments: context, current audio 
+frame and current channel. In this example we have 
+`audioRead(context, n, ch)` where both `n` and `ch` are provided by 
+the nested for loop structure.
+
+We can write samples to the audio output buffer in a similar way using 
+`audioWrite()`. This has a fourth argument which is the value of the output.
+For example `audioWrite(context, n, ch, value_to_output)`.
+
+Reading and writing from the analog buffers
+-------------------------------------------
+
+The same is true for `analogRead()` and `analogWrite()`.
+
+Note that for the analog channels we write to and read from the buffers in a separate set 
+of nested for loops. This is because the they are sampled at half audio rate by default. 
+The first of these for loops cycles through `analogFrames`, the second through
+`analogChannels`.
+
+By setting `audioWriteFrame(context, n, ch, audioReadFrame(context, n, ch))` and
+`analogWrite(context, n, ch, analogReadFrame(context, n, ch))` we have a simple 
+passthrough of audio input to output and analog input to output.
+
+
+It is also possible to address the buffers directly, for example: 
+`context->audioOut[n * context->audioChannels + ch]`.
+*/