Mercurial > hg > beaglert
diff examples/01-Basics/scope/render.cpp @ 464:8fcfbfb32aa0 prerelease
Examples reorder with subdirectories. Added header to each project. Moved Doxygen to bottom of render.cpp.
author | Robert Jack <robert.h.jack@gmail.com> |
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date | Mon, 20 Jun 2016 16:20:38 +0100 |
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children | b935f890e512 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/examples/01-Basics/scope/render.cpp Mon Jun 20 16:20:38 2016 +0100 @@ -0,0 +1,102 @@ +/* + ____ _____ _ _ +| __ )| ____| | / \ +| _ \| _| | | / _ \ +| |_) | |___| |___ / ___ \ +|____/|_____|_____/_/ \_\ + +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 <Scope.h> +#include <cmath> + +// set the frequency of the oscillators +float gFrequency = 110.0; +float gPhase; +float gInverseSampleRate; + +// instantiate the scope +Scope scope; + +bool setup(BelaContext *context, void *userData) +{ + // tell the scope how many channels and the sample rate + scope.setup(3, context->audioSampleRate); + + gPhase = 0; + gInverseSampleRate = 1.0f/context->audioSampleRate; + + return true; +} + +float lastOut = 0.0; +float lastOut2 = 0.0; +void render(BelaContext *context, void *userData) +{ + // iterate over the audio frames and create three oscillators, seperated in phase by PI/2 + for (unsigned int n=0; n<context->audioFrames; n++){ + float out = 0.8f * sinf(gPhase); + float out2 = 0.8f * sinf(gPhase - M_PI/2); + float out3 = 0.8f * sinf(gPhase + M_PI/2); + gPhase += 2.0 * M_PI * gFrequency * gInverseSampleRate; + if(gPhase > 2.0 * M_PI) + gPhase -= 2.0 * M_PI; + + // log the three oscillators to the scope + scope.log(out, out2, out3); + + // optional - tell the scope to trigger when oscillator 1 becomes less than oscillator 2 + // note this has no effect unless trigger mode is set to custom in the scope UI + if (lastOut >= lastOut2 && out < out2){ + scope.trigger(); + } + + lastOut = out; + lastOut2 = out2; + } +} + +void cleanup(BelaContext *context, void *userData) +{ + +} + +/* ------------ Project Explantation ------------ */ + +/** +\example 01-scope + +Oscilloscope in-browser +----------------------- + +This example demonstrates the scope feature of the IDE. + +The scope is instantiated at the top of the file via `Scope scope;` + +In `setup()` we define how many channels the scope should have and the sample +rate that it should run at via `scope.setup(3, context->audioSampleRate)`. + +In `render()` we choose what the scope log via `scope.log(out, out2, out3)`. +In this example the scope is logging three sine waves with different phases. To see +the output click on the <b>Open Scope</b> button. + +An additional option is to set the trigger of the oscilloscope from within `render()`. +In this example we are triggering the scope when oscillator 1 becomes less than +oscillator 2 via `scope.trigger()`. Note that this functionality only takes effect +when the triggering mode is set to custom in the scope UI. +*/