Mercurial > hg > beaglert
diff projects/scope_basic/render.cpp @ 273:0ee6eebb567a prerelease
Added scope_basic and scope_analogue example projects
author | Liam Donovan <l.b.donovan@qmul.ac.uk> |
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date | Tue, 17 May 2016 16:31:51 +0100 |
parents | |
children | 5433c83ce04e |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/projects/scope_basic/render.cpp Tue May 17 16:31:51 2016 +0100 @@ -0,0 +1,54 @@ +#include <BeagleRT.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(BeagleRTContext *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(BeagleRTContext *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(BeagleRTContext *context, void *userData) +{ + +}