comparison 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>
date Tue, 17 May 2016 16:31:51 +0100
parents
children 5433c83ce04e
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272:733006bdbca2 273:0ee6eebb567a
1 #include <BeagleRT.h>
2 #include <Scope.h>
3 #include <cmath>
4
5 // set the frequency of the oscillators
6 float gFrequency = 110.0;
7 float gPhase;
8 float gInverseSampleRate;
9
10 // instantiate the scope
11 Scope scope;
12
13 bool setup(BeagleRTContext *context, void *userData)
14 {
15 // tell the scope how many channels and the sample rate
16 scope.setup(3, context->audioSampleRate);
17
18 gPhase = 0;
19 gInverseSampleRate = 1.0f/context->audioSampleRate;
20
21 return true;
22 }
23
24 float lastOut = 0.0;
25 float lastOut2 = 0.0;
26 void render(BeagleRTContext *context, void *userData)
27 {
28 // iterate over the audio frames and create three oscillators, seperated in phase by PI/2
29 for (unsigned int n=0; n<context->audioFrames; n++){
30 float out = 0.8f * sinf(gPhase);
31 float out2 = 0.8f * sinf(gPhase - M_PI/2);
32 float out3 = 0.8f * sinf(gPhase + M_PI/2);
33 gPhase += 2.0 * M_PI * gFrequency * gInverseSampleRate;
34 if(gPhase > 2.0 * M_PI)
35 gPhase -= 2.0 * M_PI;
36
37 // log the three oscillators to the scope
38 scope.log(out, out2, out3);
39
40 // optional - tell the scope to trigger when oscillator 1 becomes less than oscillator 2
41 // note this has no effect unless trigger mode is set to custom in the scope UI
42 if (lastOut >= lastOut2 && out < out2){
43 scope.trigger();
44 }
45
46 lastOut = out;
47 lastOut2 = out2;
48 }
49 }
50
51 void cleanup(BeagleRTContext *context, void *userData)
52 {
53
54 }