annotate projects/scope_basic/render.cpp @ 273:0ee6eebb567a prerelease

Added scope_basic and scope_analogue example projects

#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)
{

}