Fundamentals/print/render.cpp

Printing to the console

This example demonstrates how to print to the console. When working within the audio thread use the function rt_printf(). This has the same functionality as printf() but is safe to call from the audio thread. However, make sure to not make too many calls to this function within a render loop as this may overload the CPU and/or stall communication with the board. In the render() function above a counter is implemented in order to only print to the console after a specified interval has passed. A counter variable is used to keep track of the amount of samples elapsed after starting the program. The usage of rt_printf() is identical to printf(): http://en.cppreference.com/w/cpp/io/c/fprintf

/*
 ____  _____ _        _
| __ )| ____| |      / \
|  _ \|  _| | |     / _ \
| |_) | |___| |___ / ___ \
|____/|_____|_____/_/   \_\
http://bela.io
*/
 
#include <Bela.h>
#include <cmath>
 
float gInterval = 0.5;
float gSecondsElapsed = 0;
int gCount = 0;
 
bool setup(BelaContext *context, void *userData)
{
 
    // Print a string
        rt_printf("This Bela example has just started running!\n");
        // Print a string containing a float
    rt_printf("Here's the value of pi: %f\n",M_PI);
 
        return true;
}
 
void render(BelaContext *context, void *userData)
{
        for(unsigned int n = 0; n < context->audioFrames; n++) {
 
                // Increment a counter on every frame
                gCount++;
 
                // Print a message every second indicating the number of seconds elapsed
                if(gCount % (int)(context->audioSampleRate*gInterval) == 0) {
                    gSecondsElapsed += gInterval;
                    rt_printf("Time elapsed: %f\n",gSecondsElapsed);
                }
 
        }
}
 
void cleanup(BelaContext *context, void *userData)
{
 
}