Messages

1

Graphics / Add vertices to a vector

« on: April 24, 2018, 02:30:13 am »

I'm trying to draw about a hundred lines on the screen. So far I'm testing my code with adding only two vertices to a vector but the code won't compile because of

error: expected primary-expression before ']' token vertices.push_back(line[]);

I'm not really experienced in C++ and any help would be greatly appreciated.

Here's my code so far.

    std::vector <sf::Vertex> vertices;

    sf::Vertex line[] =
    {
        sf::Vertex(sf::Vector2f(1, 0), sf::Color::Red),
        sf::Vertex(sf::Vector2f(1, 150), sf::Color::Green),
    };

    sf::Vertex line2[] =
    {
        sf::Vertex(sf::Vector2f(3, 0), sf::Color::Red),
        sf::Vertex(sf::Vector2f(3, 150), sf::Color::Green)
    };

    vertices.push_back(line[]);
    vertices.push_back(line2[]);

2

Audio / Re: How to get the current audio sample?

« on: March 31, 2018, 02:39:41 pm »

Thank you! When I think about it your answer makes a lot of sense. I'm new to SFML and C++ programming as a whole so I really appreciate you taking the time to explain what I was doing wrong. One last thing I want to ask is what is a good source to read more about signal processing and where did you start learning from?

3

Audio / How to get the current audio sample?

« on: March 31, 2018, 02:10:28 pm »

I'm trying to apply a Fourier Transform on the current audio sample. This is how I'm accessing all samples and storing them in a variable.

const auto samples = buffer.getSamples();

To get the current playing position I'm using

sf::Sound::getPlayingOffset() const

because this is the closest thing I found to what I'm trying to achieve. However, I don't think it will work in my case because the only usage of this method I found is to return the seconds of playback that have elapsed.

  while (sound.getStatus() == sf::Sound::Playing){
    // Display the playing position
    std::cout << "\rPlaying... " << sound.getPlayingOffset().asSeconds() << " sec";
    std::cout << std::flush;
  }

My question is is there a way I can access only the current sample that is played and apply Fourier Transform to it. If yes which methods should I be looking at?

4

Audio / Re: What values should I expect to be returned from buffer.getSample()?

« on: February 20, 2018, 02:34:09 pm »

Thank you, it's working now!

5

Audio / Re: What values should I expect to be returned from buffer.getSample()?

« on: February 20, 2018, 10:07:52 am »

When I try to find the samples of other files I get only zeros. Here's my code. This https://freesound.org/people/reaktorplayer/sounds/99674/ is the reaktor.wav I'm using.

  sf::SoundBuffer buffer;

  if(!buffer.loadFromFile("reaktor.wav")){
    std::cout << "didn't load properly";
    return -1;
  }

  const sf::Int16* samples = buffer.getSamples();

  for (int i = 0; i < 44; i++){
    std::cout << samples[i] << std::endl;
  }
 

Should I be doing something differently?

6

Audio / What values should I expect to be returned from buffer.getSample()?

« on: February 18, 2018, 08:07:53 pm »

I have an array

const sf::Int16* samples = buffer.getSamples();

and I access it like

samples[i];

and I get values ranging from -4 to 4.

Is this what the output should be because samples are returned as 16 bits signed integers and I was looking for values ranging from −32,768:32,767?