XCodeなどのConsoleへの出力

DBG("TEST")
などで、出力できる。

DBGはsystemに定義されているマクロ
https://docs.juce.com/master/group__juce__core-system.html

ログの出力

juce::Logger
で出力できる。

ここで使われているので参考に
https://docs.juce.com/master/tutorial_simple_synth_noise.html

How to use the FileLogger

FileLoggerの使い方

ログ出力サンプル

ログ出力するプロジェクトをgithubにあげました。
https://github.com/uchidama/SimpleSynthNoiseTutorialMod/

#pragma once

//==============================================================================
class MainContentComponent   : public juce::AudioAppComponent
{
public:
    MainContentComponent() : m_log_file("~/log_test.txt"), m_logger(m_log_file,"Welcome to the log",0)
    {
        juce::Logger::setCurrentLogger(&m_logger);

        setSize (800, 600);
        setAudioChannels (0, 2); // no inputs, two outputs
        
    }

    ~MainContentComponent() override
    {
        shutdownAudio();
    }

    void prepareToPlay (int samplesPerBlockExpected, double sampleRate) override
    {
        juce::String message;
        message << "Preparing to play audio...\n";
        message << " samplesPerBlockExpected = " << samplesPerBlockExpected << "\n";
        message << " sampleRate = " << sampleRate;
        juce::Logger::getCurrentLogger()->writeToLog (message);
    }

    void releaseResources() override
    {
        juce::Logger::getCurrentLogger()->writeToLog ("Releasing audio resources");
    }

    void getNextAudioBlock (const juce::AudioSourceChannelInfo& bufferToFill) override
    {
        for (auto channel = 0; channel < bufferToFill.buffer->getNumChannels(); ++channel)
        {
            // Get a pointer to the start sample in the buffer for this audio output channel
            auto* buffer = bufferToFill.buffer->getWritePointer (channel, bufferToFill.startSample);

            // Fill the required number of samples with noise between -0.125 and +0.125
            for (auto sample = 0; sample < bufferToFill.numSamples; ++sample)
                buffer[sample] = random.nextFloat() * 0.25f - 0.125f;
        }
    }

private:
    juce::Random random;
    juce::File m_log_file;
    juce::FileLogger m_logger;

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (MainContentComponent)
};

使ってるコア部分。
こんな感じ。

ログを見る

Mac OS Xで見るなら、ターミナルから

tail -n 100 -f ~/log_test.txt

で見ると便利。