Slider::getValue() gives different value that Slider is set to

1

Hello,
I have problem, probably with some types mismatch (double vs float vs int).
My Slider range is set by AudioParameterFloat from -24.00f to 24.00f, and step is set to 0.01f.
And when I set by text box editor value 0, then in sliderValueChanged() when I use:
float value = mySlider.getValue();
I get value = -0.000000536441803

I also tried: float value = (float)mySlider.getValue();
but I get the same result.

Why is that? How to prevent it? Do I need to write my own method that round float to two decimal places after comma?

For any help great thanks in advance.

2

I’m noticing similar behavior in my app. Have you found an answer to this?

3

Hmm… Sorry it was long time ago. And I don’t remember exactly what was my code.

But I suppose in that case I had set step directly on slider and simultanously on AudioProcessorParameter which was attached to slider and there was some missmatch. But I am not sure.

If it’s the case then maybe you should look something like that in your code.

I’ve just checked my current code. And I see I use only parameter to define range and step. And it works for me like that:
std::make_unique<AudioParameterFloat>( PARAM_ID, PARAM_NAME, NormalisableRange<float>( PARAM_MIN, PARAM_MAX, PARAM_STEP, PARAM_SKEW), PARAM_DEFAULT)

4

Thanks.

I just finished tracing through my code and found a function called “constrainedValue”. In my case I pass 55.00 to “setValue”, but getValue returns 54.99…

Below is JUCE’s “setValue” implementation. “constrainedValue” literally changed the value I sent to it.

    void setValue (double newValue, NotificationType notification)
{
    // for a two-value style slider, you should use the setMinValue() and setMaxValue()
    // methods to set the two values.
    jassert (style != TwoValueHorizontal && style != TwoValueVertical);

    newValue = constrainedValue (newValue);

    if (style == ThreeValueHorizontal || style == ThreeValueVertical)
    {
        jassert (static_cast<double> (valueMin.getValue()) <= static_cast<double> (valueMax.getValue()));

        newValue = jlimit (static_cast<double> (valueMin.getValue()),
                           static_cast<double> (valueMax.getValue()),
                           newValue);
    }

    if (newValue != lastCurrentValue)
    {
        if (valueBox != nullptr)
            valueBox->hideEditor (true);

        lastCurrentValue = newValue;

        // (need to do this comparison because the Value will use equalsWithSameType to compare
        // the new and old values, so will generate unwanted change events if the type changes)
        if (currentValue != newValue)
            currentValue = newValue;

        updateText();
        owner.repaint();
        updatePopupDisplay (newValue);

        triggerChangeMessage (notification);
    }
}