AffineTransform::scale blurry edges

[ImJimmi]

@StefanS

void MainComponent::resized()
{
    auto rectArea = getLocalBounds().removeFromBottom(50).reduced(10);
    rect.setBounds(rectArea);
    rect.setTransform(juce::AffineTransform::scale(0.73, 0.73));
    rect.setCentrePosition(rectArea.getCentre());
}

Components in JUCE can have a sub-pixel position/size when transformed meaning their position and or size may not always be exact integers.

In the example you gave, you’re calculating a juce::Rectangle<int> object with the first line, setting the Component’s bounds, and then scaling the Component which results in a non-integer size.
You could simply scale the rectangle before setting it as the Component’s bounds:

void MainComponent::resized()
{
    auto rectArea = getLocalBounds().removeFromBottom(50).reduced(10).toFloat();
    rectArea = rectArea.transformedBy(juce::AffineTransform::scale(0.73f, 0.73f));
    rect.setBounds(rectArea.toNearestIntEdges());
    rect.setCentrePosition(rectArea.getCentre().roundToInt());
}

If I know I’m going to be using floats somewhere in my layout, I usually find it best to use floats from the start and to only convert to an integer at the very last step.