lincollincol/compose-audiowaveform

Wrong behavior when using an alpha color

Opened this issue · 2 comments

Jhiertz commented

Hi, thank you for this compose library

I've got an issue when using a colour with an alpha in waveformBrush, the alpha is also carried over to the progressBrush.

A small example to reproduce:

var waveformProgress by remember { mutableStateOf(0F) }

AudioWaveform(
    amplitudes = amplitude,
    waveformBrush = SolidColor(Color.White.copy(alpha = .5f)),
    progressBrush = SolidColor(Color.Red),
    amplitudeType = AmplitudeType.Max,
    progress = waveformProgress,
    onProgressChange = { waveformProgress = it }
)

And here is the actual rendering, the red does not match, it also has the alpha channel

image

IbrahimEzzatSaad commented

is there any updates on those bugs?

antweb commented

If you are just using the alpha value to get a specific color and don't actually need the transparency, you can work around this by creating a solid color with compositeOver:

// The color behind the waveform
val background = MaterialTheme.colorScheme.background

AudioWaveform(
    amplitudes = amplitude,
    waveformBrush = SolidColor(Color.White.copy(alpha = .5f).compositeOver(background)),
    progressBrush = SolidColor(Color.Red),
    amplitudeType = AmplitudeType.Max,
    progress = waveformProgress,
    onProgressChange = { waveformProgress = it }
)
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