Problems with blending in FSprites

[BioRyajenka]

Hello,
after updating korge to 3.0 I noticed transparent images stopped to render properly with FSprites. The issue seems to be related to premultiplied images.

korge 2.0 / korge 3.0:

If I comment this line in FSprites, it starts to work as expected.

Don't understand the details about this function though

[soywiz]

This should be fixed now. Now all the textures are expected to be premultiplied.

[BioRyajenka]

Hello,
after being resolved, the issue is there again (sprites are yellow-ish, instead of being transparent).

1. Will you reopen the issue or do I need to create new?
2. Do you know what may be the reason?

Clarification: the issue is only related to FSprites. Its not reproduceable with ordinary views.
For FSprites, here is the snippet:

val bmp = resourcesVfs["tree.png"].readBitmap()
image(bmp).xy(50, 50)
image(bmp) {
    xy(50, 250)
    alpha = .5
}

val fSprites = FSprites(2)
addChild(fSprites.createView(bmp))
with(fSprites) {
    val left = fSprites.alloc()
    left.xy(250f, 50f)
    left.colorMul = Colors.WHITE
    left.setTexIndex(0)
    left.setTex(bmp.slice())

    val right = fSprites.alloc()
    right.xy(250f, 250f)
    right.colorMul = Colors.WHITE.withAf(.5f)
    right.setTexIndex(0)
    right.setTex(bmp.slice())
}

And the result: