how to rotate a bitmap 90 degrees

Question

There is a statement in android canvas.drawBitmap(visiblePage, 0, 0, paint);

When I add canvas.rotate(90), there is no effect. But if I wri

Answer 1

Just be careful of Bitmap type from java platform call like from comm1x's and Gnzlt's answers, because it might return null. I think it is also more flexible if the parameter can be any Number and use infix for readability, depends on your coding style.

infix fun Bitmap.rotate(degrees: Number): Bitmap? {
    return Bitmap.createBitmap(
        this,
        0,
        0,
        width,
        height,
        Matrix().apply { postRotate(degrees.toFloat()) },
        true
    )
}

How to use?

bitmap rotate 90
// or
bitmap.rotate(90)