Issue details

Running multiple instances of PixmapPacker on background thread may change Pixmap.Blending value to Pixmap.Blending.None.
This is caused by PixmapPacker.pack method changing Pixmap.Blending which is global state: https://github.com/libgdx/libgdx/blob/1.9.5/gdx/src/com/badlogic/gdx/graphics/g2d/PixmapPacker.java#L174

Reproduction steps/code

Run multiple instances on PixmapPacker on background thread. Eventually Pixmap.Blending will be changed to Pixmap.Blending.None.

Version of LibGDX and/or relevant dependencies

1.9.x

Please select the affected platforms

Probably all of them, observed on android and iOS.

• Android
• iOS (robovm)
• iOS (MOE)
• HTML/GWT
• Windows
• Linux
• MacOS