[JAVA2D] Painting in Transparent Panel

[Ted Hill]

Hello,   I am seeing some ‘distortion’ when painting in a transparent panel.   What I have: ========= I have an opaque JPanel that displays a buffered image. The image can be zoomed and panned using the AffineTransform.   I have another transparent JPanel which is added to the parent JPanel mentioned above. It also overrides paintComponent(g) and draws some strings on top of the BufferedImage in the parent panel. Because the child panel is transparent, the parent’s BufferedImage ‘shows through’ beneath the Strings. The transparent child covers about 20% of its parent and is positioned along the right hand border of the parent panel.   The transparent panel is not always visible. When mousing into a certain area of the parent panel, it is set visible and then it draws some info Strings on top of the parent. When mousing out of the ‘trigger’ area, setVisible(false) is called on the transparent child.   What I see: I *occasionally* get a “lens” effect when “looking through the transparent child” at the BufferedImage below. That is, depending on the scale and translation values of the parent, there appears to be a tiny shift in the image of perhaps one-pixel.   For example, if I mouse in and out of the area that activates the transparent child, the underlying image is sometimes seen directly on the parent panel and sometimes viewed through the transparent child. As the state changes, I see the shift mentioned above.   Changing the zoom and pan by only a small amount will often cause this “lens” effect to disappear. Then changing them again by a small amount will cause the effect to reappear.   That is, at certain scale and translation values, I never see the lens effect, at others I do.   What I’m wondering: Could this be caused by some kind of pixel round-off calculation in the child?  (Perhaps my child panel is not aligned with its parent on a pixel boundary?) If so, is there some way to prevent this?   My code base is very large, so unfortunately I can’t post a working example of this.   Thank you for your help,   Ted Hill       =========================================================================== To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message "signoff JAVA2D-INTEREST". For general help, send email to [EMAIL PROTECTED] and include in the body of the message "help".