Checking is a pixel transparent or not??

[role]

Hello I need to know a pixel is transparent or not.
I convert a color of an image to transparent with this function :

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BufferedImage image; int x, y; int col = image.getRGB(x, y); image.setRGB(x, y, col & 0x00ffffff);

The color of the image in coordinate x, y is converted to transparent.

Now i need to check whether the color is transparent or not :

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BufferedImage image; int x, y; int col = image.getRGB(x, y); if (col == ????) {    System.out.println("transparent color"); } else {    System.out.println("opaque color"); }

Anyone know about this?

What I'm confuse is the transparent color of a new created blank image (GraphicsConfiguration.createCompatibleImage(width, height, Transparency.BITMASK)) is 0, but when I use above code to convert a color to transparent, the transparent color is not 0?


Thanks

[jbanes]

To solve your testing problem, you can use a bitwise operation:

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if((col & 0xFF000000) == 0x00) {     System.out.println("transparent color"); } else {     System.out.println("opaque color"); }

Checking for partial transparency can be done with:

1	if((col & 0xFF000000) != 0xFF000000)

Any questions?

Edit: Took me a few tries to get the code right. ;-)

[role]

Wow thanks a million jbanes!!!
Now my pixel perfect collision working perfectly!! Wohoo!!
Thanks thanks thanks