I have a question regarding setting the Alpha value of pixels in a window of a Java desktop application running under Linux. A simplified version of the code from my paint function is shown below:
public void paint(Graphics g) { int alpha; Graphics2D g2d = (Graphics2D) g; Composite c = AlphaComposite.getInstance(AlphaComposite.SRC_OVER); g2d.setComposite(c); // Draw transparent rectangle alpha = 128; g2d.setPaint(new Color(0, 0, 255, alpha)); g2d.fill(new Rectangle(0, 0, 100, 100)); // Draw opaque rectangle alpha = 255; g2d.setPaint(new Color(0, 0, 255, alpha)); g2d.fill(new Rectangle(100, 0, 100, 100)); } I am using Graphics2D to draw rectangles with different values of alpha. Now, what I am really trying to do is change the alpha value of pixels in the window, however, what appears to be happening is that the alpha value I specify is used for the drawing operation and then discarded. Just as background info, I use the application window in another program that exploits the Composite extension of the X server. This program redirects the window and performs some additional processing based on the alpha value of pixels in the window. If I draw the graphics using X then the alpha value of pixels in the window is modified but not when I use Java. To summarise my question, is there a way in Java to modify the alpha value of pixels in a window? Thanks for looking at my post, any advise or suggestions gratefully received. Steve [Message sent by forum member 'spriest' (spriest)] http://forums.java.net/jive/thread.jspa?messageID=331235 =========================================================================== To unsubscribe, send email to lists...@java.sun.com and include in the body of the message "signoff JAVA2D-INTEREST". For general help, send email to lists...@java.sun.com and include in the body of the message "help".