Bespoke Composites

Java 2D
#1

I tried to implement a Composite that would give all my drawing a tint of a given colour. However, I got lots of messages about not support yet. Sorry, I don’t have the logs handy to post. Are we not able to implement Composites of own as yet?

Kev

#2

sure you can.

All you gotta do is implement the java.awt.Composite and the java.awt.CompositeContext interfaces.

I believe you require permissions to do it in an Applet though. (you could use the Composite to get pixel values from the users display… hardly the biggest of security concerns ::slight_smile: but then the ppl who design Suns APIs obviously don’t live in the real world :P)

oh… and using a Custom compositing rule will be slow as **** :-*

#3

[quote](you could use the Composite to get pixel values from the users display… hardly the biggest of security concerns ::slight_smile: but then the ppl who design Suns APIs obviously don’t live in the real world :P)
[/quote]
It would be a big concern if you could get pixel values from anywhere on the user’s display. But I can’t see how you would be able to get pixel values for anything other than images that the applet already had access to.

#4

I think the rationale behind it is;
if reading back from vram is allowed in any way,
you open yourself upto the possibility the programmer can find a way around any checks regarding exactly where in vram reading is allowed.

Its far easier from a bug prevention POV, to simply deny readback altogether.

Still, it does suk :wink:

#5

Custom compositing to the screen (or VI) is not implemented in 1.4-1.4.2.

#6

[quote]Custom compositing to the screen (or VI) is not implemented in 1.4-1.4.2.
[/quote]
urk, thats what happens when I give advice without testing :wink:

Does it affect drawing direct to Components as well, or is it just when using BufferStrategy and/or VolatileImages?

e.g. would this work?


Graphics2D g2d = (Graphics2D)frame.getGraphics();
g2d.setComposite(new MyCustomComposite());
g2d.drawImage(blahblah,0,0,null);
#7

[quote]Custom compositing to the screen (or VI) is not implemented in 1.4-1.4.2.
[/quote]
Will it be implemented in 1.5?

#8

Damn I hope so :slight_smile:

No worries Abuse, I only just got back to this thread :slight_smile:

Kev

#9

Nope, you’ll get the exception about “getRaster: not implemented yet”. It may work for VI, but will be dog-slow at first, and then the vi will be punted to system memory (because we have to poke the pixels)

Sigh… Unfortunately, I don’t think so. There were no demand for this (that’s why it’s still broken since 1.4), and the fix isn’t trivial.