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* [9fans] xor draw
@ 2013-02-14 18:51 Yaroslav
  2013-02-14 19:10 ` erik quanstrom
  0 siblings, 1 reply; 3+ messages in thread
From: Yaroslav @ 2013-02-14 18:51 UTC (permalink / raw)
  To: 9fans

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we can't do XOR drawing with draw(2) like with bitblt, can we?

--
- Yaroslav

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^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [9fans] xor draw
  2013-02-14 18:51 [9fans] xor draw Yaroslav
@ 2013-02-14 19:10 ` erik quanstrom
  2013-02-14 20:31   ` Yaroslav
  0 siblings, 1 reply; 3+ messages in thread
From: erik quanstrom @ 2013-02-14 19:10 UTC (permalink / raw)
  To: 9fans

On Thu Feb 14 13:52:09 EST 2013, yarikos@gmail.com wrote:

> we can't do XOR drawing with draw(2) like with bitblt, can we?

if there's a trivial α channel, it's possible.  otherwise one
runs the risk of α multiplication.

- erik



^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [9fans] xor draw
  2013-02-14 19:10 ` erik quanstrom
@ 2013-02-14 20:31   ` Yaroslav
  0 siblings, 0 replies; 3+ messages in thread
From: Yaroslav @ 2013-02-14 20:31 UTC (permalink / raw)
  To: Fans of the OS Plan 9 from Bell Labs

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2013/2/14 erik quanstrom <quanstro@quanstro.net>

> On Thu Feb 14 13:52:09 EST 2013, yarikos@gmail.com wrote:
>
> > we can't do XOR drawing with draw(2) like with bitblt, can we?
>
> if there's a trivial α channel, it's possible.  otherwise one
> runs the risk of α multiplication.
>
>
No alpha there - I'd like to learn the trick please.

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^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2013-02-14 20:31 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2013-02-14 18:51 [9fans] xor draw Yaroslav
2013-02-14 19:10 ` erik quanstrom
2013-02-14 20:31   ` Yaroslav

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