Re: How to draw text with fade out effect?
Re: How to draw text with fade out effect?
- Subject: Re: How to draw text with fade out effect?
- From: Peter N Lewis <email@hidden>
- Date: Fri, 30 Jan 2009 10:08:33 +0900
At 17:38 +0200 28/1/09, Oleg Krupnov wrote:
I want to produce the effect of a text string fading out when it's too
long to be displayed in a rect. This kind of effect is used in many
apps.
One option is to draw the end of the string character by character
with varying alphas.
Ie, instead of
Hello Cruel Wo...
draw
Hello Cruel Wo
then draw r at 75% alpha
then draw l at 50% alpha
then draw d at 25% alpha.
If you really want finer control, you could use a narrow clipping
rect, which would also let you draw the entire string ten times with
different alphs and different clipping rects, assuming that
performance did not become a problem. The code would actually be
pretty straight forward:
Clip to width -20
Draw string
Clip from width-20 to width -18
Draw string at Alpha 90%
Clip from width-18 to width-16
Draw string at Alpha 80%
...
Your code doesn't even have to consider if the string is long enough
to need truncating.
Enjoy,
Peter.
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