On 12 Sep 2006 11:43:25 +0200, Guillaume Cottenceau [EMAIL PROTECTED] wrote:
Karl Dane karl 'at' rince.net writes:
Hi all,
I'm trying to write a simple alpha cross-fade app: basically a slideshow
that fades one image in and the other out. However, can not get alpha
fades
to work.
I'm very new to SDL, so please don't laugh at my code! But I'd be very
grateful if anyone could point out where I'm going wrong. The code
snippet
below results in the image being displayed without any change.
Many thanks,
Karl Dane
#!/usr/bin/perl
use warnings;
use SDL::App;
our $app = SDL::App-new(
-width = 640,
-height = 480,
-depth = 24,
-fullscreen = 0,
);
for ($i=260; $i =0; $i-=1) {
print $i\n;
my $img1 = SDL::Surface-new( -name = ./img1.png );
$img1-display_format();
$img1-set_alpha(SDL_SRCALPHA, $i);
/usr/include/SDL/SDL_video.h says for this method:
* The 'alpha' parameter is ignored for surfaces that have an alpha
channel.
One solution might be to remove the alpha by converting the
surface or creating a new surface with proper properties then
blitting the original surface to it.
$img1-blit( SDL::Rect-new(
-width = 640, -height = 480), $app, undef);
$app-sync;
}
--
Guillaume Cottenceau
Create your personal SMS or WAP Service - visit http://mobilefriends.ch/
Hi Guillaume -
Thanks for your prompt reply. You mention converting the surface, I assume
to remove the alpha channel. Any ideas how I'd go about doing this? Is there
an appropriate method?
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