Re: Transparency?

[Tobias Leich]

These draw_something methods out of the SDLx packages just use blit at
the end anyway.

A tip: dont care about speed right now, just try to get things working.
Optimize at the end.

Cheers

Am 10.06.2012 18:42, schrieb Alex:
> Hi!
>
> When do we use blit and when do we use draw_something? Is blit faster / 
> better?
>
> Best regards,
> Alex
>
> -Ursprüngliche Nachricht-
> Von: Tobias Leich [mailto:em...@froggs.de] 
> Gesendet: Sonntag, 10. Juni 2012 10:47
> An: Jack Maney; sdl-devel@perl.org
> Betreff: AW: Transparency?
>
> Hi, you have to know that draw_rect works differently for your app surface 
> and regular surfaces. If you draw to your app, the pixels just get the value 
> of the color. But if you do this to a regular surface, and blit that to your 
> app surface, the pixels will be blendet...
> So create a new surface, modify that, blit and update.
>
> Cheers
>
> Jack Maney  hat geschrieben:
>
>> Hello,
>>
>> I'm not so terribly new to Perl but very new to SDL.  I was fiddling with 
>> the following "Hello, World!"-ish code in the SDL manual:
>>
>> use strict;
>> use warnings;
>>
>> use SDL;
>> use SDLx::App;
>>
>> my $app = SDLx::App->new( width=> 800, height => 600 );
>>
>> $app->draw_rect([ $app->width / 4, $app->height / 4,
>>  $app->width / 2, $app->height / 2, ],
>>  [ 0, 0, 255, 255] );
>>
>> $app->update();
>>
>> sleep(5);
>>
>> and found that changing the alpha portion of the rectangle color (eg fading 
>> the rectangle out completely via [0,0,255,0]) had no effect on the rendering 
>> of the rectangle.  I did some searching on this and found some 
>> old<http://www.velocityreviews.com/forums/t906303-problem-with-alphachannel-with-sdl-xxx-blitting.html>
>>  
>> questions<http://markmail.org/message/lqtdvmmjmiryumrw#query:+page:1+mid:q63xng5hz7lpcsbl+state:results>
>>  from 4+ years ago, but I'm wondering if there is a simple workaround or an 
>> approach that has come about since then.
>>
>> Thank you for your time,
>>
>> Jack
>>
>>
> -
> eMail ist virenfrei.
> Von AVG überprüft - www.avg.de
> Version: 2012.0.2177 / Virendatenbank: 2425/5054 - Ausgabedatum: 07.06.2012 
>

AW: Transparency?

[Alex]

Hi!

When do we use blit and when do we use draw_something? Is blit faster / better?

Best regards,
Alex

-Ursprüngliche Nachricht-
Von: Tobias Leich [mailto:em...@froggs.de] 
Gesendet: Sonntag, 10. Juni 2012 10:47
An: Jack Maney; sdl-devel@perl.org
Betreff: AW: Transparency?

Hi, you have to know that draw_rect works differently for your app surface and 
regular surfaces. If you draw to your app, the pixels just get the value of the 
color. But if you do this to a regular surface, and blit that to your app 
surface, the pixels will be blendet...
So create a new surface, modify that, blit and update.

Cheers

Jack Maney  hat geschrieben:

>Hello,
>
>I'm not so terribly new to Perl but very new to SDL.  I was fiddling with the 
>following "Hello, World!"-ish code in the SDL manual:
>
>use strict;
>use warnings;
>
>use SDL;
>use SDLx::App;
>
>my $app = SDLx::App->new( width=> 800, height => 600 );
>
>$app->draw_rect([ $app->width / 4, $app->height / 4,
>  $app->width / 2, $app->height / 2, ],
>  [ 0, 0, 255, 255] );
>
>$app->update();
>
>sleep(5);
>
>and found that changing the alpha portion of the rectangle color (eg fading 
>the rectangle out completely via [0,0,255,0]) had no effect on the rendering 
>of the rectangle.  I did some searching on this and found some 
>old<http://www.velocityreviews.com/forums/t906303-problem-with-alphachannel-with-sdl-xxx-blitting.html>
> 
>questions<http://markmail.org/message/lqtdvmmjmiryumrw#query:+page:1+mid:q63xng5hz7lpcsbl+state:results>
> from 4+ years ago, but I'm wondering if there is a simple workaround or an 
>approach that has come about since then.
>
>Thank you for your time,
>
>Jack
>
>

-
eMail ist virenfrei.
Von AVG überprüft - www.avg.de
Version: 2012.0.2177 / Virendatenbank: 2425/5054 - Ausgabedatum: 07.06.2012 

AW: Transparency?

[Tobias Leich]

Hi, you have to know that draw_rect works differently for your app surface and 
regular surfaces. If you draw to your app, the pixels just get the value of the 
color. But if you do this to a regular surface, and blit that to your app 
surface, the pixels will be blendet...
So create a new surface, modify that, blit and update.

Cheers

Jack Maney  hat geschrieben:

>Hello,
>
>I'm not so terribly new to Perl but very new to SDL.  I was fiddling with the 
>following "Hello, World!"-ish code in the SDL manual:
>
>use strict;
>use warnings;
>
>use SDL;
>use SDLx::App;
>
>my $app = SDLx::App->new( width=> 800, height => 600 );
>
>$app->draw_rect([ $app->width / 4, $app->height / 4,
>  $app->width / 2, $app->height / 2, ],
>  [ 0, 0, 255, 255] );
>
>$app->update();
>
>sleep(5);
>
>and found that changing the alpha portion of the rectangle color (eg fading 
>the rectangle out completely via [0,0,255,0]) had no effect on the rendering 
>of the rectangle.  I did some searching on this and found some 
>old
> 
>questions
> from 4+ years ago, but I'm wondering if there is a simple workaround or an 
>approach that has come about since then.
>
>Thank you for your time,
>
>Jack
>
>

Transparency?

[Jack Maney]

Hello,

I'm not so terribly new to Perl but very new to SDL.  I was fiddling with the 
following "Hello, World!"-ish code in the SDL manual:

use strict;
use warnings;

use SDL;
use SDLx::App;

my $app = SDLx::App->new( width=> 800, height => 600 );

$app->draw_rect([ $app->width / 4, $app->height / 4,
  $app->width / 2, $app->height / 2, ],
  [ 0, 0, 255, 255] );

$app->update();

sleep(5);

and found that changing the alpha portion of the rectangle color (eg fading the 
rectangle out completely via [0,0,255,0]) had no effect on the rendering of the 
rectangle.  I did some searching on this and found some 
old
 
questions
 from 4+ years ago, but I'm wondering if there is a simple workaround or an 
approach that has come about since then.

Thank you for your time,

Jack