[SDL] Converting a surface to another color

[Josh Matthews]

Your best bet would probably be creating a default image in the GIMP with an
alpha mask, then load that with SDL_Image and overwrite the pixel data.
Alternatively, you could avoid the alpha mask and just use a color key by
creating an image with an inverted circle filled with pink.  In SDL, make a
surface, fill it with your gradient, then copy the pink pixels into your
surface from your image, set the surface's color key and voila!

On 12/31/06, Viktor Dick <dickviktor at gmx.net> wrote:
>
> Thanks. If I understand rightly, the gradient function would put the
> lines with lineColor or something like that. Is there someone that could
> give me some code how to apply an alpa mask? I'm not familiar with
> transparency under SDL and I did not found any tutorial explaining this
> well enough.
> Thanks.
>
> Josh Matthews schrieb:
> > What if you had a gradient function that created rectangles, then used a
> > circular alpha mask?
> >
> > On 12/31/06, *Viktor Dick* < dickviktor at gmx.net
> > <mailto:dickviktor at gmx.net>> wrote:
> >
> >     Hello,
> >     I'm trying to write a simple 2D-program with SDL (I do not want to
> >     use OpenGL).
> >     It is almost ready, but at the moment I paint the marbles of the
> >     players with
> >     filledCircleColor. I have painted a circle with gimp with a gradient
> >     from red
> >     (bottom) to white (top) so it looks better. I can load the image to
> >     the program,
> >     but I need more colors and I do not want create an extra file for
> >     each color. I
> >     need also blue, green etc. marbles. Does anyone know how to change
> >     the color in
> >     a loaded surface? In the far future, it should also be possible to
> >     let the users
> >     switch their colors, so it would not be possible to give a picture
> >     of each
> >     possible color with the package.
> >     Thanks
> >     Viktor
> >
> >
> >     _______________________________________________
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> >     SDL at libsdl.org <mailto:SDL at libsdl.org>
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> >
> >
> >
> >
> > --
> > Cheers,
> > Josh
> >
> > PGP: http://revvy.box43.net/Josh_Matthews.asc
> >
> >
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> >
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-- 
Cheers,
Josh

PGP: http://revvy.box43.net/Josh_Matthews.asc
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