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><H1 |
><A |
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>SDL_DisplayFormatAlpha</A |
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><A |
NAME="AEN2013" |
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><H2 |
>Name</H2 |
>SDL_DisplayFormatAlpha -- Convert a surface to the display format</DIV |
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><H2 |
>Synopsis</H2 |
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><P |
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><PRE |
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>#include "SDL.h"</PRE |
><P |
><CODE |
><CODE |
CLASS="FUNCDEF" |
>SDL_Surface *<B |
CLASS="FSFUNC" |
>SDL_DisplayFormatAlpha</B |
></CODE |
>(SDL_Surface *surface);</CODE |
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><H2 |
>Description</H2 |
><P |
>This function takes a surface and copies it to a new surface of the |
pixel format and colors of the video framebuffer plus an alpha channel, |
suitable for fast blitting onto the display surface. It calls |
<A |
HREF="sdlconvertsurface.html" |
>SDL_ConvertSurface</A |
></P |
><P |
>If you want to take advantage of hardware colorkey or alpha blit |
acceleration, you should set the colorkey and alpha value before |
calling this function.</P |
><P |
>This function can be used to convert a colourkey to an alpha channel, |
if the <TT |
CLASS="LITERAL" |
>SDL_SRCCOLORKEY</TT |
> flag is set on the surface. |
The generated surface will then be transparent (alpha=0) where the |
pixels match the colourkey, and opaque (alpha=255) elsewhere.</P |
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><H2 |
>Return Value</H2 |
><P |
>If the conversion fails or runs out of memory, it returns |
<SPAN |
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>NULL</SPAN |
></P |
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><H2 |
>See Also</H2 |
><P |
><A |
HREF="sdlconvertsurface.html" |
>SDL_ConvertSurface</A |
>, |
<A |
HREF="sdlsetalpha.html" |
>SDL_SetAlpha</A |
>, |
<A |
HREF="sdlsetcolorkey.html" |
>SDL_SetColorKey</A |
>, |
<A |
HREF="sdldisplayformat.html" |
>SDL_DisplayFormat</A |
>, |
<A |
HREF="sdlsurface.html" |
>SDL_Surface</A |
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