/
sdldisplayformatalpha.html
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/
sdldisplayformatalpha.html
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<HTML
><HEAD
><TITLE
>SDL_DisplayFormatAlpha</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+
"><LINK
REL="HOME"
TITLE="SDL Library Documentation"
HREF="index.html"><LINK
REL="UP"
TITLE="Video"
HREF="video.html"><LINK
REL="PREVIOUS"
TITLE="SDL_DisplayFormat"
HREF="sdldisplayformat.html"><LINK
REL="NEXT"
TITLE="SDL_WarpMouse"
HREF="sdlwarpmouse.html"></HEAD
><BODY
CLASS="REFENTRY"
BGCOLOR="#FFF8DC"
TEXT="#000000"
LINK="#0000ee"
VLINK="#551a8b"
ALINK="#ff0000"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
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><TR
><TH
COLSPAN="3"
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>SDL Library Documentation</TH
></TR
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><TD
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HREF="sdldisplayformat.html"
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>Prev</A
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><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><H1
><A
NAME="SDLDISPLAYFORMATALPHA"
></A
>SDL_DisplayFormatAlpha</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN2432"
></A
><H2
>Name</H2
>SDL_DisplayFormatAlpha -- Convert a surface to the display format</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN2435"
></A
><H2
>Synopsis</H2
><DIV
CLASS="FUNCSYNOPSIS"
><A
NAME="AEN2436"
></A
><P
></P
><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>SDL_Surface *<B
CLASS="FSFUNC"
>SDL_DisplayFormatAlpha</B
></CODE
>(SDL_Surface *surface);</CODE
></P
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN2442"
></A
><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
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN2449"
></A
><H2
>Return Value</H2
><P
>If the conversion fails or runs out of memory, it returns
<SPAN
CLASS="RETURNVALUE"
>NULL</SPAN
></P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN2453"
></A
><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
></P
></DIV
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><A
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ACCESSKEY="P"
>Prev</A
></TD
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>Home</A
></TD
><TD
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><A
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></TD
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><TR
><TD
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>SDL_DisplayFormat</TD
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>