242 lines
3.4 KiB
HTML
242 lines
3.4 KiB
HTML
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<HTML
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><HEAD
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><TITLE
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>SDL_DisplayFormatAlpha</TITLE
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><META
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NAME="GENERATOR"
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CONTENT="Modular DocBook HTML Stylesheet Version 1.64
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"><LINK
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REL="HOME"
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TITLE="SDL Library Documentation"
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HREF="index.html"><LINK
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REL="UP"
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TITLE="Video"
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HREF="video.html"><LINK
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REL="PREVIOUS"
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TITLE="SDL_DisplayFormat"
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HREF="sdldisplayformat.html"><LINK
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REL="NEXT"
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TITLE="SDL_WarpMouse"
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HREF="sdlwarpmouse.html"></HEAD
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><BODY
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CLASS="REFENTRY"
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BGCOLOR="#FFF8DC"
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TEXT="#000000"
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LINK="#0000ee"
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VLINK="#551a8b"
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ALINK="#ff0000"
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><DIV
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CLASS="NAVHEADER"
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><TABLE
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WIDTH="100%"
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BORDER="0"
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CELLPADDING="0"
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CELLSPACING="0"
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><TR
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><TH
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COLSPAN="3"
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ALIGN="center"
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>SDL Library Documentation</TH
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></TR
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><TR
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><TD
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WIDTH="10%"
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ALIGN="left"
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VALIGN="bottom"
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><A
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HREF="sdldisplayformat.html"
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>Prev</A
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></TD
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><TD
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WIDTH="80%"
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ALIGN="center"
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VALIGN="bottom"
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></TD
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><TD
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WIDTH="10%"
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ALIGN="right"
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VALIGN="bottom"
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><A
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HREF="sdlwarpmouse.html"
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>Next</A
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></TD
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></TR
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></TABLE
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><HR
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ALIGN="LEFT"
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WIDTH="100%"></DIV
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><H1
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><A
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NAME="SDLDISPLAYFORMATALPHA"
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>SDL_DisplayFormatAlpha</A
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></H1
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><DIV
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CLASS="REFNAMEDIV"
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><A
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NAME="AEN2013"
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></A
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><H2
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>Name</H2
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>SDL_DisplayFormatAlpha -- Convert a surface to the display format</DIV
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><DIV
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CLASS="REFSYNOPSISDIV"
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><A
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NAME="AEN2016"
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></A
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><H2
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>Synopsis</H2
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><DIV
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CLASS="FUNCSYNOPSIS"
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><A
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NAME="AEN2017"
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></A
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><P
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></P
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><PRE
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CLASS="FUNCSYNOPSISINFO"
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>#include "SDL.h"</PRE
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><P
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><CODE
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><CODE
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CLASS="FUNCDEF"
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>SDL_Surface *<B
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CLASS="FSFUNC"
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>SDL_DisplayFormatAlpha</B
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></CODE
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>(SDL_Surface *surface);</CODE
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></P
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><P
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></P
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></DIV
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></DIV
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><DIV
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CLASS="REFSECT1"
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><A
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NAME="AEN2023"
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></A
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><H2
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>Description</H2
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><P
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>This function takes a surface and copies it to a new surface of the
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pixel format and colors of the video framebuffer plus an alpha channel,
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suitable for fast blitting onto the display surface. It calls
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<A
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HREF="sdlconvertsurface.html"
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>SDL_ConvertSurface</A
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></P
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><P
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>If you want to take advantage of hardware colorkey or alpha blit
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acceleration, you should set the colorkey and alpha value before
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calling this function.</P
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><P
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>This function can be used to convert a colourkey to an alpha channel,
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if the <TT
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CLASS="LITERAL"
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>SDL_SRCCOLORKEY</TT
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> flag is set on the surface.
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The generated surface will then be transparent (alpha=0) where the
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pixels match the colourkey, and opaque (alpha=255) elsewhere.</P
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></DIV
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><DIV
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CLASS="REFSECT1"
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><A
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NAME="AEN2030"
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></A
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><H2
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>Return Value</H2
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><P
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>If the conversion fails or runs out of memory, it returns
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<SPAN
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CLASS="RETURNVALUE"
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>NULL</SPAN
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></P
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></DIV
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><DIV
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CLASS="REFSECT1"
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><A
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NAME="AEN2034"
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></A
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><H2
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>See Also</H2
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><P
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><A
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HREF="sdlconvertsurface.html"
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>SDL_ConvertSurface</A
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>,
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<A
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HREF="sdlsetalpha.html"
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>SDL_SetAlpha</A
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>,
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<A
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HREF="sdlsetcolorkey.html"
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>SDL_SetColorKey</A
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>,
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<A
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HREF="sdldisplayformat.html"
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>SDL_DisplayFormat</A
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>,
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<A
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HREF="sdlsurface.html"
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>SDL_Surface</A
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></P
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></DIV
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><DIV
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CLASS="NAVFOOTER"
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><HR
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ALIGN="LEFT"
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WIDTH="100%"><TABLE
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WIDTH="100%"
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BORDER="0"
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CELLPADDING="0"
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CELLSPACING="0"
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><TR
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><TD
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WIDTH="33%"
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ALIGN="left"
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VALIGN="top"
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><A
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HREF="sdldisplayformat.html"
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>Prev</A
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></TD
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><TD
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WIDTH="34%"
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ALIGN="center"
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VALIGN="top"
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><A
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HREF="index.html"
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>Home</A
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></TD
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><TD
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WIDTH="33%"
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ALIGN="right"
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VALIGN="top"
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><A
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HREF="sdlwarpmouse.html"
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>Next</A
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></TD
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></TR
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><TR
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><TD
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WIDTH="33%"
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ALIGN="left"
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VALIGN="top"
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>SDL_DisplayFormat</TD
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><TD
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WIDTH="34%"
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ALIGN="center"
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VALIGN="top"
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><A
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HREF="video.html"
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>Up</A
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></TD
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><TD
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WIDTH="33%"
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ALIGN="right"
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VALIGN="top"
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>SDL_WarpMouse</TD
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></TR
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></TABLE
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></DIV
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></BODY
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></HTML
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>
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