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<HTML><HEAD><TITLE>SDL_MapRGBA</TITLE><METANAME="GENERATOR"CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+"><LINKREL="HOME"TITLE="SDL Library Documentation"HREF="index.html"><LINKREL="UP"TITLE="Video"HREF="video.html"><LINKREL="PREVIOUS"TITLE="SDL_MapRGB"HREF="sdlmaprgb.html"><LINKREL="NEXT"TITLE="SDL_GetRGB"HREF="sdlgetrgb.html"></HEAD><BODYCLASS="REFENTRY"BGCOLOR="#FFF8DC"TEXT="#000000"LINK="#0000ee"VLINK="#551a8b"ALINK="#ff0000"><DIVCLASS="NAVHEADER"><TABLESUMMARY="Header navigation table"WIDTH="100%"BORDER="0"CELLPADDING="0"CELLSPACING="0"><TR><THCOLSPAN="3"ALIGN="center">SDL Library Documentation</TH></TR><TR><TDWIDTH="10%"ALIGN="left"VALIGN="bottom"><AHREF="sdlmaprgb.html"ACCESSKEY="P">Prev</A></TD><TDWIDTH="80%"ALIGN="center"VALIGN="bottom"></TD><TDWIDTH="10%"ALIGN="right"VALIGN="bottom"><AHREF="sdlgetrgb.html"ACCESSKEY="N">Next</A></TD></TR></TABLE><HRALIGN="LEFT"WIDTH="100%"></DIV><H1><ANAME="SDLMAPRGBA"></A>SDL_MapRGBA</H1><DIVCLASS="REFNAMEDIV"><ANAME="AEN1687"></A><H2>Name</H2>SDL_MapRGBA -- Map a RGBA color value to a pixel format.</DIV><DIVCLASS="REFSYNOPSISDIV"><ANAME="AEN1690"></A><H2>Synopsis</H2><DIVCLASS="FUNCSYNOPSIS"><ANAME="AEN1691"></A><P></P><PRECLASS="FUNCSYNOPSISINFO">#include "SDL.h"</PRE><P><CODE><CODECLASS="FUNCDEF">Uint32 <BCLASS="FSFUNC">SDL_MapRGBA</B></CODE>(SDL_PixelFormat *fmt, Uint8 r, Uint8 g, Uint8 b, Uint8 a);</CODE></P><P></P></DIV></DIV><DIVCLASS="REFSECT1"><ANAME="AEN1697"></A><H2>Description</H2><P>Maps the RGBA color value to the specified pixel format and returns thepixel value as a 32-bit int.</P><P>If the format has a palette (8-bit) the index of the closest matchingcolor in the palette will be returned.</P><P>If the specified pixel format has no alpha component the alpha valuewill be ignored (as it will be in formats with a palette).</P></DIV><DIVCLASS="REFSECT1"><ANAME="AEN1702"></A><H2>Return Value</H2><P>A pixel value best approximating the given RGBA color value for a givenpixel format. If the pixel format bpp (color depth) is less than 32-bppthen the unused upper bits of the return value can safely be ignored(e.g., with a 16-bpp format the return value can be assigned to a<SPANCLASS="TYPE">Uint16</SPAN>, and similarly a <SPANCLASS="TYPE">Uint8</SPAN> for an 8-bppformat).</P></DIV><DIVCLASS="REFSECT1"><ANAME="AEN1707"></A><H2>See Also</H2><P><AHREF="sdlgetrgb.html">SDL_GetRGB</A>,<AHREF="sdlgetrgba.html">SDL_GetRGBA</A>,<AHREF="sdlmaprgb.html">SDL_MapRGB</A>,<AHREF="sdlpixelformat.html">SDL_PixelFormat</A></P></DIV><DIVCLASS="NAVFOOTER"><HRALIGN="LEFT"WIDTH="100%"><TABLESUMMARY="Footer navigation table"WIDTH="100%"BORDER="0"CELLPADDING="0"CELLSPACING="0"><TR><TDWIDTH="33%"ALIGN="left"VALIGN="top"><AHREF="sdlmaprgb.html"ACCESSKEY="P">Prev</A></TD><TDWIDTH="34%"ALIGN="center"VALIGN="top"><AHREF="index.html"ACCESSKEY="H">Home</A></TD><TDWIDTH="33%"ALIGN="right"VALIGN="top"><AHREF="sdlgetrgb.html"ACCESSKEY="N">Next</A></TD></TR><TR><TDWIDTH="33%"ALIGN="left"VALIGN="top">SDL_MapRGB</TD><TDWIDTH="34%"ALIGN="center"VALIGN="top"><AHREF="video.html"ACCESSKEY="U">Up</A></TD><TDWIDTH="33%"ALIGN="right"VALIGN="top">SDL_GetRGB</TD></TR></TABLE></DIV></BODY></HTML>⌨️ 快捷键说明
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