Mercurial > sdl-ios-xcode
view docs/html/sdlgetrgba.html @ 1905:36d52b1f0504
Prefer the D3D renderer over GDI, at least for testing.
Added support for the SDL_VIDEO_RENDERER environment variable to pick the desired render driver.
Implemented WritePixels support for the D3D renderer.
author | Sam Lantinga <slouken@libsdl.org> |
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date | Fri, 14 Jul 2006 08:22:45 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >SDL_GetRGBA</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_GetRGB" HREF="sdlgetrgb.html"><LINK REL="NEXT" TITLE="SDL_CreateRGBSurface" HREF="sdlcreatergbsurface.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" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >SDL Library Documentation</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="sdlgetrgb.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlcreatergbsurface.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLGETRGBA" ></A >SDL_GetRGBA</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN1747" ></A ><H2 >Name</H2 >SDL_GetRGBA -- Get RGBA values from a pixel in the specified pixel format.</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN1750" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN1751" ></A ><P ></P ><PRE CLASS="FUNCSYNOPSISINFO" >#include "SDL.h"</PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >void <B CLASS="FSFUNC" >SDL_GetRGBA</B ></CODE >(Uint32 pixel, SDL_PixelFormat *fmt, Uint8 *r, Uint8 *g, Uint8 *b, Uint8 *a);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1757" ></A ><H2 >Description</H2 ><P >Get RGBA component values from a pixel stored in the specified pixel format.</P ><P >This function uses the entire 8-bit [0..255] range when converting color components from pixel formats with less than 8-bits per RGB component (e.g., a completely white pixel in 16-bit RGB565 format would return [0xff, 0xff, 0xff] not [0xf8, 0xfc, 0xf8]).</P ><P >If the surface has no alpha component, the alpha will be returned as 0xff (100% opaque).</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1762" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlgetrgb.html" >SDL_GetRGB</A >, <A HREF="sdlmaprgb.html" >SDL_MapRGB</A >, <A HREF="sdlmaprgba.html" >SDL_MapRGBA</A >, <A HREF="sdlpixelformat.html" >SDL_PixelFormat</A ></P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="sdlgetrgb.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="sdlcreatergbsurface.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_GetRGB</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="video.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_CreateRGBSurface</TD ></TR ></TABLE ></DIV ></BODY ></HTML >