Mercurial > sdl-ios-xcode

view docs/html/sdlgetrgba.html @ 1257:448a9a64537b

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
[PATCH] SDL_GetVideoMode() does not find best mode, part 2 Following commit 1.51, I come accross a problem when SDL must choose between several video modes that could suit the one asked. If I ask 320x240 with this list: 768x480 768x240 640x400 640x200 384x480 384x240 320x400 320x200 The smallest selectables modes are 384x240 and 320x400. And SDL choose the later in this list, but 384x240 is more suitable. So I added a check to compare the pixel count (surface) of modes, and select the one which has the smallest pixel count. In my example, 384x240 has 92160 pixels, and 320x400 has 128000 pixels. So now SDL will choose 384x240 for the asked 320x240 mode.
author Patrice Mandin <patmandin@gmail.com>
date Thu, 19 Jan 2006 21:28:52 +0000
parents 355632dca928
children
line wrap: on
line source

<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&nbsp;--&nbsp;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
>