view docs/html/sdlsetcolorkey.html @ 641:df178851293b

Date: 28 Jun 2003 22:42:52 +0100 From: Alan Swanson Subject: Re: [SDL] New XFree 4.3 Video Mode Patch I have a wee amendment that moves the qsort in set_best_resolution to only occur after failing to find an exact match only. This would make absolutely sure we get a user set mode. While I've never had any problems for my normal resolutions (1280x1024, 1024x768, 800x600 & 640,480) while closely examining the output from qsort I've noticed it doesn't seem to sort the modes fully. These is one definite wrong at 1152x768 and a few that just look wrong to me. From a program (attached) I made to examine this more easily. X has sorted its mode list using the same method as ours (plus frequency), and our user modes get inserted without any other movement. On the patch I've made I've also changed cmpmodes to sort on vertical resolution and then horizontal. Ie vertical is now most significant bit.
author Sam Lantinga <slouken@libsdl.org>
date Sat, 28 Jun 2003 21:52:26 +0000
parents e5bc29de3f0a
children 355632dca928
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>SDL_SetColorKey</TITLE
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><H1
><A
NAME="SDLSETCOLORKEY"
>SDL_SetColorKey</A
></H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN1661"
></A
><H2
>Name</H2
>SDL_SetColorKey&nbsp;--&nbsp;Sets the color key (transparent pixel) in a blittable surface and
RLE acceleration.</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN1664"
></A
><H2
>Synopsis</H2
><DIV
CLASS="FUNCSYNOPSIS"
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><P
></P
><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>int <B
CLASS="FSFUNC"
>SDL_SetColorKey</B
></CODE
>(SDL_Surface *surface, Uint32 flag, Uint32 key);</CODE
></P
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN1671"
></A
><H2
>Description</H2
><P
> Sets the color key (transparent pixel) in a blittable surface and enables or
 disables RLE blit acceleration.</P
><P
>RLE acceleration can substantially speed up blitting of images with large
horizontal runs of transparent pixels (i.e., pixels that match the
<TT
CLASS="PARAMETER"
><I
>key</I
></TT
> value). The <TT
CLASS="PARAMETER"
><I
>key</I
></TT
> must be of the same pixel format as the <TT
CLASS="PARAMETER"
><I
>surface</I
></TT
>, <A
HREF="sdlmaprgb.html"
><TT
CLASS="FUNCTION"
>SDL_MapRGB</TT
></A
> is often useful for obtaining an acceptable value.</P
><P
>If <TT
CLASS="PARAMETER"
><I
>flag</I
></TT
> is <TT
CLASS="LITERAL"
>SDL_SRCCOLORKEY</TT
> then
<TT
CLASS="PARAMETER"
><I
>key</I
></TT
> is the transparent pixel value in the source image of a
blit.</P
><P
>If <TT
CLASS="PARAMETER"
><I
>flag</I
></TT
> is OR'd with
<TT
CLASS="LITERAL"
>SDL_RLEACCEL</TT
> then the surface will be draw using RLE
acceleration when drawn with
<A
HREF="sdlblitsurface.html"
>SDL_BlitSurface</A
>.  The surface will
actually be encoded for RLE acceleration the first time
<A
HREF="sdlblitsurface.html"
>SDL_BlitSurface</A
> or
<A
HREF="sdldisplayformat.html"
>SDL_DisplayFormat</A
> is called on the
surface.</P
><P
>If <TT
CLASS="PARAMETER"
><I
>flag</I
></TT
> is 0, this function clears
any current color key.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN1692"
></A
><H2
>Return Value</H2
><P
>This function returns <SPAN
CLASS="RETURNVALUE"
>0</SPAN
>, or
<SPAN
CLASS="RETURNVALUE"
>-1</SPAN
> if there was an error.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN1697"
></A
><H2
>See Also</H2
><P
><A
HREF="sdlblitsurface.html"
><TT
CLASS="FUNCTION"
>SDL_BlitSurface</TT
></A
>,
<A
HREF="sdldisplayformat.html"
><TT
CLASS="FUNCTION"
>SDL_DisplayFormat</TT
></A
>,
<A
HREF="sdlmaprgb.html"
><TT
CLASS="FUNCTION"
>SDL_MapRGB</TT
></A
>,
<A
HREF="sdlsetalpha.html"
><TT
CLASS="FUNCTION"
>SDL_SetAlpha</TT
></A
></P
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