view docs/html/sdlupdaterects.html @ 270:37fa1484f71b

From: "Mattias Engdeg�rd" <f91-men@nada.kth.se> To: slouken@devolution.com Subject: Re: [SDL] Question about SDL_FillRect() I benchmarked with and without clipping UpdateRects and was unable to find any difference on my moderately slow machine. Anyway, I haven't added clipping in this patch, but fixed a couple of bugs and generally cleaned up some of the X11 image code. Most importantly, UpdateRects now checks for both zero height and width. Also, I eliminated the entire code to byteswap X11 images since X11 can do that automatically if you ask it nicely :-)
author Sam Lantinga <slouken@libsdl.org>
date Fri, 18 Jan 2002 22:02:03 +0000
parents e5bc29de3f0a
children 355632dca928
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><H1
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>SDL_UpdateRects</A
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><A
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><H2
>Name</H2
>SDL_UpdateRects&nbsp;--&nbsp;Makes sure the given list of rectangles is updated on the given screen.</DIV
><DIV
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>Synopsis</H2
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><P
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><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>void <B
CLASS="FSFUNC"
>SDL_UpdateRects</B
></CODE
>(SDL_Surface *screen, int numrects, SDL_Rect *rects);</CODE
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><A
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><H2
>Description</H2
><P
>Makes sure the given list of rectangles is updated on the given screen.
The rectangles must all be confined within the screen boundaries (no
clipping is done).</P
><P
>This function should not be called while <TT
CLASS="PARAMETER"
><I
>screen</I
></TT
> is
<A
HREF="sdllocksurface.html"
>locked</A
>.</P
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
>It is adviced to call this function only once per frame, since each
call has some processing overhead. This is no restriction since you
can pass any number of rectangles each time.</P
><P
>The rectangles are not automatically merged or checked for overlap. In
general, the programmer can use his knowledge about his particular
rectangles to merge them in an efficient way, to avoid overdraw.</P
></BLOCKQUOTE
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><A
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><H2
>See Also</H2
><P
><A
HREF="sdlupdaterect.html"
><TT
CLASS="FUNCTION"
>SDL_UpdateRect</TT
></A
>,
<A
HREF="sdlrect.html"
><SPAN
CLASS="STRUCTNAME"
>SDL_Rect</SPAN
></A
>,
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HREF="sdlsurface.html"
><SPAN
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>SDL_Surface</SPAN
></A
>,
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HREF="sdllocksurface.html"
><TT
CLASS="FUNCTION"
>SDL_LockSurface</TT
></A
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