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Adam Strzelecki to SDL Since current DirectFB implementation is incomplete for YUV surfaces (actually causes segmentation faults when trying Lock and use YUV planar textures) I decided to fix it a bit. Here's a patch that should make DirectFB properly support YUV both packed and planar (3 planes). (1) Removed SDL_BYTESPERPIXEL at all in favor of DFB_BYTES_PER_PIXEL(SDLToDFBPixelFormat(fmt)) which does return always proper BPP for YUVs too, coz SDL_BYTESPERPIXEL returns incorrect values for FOURCCs (2) Fixed data->pixels allocation for planar YUVs in CreateTexture, it should allocate 150% more space (3) Copy other planes for planar YUVs in UpdateTexture (4) Moved checking if format is supported at all with DirectFB on CreateTexture at the beginning of the code Waiting for comments, -- Adam Strzelecki | nanoant.com
author Sam Lantinga <slouken@libsdl.org>
date Sun, 04 Oct 2009 04:03:37 +0000
parents 355632dca928
children
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>SDL_AddTimer</TITLE
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><H1
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>SDL_AddTimer</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN8482"
></A
><H2
>Name</H2
>SDL_AddTimer&nbsp;--&nbsp;Add a timer which will call a callback after the specified number of milliseconds has
elapsed.</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN8485"
></A
><H2
>Synopsis</H2
><DIV
CLASS="FUNCSYNOPSIS"
><A
NAME="AEN8486"
></A
><P
></P
><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>SDL_TimerID <B
CLASS="FSFUNC"
>SDL_AddTimer</B
></CODE
>(Uint32 interval, SDL_NewTimerCallback callback, void *param);</CODE
></P
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="SDLNEWTIMERCALLBACK"
></A
><H2
>Callback</H2
><PRE
CLASS="PROGRAMLISTING"
>/* type definition for the "new" timer callback function */
typedef Uint32 (*SDL_NewTimerCallback)(Uint32 interval, void *param);</PRE
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN8495"
></A
><H2
>Description</H2
><P
>Adds a callback function to be run after the specified number of
milliseconds has elapsed. The callback function is passed the current
timer interval and the user supplied parameter from the
<TT
CLASS="FUNCTION"
>SDL_AddTimer</TT
> call and returns the next timer
interval. If the returned value from the callback is the same as the one
passed in, the periodic alarm continues, otherwise a new alarm is
scheduled.</P
><P
>To cancel a currently running timer call
<A
HREF="sdlremovetimer.html"
>SDL_RemoveTimer</A
> with the
timer ID returned from
<TT
CLASS="FUNCTION"
>SDL_AddTimer</TT
>.</P
><P
>The timer callback function may run in a different thread than your
main program, and so shouldn't call any functions from within itself.
You may always call <A
HREF="sdlpushevent.html"
>SDL_PushEvent</A
>, however.</P
><P
>The granularity of the timer is platform-dependent, but you should count
on it being at least 10 ms as this is the most common number.
This means that if
you request a 16 ms timer, your callback will run approximately 20 ms
later on an unloaded system.  If you wanted to set a flag signaling
a frame update at 30 frames per second (every 33 ms), you might set a
timer for 30 ms (see example below).

If you use this function, you need to pass <TT
CLASS="LITERAL"
>SDL_INIT_TIMER</TT
>
to <A
HREF="sdlinit.html"
>SDL_Init</A
>.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN8507"
></A
><H2
>Return Value</H2
><P
>Returns an ID value for the added timer or
<SPAN
CLASS="RETURNVALUE"
>NULL</SPAN
> if there was an error.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN8511"
></A
><H2
>Examples</H2
><P
><PRE
CLASS="PROGRAMLISTING"
>my_timer_id = SDL_AddTimer((33/10)*10, my_callbackfunc, my_callback_param);</PRE
></P
></DIV
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><A
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></A
><H2
>See Also</H2
><P
><A
HREF="sdlremovetimer.html"
><TT
CLASS="FUNCTION"
>SDL_RemoveTimer</TT
></A
>,
<A
HREF="sdlpushevent.html"
><TT
CLASS="FUNCTION"
>SDL_PushEvent</TT
></A
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