view docs/html/sdlsyswmevent.html @ 1259:36f24cdfcda7

te: Thu, 17 Apr 2003 11:25:26 -0700 From: "Jim" Subject: [SDL] Frame buffer patches... Would seem that GCC 3.2.2 promotes all signed values to unsigned if any single vlaue is unsigned in an expression... for instance when calculating an elo touch position....evertyhign is an (int) except for cach_vinfo.xres which is unsigned. THerefore if y ou reverse the SDL_ELO_MIN_X and SDL_ELO_MAX_X values the resulging negative value pegs the expression to it's max. Attached it the accumu lated patch to typecast the unsigned values to (int) - *dx = (cache_vinfo.xres - (cache_vinfo.xres * (input_x - ELO_MIN_X)) / width); + *dx = ((int)cache_vinfo.xres - ((int)cache_vinfo.xres * (input_x - ELO_MIN_X)) / width); and also to provide quite failure to operations which have the screen currently locked... The touch screen I'm using the original values were exactly opposite of any position I touched on the screen - evaluating the math the expr ession SHOULD have handled reversing the min and max values - and after casting the unsigned .xres and .yres to a signed int - worked well. .. Jim
author Sam Lantinga <slouken@libsdl.org>
date Tue, 24 Jan 2006 06:36:43 +0000
parents 355632dca928
children
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>SDL_SysWMEvent</H1
><DIV
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><H2
>Name</H2
>SDL_SysWMEvent&nbsp;--&nbsp;Platform-dependent window manager event.</DIV
><DIV
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><H2
>Description</H2
><P
>The system window manager event contains a pointer to system-specific 
information about unknown window manager events.  If you enable this event
using 
<A
HREF="sdleventstate.html"
><TT
CLASS="FUNCTION"
>SDL_EventState()</TT
></A
>, 
it will be generated whenever unhandled events are received from the window 
manager.  This can be used, for example, to implement cut-and-paste in your 
application.

<PRE
CLASS="PROGRAMLISTING"
>typedef struct {
         Uint8 type;   /* Always SDL_SYSWMEVENT */
         SDL_SysWMmsg *msg;
 } SDL_SysWMEvent;</PRE
>

If you want to obtain system-specific information about the window manager,
you can fill the version member of a <SPAN
CLASS="STRUCTNAME"
>SDL_SysWMinfo</SPAN
> 
structure (details can be found in <TT
CLASS="FILENAME"
>SDL_syswm.h</TT
>, which must be included) using the <TT
CLASS="FUNCTION"
>SDL_VERSION()</TT
> macro found in 
<TT
CLASS="FILENAME"
>SDL_version.h</TT
>, and pass it to the 
function:
<DIV
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><P
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><P
><CODE
><CODE
CLASS="FUNCDEF"
>int <B
CLASS="FSFUNC"
>SDL_GetWMInfo</B
></CODE
>(SDL_SysWMinfo *info);</CODE
></P
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>SDL_EventState</TT
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