Mercurial > sdl-ios-xcode
view docs/html/sdluserevent.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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<HTML ><HEAD ><TITLE >SDL_UserEvent</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="SDL Event Structures." HREF="eventstructures.html"><LINK REL="PREVIOUS" TITLE="SDL_SysWMEvent" HREF="sdlsyswmevent.html"><LINK REL="NEXT" TITLE="SDL_QuitEvent" HREF="sdlquitevent.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="sdlsyswmevent.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlquitevent.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLUSEREVENT" ></A >SDL_UserEvent</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN4565" ></A ><H2 >Name</H2 >SDL_UserEvent -- A user-defined event type</DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN4568" ></A ><H2 >Structure Definition</H2 ><PRE CLASS="PROGRAMLISTING" >typedef struct{ Uint8 type; int code; void *data1; void *data2; } SDL_UserEvent;</PRE ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN4571" ></A ><H2 >Structure Data</H2 ><DIV CLASS="INFORMALTABLE" ><A NAME="AEN4573" ></A ><P ></P ><TABLE BORDER="0" CLASS="CALSTABLE" ><TBODY ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >type</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_USEREVENT</TT > through to <TT CLASS="LITERAL" >SDL_NUMEVENTS-1</TT ></TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >code</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >User defined event code</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >data1</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >User defined data pointer</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >data2</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >User defined data pointer</TD ></TR ></TBODY ></TABLE ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN4594" ></A ><H2 >Description</H2 ><P ><SPAN CLASS="STRUCTNAME" >SDL_UserEvent</SPAN > is in the <TT CLASS="STRUCTFIELD" ><I >user</I ></TT > member of the structure <A HREF="sdlevent.html" ><SPAN CLASS="STRUCTNAME" >SDL_Event</SPAN ></A >. This event is unique, it is never created by SDL but only by the user. The event can be pushed onto the event queue using <A HREF="sdlpushevent.html" ><TT CLASS="FUNCTION" >SDL_PushEvent</TT ></A >. The contents of the structure members or completely up to the programmer, the only requirement is that <TT CLASS="STRUCTFIELD" ><I >type</I ></TT > is a value from <TT CLASS="LITERAL" >SDL_USEREVENT</TT > to <TT CLASS="LITERAL" >SDL_NUMEVENTS-1</TT > (inclusive).</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN4606" ></A ><H2 >Examples</H2 ><P ><PRE CLASS="PROGRAMLISTING" >SDL_Event event; event.type = SDL_USEREVENT; event.user.code = my_event_code; event.user.data1 = significant_data; event.user.data2 = 0; SDL_PushEvent(&event);</PRE ></P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN4610" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlevent.html" ><SPAN CLASS="STRUCTNAME" >SDL_Event</SPAN ></A >, <A HREF="sdlpushevent.html" ><TT CLASS="FUNCTION" >SDL_PushEvent</TT ></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="sdlsyswmevent.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="sdlquitevent.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_SysWMEvent</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="eventstructures.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_QuitEvent</TD ></TR ></TABLE ></DIV ></BODY ></HTML >