Mercurial > sdl-ios-xcode
view docs/html/sdlmousemotionevent.html @ 2042:3908e1f808e1
Fixed bug #292
I might be on crack here.
It looks like SDL_ConvertMono() in src/audio/SDL_audiocvt.c adds the left and
right channels of a stereo stream together, and clamps the new mono channel if
it would overflow.
Shouldn't it be dividing by 2 to average the two sample points instead of
clamping? Otherwise the mono sample point's volume doubles in the conversion.
This would also make the conversion faster, as it replaces two branches per
sample frame with a bitwise shift.
--ryan.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sun, 24 Sep 2006 15:56:36 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >SDL_MouseMotionEvent</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_KeyboardEvent" HREF="sdlkeyboardevent.html"><LINK REL="NEXT" TITLE="SDL_MouseButtonEvent" HREF="sdlmousebuttonevent.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="sdlkeyboardevent.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlmousebuttonevent.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLMOUSEMOTIONEVENT" ></A >SDL_MouseMotionEvent</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN4079" ></A ><H2 >Name</H2 >SDL_MouseMotionEvent -- Mouse motion event structure</DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN4082" ></A ><H2 >Structure Definition</H2 ><PRE CLASS="PROGRAMLISTING" >typedef struct{ Uint8 type; Uint8 state; Uint16 x, y; Sint16 xrel, yrel; } SDL_MouseMotionEvent;</PRE ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN4085" ></A ><H2 >Structure Data</H2 ><DIV CLASS="INFORMALTABLE" ><A NAME="AEN4087" ></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_MOUSEMOTION</TT ></TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >state</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >The current button state</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >x</I ></TT >, <TT CLASS="STRUCTFIELD" ><I >y</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >The X/Y coordinates of the mouse</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >xrel</I ></TT >, <TT CLASS="STRUCTFIELD" ><I >yrel</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Relative motion in the X/Y direction</TD ></TR ></TBODY ></TABLE ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN4109" ></A ><H2 >Description</H2 ><P ><SPAN CLASS="STRUCTNAME" >SDL_MouseMotionEvent</SPAN > is a member of the <A HREF="sdlevent.html" ><SPAN CLASS="STRUCTNAME" >SDL_Event</SPAN ></A > union and is used when an event of type <TT CLASS="LITERAL" >SDL_MOUSEMOTION</TT > is reported.</P ><P >Simply put, a <TT CLASS="LITERAL" >SDL_MOUSEMOTION</TT > type event occurs when a user moves the mouse within the application window or when <A HREF="sdlwarpmouse.html" ><TT CLASS="FUNCTION" >SDL_WarpMouse</TT ></A > is called. Both the absolute (<TT CLASS="STRUCTFIELD" ><I >x</I ></TT > and <TT CLASS="STRUCTFIELD" ><I >y</I ></TT >) and relative (<TT CLASS="STRUCTFIELD" ><I >xrel</I ></TT > and <TT CLASS="STRUCTFIELD" ><I >yrel</I ></TT >) coordinates are reported along with the current button states (<TT CLASS="STRUCTFIELD" ><I >state</I ></TT >). The button state can be interpreted using the <TT CLASS="LITERAL" >SDL_BUTTON</TT > macro (see <A HREF="sdlgetmousestate.html" ><TT CLASS="FUNCTION" >SDL_GetMouseState</TT ></A >).</P ><P >If the cursor is hidden (<A HREF="sdlshowcursor.html" ><TT CLASS="FUNCTION" >SDL_ShowCursor</TT >(0)</A >) and the input is grabbed (<A HREF="sdlwmgrabinput.html" ><TT CLASS="FUNCTION" >SDL_WM_GrabInput</TT >(SDL_GRAB_ON)</A >), then the mouse will give relative motion events even when the cursor reaches the edge fo the screen. This is currently only implemented on Windows and Linux/Unix-a-likes.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN4133" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlevent.html" ><SPAN CLASS="STRUCTNAME" >SDL_Event</SPAN ></A >, <A HREF="sdlmousebuttonevent.html" ><SPAN CLASS="STRUCTNAME" >SDL_MouseButtonEvent</SPAN ></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="sdlkeyboardevent.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="sdlmousebuttonevent.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_KeyboardEvent</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_MouseButtonEvent</TD ></TR ></TABLE ></DIV ></BODY ></HTML >