Mercurial > sdl-ios-xcode
view docs/html/sdlfillrect.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_FillRect</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="Video" HREF="video.html"><LINK REL="PREVIOUS" TITLE="SDL_BlitSurface" HREF="sdlblitsurface.html"><LINK REL="NEXT" TITLE="SDL_DisplayFormat" HREF="sdldisplayformat.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="sdlblitsurface.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdldisplayformat.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLFILLRECT" ></A >SDL_FillRect</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN2351" ></A ><H2 >Name</H2 >SDL_FillRect -- This function performs a fast fill of the given rectangle with some color</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN2354" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN2355" ></A ><P ></P ><PRE CLASS="FUNCSYNOPSISINFO" >#include "SDL.h"</PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >int <B CLASS="FSFUNC" >SDL_FillRect</B ></CODE >(SDL_Surface *dst, SDL_Rect *dstrect, Uint32 color);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN2361" ></A ><H2 >Description</H2 ><P >This function performs a fast fill of the given rectangle with <TT CLASS="PARAMETER" ><I >color</I ></TT >. If <TT CLASS="PARAMETER" ><I >dstrect</I ></TT > is <TT CLASS="LITERAL" >NULL</TT >, the whole surface will be filled with <TT CLASS="PARAMETER" ><I >color</I ></TT >.</P ><P >The color should be a pixel of the format used by the surface, and can be generated by the <A HREF="sdlmaprgb.html" >SDL_MapRGB</A > or <A HREF="sdlmaprgba.html" >SDL_MapRGBA</A > functions. If the color value contains an alpha value then the destination is simply "filled" with that alpha information, no blending takes place.</P ><P >If there is a clip rectangle set on the destination (set via <A HREF="sdlsetcliprect.html" >SDL_SetClipRect</A >) then this function will clip based on the intersection of the clip rectangle and the <TT CLASS="PARAMETER" ><I >dstrect</I ></TT > rectangle and the dstrect rectangle will be modified to represent the area actually filled.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN2374" ></A ><H2 >Return Value</H2 ><P >This function returns <SPAN CLASS="RETURNVALUE" >0</SPAN > on success, or <SPAN CLASS="RETURNVALUE" >-1</SPAN > on error.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN2379" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlmaprgb.html" ><TT CLASS="FUNCTION" >SDL_MapRGB</TT ></A >, <A HREF="sdlmaprgb.html" ><TT CLASS="FUNCTION" >SDL_MapRGBA</TT ></A >, <A HREF="sdlblitsurface.html" ><TT CLASS="FUNCTION" >SDL_BlitSurface</TT ></A >, <A HREF="sdlrect.html" ><SPAN CLASS="STRUCTNAME" >SDL_Rect</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="sdlblitsurface.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="sdldisplayformat.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_BlitSurface</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="video.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_DisplayFormat</TD ></TR ></TABLE ></DIV ></BODY ></HTML >