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Date: Tue, 12 Aug 2003 14:26:19 +0200 (MEST) From: "Mattias Engdeg?rd" Subject: bug in SDL_GetRGB/GetRGBA There's an embarrassing bug in GetRGB/GetRGBA which apparently has been there for years. It incorrectly converts colours with < 8 bits/channel. It came to my attention today in #sdl. What it does now is (for each channel): rv = (pixel & fmt->Rmask) >> fmt->Rshift; *r = (rv << fmt->Rloss) + (rv >> (8 - fmt->Rloss)); which is wrong; the last line should be *r = (rv << fmt->Rloss) + (rv >> (8 - (fmt->Rloss << 1)));
author Sam Lantinga <slouken@libsdl.org>
date Tue, 12 Aug 2003 15:17:20 +0000
parents e5bc29de3f0a
children 355632dca928
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<HTML
><HEAD
><TITLE
>SDL_LoadBMP</TITLE
><META
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CONTENT="Modular DocBook HTML Stylesheet Version 1.64
"><LINK
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><H1
><A
NAME="SDLLOADBMP"
>SDL_LoadBMP</A
></H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN1605"
></A
><H2
>Name</H2
>SDL_LoadBMP&nbsp;--&nbsp;Load a Windows BMP file into an SDL_Surface.</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN1608"
></A
><H2
>Synopsis</H2
><DIV
CLASS="FUNCSYNOPSIS"
><A
NAME="AEN1609"
></A
><P
></P
><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>SDL_Surface *<B
CLASS="FSFUNC"
>SDL_LoadBMP</B
></CODE
>(const char *file);</CODE
></P
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN1615"
></A
><H2
>Description</H2
><P
>Loads a surface from a named Windows BMP file.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN1618"
></A
><H2
>Return Value</H2
><P
>Returns the new surface, or <TT
CLASS="LITERAL"
>NULL</TT
> 
if there was an error.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN1622"
></A
><H2
>See Also</H2
><P
><A
HREF="sdlsavebmp.html"
><TT
CLASS="FUNCTION"
>SDL_SaveBMP</TT
></A
></P
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