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From Bug #36:
There are a couple of issues with the selection of Altivec alpha-blitting
routines in CalculateAlphaBlit() in src/video/SDL_Blit_A.c.
1) There's no check for the presence of Altivec when checking if the
Blit32to565PixelAlphaAltivec() routine can be selected.
2) Altivec cannot be used in video memory, and there's no check if the
destination surface is a hardware surface. (Alpha-blitting to a hardware
surface with GPU support is a bad idea, but somebody's bound to do it anyway.)
Patch to fix these attached.
author | Ryan C. Gordon <icculus@icculus.org> |
---|---|
date | Sun, 08 Jan 2006 21:18:15 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >SDL_MapRGB</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_SetGammaRamp" HREF="sdlsetgammaramp.html"><LINK REL="NEXT" TITLE="SDL_MapRGBA" HREF="sdlmaprgba.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="sdlsetgammaramp.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlmaprgba.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLMAPRGB" ></A >SDL_MapRGB</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN1652" ></A ><H2 >Name</H2 >SDL_MapRGB -- Map a RGB color value to a pixel format.</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN1655" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN1656" ></A ><P ></P ><PRE CLASS="FUNCSYNOPSISINFO" >#include "SDL.h"</PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >Uint32 <B CLASS="FSFUNC" >SDL_MapRGB</B ></CODE >(SDL_PixelFormat *fmt, Uint8 r, Uint8 g, Uint8 b);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1662" ></A ><H2 >Description</H2 ><P >Maps the RGB color value to the specified pixel format and returns the pixel value as a 32-bit int.</P ><P >If the format has a palette (8-bit) the index of the closest matching color in the palette will be returned.</P ><P >If the specified pixel format has an alpha component it will be returned as all 1 bits (fully opaque).</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1667" ></A ><H2 >Return Value</H2 ><P >A pixel value best approximating the given RGB color value for a given pixel format. If the pixel format bpp (color depth) is less than 32-bpp then the unused upper bits of the return value can safely be ignored (e.g., with a 16-bpp format the return value can be assigned to a <SPAN CLASS="TYPE" >Uint16</SPAN >, and similarly a <SPAN CLASS="TYPE" >Uint8</SPAN > for an 8-bpp format).</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1672" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlgetrgb.html" ><TT CLASS="FUNCTION" >SDL_GetRGB</TT ></A >, <A HREF="sdlgetrgba.html" ><TT CLASS="FUNCTION" >SDL_GetRGBA</TT ></A >, <A HREF="sdlmaprgba.html" ><TT CLASS="FUNCTION" >SDL_MapRGBA</TT ></A >, <A HREF="sdlpixelformat.html" ><SPAN CLASS="STRUCTNAME" >SDL_PixelFormat</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="sdlsetgammaramp.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="sdlmaprgba.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_SetGammaRamp</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_MapRGBA</TD ></TR ></TABLE ></DIV ></BODY ></HTML >