Mercurial > sdl-ios-xcode

view docs/html/sdloverlay.html @ 1555:780fd5b61df1

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Fixed bug #89 Date: Sun, 23 Oct 2005 16:39:03 +0200 From: "A. Schmid" <sahib@phreaker.net> Subject: [SDL] no software surfaces with svgalib driver? Hi, I noticed that the SDL (1.2.9) svgalib driver only makes use of linear addressable (framebuffer) video modes. On older systems (like one of mine), linear addressable modes are often not available. Especially for cards with VESA VBE < 2.0 the svgalib vesa driver is unusable, since VESA only supports framebuffering for VBE 2.0 and later. The changes necessary to add support for software surfaces seem to be relatively small. I only had to hack src/video/svga/SDL_svgavideo.c (see attached patch). The code worked fine for me, but it is no more than a proof of concept and should be reviewed (probably has a memory leak when switching modes). It also uses the vgagl library (included in the svgalib package) and needs to be linked against it. -Alex
author Sam Lantinga <slouken@libsdl.org>
date Sun, 19 Mar 2006 12:05:16 +0000
parents 355632dca928
children
line wrap: on
line source

<HTML
><HEAD
><TITLE
>SDL_Overlay</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_VideoInfo"
HREF="sdlvideoinfo.html"><LINK
REL="NEXT"
TITLE="Window Management"
HREF="wm.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="sdlvideoinfo.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
></TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="wm.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><H1
><A
NAME="SDLOVERLAY"
></A
>SDL_Overlay</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN3464"
></A
><H2
>Name</H2
>SDL_Overlay&nbsp;--&nbsp;YUV video overlay</DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN3467"
></A
><H2
>Structure Definition</H2
><PRE
CLASS="PROGRAMLISTING"
>typedef struct{
  Uint32 format;
  int w, h;
  int planes;
  Uint16 *pitches;
  Uint8 **pixels;
  Uint32 hw_overlay:1;
} SDL_Overlay;</PRE
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN3470"
></A
><H2
>Structure Data</H2
><DIV
CLASS="INFORMALTABLE"
><A
NAME="AEN3472"
></A
><P
></P
><TABLE
BORDER="0"
CLASS="CALSTABLE"
><TBODY
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>format</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Overlay format (see below)</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>w, h</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Width and height of overlay</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>planes</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Number of planes in the overlay. Usually either 1 or 3</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>pitches</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>An array of pitches, one for each plane. Pitch is the length of a row in bytes.</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>pixels</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>An array of pointers to teh data of each plane. The overlay should be locked before these pointers are used.</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>hw_overlay</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>This will be set to 1 if the overlay is hardware accelerated.</TD
></TR
></TBODY
></TABLE
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN3499"
></A
><H2
>Description</H2
><P
>A <SPAN
CLASS="STRUCTNAME"
>SDL_Overlay</SPAN
> is similar to a <A
HREF="sdlsurface.html"
><SPAN
CLASS="STRUCTNAME"
>SDL_Surface</SPAN
></A
> except it stores a YUV overlay. All the fields are read only, except for <TT
CLASS="STRUCTFIELD"
><I
>pixels</I
></TT
> which should be <A
HREF="sdllockyuvoverlay.html"
>locked</A
> before use. The <TT
CLASS="STRUCTFIELD"
><I
>format</I
></TT
> field stores the format of the overlay which is one of the following:
<PRE
CLASS="PROGRAMLISTING"
>#define SDL_YV12_OVERLAY  0x32315659  /* Planar mode: Y + V + U */
#define SDL_IYUV_OVERLAY  0x56555949  /* Planar mode: Y + U + V */
#define SDL_YUY2_OVERLAY  0x32595559  /* Packed mode: Y0+U0+Y1+V0 */
#define SDL_UYVY_OVERLAY  0x59565955  /* Packed mode: U0+Y0+V0+Y1 */
#define SDL_YVYU_OVERLAY  0x55595659  /* Packed mode: Y0+V0+Y1+U0 */</PRE
>
More information on YUV formats can be found at <A
HREF="http://www.webartz.com/fourcc/indexyuv.htm"
TARGET="_top"
>http://www.webartz.com/fourcc/indexyuv.htm</A
>.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN3510"
></A
><H2
>See Also</H2
><P
><A
HREF="sdlcreateyuvoverlay.html"
><TT
CLASS="FUNCTION"
>SDL_CreateYUVOverlay</TT
></A
>,
<A
HREF="sdllockyuvoverlay.html"
><TT
CLASS="FUNCTION"
>SDL_LockYUVOverlay</TT
></A
>,
<A
HREF="sdlunlockyuvoverlay.html"
><TT
CLASS="FUNCTION"
>SDL_UnlockYUVOverlay</TT
></A
>,
<A
HREF="sdlfreeyuvoverlay.html"
><TT
CLASS="FUNCTION"
>SDL_FreeYUVOverlay</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="sdlvideoinfo.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="wm.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>SDL_VideoInfo</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="video.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>Window Management</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>