Mercurial > sdl-ios-xcode

view docs/html/sdlsetvideomode.html @ 1259:36f24cdfcda7

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
te: Thu, 17 Apr 2003 11:25:26 -0700 From: "Jim" Subject: [SDL] Frame buffer patches... Would seem that GCC 3.2.2 promotes all signed values to unsigned if any single vlaue is unsigned in an expression... for instance when calculating an elo touch position....evertyhign is an (int) except for cach_vinfo.xres which is unsigned. THerefore if y ou reverse the SDL_ELO_MIN_X and SDL_ELO_MAX_X values the resulging negative value pegs the expression to it's max. Attached it the accumu lated patch to typecast the unsigned values to (int) - *dx = (cache_vinfo.xres - (cache_vinfo.xres * (input_x - ELO_MIN_X)) / width); + *dx = ((int)cache_vinfo.xres - ((int)cache_vinfo.xres * (input_x - ELO_MIN_X)) / width); and also to provide quite failure to operations which have the screen currently locked... The touch screen I'm using the original values were exactly opposite of any position I touched on the screen - evaluating the math the expr ession SHOULD have handled reversing the min and max values - and after casting the unsigned .xres and .yres to a signed int - worked well. .. Jim
author Sam Lantinga <slouken@libsdl.org>
date Tue, 24 Jan 2006 06:36:43 +0000
parents 355632dca928
children
line wrap: on
line source

<HTML
><HEAD
><TITLE
>SDL_SetVideoMode</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_VideoModeOK"
HREF="sdlvideomodeok.html"><LINK
REL="NEXT"
TITLE="SDL_UpdateRect"
HREF="sdlupdaterect.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="sdlvideomodeok.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
></TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="sdlupdaterect.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><H1
><A
NAME="SDLSETVIDEOMODE"
></A
>SDL_SetVideoMode</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN1239"
></A
><H2
>Name</H2
>SDL_SetVideoMode&nbsp;--&nbsp;Set up a video mode with the specified width, height and bits-per-pixel.</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN1242"
></A
><H2
>Synopsis</H2
><DIV
CLASS="FUNCSYNOPSIS"
><A
NAME="AEN1243"
></A
><P
></P
><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>SDL_Surface *<B
CLASS="FSFUNC"
>SDL_SetVideoMode</B
></CODE
>(int width, int height, int bpp, Uint32 flags);</CODE
></P
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN1249"
></A
><H2
>Description</H2
><P
>Set up a video mode with the specified width, height and bits-per-pixel.</P
><P
>If <TT
CLASS="PARAMETER"
><I
>bpp</I
></TT
> is 0, it is treated as the 
current display bits per pixel.</P
><P
>The <TT
CLASS="PARAMETER"
><I
>flags</I
></TT
> parameter is the same as the <TT
CLASS="STRUCTFIELD"
><I
>flags</I
></TT
> field of the <A
HREF="sdlsurface.html"
><SPAN
CLASS="STRUCTNAME"
>SDL_Surface</SPAN
></A
> structure. OR'd combinations of the following values are valid.</P
><DIV
CLASS="INFORMALTABLE"
><A
NAME="AEN1259"
></A
><P
></P
><TABLE
BORDER="1"
CLASS="CALSTABLE"
><TBODY
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="LITERAL"
>SDL_SWSURFACE</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Create the video surface in system memory</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="LITERAL"
>SDL_HWSURFACE</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Create the video surface in video memory</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="LITERAL"
>SDL_ASYNCBLIT</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Enables the use of asynchronous updates of the display surface. This will
usually slow down blitting on single CPU machines, but may provide a speed
increase on SMP systems.</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="LITERAL"
>SDL_ANYFORMAT</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Normally, if a video surface of the requested bits-per-pixel (<TT
CLASS="PARAMETER"
><I
>bpp</I
></TT
>) is not available, SDL will emulate one with a shadow surface. Passing <TT
CLASS="LITERAL"
>SDL_ANYFORMAT</TT
> prevents this and causes SDL to use the video surface, regardless of its pixel depth.</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="LITERAL"
>SDL_HWPALETTE</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Give SDL exclusive palette access. Without this flag you may not always get the the colors you request with <A
HREF="sdlsetcolors.html"
><TT
CLASS="FUNCTION"
>SDL_SetColors</TT
></A
> or <A
HREF="sdlsetpalette.html"
><TT
CLASS="FUNCTION"
>SDL_SetPalette</TT
></A
>.</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="LITERAL"
>SDL_DOUBLEBUF</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Enable hardware double buffering; only valid with SDL_HWSURFACE. Calling
<A
HREF="sdlflip.html"
><TT
CLASS="FUNCTION"
>SDL_Flip</TT
></A
> will flip the
buffers and update the screen. All drawing will take place on the surface
that is not displayed at the moment. If double buffering could not be enabled
then <TT
CLASS="FUNCTION"
>SDL_Flip</TT
> will just perform a
<A
HREF="sdlupdaterect.html"
><TT
CLASS="FUNCTION"
>SDL_UpdateRect</TT
></A
>
on the entire screen.</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="LITERAL"
>SDL_FULLSCREEN</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>SDL will attempt to use a fullscreen mode. If a hardware resolution change is
not possible (for whatever reason), the next higher resolution will be used and
the display window centered on a black background.</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="LITERAL"
>SDL_OPENGL</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Create an OpenGL rendering context. You should have previously set OpenGL video attributes with <A
HREF="sdlglsetattribute.html"
><TT
CLASS="FUNCTION"
>SDL_GL_SetAttribute</TT
></A
>.</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="LITERAL"
>SDL_OPENGLBLIT</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Create an OpenGL rendering context, like above, but allow normal blitting
operations. The screen (2D) surface may have an alpha channel, and
<A
HREF="sdlupdaterects.html"
><TT
CLASS="FUNCTION"
>SDL_UpdateRects</TT
></A
>
must be used for updating changes to the screen surface. NOTE: This option
is kept for compatibility only, and is <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>not</I
></SPAN
> recommended for
new code.</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="LITERAL"
>SDL_RESIZABLE</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Create a resizable window. When the window is resized by the user a <A
HREF="sdlresizeevent.html"
><TT
CLASS="LITERAL"
>SDL_VIDEORESIZE</TT
></A
> event is generated and <TT
CLASS="FUNCTION"
>SDL_SetVideoMode</TT
> can be called again with the new size.</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="LITERAL"
>SDL_NOFRAME</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>If possible, <TT
CLASS="LITERAL"
>SDL_NOFRAME</TT
> causes SDL to create a window with no title bar or frame decoration. Fullscreen modes automatically have this flag set.</TD
></TR
></TBODY
></TABLE
><P
></P
></DIV
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
>Whatever <TT
CLASS="PARAMETER"
><I
>flags</I
></TT
> <TT
CLASS="FUNCTION"
>SDL_SetVideoMode</TT
> could satisfy are set in the <TT
CLASS="STRUCTFIELD"
><I
>flags</I
></TT
> member of the returned surface.</P
></BLOCKQUOTE
></DIV
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
>The <TT
CLASS="PARAMETER"
><I
>bpp</I
></TT
> parameter is the number of bits per pixel,
so a <TT
CLASS="PARAMETER"
><I
>bpp</I
></TT
> of 24 uses the packed representation of
3 bytes/pixel. For the more common 4 bytes/pixel mode, use a
<TT
CLASS="PARAMETER"
><I
>bpp</I
></TT
> of 32. Somewhat oddly, both 15 and 16 will
request a 2 bytes/pixel mode, but different pixel formats.</P
></BLOCKQUOTE
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN1336"
></A
><H2
>Return Value</H2
><P
>The framebuffer surface, or <SPAN
CLASS="RETURNVALUE"
>NULL</SPAN
> if it fails.
The surface returned is freed by SDL_Quit() and should nt be freed by
the caller.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN1340"
></A
><H2
>See Also</H2
><P
><A
HREF="sdllocksurface.html"
><TT
CLASS="FUNCTION"
>SDL_LockSurface</TT
></A
>,
<A
HREF="sdlsetcolors.html"
><TT
CLASS="FUNCTION"
>SDL_SetColors</TT
></A
>,
<A
HREF="sdlflip.html"
><TT
CLASS="FUNCTION"
>SDL_Flip</TT
></A
>,
<A
HREF="sdlsurface.html"
><SPAN
CLASS="STRUCTNAME"
>SDL_Surface</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="sdlvideomodeok.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="sdlupdaterect.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>SDL_VideoModeOK</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_UpdateRect</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>