Mercurial > sdl-ios-xcode
view docs/html/sdlsurface.html @ 1643:51038e80ae59
More general fix for bug #189
The clipping is done at a higher level, and the low level functions are
passed clipped rectangles. Drivers which don't support source clipping
have not been changed, so the image will be squished instead of clipped,
but at least they will no longer crash when the destination rect was out
of bounds.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Mon, 17 Apr 2006 06:47:23 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >SDL_Surface</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_PixelFormat" HREF="sdlpixelformat.html"><LINK REL="NEXT" TITLE="SDL_VideoInfo" HREF="sdlvideoinfo.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="sdlpixelformat.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlvideoinfo.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLSURFACE" ></A >SDL_Surface</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN3263" ></A ><H2 >Name</H2 >SDL_Surface -- Graphical Surface Structure</DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN3266" ></A ><H2 >Structure Definition</H2 ><PRE CLASS="PROGRAMLISTING" >typedef struct SDL_Surface { Uint32 flags; /* Read-only */ SDL_PixelFormat *format; /* Read-only */ int w, h; /* Read-only */ Uint16 pitch; /* Read-only */ void *pixels; /* Read-write */ /* clipping information */ SDL_Rect clip_rect; /* Read-only */ /* Reference count -- used when freeing surface */ int refcount; /* Read-mostly */ /* This structure also contains private fields not shown here */ } SDL_Surface;</PRE ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN3269" ></A ><H2 >Structure Data</H2 ><DIV CLASS="INFORMALTABLE" ><A NAME="AEN3271" ></A ><P ></P ><TABLE BORDER="0" CLASS="CALSTABLE" ><TBODY ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >flags</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Surface flags</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >format</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Pixel <A HREF="sdlpixelformat.html" >format</A ></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 the surface</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >pitch</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Length of a surface scanline in bytes</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >pixels</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Pointer to the actual pixel data</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="STRUCTFIELD" ><I >clip_rect</I ></TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >surface clip <A HREF="sdlrect.html" >rectangle</A ></TD ></TR ></TBODY ></TABLE ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN3300" ></A ><H2 >Description</H2 ><P ><SPAN CLASS="STRUCTNAME" >SDL_Surface</SPAN >'s represent areas of "graphical" memory, memory that can be drawn to. The video framebuffer is returned as a <SPAN CLASS="STRUCTNAME" >SDL_Surface</SPAN > by <A HREF="sdlsetvideomode.html" ><TT CLASS="FUNCTION" >SDL_SetVideoMode</TT ></A > and <A HREF="sdlgetvideosurface.html" ><TT CLASS="FUNCTION" >SDL_GetVideoSurface</TT ></A >. Most of the fields should be pretty obvious. <TT CLASS="STRUCTFIELD" ><I >w</I ></TT > and <TT CLASS="STRUCTFIELD" ><I >h</I ></TT > are the width and height of the surface in pixels. <TT CLASS="STRUCTFIELD" ><I >pixels</I ></TT > is a pointer to the actual pixel data, the surface should be <A HREF="sdllocksurface.html" >locked</A > before accessing this field. The <TT CLASS="STRUCTFIELD" ><I >clip_rect</I ></TT > field is the clipping rectangle as set by <A HREF="sdlsetcliprect.html" ><TT CLASS="FUNCTION" >SDL_SetClipRect</TT ></A >.</P ><P >The following are supported in the <TT CLASS="STRUCTFIELD" ><I >flags</I ></TT > field.</P ><DIV CLASS="INFORMALTABLE" ><A NAME="AEN3318" ></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" >Surface is stored in system memory</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_HWSURFACE</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Surface is stored in video memory</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_ASYNCBLIT</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Surface uses asynchronous blits if possible</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_ANYFORMAT</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Allows any pixel-format (Display surface)</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_HWPALETTE</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Surface has exclusive palette</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_DOUBLEBUF</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Surface is double buffered (Display surface)</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_FULLSCREEN</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Surface is full screen (Display Surface)</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_OPENGL</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Surface has an OpenGL context (Display Surface)</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_OPENGLBLIT</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Surface supports OpenGL blitting (Display Surface)</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_RESIZABLE</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Surface is resizable (Display Surface)</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_HWACCEL</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Surface blit uses hardware acceleration</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_SRCCOLORKEY</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Surface use colorkey blitting</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_RLEACCEL</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Colorkey blitting is accelerated with RLE</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_SRCALPHA</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Surface blit uses alpha blending</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_PREALLOC</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >Surface uses preallocated memory</TD ></TR ></TBODY ></TABLE ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN3381" ></A ><H2 >See Also</H2 ><P ><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="sdlpixelformat.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="sdlvideoinfo.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_PixelFormat</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_VideoInfo</TD ></TR ></TABLE ></DIV ></BODY ></HTML >