Mercurial > sdl-ios-xcode
view docs/html/sdlcreatergbsurface.html @ 4392:2b8c1aea633b SDL-1.2
Fixed bug #898
Jeremiah Morris 2009-12-09 16:07:17 PST
No-op GlobalToLocal translations in fullscreen mode
On my MacBook Pro running 10.6, I noticed a small upward bias on mouse movement
in a fullscreen SDL application. The app uses WarpCursor and GetMouseState in a
loop to measure relative movement. I tracked it down to NSWindow's
convertBaseToScreen: routine, which added a 2-pixel offset on the Y coordinate
instead of the expected (+0,+0) translation.
In fullscreen mode, QZ_PrivateWarpCursor() does not translate the desired
position through QZ_PrivateGlobalToLocal() before passing it to the Core
Graphics system. However, QZ_GetMouseLocation() does call the reverse
QZ_PrivateLocalToGlobal() even in fullscreen mode. This asymmetry caused
problems each time the mouse was moved.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Fri, 11 Dec 2009 15:31:37 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >SDL_CreateRGBSurface</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_GetRGBA" HREF="sdlgetrgba.html"><LINK REL="NEXT" TITLE="SDL_CreateRGBSurfaceFrom" HREF="sdlcreatergbsurfacefrom.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="sdlgetrgba.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlcreatergbsurfacefrom.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLCREATERGBSURFACE" ></A >SDL_CreateRGBSurface</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN1773" ></A ><H2 >Name</H2 >SDL_CreateRGBSurface -- Create an empty SDL_Surface</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN1776" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN1777" ></A ><P ></P ><PRE CLASS="FUNCSYNOPSISINFO" >#include "SDL.h"</PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >SDL_Surface *<B CLASS="FSFUNC" >SDL_CreateRGBSurface</B ></CODE >(Uint32 flags, int width, int height, int depth, Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1783" ></A ><H2 >Description</H2 ><P >Allocate an empty surface (must be called after <A HREF="sdlsetvideomode.html" >SDL_SetVideoMode</A >)</P ><P >If <TT CLASS="PARAMETER" ><I >depth</I ></TT > is 8 bits an empty palette is allocated for the surface, otherwise a 'packed-pixel' <A HREF="sdlpixelformat.html" ><SPAN CLASS="STRUCTNAME" >SDL_PixelFormat</SPAN ></A > is created using the <TT CLASS="PARAMETER" ><I >[RGBA]mask</I ></TT >'s provided (see <A HREF="sdlpixelformat.html" ><SPAN CLASS="STRUCTNAME" >SDL_PixelFormat</SPAN ></A >). The <TT CLASS="PARAMETER" ><I >flags</I ></TT > specifies the type of surface that should be created, it is an OR'd combination of the following possible values.</P ><DIV CLASS="INFORMALTABLE" ><A NAME="AEN1795" ></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" >SDL will create the surface in system memory. This improves the performance of pixel level access, however you may not be able to take advantage of some types of hardware blitting.</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_HWSURFACE</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >SDL will attempt to create the surface in video memory. This will allow SDL to take advantage of Video->Video blits (which are often accelerated).</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_SRCCOLORKEY</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >This flag turns on colourkeying for blits from this surface. If <TT CLASS="LITERAL" >SDL_HWSURFACE</TT > is also specified and colourkeyed blits are hardware-accelerated, then SDL will attempt to place the surface in video memory. Use <A HREF="sdlsetcolorkey.html" ><TT CLASS="FUNCTION" >SDL_SetColorKey</TT ></A > to set or clear this flag after surface creation.</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" ><TT CLASS="LITERAL" >SDL_SRCALPHA</TT ></TD ><TD ALIGN="LEFT" VALIGN="TOP" >This flag turns on alpha-blending for blits from this surface. If <TT CLASS="LITERAL" >SDL_HWSURFACE</TT > is also specified and alpha-blending blits are hardware-accelerated, then the surface will be placed in video memory if possible. Use <A HREF="sdlsetalpha.html" ><TT CLASS="FUNCTION" >SDL_SetAlpha</TT ></A > to set or clear this flag after surface creation.</TD ></TR ></TBODY ></TABLE ><P ></P ></DIV ><DIV CLASS="NOTE" ><BLOCKQUOTE CLASS="NOTE" ><P ><B >Note: </B >If an alpha-channel is specified (that is, if <TT CLASS="PARAMETER" ><I >Amask</I ></TT > is nonzero), then the <TT CLASS="LITERAL" >SDL_SRCALPHA</TT > flag is automatically set. You may remove this flag by calling <A HREF="sdlsetalpha.html" ><TT CLASS="FUNCTION" >SDL_SetAlpha</TT ></A > after surface creation.</P ></BLOCKQUOTE ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1826" ></A ><H2 >Return Value</H2 ><P >Returns the created surface, or <SPAN CLASS="RETURNVALUE" >NULL</SPAN > upon error.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1830" ></A ><H2 >Example</H2 ><PRE CLASS="PROGRAMLISTING" > /* Create a 32-bit surface with the bytes of each pixel in R,G,B,A order, as expected by OpenGL for textures */ SDL_Surface *surface; Uint32 rmask, gmask, bmask, amask; /* SDL interprets each pixel as a 32-bit number, so our masks must depend on the endianness (byte order) of the machine */ #if SDL_BYTEORDER == SDL_BIG_ENDIAN rmask = 0xff000000; gmask = 0x00ff0000; bmask = 0x0000ff00; amask = 0x000000ff; #else rmask = 0x000000ff; gmask = 0x0000ff00; bmask = 0x00ff0000; amask = 0xff000000; #endif surface = SDL_CreateRGBSurface(SDL_SWSURFACE, width, height, 32, rmask, gmask, bmask, amask); if(surface == NULL) { fprintf(stderr, "CreateRGBSurface failed: %s\n", SDL_GetError()); exit(1); }</PRE ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1833" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlcreatergbsurfacefrom.html" ><TT CLASS="FUNCTION" >SDL_CreateRGBSurfaceFrom</TT ></A >, <A HREF="sdlfreesurface.html" ><TT CLASS="FUNCTION" >SDL_FreeSurface</TT ></A >, <A HREF="sdlsetvideomode.html" ><TT CLASS="FUNCTION" >SDL_SetVideoMode</TT ></A >, <A HREF="sdllocksurface.html" ><TT CLASS="FUNCTION" >SDL_LockSurface</TT ></A >, <A HREF="sdlpixelformat.html" ><SPAN CLASS="STRUCTNAME" >SDL_PixelFormat</SPAN ></A >, <A HREF="sdlsurface.html" ><SPAN CLASS="STRUCTNAME" >SDL_Surface</SPAN ></A > <A HREF="sdlsetalpha.html" ><TT CLASS="FUNCTION" >SDL_SetAlpha</TT ></A > <A HREF="sdlsetcolorkey.html" ><TT CLASS="FUNCTION" >SDL_SetColorKey</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="sdlgetrgba.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="sdlcreatergbsurfacefrom.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_GetRGBA</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_CreateRGBSurfaceFrom</TD ></TR ></TABLE ></DIV ></BODY ></HTML >