Mercurial > sdl-ios-xcode
view docs/html/sdlcreatecursor.html @ 4355:9b464226e541 SDL-1.2
Fixed bug #855
Ludwig Nussel 2009-10-18 06:31:52 PDT
an mprotect call was added to fix bug 528. However that results in a buffer
that allows writing and code execution. Ie the no-execute security features of
modern operating systems are defeated this way. Two mprotect calls are needed.
One to make the buffer executable but not writeable when done and another one
to make the buffer writeable again if the content needs to be changed.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sun, 18 Oct 2009 17:31:37 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >SDL_CreateCursor</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_WarpMouse" HREF="sdlwarpmouse.html"><LINK REL="NEXT" TITLE="SDL_FreeCursor" HREF="sdlfreecursor.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="sdlwarpmouse.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlfreecursor.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLCREATECURSOR" ></A >SDL_CreateCursor</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN2487" ></A ><H2 >Name</H2 >SDL_CreateCursor -- Creates a new mouse cursor.</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN2490" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN2491" ></A ><P ></P ><PRE CLASS="FUNCSYNOPSISINFO" >#include "SDL.h"</PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >SDL_Cursor *<B CLASS="FSFUNC" >SDL_CreateCursor</B ></CODE >(Uint8 *data, Uint8 *mask, int w, int h, int hot_x, int hot_y);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN2497" ></A ><H2 >Description</H2 ><P >Create a cursor using the specified <TT CLASS="PARAMETER" ><I >data</I ></TT > and <TT CLASS="PARAMETER" ><I >mask</I ></TT > (in MSB format). The cursor width must be a multiple of 8 bits.</P ><P >The cursor is created in black and white according to the following: <DIV CLASS="INFORMALTABLE" ><A NAME="AEN2503" ></A ><P ></P ><TABLE BORDER="1" CLASS="CALSTABLE" ><THEAD ><TR ><TH ALIGN="LEFT" VALIGN="TOP" >Data / Mask</TH ><TH ALIGN="LEFT" VALIGN="TOP" >Resulting pixel on screen</TH ></TR ></THEAD ><TBODY ><TR ><TD ALIGN="LEFT" VALIGN="TOP" >0 / 1</TD ><TD ALIGN="LEFT" VALIGN="TOP" >White</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" >1 / 1</TD ><TD ALIGN="LEFT" VALIGN="TOP" >Black</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" >0 / 0</TD ><TD ALIGN="LEFT" VALIGN="TOP" >Transparent</TD ></TR ><TR ><TD ALIGN="LEFT" VALIGN="TOP" >1 / 0</TD ><TD ALIGN="LEFT" VALIGN="TOP" >Inverted color if possible, black if not.</TD ></TR ></TBODY ></TABLE ><P ></P ></DIV ></P ><P >Cursors created with this function must be freed with <A HREF="sdlfreecursor.html" >SDL_FreeCursor</A >.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN2524" ></A ><H2 >Example</H2 ><PRE CLASS="PROGRAMLISTING" >/* Stolen from the mailing list */ /* Creates a new mouse cursor from an XPM */ /* XPM */ static const char *arrow[] = { /* width height num_colors chars_per_pixel */ " 32 32 3 1", /* colors */ "X c #000000", ". c #ffffff", " c None", /* pixels */ "X ", "XX ", "X.X ", "X..X ", "X...X ", "X....X ", "X.....X ", "X......X ", "X.......X ", "X........X ", "X.....XXXXX ", "X..X..X ", "X.X X..X ", "XX X..X ", "X X..X ", " X..X ", " X..X ", " X..X ", " XX ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", "0,0" }; static SDL_Cursor *init_system_cursor(const char *image[]) { int i, row, col; Uint8 data[4*32]; Uint8 mask[4*32]; int hot_x, hot_y; i = -1; for ( row=0; row<32; ++row ) { for ( col=0; col<32; ++col ) { if ( col % 8 ) { data[i] <<= 1; mask[i] <<= 1; } else { ++i; data[i] = mask[i] = 0; } switch (image[4+row][col]) { case 'X': data[i] |= 0x01; mask[i] |= 0x01; break; case '.': mask[i] |= 0x01; break; case ' ': break; } } } sscanf(image[4+row], "%d,%d", &hot_x, &hot_y); return SDL_CreateCursor(data, mask, 32, 32, hot_x, hot_y); }</PRE ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN2527" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlfreecursor.html" ><TT CLASS="FUNCTION" >SDL_FreeCursor</TT ></A >, <A HREF="sdlsetcursor.html" ><TT CLASS="FUNCTION" >SDL_SetCursor</TT ></A >, <A HREF="sdlshowcursor.html" ><TT CLASS="FUNCTION" >SDL_ShowCursor</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="sdlwarpmouse.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="sdlfreecursor.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_WarpMouse</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_FreeCursor</TD ></TR ></TABLE ></DIV ></BODY ></HTML >