Mercurial > sdl-ios-xcode

view docs/html/sdlcreatecursor.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_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&nbsp;--&nbsp;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&#60;32; ++row ) {
    for ( col=0; col&#60;32; ++col ) {
      if ( col % 8 ) {
        data[i] &#60;&#60;= 1;
        mask[i] &#60;&#60;= 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", &#38;hot_x, &#38;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
>