view docs/html/sdljoystickopen.html @ 1240:3b8a43c428bb

From Bug #36: There are a couple of issues with the selection of Altivec alpha-blitting routines in CalculateAlphaBlit() in src/video/SDL_Blit_A.c. 1) There's no check for the presence of Altivec when checking if the Blit32to565PixelAlphaAltivec() routine can be selected. 2) Altivec cannot be used in video memory, and there's no check if the destination surface is a hardware surface. (Alpha-blitting to a hardware surface with GPU support is a bad idea, but somebody's bound to do it anyway.) Patch to fix these attached.
author Ryan C. Gordon <icculus@icculus.org>
date Sun, 08 Jan 2006 21:18:15 +0000
parents 355632dca928
children
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>SDL_JoystickOpen</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN6096"
></A
><H2
>Name</H2
>SDL_JoystickOpen&nbsp;--&nbsp;Opens a joystick for use.</DIV
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>Synopsis</H2
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><P
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><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>SDL_Joystick *<B
CLASS="FSFUNC"
>SDL_JoystickOpen</B
></CODE
>(int index);</CODE
></P
><P
></P
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><DIV
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><A
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></A
><H2
>Description</H2
><P
>Opens a joystick for use within SDL. The <TT
CLASS="PARAMETER"
><I
>index</I
></TT
> refers to the N'th joystick in the system. A joystick must be opened before it game be used.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN6110"
></A
><H2
>Return Value</H2
><P
>Returns a <SPAN
CLASS="STRUCTNAME"
>SDL_Joystick</SPAN
> structure on success. <SPAN
CLASS="RETURNVALUE"
>NULL</SPAN
> on failure.</P
></DIV
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><H2
>Examples</H2
><P
><PRE
CLASS="PROGRAMLISTING"
>SDL_Joystick *joy;
// Check for joystick
if(SDL_NumJoysticks()&#62;0){
  // Open joystick
  joy=SDL_JoystickOpen(0);
  
  if(joy)
  {
    printf("Opened Joystick 0\n");
    printf("Name: %s\n", SDL_JoystickName(0));
    printf("Number of Axes: %d\n", SDL_JoystickNumAxes(joy));
    printf("Number of Buttons: %d\n", SDL_JoystickNumButtons(joy));
    printf("Number of Balls: %d\n", SDL_JoystickNumBalls(joy));
  }
  else
    printf("Couldn't open Joystick 0\n");
  
  // Close if opened
  if(SDL_JoystickOpened(0))
    SDL_JoystickClose(joy);
}</PRE
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>See Also</H2
><P
><A
HREF="sdljoystickclose.html"
><TT
CLASS="FUNCTION"
>SDL_JoystickClose</TT
></A
></P
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