view docs/html/sdljoystickopen.html @ 3880:74e828c64315 SDL-1.2

Fixed bug #292 I might be on crack here. It looks like SDL_ConvertMono() in src/audio/SDL_audiocvt.c adds the left and right channels of a stereo stream together, and clamps the new mono channel if it would overflow. Shouldn't it be dividing by 2 to average the two sample points instead of clamping? Otherwise the mono sample point's volume doubles in the conversion. This would also make the conversion faster, as it replaces two branches per sample frame with a bitwise shift. --ryan.
author Sam Lantinga <slouken@libsdl.org>
date Sun, 24 Sep 2006 15:45:37 +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
><DIV
CLASS="REFSYNOPSISDIV"
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><H2
>Synopsis</H2
><DIV
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><P
></P
><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
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN6106"
></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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CLASS="REFSECT1"
><A
NAME="AEN6115"
></A
><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
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